feat: LoTW upload + logbook (port from Iu-yang1's fork)

- Port TQ8 signing/upload pipeline (core/data/lotw: LoTWConfig, LoTWKeyMaterial,
  LoTWSigner, LoTWStorage, LoTWUploadRepository) with bundled ARRL config.tq6
- Multi-grid station locations: primary grid in GRIDSQUARE + full set in
  MY_VUCC_GRIDS (unsigned tSTATION extra, IOTA precedent); signer matches
  myGrid against the whole grid set
- Satellite-name normalization: SatNOGS names ("SO-50 (SaudiOSCAR 50)") resolve
  to official LoTW names by exact-then-substring match
- Logbook storage: separate QsoDatabase (version 1, no migration on existing
  installs), QsoRepository with dedupe/confirmation merge; LoTW sync (manual +
  auto) feeds confirmations into the logbook and marks local uploads confirmed
- Radar Log tab: single-callsign recording, per-satellite mode preset
  (CW/SSB/FT4), English social post generation (copy/share), LoTW upload with
  one-shot preview confirmation + receipts ledger
- Settings: 日志本 section (records + confirmation state, delete on tap) above
  LoTW config; LoTW upload config (TrustedQSL .p12 import + password, station
  grid list incl. IOTA/CQZ/ITUZ)
- i18n strings (en/zh)

core/data/src/main/java/com/rtbishop/look4sat/core/data/database/QsoDao.kt

@@ -0,0 +1,47 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import androidx.room.Transaction
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface QsoDao {
+    @Query("SELECT * FROM qso_records ORDER BY startUtcMillis DESC, id DESC")
+    fun observeAll(): Flow<List<QsoEntity>>
+
+    @Query("SELECT * FROM qso_records WHERE id = :id LIMIT 1")
+    suspend fun find(id: Long): QsoEntity?
+
+    @Query("SELECT * FROM qso_records ORDER BY startUtcMillis DESC, id DESC")
+    suspend fun getAll(): List<QsoEntity>
+
+    @Query("SELECT dedupeKey FROM qso_records")
+    suspend fun getDedupeKeys(): List<String>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun save(record: QsoEntity): Long
+
+    @Insert(onConflict = OnConflictStrategy.IGNORE)
+    suspend fun importRecords(records: List<QsoEntity>): List<Long>
+
+    @Transaction
+    suspend fun saveBatch(records: List<QsoEntity>) {
+        records.forEach { save(it) }
+    }
+
+    @Query("DELETE FROM qso_records WHERE id = :id")
+    suspend fun delete(id: Long)
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/database/QsoDatabase.kt

@@ -0,0 +1,24 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+
+/**
+ * Separate database for the logbook (QSO records, LoTW confirmations and
+ * upload receipts). Kept apart from [Look4SatDb] so existing installations
+ * never need a migration of the satellite database.
+ */
+@Database(entities = [QsoEntity::class], version = 1, exportSchema = false)
+abstract class QsoDatabase : RoomDatabase() {
+    abstract fun qsoDao(): QsoDao
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/database/entity/QsoEntity.kt

@@ -0,0 +1,54 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.database.entity
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.Index
+import androidx.room.PrimaryKey
+
+@Entity(
+    tableName = "qso_records",
+    indices = [Index(value = ["dedupeKey"])]
+)
+data class QsoEntity(
+    @PrimaryKey(autoGenerate = true) val id: Long = 0L,
+    val startUtcMillis: Long,
+    val endUtcMillis: Long?,
+    val theirCallsign: String,
+    val myCallsign: String,
+    val theirGrid: String,
+    val myGrid: String,
+    val sentReport: String,
+    val receivedReport: String,
+    val txFrequencyHz: Long?,
+    val rxFrequencyHz: Long?,
+    val band: String,
+    val rxBand: String,
+    @ColumnInfo(defaultValue = "'MFSK'") val mode: String,
+    @ColumnInfo(defaultValue = "'FT4'") val submode: String,
+    val satelliteName: String,
+    val transponderName: String,
+    val satelliteMode: String,
+    val passAosUtcMillis: Long?,
+    val automatic: Boolean,
+    val status: String,
+    @ColumnInfo(defaultValue = "''") val dedupeKey: String,
+    @ColumnInfo(defaultValue = "''") val propagationMode: String = "",
+    @ColumnInfo(defaultValue = "0") val lotwConfirmed: Boolean = false,
+    @ColumnInfo(defaultValue = "0") val lotwReceived: Boolean = false,
+    @ColumnInfo(defaultValue = "''") val lotwQslDate: String = "",
+    @ColumnInfo(defaultValue = "''") val vuccGrids: String = "",
+    val dxcc: Int? = null,
+    @ColumnInfo(defaultValue = "''") val country: String = "",
+    val cqZone: Int? = null,
+    @ColumnInfo(defaultValue = "''") val region: String = "",
+    @ColumnInfo(defaultValue = "''") val comment: String = ""
+)

core/data/src/main/java/com/rtbishop/look4sat/core/data/injection/MainContainer.kt

@@ -26,13 +26,16 @@ import androidx.room.Room
 import com.rtbishop.look4sat.core.data.database.Look4SatDb
 import com.rtbishop.look4sat.core.data.database.MIGRATION_1_2
 import com.rtbishop.look4sat.core.data.database.MIGRATION_2_3
+import com.rtbishop.look4sat.core.data.database.QsoDatabase
 import com.rtbishop.look4sat.core.data.framework.BluetoothReporter
 import com.rtbishop.look4sat.core.data.framework.Ft817Controller
 import com.rtbishop.look4sat.core.data.framework.Ic705Controller
 import com.rtbishop.look4sat.core.data.framework.NetworkReporter
 import com.rtbishop.look4sat.core.data.framework.RadioTrackingService
+import com.rtbishop.look4sat.core.data.lotw.LoTWUploadRepository
 import com.rtbishop.look4sat.core.data.repository.AmSatRepository
 import com.rtbishop.look4sat.core.data.repository.DatabaseRepo
+import com.rtbishop.look4sat.core.data.repository.QsoRepository
 import com.rtbishop.look4sat.core.data.repository.SatelliteRepo
 import com.rtbishop.look4sat.core.data.repository.SelectionRepo
 import com.rtbishop.look4sat.core.data.repository.SensorsRepo
@@ -46,8 +49,10 @@ import com.rtbishop.look4sat.core.data.usecase.AddToCalendar
 import com.rtbishop.look4sat.core.data.usecase.AudioCapture
 import com.rtbishop.look4sat.core.data.usecase.SaveImage
 import com.rtbishop.look4sat.core.data.usecase.ShowToast
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.domain.repository.IDatabaseRepo
+import com.rtbishop.look4sat.core.domain.repository.ILoTWUploadRepository
 import com.rtbishop.look4sat.core.domain.repository.IMainContainer
 import com.rtbishop.look4sat.core.domain.repository.IRadioController
 import com.rtbishop.look4sat.core.domain.repository.IRadioTrackingService
@@ -90,6 +95,11 @@ class MainContainer(private val context: Context) : IMainContainer {
     override val updateRepo by lazy { UpdateRepository(remoteSource) }
     override val wavelogRepo: IWavelogRepository by lazy { WavelogRepository() }
     override val lotwRepo: ILoTWRepository by lazy { LoTWRepository() }
+    override val qsoRepository: IQsoRepository by lazy {
+        val database = Room.databaseBuilder(context, QsoDatabase::class.java, "Look4SatQsoDB").build()
+        QsoRepository(database.qsoDao(), Dispatchers.IO)
+    }
+    override val lotwUploadRepository: ILoTWUploadRepository by lazy { LoTWUploadRepository(context) }
     override val radioTrackingService: IRadioTrackingService by lazy {
         val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWConfig.kt

@@ -0,0 +1,132 @@
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.displayMode
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import com.rtbishop.look4sat.core.domain.repository.LoTWStation
+import org.w3c.dom.Element
+import org.xml.sax.InputSource
+import org.xml.sax.SAXException
+import java.io.InputStream
+import java.io.StringReader
+import java.util.Locale
+import java.util.zip.GZIPInputStream
+import javax.xml.parsers.DocumentBuilderFactory
+
+/** Bundled ARRL configuration 11.34 from https://lotw.arrl.org/lotw/config.tq6. */
+internal class LoTWConfig(input: InputStream) {
+    private val root = input.use { source -> GZIPInputStream(source).use { gzip ->
+        val xml = gzip.bufferedReader(Charsets.UTF_8).readText()
+        require(!xml.contains("<!DOCTYPE", true) && !xml.contains("<!ENTITY", true))
+        // Android's DOM provider does not support Xerces-specific setFeature flags.
+        DocumentBuilderFactory.newInstance().apply { isExpandEntityReferences = false }.newDocumentBuilder().apply {
+            setEntityResolver { _, _ -> throw SAXException("External entities are not permitted") }
+        }.parse(InputSource(StringReader(xml))).documentElement
+    } }
+    private val config = root.elements("tqslconfig").single()
+    val version = config.getAttribute("majorversion") + "." + config.getAttribute("minorversion")
+    private val spec = config.elements("sigspec").single { it.getAttribute("version") == "2.0" }
+    val stationOrder = spec.elements("tSTATION").single().childElements().map { it.tagName }
+    val contactOrder = spec.elements("tCONTACT").single().childElements().map { it.tagName }
+    private val bands = config.elements("bands").single().elements("band")
+    private val satellites = config.elements("satellite").associateBy { it.getAttribute("name").uppercase(Locale.US) }
+    private val modes = config.elements("modes").single().elements("mode").map { it.textContent }.toSet()
+
+    fun mode(record: QsoRecord): String {
+        val display = record.displayMode
+        if (display in modes) return display
+        val mapped = config.elements("adifmode").firstOrNull { it.textContent.equals(display, true) }?.getAttribute("mode")
+        return mapped ?: fail(LoTWProblem.MODE, display)
+    }
+
+    fun band(explicit: String, frequency: Long?, required: Boolean): String {
+        if (frequency != null && frequency <= 0) fail(LoTWProblem.BAND)
+        val frequencyBand = frequency?.let { hz -> bands.firstOrNull { band ->
+            val unit = if (band.getAttribute("spectrum") == "HF") 1_000.0 else 1_000_000.0
+            val mhz = hz / unit
+            mhz >= band.getAttribute("low").toDouble() && mhz <= band.getAttribute("high").toDouble()
+        }?.textContent }
+        val value = explicit.trim().uppercase(Locale.US).ifBlank { frequencyBand.orEmpty() }
+        if (value.isBlank() && !required && frequency == null) return ""
+        if (bands.none { it.textContent == value } || (frequency != null && frequencyBand != value)) fail(LoTWProblem.BAND, value)
+        return value
+    }
+
+    fun satellite(name: String, date: String): String {
+        val normalized = name.trim().uppercase(Locale.US)
+        // Look4Sat satellite names come from SatNOGS (e.g. "SO-50 (SaudiOSCAR 50)");
+        // the bundled config only knows the official LoTW name ("SO-50"). Exact match
+        // first, then accept any satellite whose official name is a substring of the
+        // Look4Sat name (covers SO-50, AO-91, IO-86, CAS-7B …). Failing that the
+        // contact is unavailable for upload.
+        val sat = satellites[normalized]
+            ?: satellites.entries.firstOrNull { (official, _) ->
+                official.length > 1 && normalized.contains(official)
+            }?.value
+            ?: fail(LoTWProblem.SATELLITE, normalized)
+        val first = sat.getAttribute("startDate")
+        val last = sat.getAttribute("endDate")
+        if ((first.isNotBlank() && date < first) || (last.isNotBlank() && date > last)) fail(LoTWProblem.SATELLITE, normalized)
+        return sat.getAttribute("name").uppercase(Locale.US)
+    }
+
+    fun propagation(value: String): String {
+        val normalized = value.trim().uppercase(Locale.US)
+        if (normalized.isNotBlank() && config.elements("propmode").none { it.getAttribute("name") == normalized || it.textContent == normalized }) {
+            fail(LoTWProblem.INVALID_CONTACT, normalized)
+        }
+        return normalized
+    }
+
+    fun stationFields(station: LoTWStation, dxcc: Int): Map<String, String> {
+        fun normalized(value: String) = value.trim().uppercase(Locale.US)
+        val grids = station.grid.split(',').map(::normalized).filter(String::isNotBlank).distinct()
+        if (grids.size !in 1..4 || grids.any { !it.matches(Regex("[A-R]{2}[0-9]{2}([A-X]{2}([0-9]{2})?)?")) }) {
+            fail(LoTWProblem.STATION_GRID)
+        }
+        // The primary grid goes into GRIDSQUARE (the field the config's tSTATION
+        // order signs); the full multi-grid set goes into MY_VUCC_GRIDS, an extra
+        // station field that TQSL stores but does not sign (same precedent as IOTA).
+        val fields = linkedMapOf("GRIDSQUARE" to grids.first())
+        if (grids.size > 1) fields["MY_VUCC_GRIDS"] = grids.joinToString(",")
+        fun zone(name: String, value: String, maximum: Int) {
+            if (value.isBlank()) return
+            val number = value.trim().toIntOrNull()?.takeIf { it in 1..maximum } ?: fail(LoTWProblem.STATION_ZONE)
+            fields[name] = number.toString()
+        }
+        zone("CQZ", station.cqZone, 40)
+        zone("ITUZ", station.ituZone, 90)
+        if (station.iota.isNotBlank()) {
+            val iota = normalized(station.iota)
+            if (!iota.matches(Regex("(AF|AN|AS|EU|NA|OC|SA)-[0-9]{3}"))) fail(LoTWProblem.STATION_IOTA)
+            fields["IOTA"] = iota
+        }
+        val pageFields = config.elements("page").filter { it.getAttribute("dependency") == dxcc.toString() }
+            .flatMap { it.elements("pageField") }.map { it.textContent }
+        val primary = pageFields.firstOrNull { it in setOf("US_STATE", "CA_PROVINCE", "RU_OBLAST", "CN_PROVINCE", "AU_STATE", "JA_PREFECTURE", "FI_KUNTA") }
+        val secondary = pageFields.firstOrNull { it in setOf("US_COUNTY", "JA_CITY_GUN_KU") }
+        fun region(name: String?, value: String) {
+            if (value.isBlank()) return
+            if (name == null) fail(LoTWProblem.STATION_REGION)
+            val field = config.elements("field").single { it.getAttribute("Id") == name }
+            val dependency = when (field.getAttribute("dependsOn")) {
+                "DXCC" -> dxcc.toString()
+                else -> fields[field.getAttribute("dependsOn")]
+            }
+            val options = field.elements("enums").filter {
+                it.getAttribute("dependency").isBlank() || it.getAttribute("dependency") == dependency
+            }.flatMap { it.elements("enum") }.map { it.getAttribute("value").uppercase(Locale.US) }
+            val code = normalized(value)
+            if (code !in options) fail(LoTWProblem.STATION_REGION, name)
+            fields[name] = code
+        }
+        region(primary, station.region)
+        region(secondary, station.county)
+        return fields
+    }
+}
+
+private fun Element.elements(tag: String): List<Element> = getElementsByTagName(tag).let { nodes ->
+    (0 until nodes.length).map { nodes.item(it) as Element }
+}
+private fun Element.childElements(): List<Element> = (0 until childNodes.length).mapNotNull { childNodes.item(it) as? Element }

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWKeyMaterial.kt

@@ -0,0 +1,109 @@
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.repository.LoTWCertificate
+import com.rtbishop.look4sat.core.domain.repository.LoTWOperationException
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import java.security.KeyStore
+import java.security.PrivateKey
+import java.security.Signature
+import java.security.cert.X509Certificate
+import java.text.SimpleDateFormat
+import java.util.Collections
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+internal data class LoTWKeyMaterial(val key: PrivateKey, val certificate: X509Certificate, val info: LoTWCertificate) {
+    companion object {
+        fun read(bytes: ByteArray, password: CharArray, now: Long): LoTWKeyMaterial {
+            if (bytes.isEmpty() || bytes.size > MAX_CERTIFICATE_BYTES) fail(LoTWProblem.CERTIFICATE_INVALID)
+            val store = try {
+                KeyStore.getInstance("PKCS12").apply { bytes.inputStream().use { load(it, password) } }
+            } catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_PASSWORD) }
+            val aliases = Collections.list(store.aliases()).filter { store.isKeyEntry(it) }
+            if (aliases.size != 1) fail(LoTWProblem.CERTIFICATE_INVALID)
+            val alias = aliases.single()
+            val key = try { store.getKey(alias, password) as? PrivateKey }
+            catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_PASSWORD) }
+                ?: fail(LoTWProblem.CERTIFICATE_INVALID)
+            val cert = store.getCertificate(alias) as? X509Certificate ?: fail(LoTWProblem.CERTIFICATE_INVALID)
+            if (key.algorithm != "RSA" || cert.publicKey.algorithm != "RSA") fail(LoTWProblem.CERTIFICATE_INVALID)
+            try { cert.checkValidity(Date(now)) } catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_EXPIRED) }
+            val info = try { metadata(cert) } catch (_: Exception) { fail(LoTWProblem.CERTIFICATE_INVALID) }
+            // Use the platform's crypto implementation, including PKCS#1 padding. No custom cryptography.
+            val challenge = "Look4Sat LoTW certificate key check".toByteArray(Charsets.US_ASCII)
+            val signed = Signature.getInstance("SHA1withRSA").run { initSign(key); update(challenge); sign() }
+            val valid = Signature.getInstance("SHA1withRSA").run { initVerify(cert); update(challenge); verify(signed) }
+            if (!valid) fail(LoTWProblem.CERTIFICATE_INVALID)
+            return LoTWKeyMaterial(key, cert, info)
+        }
+
+        private fun metadata(cert: X509Certificate): LoTWCertificate {
+            val oid = byteArrayOf(0x2b, 0x06, 0x01, 0x04, 0x01, 0xe0.toByte(), 0x3c, 0x01, 0x01)
+            val subject = DerValue.read(cert.subjectX500Principal.encoded).single()
+            require(subject.tag == 0x30)
+            val calls = subject.children().flatMap { it.children() }.mapNotNull { attribute ->
+                val pair = attribute.children()
+                if (pair.size == 2 && pair[0].tag == 6 && pair[0].data.contentEquals(oid)) pair[1].text() else null
+            }
+            val call = calls.single().trim().uppercase(Locale.US)
+            require(call.matches(Regex("[A-Z0-9]+(/[A-Z0-9]+)*")) && call.any(Char::isDigit) && call.any(Char::isLetter))
+            val first = extension(cert, "2")
+            val last = extension(cert, "3").takeUnless { it == "0000-00-00" }.orEmpty()
+            require(validDate(first) && (last.isBlank() || validDate(last)) && (last.isBlank() || last >= first))
+            val dxcc = extension(cert, "4").toInt()
+            require(dxcc > 0)
+            return LoTWCertificate(call, dxcc, cert.serialNumber.toString(16), utc(cert.notAfter.time, "yyyy-MM-dd"), first, last)
+        }
+
+        private fun extension(cert: X509Certificate, suffix: String): String {
+            val bytes = cert.getExtensionValue("1.3.6.1.4.1.12348.1.$suffix") ?: return ""
+            val outer = DerValue.read(bytes).single()
+            require(outer.tag == 4)
+            // TrustedQSL uses raw ASCII extension values. Also accept DER string-wrapped values.
+            return if (outer.data.all { it.toInt() in 32..126 || it.toInt() == 0 }) {
+                outer.data.toString(Charsets.US_ASCII).trim('\u0000', ' ')
+            } else DerValue.read(outer.data).single().text().trim()
+        }
+    }
+}
+
+internal const val MAX_CERTIFICATE_BYTES = 1024 * 1024
+internal fun fail(problem: LoTWProblem, detail: String = ""): Nothing = throw LoTWOperationException(problem, detail)
+internal fun utc(millis: Long, pattern: String): String = SimpleDateFormat(pattern, Locale.US).apply {
+    timeZone = TimeZone.getTimeZone("UTC")
+}.format(Date(millis))
+internal fun validDate(value: String): Boolean = value.matches(Regex("[0-9]{4}-[0-9]{2}-[0-9]{2}")) && runCatching {
+    SimpleDateFormat("yyyy-MM-dd", Locale.US).apply { isLenient = false }.parse(value) != null
+}.getOrDefault(false)
+
+/** Only bounded DER metadata decoding; cryptographic verification is delegated to JCA. */
+internal data class DerValue(val tag: Int, val data: ByteArray) {
+    fun children(): List<DerValue> = read(data)
+    fun text(): String = when (tag) {
+        12, 19, 20, 22, 23, 24 -> data.toString(Charsets.UTF_8)
+        30 -> data.toString(Charsets.UTF_16BE)
+        else -> error("Not an ASN.1 string")
+    }
+    companion object {
+        fun read(bytes: ByteArray): List<DerValue> {
+            val result = mutableListOf<DerValue>()
+            var offset = 0
+            while (offset < bytes.size) {
+                require(bytes.size - offset >= 2)
+                val tag = bytes[offset++].toInt() and 255
+                var length = bytes[offset++].toInt() and 255
+                if (length and 128 != 0) {
+                    val size = length and 127
+                    require(size in 1..3 && size <= bytes.size - offset)
+                    length = 0
+                    repeat(size) { length = (length shl 8) or (bytes[offset++].toInt() and 255) }
+                }
+                require(length <= bytes.size - offset)
+                result += DerValue(tag, bytes.copyOfRange(offset, offset + length))
+                offset += length
+            }
+            return result
+        }
+    }
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWSigner.kt

@@ -0,0 +1,84 @@
+package com.rtbishop.look4sat.core.data.lotw
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.logbook.isSatellite
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import java.io.ByteArrayOutputStream
+import java.math.BigDecimal
+import java.security.MessageDigest
+import java.security.Signature
+import java.util.Locale
+import java.util.zip.GZIPOutputStream
+import kotlin.io.encoding.Base64
+
+internal data class LoTWContact(val record: QsoRecord, val fields: Map<String, String>, val signData: String, val fingerprint: String)
+
+internal class LoTWSigner(private val config: LoTWConfig) {
+    fun contact(record: QsoRecord, key: LoTWKeyMaterial, station: Map<String, String>, now: Long): LoTWContact {
+        val call = record.theirCallsign.trim().uppercase(Locale.US)
+        if (record.status != QsoStatus.COMPLETE || !call.matches(Regex("[A-Z0-9]+(/[A-Z0-9]+)*")) ||
+            !call.any(Char::isLetter) || !call.any(Char::isDigit)) fail(LoTWProblem.INVALID_CONTACT, call)
+        if (!record.myCallsign.trim().equals(key.info.callsign, true)) fail(LoTWProblem.CALLSIGN_MISMATCH, call)
+        val date = utc(record.startUtcMillis, "yyyy-MM-dd")
+        if (date < key.info.firstQsoDate || (key.info.lastQsoDate.isNotBlank() && date > key.info.lastQsoDate) || record.startUtcMillis > now) {
+            fail(LoTWProblem.QSO_DATE, call)
+        }
+        val grids = buildList {
+            addAll(station.getValue("GRIDSQUARE").split(',').map(String::trim))
+            station["MY_VUCC_GRIDS"]?.split(',')?.map(String::trim)?.let(::addAll)
+        }.filter(String::isNotBlank)
+        if (record.myGrid.isNotBlank() && grids.none { grid ->
+            val local = record.myGrid.trim().uppercase(Locale.US)
+            grid.startsWith(local) || local.startsWith(grid)
+        }) fail(LoTWProblem.LOCATION_MISMATCH, call)
+        fun mhz(hz: Long?): String = hz?.let { BigDecimal.valueOf(it, 6).stripTrailingZeros().toPlainString() }.orEmpty()
+        val fields = linkedMapOf(
+            "BAND" to config.band(record.band, record.txFrequencyHz, true),
+            "BAND_RX" to config.band(record.rxBand, record.rxFrequencyHz, false),
+            "CALL" to call,
+            "FREQ" to mhz(record.txFrequencyHz),
+            "FREQ_RX" to mhz(record.rxFrequencyHz),
+            "MODE" to config.mode(record),
+            "PROP_MODE" to if (record.isSatellite) "SAT" else config.propagation(record.propagationMode),
+            "QSO_DATE" to date,
+            "QSO_TIME" to utc(record.startUtcMillis, "HH:mm:ss'Z'"),
+            "SAT_NAME" to if (record.isSatellite) config.satellite(record.satelliteName, date) else ""
+        ).filterValues { it.isNotBlank() }
+        val signData = (config.stationOrder.map { station[it].orEmpty() } + config.contactOrder.map { fields[it].orEmpty() }).joinToString("")
+        val identity = field("CALL", key.info.callsign) + field("DXCC", key.info.dxcc.toString()) +
+            station.toSortedMap().entries.joinToString("") { field(it.key, it.value) } +
+            fields.entries.joinToString("") { field(it.key, it.value) }
+        val hash = MessageDigest.getInstance("SHA-256").digest(identity.toByteArray(Charsets.UTF_8)).joinToString("") { "%02x".format(it) }
+        return LoTWContact(record, fields, signData, hash)
+    }
+
+    fun sign(contacts: List<LoTWContact>, key: LoTWKeyMaterial, station: Map<String, String>): ByteArray {
+        val text = buildString {
+            append(field("TQSL_IDENT", "Look4Sat LoTW Config: V${config.version} AllowDupes: false"))
+            append(field("REC_TYPE", "tCERT")); append(field("CERT_UID", "1"))
+            append(field("CERTIFICATE", Base64.Default.encode(key.certificate.encoded).chunked(64).joinToString("\n")))
+            append("<eor>\n")
+            append(field("REC_TYPE", "tSTATION")); append(field("STATION_UID", "1")); append(field("CERT_UID", "1"))
+            append(field("CALL", key.info.callsign)); append(field("DXCC", key.info.dxcc.toString()))
+            station.forEach { (name, value) -> append(field(name, value)) }
+            append("<eor>\n")
+            contacts.forEach { contact ->
+                append(field("REC_TYPE", "tCONTACT")); append(field("STATION_UID", "1"))
+                contact.fields.forEach { (name, value) -> append(field(name, value)) }
+                // SHA-1 is required by the LoTW V2.0 wire format, not chosen for general-purpose signing.
+                val signature = Signature.getInstance("SHA1withRSA").run {
+                    initSign(key.key); update(contact.signData.toByteArray(Charsets.UTF_8)); sign()
+                }
+                val encoded = Base64.Default.encode(signature).chunked(64).joinToString("\n")
+                append("<SIGN_LOTW_V2.0:${encoded.length}:6>$encoded\n")
+                append(field("SIGNDATA", contact.signData)); append("<eor>\n")
+            }
+        }
+        return ByteArrayOutputStream().also { output ->
+            GZIPOutputStream(output).use { it.write(text.toByteArray(Charsets.UTF_8)) }
+        }.toByteArray()
+    }
+}
+
+private fun field(name: String, value: String): String = "<$name:${value.toByteArray(Charsets.UTF_8).size}>$value\n"

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWStorage.kt

@@ -0,0 +1,61 @@
+package com.rtbishop.look4sat.core.data.lotw
+
+import android.content.Context
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import android.util.AtomicFile
+import java.io.File
+import java.security.KeyStore
+import javax.crypto.Cipher
+import javax.crypto.KeyGenerator
+import javax.crypto.SecretKey
+import javax.crypto.spec.GCMParameterSpec
+
+internal interface LoTWStorage {
+    fun read(name: String): ByteArray?
+    fun write(name: String, data: ByteArray)
+    fun delete(name: String)
+}
+
+/** P12 backups and their saved passwords are encrypted at rest and excluded from Android/cloud backup. */
+internal class AndroidLoTWStorage(context: Context) : LoTWStorage {
+    private val directory = File(context.noBackupFilesDir, "lotw")
+    private val store by lazy { KeyStore.getInstance("AndroidKeyStore").apply { load(null) } }
+    private fun file(name: String): AtomicFile {
+        require(name.matches(Regex("[a-z]+")))
+        check(directory.isDirectory || directory.mkdirs())
+        return AtomicFile(File(directory, name))
+    }
+    private fun key(): SecretKey = (store.getKey(ALIAS, null) as? SecretKey) ?: KeyGenerator.getInstance(
+        KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore"
+    ).run {
+        init(KeyGenParameterSpec.Builder(ALIAS, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
+            .setBlockModes(KeyProperties.BLOCK_MODE_GCM).setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+            .setKeySize(256).build())
+        generateKey()
+    }
+    @Synchronized override fun read(name: String): ByteArray? {
+        val file = file(name)
+        if (!file.baseFile.exists() && !File(file.baseFile.path + ".bak").exists()) return null
+        val bytes = file.readFully()
+        require(bytes.size in 29..(16 * 1024 * 1024) && bytes[0] == 1.toByte())
+        return Cipher.getInstance("AES/GCM/NoPadding").run {
+            init(Cipher.DECRYPT_MODE, key(), GCMParameterSpec(128, bytes.copyOfRange(1, 13)))
+            updateAAD(name.toByteArray(Charsets.UTF_8))
+            doFinal(bytes, 13, bytes.size - 13)
+        }
+    }
+    @Synchronized override fun write(name: String, data: ByteArray) {
+        val cipher = Cipher.getInstance("AES/GCM/NoPadding").apply {
+            init(Cipher.ENCRYPT_MODE, key())
+            updateAAD(name.toByteArray(Charsets.UTF_8))
+        }
+        val bytes = byteArrayOf(1) + cipher.iv + cipher.doFinal(data)
+        val file = file(name)
+        val stream = file.startWrite()
+        try { stream.write(bytes); file.finishWrite(stream) }
+        catch (error: Exception) { file.failWrite(stream); throw error }
+    }
+    @Synchronized override fun delete(name: String) = file(name).delete()
+    private companion object { const val ALIAS = "look4sat.lotw.storage.v1" }
+}

core/data/src/main/java/com/rtbishop/look4sat/core/data/lotw/LoTWUploadRepository.kt

@@ -0,0 +1,369 @@
+package com.rtbishop.look4sat.core.data.lotw
+
+import android.content.Context
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.repository.ILoTWUploadRepository
+import com.rtbishop.look4sat.core.domain.repository.LoTWCertificate
+import com.rtbishop.look4sat.core.domain.repository.LoTWOperationException
+import com.rtbishop.look4sat.core.domain.repository.LoTWProblem
+import com.rtbishop.look4sat.core.domain.repository.LoTWStation
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadAudit
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadPreview
+import com.rtbishop.look4sat.core.domain.repository.LoTWUploadResult
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ensureActive
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import okhttp3.Call
+import okhttp3.Callback
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.MultipartBody
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.RequestBody.Companion.toRequestBody
+import okhttp3.Response
+import java.io.ByteArrayOutputStream
+import java.io.DataInputStream
+import java.io.DataOutputStream
+import java.io.IOException
+import java.nio.ByteBuffer
+import java.nio.CharBuffer
+import java.util.Locale
+import java.util.UUID
+import java.util.concurrent.TimeUnit
+import kotlin.coroutines.coroutineContext
+import kotlin.coroutines.resume
+
+private fun readBoundedBody(response: Response, limit: Int): String = response.body.charStream().use { reader ->
+    val result = StringBuilder()
+    val buffer = CharArray(8192)
+    while (true) {
+        val count = reader.read(buffer)
+        if (count < 0) break
+        require(result.length <= limit - count) { "Response exceeds size limit" }
+        result.append(buffer, 0, count)
+    }
+    result.toString()
+}
+
+class LoTWUploadRepository internal constructor(
+    private val storage: LoTWStorage,
+    private val config: () -> LoTWConfig,
+    client: OkHttpClient = OkHttpClient(),
+    private val now: () -> Long = System::currentTimeMillis
+) : ILoTWUploadRepository {
+    constructor(context: Context) : this(AndroidLoTWStorage(context), { LoTWConfig(context.assets.open("lotw/config.tq6")) })
+    private val client = client.newBuilder().connectTimeout(30, TimeUnit.SECONDS).readTimeout(120, TimeUnit.SECONDS)
+        .callTimeout(180, TimeUnit.SECONDS).retryOnConnectionFailure(false).followRedirects(false).followSslRedirects(false).build()
+    private val mutex = Mutex()
+    @Volatile private var pending: Pending? = null
+    private data class Pending(val preview: LoTWUploadPreview, val data: ByteArray, val hashes: List<String>, val created: Long)
+    private data class SigningContext(val key: LoTWKeyMaterial, val signer: LoTWSigner, val location: Map<String, String>)
+
+    override suspend fun certificate(): LoTWCertificate? = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val bytes = storage.read("certificate") ?: return@withLock null
+            try {
+                readBundle(bytes).let { bundle ->
+                    bundle.p12.fill(0)
+                    bundle.password?.fill(0)
+                    bundle.info.copy(passwordSaved = bundle.password != null)
+                }
+            } finally { bytes.fill(0) }
+        }
+    }
+
+    override suspend fun importCertificate(data: ByteArray, password: CharArray): LoTWCertificate = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val passwordBytes = encodePassword(password)
+            try {
+                if (passwordBytes.size > MAX_CERTIFICATE_PASSWORD_BYTES) fail(LoTWProblem.CERTIFICATE_PASSWORD)
+                val key = LoTWKeyMaterial.read(data, password, now())
+                val bytes = encodeBundle(key.info, data, passwordBytes)
+                try { storage.write("certificate", bytes) } finally { bytes.fill(0) }
+                discardPreview()
+                key.info.copy(passwordSaved = true)
+            } finally {
+                passwordBytes.fill(0)
+                password.fill('\u0000')
+                data.fill(0)
+            }
+        }
+    }
+
+    override suspend fun saveCertificatePassword(password: CharArray): LoTWCertificate = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+            val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+            val passwordBytes = encodePassword(password)
+            try {
+                if (passwordBytes.size > MAX_CERTIFICATE_PASSWORD_BYTES) fail(LoTWProblem.CERTIFICATE_PASSWORD)
+                val key = LoTWKeyMaterial.read(bundle.p12, password, now())
+                val bytes = encodeBundle(key.info, bundle.p12, passwordBytes)
+                try { storage.write("certificate", bytes) } finally { bytes.fill(0) }
+                discardPreview()
+                key.info.copy(passwordSaved = true)
+            } finally {
+                bundle.p12.fill(0)
+                bundle.password?.fill(0)
+                passwordBytes.fill(0)
+                password.fill('\u0000')
+            }
+        }
+    }
+
+    override suspend fun station(): LoTWStation? = withContext(Dispatchers.IO) {
+        mutex.withLock { readStation() }
+    }
+
+    override suspend fun saveStation(station: LoTWStation): LoTWStation = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+            val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+            val normalized = station.normalized()
+            try { config().stationFields(normalized, bundle.info.dxcc) }
+            finally {
+                bundle.p12.fill(0)
+                bundle.password?.fill(0)
+            }
+            writeStation(normalized)
+            discardPreview()
+            normalized
+        }
+    }
+
+    override suspend fun removeCertificate() = withContext(Dispatchers.IO) {
+        mutex.withLock { discardPreview(); storage.delete("certificate") }
+    }
+
+    override suspend fun audit(records: List<QsoRecord>): LoTWUploadAudit = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val signing = signingContext()
+            val ledger = ledger()
+            val unique = hashSetOf<String>()
+            var pendingCount = 0
+            var uploaded = 0
+            var unknown = 0
+            var unavailable = 0
+            records.sortedBy { it.startUtcMillis }.forEach { record ->
+                coroutineContext.ensureActive()
+                when {
+                    record.status != QsoStatus.COMPLETE -> unavailable++
+                    record.lotwReceived -> uploaded++
+                    else -> {
+                        val contact = try {
+                            signing.signer.contact(record, signing.key, signing.location, now())
+                        } catch (_: LoTWOperationException) {
+                            unavailable++
+                            null
+                        }
+                        if (contact != null) when {
+                            !unique.add(contact.fingerprint) -> unavailable++
+                            ledger[contact.fingerprint] == "accepted" -> uploaded++
+                            ledger[contact.fingerprint] == "unknown" -> unknown++
+                            else -> pendingCount++
+                        }
+                    }
+                }
+            }
+            LoTWUploadAudit(records.size, pendingCount, uploaded, unknown, unavailable)
+        }
+    }
+
+    override suspend fun prepare(records: List<QsoRecord>, resubmit: Boolean): LoTWUploadPreview = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            discardPreview()
+            if (records.size > 10_000) fail(LoTWProblem.TOO_MANY_CONTACTS)
+            val signing = signingContext()
+            val ledger = ledger()
+            var skipped = 0
+            var unknown = 0
+            val unique = hashSetOf<String>()
+            val contacts = records.sortedBy { it.startUtcMillis }.mapNotNull { record ->
+                coroutineContext.ensureActive()
+                if (record.status != QsoStatus.COMPLETE || (record.lotwReceived && !resubmit)) { skipped++; return@mapNotNull null }
+                val contact = signing.signer.contact(record, signing.key, signing.location, now())
+                val previous = ledger[contact.fingerprint]
+                when {
+                    (previous == "accepted" && !resubmit) || !unique.add(contact.fingerprint) -> { skipped++; null }
+                    previous == "unknown" && !resubmit -> { skipped++; unknown++; null }
+                    else -> contact
+                }
+            }
+            val preview = LoTWUploadPreview(
+                UUID.randomUUID().toString(), signing.key.info.callsign, signing.key.info.dxcc, signing.location.getValue("GRIDSQUARE"),
+                contacts.size, skipped,
+                contacts.firstOrNull()?.record?.let { utc(it.startUtcMillis, "yyyy-MM-dd HH:mm:ss") }.orEmpty(),
+                contacts.lastOrNull()?.record?.let { utc(it.startUtcMillis, "yyyy-MM-dd HH:mm:ss") }.orEmpty(),
+                contacts.map { "${utc(it.record.startUtcMillis, "MM-dd HH:mm")} ${it.record.theirCallsign} ${it.fields["MODE"]} ${it.fields["SAT_NAME"].orEmpty()}" },
+                unknown
+            )
+            if (contacts.isNotEmpty()) pending = Pending(
+                preview,
+                signing.signer.sign(contacts, signing.key, signing.location),
+                contacts.map { it.fingerprint },
+                now()
+            )
+            preview
+        }
+    }
+
+    override suspend fun upload(previewId: String): LoTWUploadResult = withContext(Dispatchers.IO) {
+        mutex.withLock {
+            val payload = pending?.takeIf { it.preview.id == previewId && now() - it.created in 0..900_000 }
+                ?: return@withLock LoTWUploadResult.ExpiredPreview
+            pending = null // A preview is a one-shot authorization, including across failures.
+            val ledger = ledger()
+            payload.hashes.forEach { ledger[it] = "unknown" }
+            saveLedger(ledger) // Persist BEFORE the POST, so process death/cancellation cannot cause an automatic retry.
+            try {
+                val result = post(payload.data, payload.preview.count)
+                when (result) {
+                    is LoTWUploadResult.Accepted -> payload.hashes.forEach { ledger[it] = "accepted" }
+                    is LoTWUploadResult.Rejected -> payload.hashes.forEach { ledger.remove(it) }
+                    else -> Unit
+                }
+                saveLedger(ledger)
+                result
+            } finally { payload.data.fill(0) }
+        }
+    }
+
+    override fun discardPreview() { pending?.data?.fill(0); pending = null }
+
+    private fun signingContext(): SigningContext {
+        val stored = storage.read("certificate") ?: fail(LoTWProblem.CERTIFICATE_MISSING)
+        val bundle = try { readBundle(stored) } finally { stored.fill(0) }
+        val passwordBytes = bundle.password ?: run {
+            bundle.p12.fill(0)
+            fail(LoTWProblem.CERTIFICATE_PASSWORD)
+        }
+        val password = decodePassword(passwordBytes)
+        return try {
+            val key = LoTWKeyMaterial.read(bundle.p12, password, now())
+            val tqslConfig = config()
+            val signer = LoTWSigner(tqslConfig)
+            val station = readStation() ?: fail(LoTWProblem.STATION_GRID)
+            SigningContext(key, signer, tqslConfig.stationFields(station, key.info.dxcc))
+        } finally {
+            bundle.p12.fill(0)
+            passwordBytes.fill(0)
+            password.fill('\u0000')
+        }
+    }
+
+    private fun readStation(): LoTWStation? = storage.read("station")?.inputStream()?.let { stream ->
+        DataInputStream(stream).use { input ->
+            require(input.readInt() == 1)
+            LoTWStation(input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF())
+        }
+    }
+
+    private fun writeStation(station: LoTWStation) {
+        val bytes = ByteArrayOutputStream().also { stream -> DataOutputStream(stream).use { output ->
+            output.writeInt(1)
+            listOf(station.grid, station.cqZone, station.ituZone, station.region, station.county, station.iota).forEach(output::writeUTF)
+        } }.toByteArray()
+        try { storage.write("station", bytes) } finally { bytes.fill(0) }
+    }
+
+    private suspend fun post(data: ByteArray, count: Int): LoTWUploadResult = suspendCancellableCoroutine { continuation ->
+        val body = MultipartBody.Builder().setType(MultipartBody.FORM)
+            .addFormDataPart("upfile", "look4sat-${UUID.randomUUID()}.tq8", data.toRequestBody("application/octet-stream".toMediaType())).build()
+        val call = client.newCall(Request.Builder().url("https://lotw.arrl.org/lotw/upload").post(body).build())
+        continuation.invokeOnCancellation { call.cancel() }
+        call.enqueue(object : Callback {
+            override fun onFailure(call: Call, e: IOException) {
+                if (continuation.isActive) continuation.resume(LoTWUploadResult.Unknown)
+            }
+            override fun onResponse(call: Call, response: Response) {
+                val result = try {
+                    response.use {
+                        if (!it.isSuccessful) LoTWUploadResult.Unknown else parseLoTWUploadResponse(readBoundedBody(it, 256 * 1024), count)
+                    }
+                } catch (_: Exception) { LoTWUploadResult.Unknown }
+                if (continuation.isActive) continuation.resume(result)
+            }
+        })
+    }
+
+    private fun ledger(): MutableMap<String, String> = storage.read("receipts")?.inputStream()?.let { stream ->
+        DataInputStream(stream).use { input ->
+            require(input.readInt() == 1)
+            val size = input.readInt().also { require(it in 0..200_000) }
+            val entries = linkedMapOf<String, String>()
+            repeat(size) { entries[input.readUTF()] = input.readUTF() }
+            entries
+        }
+    } ?: linkedMapOf()
+
+    private fun saveLedger(entries: Map<String, String>) {
+        val bytes = ByteArrayOutputStream().also { stream -> DataOutputStream(stream).use { output ->
+            output.writeInt(1); output.writeInt(entries.size)
+            entries.forEach { (hash, status) -> output.writeUTF(hash); output.writeUTF(status) }
+        } }.toByteArray()
+        storage.write("receipts", bytes)
+    }
+}
+
+internal fun parseLoTWUploadResponse(body: String, count: Int): LoTWUploadResult {
+    val markers = Regex("<!--\\s*\\.UPL\\.\\s*(accepted|rejected)\\s*-->", RegexOption.IGNORE_CASE)
+        .findAll(body).map { it.groupValues[1].lowercase() }.toList()
+    return when (markers.singleOrNull()) {
+        "accepted" -> LoTWUploadResult.Accepted(count)
+        "rejected" -> {
+            val message = Regex("<!--\\s*\\.UPLMESSAGE\\.\\s*(.*?)-->", setOf(RegexOption.IGNORE_CASE, RegexOption.DOT_MATCHES_ALL))
+                .find(body)?.groupValues?.get(1).orEmpty().replace(Regex("<[^>]*>"), " ")
+                .replace(Regex("[\\p{Cc}\\s]+"), " ").trim().take(500)
+            LoTWUploadResult.Rejected(message)
+        }
+        else -> LoTWUploadResult.Unknown
+    }
+}
+
+private data class StoredCertificate(val info: LoTWCertificate, val p12: ByteArray, val password: ByteArray?)
+
+private fun encodeBundle(info: LoTWCertificate, p12: ByteArray, password: ByteArray): ByteArray = ByteArrayOutputStream().also { stream ->
+    DataOutputStream(stream).use { output ->
+        output.writeInt(2)
+        output.writeUTF(info.callsign); output.writeInt(info.dxcc); output.writeUTF(info.serial)
+        output.writeUTF(info.expires); output.writeUTF(info.firstQsoDate); output.writeUTF(info.lastQsoDate)
+        output.writeInt(password.size); output.write(password)
+        output.writeInt(p12.size); output.write(p12)
+    }
+}.toByteArray()
+
+private fun readBundle(bytes: ByteArray): StoredCertificate = DataInputStream(bytes.inputStream()).use { input ->
+    val version = input.readInt().also { require(it in 1..2) }
+    val info = LoTWCertificate(input.readUTF(), input.readInt(), input.readUTF(), input.readUTF(), input.readUTF(), input.readUTF())
+    val password = if (version >= 2) {
+        val size = input.readInt().also { require(it in 0..MAX_CERTIFICATE_PASSWORD_BYTES) }
+        ByteArray(size).also { input.readFully(it) }
+    } else null
+    val p12Size = input.readInt().also { require(it in 1..MAX_CERTIFICATE_BYTES) }
+    StoredCertificate(info, ByteArray(p12Size).also { input.readFully(it) }, password)
+}
+
+private fun encodePassword(password: CharArray): ByteArray {
+    val buffer = Charsets.UTF_8.encode(CharBuffer.wrap(password))
+    return ByteArray(buffer.remaining()).also(buffer::get)
+}
+
+private fun decodePassword(password: ByteArray): CharArray {
+    val buffer = Charsets.UTF_8.decode(ByteBuffer.wrap(password))
+    return CharArray(buffer.remaining()).also(buffer::get)
+}
+
+private fun LoTWStation.normalized() = LoTWStation(
+    grid.trim().uppercase(Locale.US),
+    cqZone.trim(),
+    ituZone.trim(),
+    region.trim().uppercase(Locale.US),
+    county.trim().uppercase(Locale.US),
+    iota.trim().uppercase(Locale.US)
+)
+
+private const val MAX_CERTIFICATE_PASSWORD_BYTES = 16 * 1024

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/QsoRepository.kt

@@ -0,0 +1,199 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import com.rtbishop.look4sat.core.data.database.QsoDao
+import com.rtbishop.look4sat.core.data.database.entity.QsoEntity
+import com.rtbishop.look4sat.core.domain.logbook.AdifCodec
+import com.rtbishop.look4sat.core.domain.logbook.AdifImportResult
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+import com.rtbishop.look4sat.core.domain.logbook.QsoStatus
+import com.rtbishop.look4sat.core.domain.logbook.sameConfirmedContact
+import com.rtbishop.look4sat.core.domain.logbook.withConfirmation
+import com.rtbishop.look4sat.core.domain.logbook.confirmationLookupKey
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import java.util.Locale
+
+class QsoRepository(
+    private val dao: QsoDao,
+    private val dispatcher: CoroutineDispatcher
+) : IQsoRepository {
+    private val importMutex = Mutex()
+
+    override val records: Flow<List<QsoRecord>> = dao.observeAll().map { records -> records.map(QsoEntity::toDomain) }
+
+    override suspend fun find(id: Long): QsoRecord? = withContext(dispatcher) { dao.find(id)?.toDomain() }
+
+    override suspend fun save(record: QsoRecord): Long = withContext(dispatcher) {
+        importMutex.withLock {
+            val previous = if (record.id != 0L) dao.find(record.id)?.toDomain() else null
+            val saved = if (previous?.lotwConfirmed == true && sameConfirmedContact(record, previous)) {
+                record.withConfirmation(previous)
+            } else if (previous?.lotwConfirmed == true) record.copy(
+                lotwConfirmed = false, lotwQslDate = "", vuccGrids = emptyList(),
+                dxcc = null, country = "", cqZone = null, region = ""
+            ) else record
+            val received = if (previous != null && (
+                stableQsoKey(record) != stableQsoKey(previous) || record.myGrid != previous.myGrid ||
+                    record.rxFrequencyHz != previous.rxFrequencyHz || record.band != previous.band ||
+                    record.rxBand != previous.rxBand || record.propagationMode != previous.propagationMode
+                )) false else saved.lotwReceived
+            dao.save(saved.copy(lotwReceived = received).toEntity())
+        }
+    }
+
+    override suspend fun delete(id: Long) = withContext(dispatcher) { importMutex.withLock { dao.delete(id) } }
+
+    override suspend fun exportAdi(ids: Set<Long>?, includeIncomplete: Boolean): String = withContext(dispatcher) {
+        val records = dao.getAll()
+            .asSequence()
+            .filter { ids == null || it.id in ids }
+            .map(QsoEntity::toDomain)
+            .filter { includeIncomplete || it.status == QsoStatus.COMPLETE }
+            .toList()
+        AdifCodec.encode(records)
+    }
+
+    override suspend fun importAdi(content: String): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock {
+            mergeRecords(AdifCodec.decode(content))
+        }
+    }
+
+    override suspend fun mergeConfirmed(records: List<QsoRecord>): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock { mergeRecords(records.filter { it.lotwConfirmed }) }
+    }
+
+    override suspend fun mergeLoTW(records: List<QsoRecord>): AdifImportResult = withContext(dispatcher) {
+        importMutex.withLock { mergeRecords(records, fromLoTW = true) }
+    }
+
+    private suspend fun mergeRecords(records: List<QsoRecord>, fromLoTW: Boolean = false): AdifImportResult {
+        val working = dao.getAll().map(QsoEntity::toDomain).toMutableList()
+        val lookup = working.indices.groupBy { working[it].confirmationLookupKey() }
+            .mapValues { it.value.toMutableList() }.toMutableMap()
+        val knownKeys = working.mapTo(mutableSetOf(), ::stableQsoKey)
+        val changes = linkedMapOf<Int, QsoRecord>()
+        var imported = 0
+        var updated = 0
+        var skipped = 0
+        records.forEach { remote ->
+            if (!fromLoTW && !remote.lotwConfirmed && stableQsoKey(remote) in knownKeys) { skipped++; return@forEach }
+            val candidates = if (fromLoTW || remote.lotwConfirmed) lookup[remote.confirmationLookupKey()].orEmpty()
+                .filter { sameConfirmedContact(working[it], remote) } else emptyList()
+            val exact = candidates.filter { working[it].startUtcMillis == remote.startUtcMillis }
+            val match = exact.singleOrNull() ?: candidates.singleOrNull()
+            if (match == null) {
+                if (stableQsoKey(remote) in knownKeys) { skipped++; return@forEach }
+                val added = remote.copy(id = 0L)
+                changes[working.size] = added
+                lookup.getOrPut(added.confirmationLookupKey()) { mutableListOf() }.add(working.size)
+                knownKeys += stableQsoKey(added)
+                working += added
+                imported++
+            } else {
+                val previous = working[match]
+                val merged = previous.withConfirmation(remote)
+                if (merged == previous) skipped++ else {
+                    working[match] = merged
+                    changes[match] = merged
+                    updated++
+                }
+            }
+        }
+        dao.saveBatch(changes.values.map(QsoRecord::toEntity))
+        return AdifImportResult(imported, skipped, updated)
+    }
+}
+
+private fun QsoEntity.toDomain() = QsoRecord(
+    id = id,
+    startUtcMillis = startUtcMillis,
+    endUtcMillis = endUtcMillis,
+    theirCallsign = theirCallsign,
+    myCallsign = myCallsign,
+    theirGrid = theirGrid,
+    myGrid = myGrid,
+    sentReport = sentReport,
+    receivedReport = receivedReport,
+    txFrequencyHz = txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz,
+    band = band,
+    rxBand = rxBand,
+    mode = mode,
+    submode = submode,
+    satelliteName = satelliteName,
+    transponderName = transponderName,
+    satelliteMode = satelliteMode,
+    passAosUtcMillis = passAosUtcMillis,
+    automatic = automatic,
+    status = runCatching { QsoStatus.valueOf(status) }.getOrDefault(QsoStatus.DRAFT),
+    propagationMode = propagationMode,
+    lotwConfirmed = lotwConfirmed,
+    lotwReceived = lotwReceived,
+    lotwQslDate = lotwQslDate,
+    vuccGrids = vuccGrids.split(',').filter(String::isNotBlank),
+    dxcc = dxcc,
+    country = country,
+    cqZone = cqZone,
+    region = region,
+    comment = comment
+)
+
+private fun QsoRecord.toEntity() = QsoEntity(
+    id = id,
+    startUtcMillis = startUtcMillis,
+    endUtcMillis = endUtcMillis,
+    theirCallsign = theirCallsign.trim().uppercase(Locale.US),
+    myCallsign = myCallsign.trim().uppercase(Locale.US),
+    theirGrid = theirGrid.trim().uppercase(Locale.US),
+    myGrid = myGrid.trim().uppercase(Locale.US),
+    sentReport = sentReport.trim(),
+    receivedReport = receivedReport.trim(),
+    txFrequencyHz = txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz,
+    band = band,
+    rxBand = rxBand,
+    mode = mode.trim(),
+    submode = submode.trim(),
+    satelliteName = satelliteName,
+    transponderName = transponderName,
+    satelliteMode = satelliteMode,
+    passAosUtcMillis = passAosUtcMillis,
+    automatic = automatic,
+    status = status.name,
+    dedupeKey = stableQsoKey(this),
+    propagationMode = propagationMode.ifBlank { if (satelliteName.isNotBlank()) "SAT" else "" },
+    lotwConfirmed = lotwConfirmed,
+    lotwReceived = lotwReceived,
+    lotwQslDate = lotwQslDate,
+    vuccGrids = vuccGrids.joinToString(","),
+    dxcc = dxcc,
+    country = country,
+    cqZone = cqZone,
+    region = region,
+    comment = comment
+)
+
+internal fun stableQsoKey(record: QsoRecord): String = listOf(
+    record.startUtcMillis.toString(),
+    record.theirCallsign.trim().uppercase(Locale.US),
+    record.myCallsign.trim().uppercase(Locale.US),
+    record.txFrequencyHz?.toString().orEmpty(),
+    record.mode.trim().uppercase(Locale.US),
+    record.submode.trim().uppercase(Locale.US),
+    record.satelliteName.trim().uppercase(Locale.US)
+).joinToString("|")

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SettingsRepo.kt

@@ -877,6 +877,31 @@ class SettingsRepo(
     }
     //endregion
 
+    //region # Per-satellite logbook mode preset settings
+    private val keySatelliteModes = "satelliteModes"
+
+    override fun getSatelliteMode(catnum: Int): String {
+        val json = preferences.getString(keySatelliteModes, "{}") ?: "{}"
+        return try {
+            JSONObject(json).optString(catnum.toString(), "")
+        } catch (_: Exception) {
+            ""
+        }
+    }
+
+    override fun setSatelliteMode(catnum: Int, mode: String) {
+        val json = preferences.getString(keySatelliteModes, "{}") ?: "{}"
+        val updated = try {
+            val obj = JSONObject(json)
+            if (mode.isBlank()) obj.remove(catnum.toString()) else obj.put(catnum.toString(), mode.uppercase())
+            obj.toString()
+        } catch (_: Exception) {
+            if (mode.isBlank()) "{}" else """{"$catnum": "${mode.uppercase()}"}"""
+        }
+        preferences.edit { putString(keySatelliteModes, updated) }
+    }
+    //endregion
+
     //region # AMSAT status report settings
     private val keyAmSatCallsign = "amSatCallsign"
 

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepoTest.kt

@@ -298,6 +298,8 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
 
     override fun getSatelliteOffset(catnum: Int): String = ""
+    override fun getSatelliteMode(catnum: Int): String = ""
+    override fun setSatelliteMode(catnum: Int, mode: String) {}
 
     override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
 

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/SelectionRepoSearchTest.kt

@@ -343,6 +343,8 @@ private class FakeSettingsRepoForSearch : ISettingsRepo {
     override fun updateDataSourcesStatus(status: Map<String, Int>) = Unit
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
     override fun getSatelliteOffset(catnum: Int): String = ""
+    override fun getSatelliteMode(catnum: Int): String = ""
+    override fun setSatelliteMode(catnum: Int, mode: String) {}
     override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
     override fun getAmSatCallsign(): String = ""
     override fun setAmSatCallsign(callsign: String) = Unit

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/AdifCodec.kt

@@ -0,0 +1,163 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
+
+/** Small ADI codec for the logbook's actual field set (ADIF 3.1.7). */
+object AdifCodec {
+    private val utc = TimeZone.getTimeZone("UTC")
+
+    fun encode(records: List<QsoRecord>): String = buildString {
+        append(field("ADIF_VER", "3.1.7"))
+        append(field("PROGRAMID", "Look4Sat"))
+        append("<EOH>\r\n")
+        records.forEach { record ->
+            val startDate = format(record.startUtcMillis, "yyyyMMdd")
+            val startTime = format(record.startUtcMillis, "HHmmss")
+            append(field("QSO_DATE", startDate))
+            append(field("TIME_ON", startTime))
+            record.endUtcMillis?.let {
+                append(field("QSO_DATE_OFF", format(it, "yyyyMMdd")))
+                append(field("TIME_OFF", format(it, "HHmmss")))
+            }
+            append(field("CALL", record.theirCallsign))
+            append(field("STATION_CALLSIGN", record.myCallsign))
+            appendOptional("MODE", record.mode)
+            appendOptional("SUBMODE", record.submode)
+            appendOptional("GRIDSQUARE", record.theirGrid)
+            appendOptional("MY_GRIDSQUARE", record.myGrid)
+            appendOptional("RST_SENT", record.sentReport)
+            appendOptional("RST_RCVD", record.receivedReport)
+            record.txFrequencyHz?.let { append(field("FREQ", hzToMhz(it))) }
+            record.rxFrequencyHz?.let { append(field("FREQ_RX", hzToMhz(it))) }
+            appendOptional("BAND", record.band)
+            appendOptional("BAND_RX", record.rxBand)
+            appendOptional("PROP_MODE", record.propagationMode.ifBlank { if (record.satelliteName.isNotBlank()) "SAT" else "" })
+            appendOptional("SAT_NAME", record.satelliteName)
+            appendOptional("SAT_MODE", record.satelliteMode)
+            if (record.lotwConfirmed) append(field("LOTW_QSL_RCVD", "Y"))
+            if (record.lotwReceived) append(field("LOTW_QSL_SENT", "Y"))
+            appendOptional("LOTW_QSLRDATE", record.lotwQslDate)
+            appendOptional("VUCC_GRIDS", record.vuccGrids.joinToString(","))
+            record.dxcc?.let { append(field("DXCC", it.toString())) }
+            appendOptional("COUNTRY", record.country)
+            record.cqZone?.let { append(field("CQZ", it.toString())) }
+            appendOptional("STATE", record.region)
+            appendOptional("COMMENT", record.comment)
+            appendOptional("APP_LOOK4SAT_TRANSPONDER", record.transponderName)
+            record.passAosUtcMillis?.let { append(field("APP_LOOK4SAT_PASS_AOS", it.toString())) }
+            append(field("APP_LOOK4SAT_AUTOMATIC", if (record.automatic) "Y" else "N"))
+            append(field("APP_LOOK4SAT_STATUS", record.status.name))
+            append("<EOR>\r\n")
+        }
+    }
+
+    fun decode(content: String): List<QsoRecord> = decodeRecords(splitRecords(content))
+
+    fun decodeRecords(records: List<Map<String, String>>): List<QsoRecord> = records.mapNotNull { values ->
+        val call = values["CALL"].orEmpty().trim().uppercase(Locale.US)
+        val date = values["QSO_DATE"].orEmpty()
+        val time = values["TIME_ON"].orEmpty()
+        if (call.isBlank() || date.length != 8 || time.length !in setOf(4, 6)) return@mapNotNull null
+        val start = parse(date, time) ?: return@mapNotNull null
+        val end = values["QSO_DATE_OFF"]?.let { endDate ->
+            values["TIME_OFF"]?.let { endTime -> parse(endDate, endTime) }
+        }
+        QsoRecord(
+            startUtcMillis = start,
+            endUtcMillis = end,
+            theirCallsign = call,
+            myCallsign = values["STATION_CALLSIGN"].orEmpty().uppercase(Locale.US),
+            theirGrid = values["GRIDSQUARE"].orEmpty().uppercase(Locale.US),
+            myGrid = values["MY_GRIDSQUARE"].orEmpty().uppercase(Locale.US),
+            sentReport = values["RST_SENT"].orEmpty(),
+            receivedReport = values["RST_RCVD"].orEmpty(),
+            txFrequencyHz = mhzToHz(values["FREQ"]),
+            rxFrequencyHz = mhzToHz(values["FREQ_RX"]),
+            band = values["BAND"].orEmpty(),
+            rxBand = values["BAND_RX"].orEmpty(),
+            mode = values["MODE"].orEmpty(),
+            submode = values["SUBMODE"].orEmpty(),
+            satelliteName = values["SAT_NAME"].orEmpty(),
+            transponderName = values["APP_LOOK4SAT_TRANSPONDER"].orEmpty(),
+            satelliteMode = values["SAT_MODE"].orEmpty(),
+            passAosUtcMillis = values["APP_LOOK4SAT_PASS_AOS"]?.toLongOrNull(),
+            automatic = values["APP_LOOK4SAT_AUTOMATIC"].equals("Y", true),
+            status = values["APP_LOOK4SAT_STATUS"]?.let { runCatching { QsoStatus.valueOf(it) }.getOrNull() }
+                ?: QsoStatus.COMPLETE,
+            propagationMode = values["PROP_MODE"].orEmpty().trim().uppercase(Locale.US),
+            lotwConfirmed = values["LOTW_QSL_RCVD"].equals("Y", true),
+            lotwReceived = values["LOTW_QSL_SENT"].equals("Y", true),
+            lotwQslDate = values["LOTW_QSLRDATE"].orEmpty(),
+            vuccGrids = values["VUCC_GRIDS"].orEmpty().split(',').map { it.trim().uppercase(Locale.US) }
+                .filter { it.matches(Regex("[A-R]{2}[0-9]{2}([A-X]{2}([0-9]{2})?)?")) }.distinct(),
+            dxcc = values["DXCC"]?.toIntOrNull(),
+            country = values["COUNTRY"].orEmpty(),
+            cqZone = values["CQZ"]?.toIntOrNull()?.takeIf { it in 1..40 },
+            region = values["STATE"].orEmpty().substringBefore(" // ").trim().uppercase(Locale.US),
+            comment = values["COMMENT"].orEmpty()
+        )
+    }
+
+    private fun splitRecords(content: String): List<Map<String, String>> {
+        val records = mutableListOf<Map<String, String>>()
+        var values = linkedMapOf<String, String>()
+        var index = 0
+        while (index < content.length) {
+            val start = content.indexOf('<', index)
+            if (start < 0) break
+            val end = content.indexOf('>', start + 1)
+            if (end < 0) break
+            val descriptor = content.substring(start + 1, end)
+            val parts = descriptor.split(':')
+            val name = parts.first().trim().uppercase(Locale.US)
+            index = end + 1
+            when (name) {
+                "EOH" -> values.clear()
+                "EOR" -> {
+                    if (values.isNotEmpty()) records += values.toMap()
+                    values = linkedMapOf()
+                }
+                else -> {
+                    val length = parts.getOrNull(1)?.toIntOrNull() ?: continue
+                    if (length < 0 || index + length > content.length) continue
+                    values[name] = content.substring(index, index + length)
+                    index += length
+                }
+            }
+        }
+        return records
+    }
+
+    private fun StringBuilder.appendOptional(name: String, value: String) {
+        if (value.isNotBlank()) append(field(name, value))
+    }
+
+    private fun field(name: String, value: String): String = "<$name:${value.length}>$value"
+
+    private fun hzToMhz(value: Long): String = String.format(Locale.US, "%.6f", value / 1_000_000.0)
+
+    private fun mhzToHz(value: String?): Long? = value?.toDoubleOrNull()?.let { (it * 1_000_000.0).toLong() }
+
+    private fun format(value: Long, pattern: String): String =
+        SimpleDateFormat(pattern, Locale.US).apply { timeZone = utc }.format(Date(value))
+
+    private fun parse(date: String, time: String): Long? = runCatching {
+        val normalizedTime = if (time.length == 4) "${time}00" else time
+        SimpleDateFormat("yyyyMMddHHmmss", Locale.US).apply {
+            isLenient = false
+            timeZone = utc
+        }.parse(date + normalizedTime)?.time
+    }.getOrNull()
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/IQsoRepository.kt

@@ -0,0 +1,24 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import kotlinx.coroutines.flow.Flow
+
+interface IQsoRepository {
+    val records: Flow<List<QsoRecord>>
+
+    suspend fun find(id: Long): QsoRecord?
+    suspend fun save(record: QsoRecord): Long
+    suspend fun delete(id: Long)
+    suspend fun exportAdi(ids: Set<Long>? = null, includeIncomplete: Boolean = false): String
+    suspend fun importAdi(content: String): AdifImportResult
+    suspend fun mergeConfirmed(records: List<QsoRecord>): AdifImportResult
+    suspend fun mergeLoTW(records: List<QsoRecord>): AdifImportResult
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/LoTWReportBridge.kt

@@ -0,0 +1,25 @@
+package com.rtbishop.look4sat.core.domain.logbook
+
+import com.rtbishop.look4sat.core.domain.model.GridQso
+
+/** Bridge a LoTW report QSO (confirmed, download side) into a logbook record
+ *  so the logbook can show downloaded confirmations and mark local uploads
+ *  as confirmed (matched by [sameConfirmedContact]). */
+fun GridQso.toConfirmedRecord(accountCallsign: String): QsoRecord = QsoRecord(
+    startUtcMillis = epochMs,
+    theirCallsign = call,
+    myCallsign = accountCallsign.trim().uppercase(),
+    myGrid = (myGrids.firstOrNull() ?: myGrid).orEmpty(),
+    vuccGrids = myGrids.toList(),
+    band = bandUp,
+    rxBand = bandDown,
+    mode = mode,
+    satelliteName = satName,
+    propagationMode = "SAT",
+    status = QsoStatus.COMPLETE,
+    lotwConfirmed = true,
+    dxcc = dxcc,
+    country = country.orEmpty(),
+    cqZone = cqz,
+    region = state.orEmpty()
+)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/QsoConfirmationMerge.kt

@@ -0,0 +1,65 @@
+package com.rtbishop.look4sat.core.domain.logbook
+
+import java.util.Locale
+import kotlin.math.abs
+
+/** LoTW official name vs SatNOGS name ("SO-50 (SaudiOSCAR 50)"): compare the
+ *  parenthetical-free prefix so local records and downloaded confirmations match. */
+fun satMatchKey(name: String): String = name.substringBefore('(').trim().uppercase(Locale.US)
+
+/** LoTW omits frequency and may round time to a minute. Only merge an unambiguous contact. */
+fun sameConfirmedContact(local: QsoRecord, remote: QsoRecord): Boolean =
+    local.theirCallsign.trim().equals(remote.theirCallsign.trim(), true) &&
+        (local.myCallsign.isBlank() || remote.myCallsign.isBlank() || local.myCallsign.equals(remote.myCallsign, true)) &&
+        satMatchKey(local.satelliteName) == satMatchKey(remote.satelliteName) &&
+        local.isSatellite == remote.isSatellite &&
+        local.displayMode == remote.displayMode &&
+        (local.band.isBlank() || remote.band.isBlank() || local.band.equals(remote.band, true)) &&
+        abs(local.startUtcMillis - remote.startUtcMillis) < 60_000L
+
+fun QsoRecord.confirmationLookupKey(): String = listOf(
+    theirCallsign.trim().uppercase(Locale.US), satMatchKey(satelliteName), displayMode
+).joinToString("|")
+
+fun QsoRecord.withConfirmation(confirmed: QsoRecord): QsoRecord = copy(
+    myCallsign = myCallsign.ifBlank { confirmed.myCallsign },
+    theirGrid = confirmed.theirGrid.ifBlank { theirGrid },
+    myGrid = myGrid.ifBlank { confirmed.myGrid },
+    sentReport = sentReport.ifBlank { confirmed.sentReport },
+    receivedReport = receivedReport.ifBlank { confirmed.receivedReport },
+    txFrequencyHz = txFrequencyHz ?: confirmed.txFrequencyHz,
+    rxFrequencyHz = rxFrequencyHz ?: confirmed.rxFrequencyHz,
+    band = band.ifBlank { confirmed.band },
+    rxBand = rxBand.ifBlank { confirmed.rxBand },
+    propagationMode = propagationMode.ifBlank { confirmed.propagationMode },
+    status = QsoStatus.COMPLETE,
+    lotwConfirmed = lotwConfirmed || confirmed.lotwConfirmed,
+    lotwReceived = lotwReceived || confirmed.lotwReceived || confirmed.lotwConfirmed,
+    lotwQslDate = confirmed.lotwQslDate.ifBlank { lotwQslDate },
+    vuccGrids = confirmed.vuccGrids.ifEmpty { vuccGrids },
+    dxcc = confirmed.dxcc ?: dxcc,
+    country = confirmed.country.ifBlank { country },
+    cqZone = confirmed.cqZone ?: cqZone,
+    region = confirmed.region.ifBlank { region }
+)
+
+val QsoRecord.displayMode: String
+    get() = submode.ifBlank { mode }.trim().uppercase(Locale.US)
+
+val QsoRecord.isSatellite: Boolean
+    get() = propagationMode.equals("SAT", true) || (propagationMode.isBlank() && satelliteName.isNotBlank())
+
+fun frequencyBand(hz: Long?): String = when (hz) {
+    null -> ""
+    in 28_000_000L..29_700_000L -> "10M"
+    in 50_000_000L..54_000_000L -> "6M"
+    in 144_000_000L..148_000_000L -> "2M"
+    in 219_000_000L..225_000_000L -> "1.25M"
+    in 420_000_000L..450_000_000L -> "70CM"
+    in 902_000_000L..928_000_000L -> "33CM"
+    in 1_240_000_000L..1_300_000_000L -> "23CM"
+    in 2_300_000_000L..2_450_000_000L -> "13CM"
+    in 5_650_000_000L..5_925_000_000L -> "6CM"
+    in 10_000_000_000L..10_500_000_000L -> "3CM"
+    else -> ""
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/logbook/QsoModels.kt

@@ -0,0 +1,48 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+enum class QsoStatus { DRAFT, COMPLETE, ABORTED }
+
+data class QsoRecord(
+    val id: Long = 0L,
+    val startUtcMillis: Long,
+    val endUtcMillis: Long? = null,
+    val theirCallsign: String,
+    val myCallsign: String,
+    val theirGrid: String = "",
+    val myGrid: String = "",
+    val sentReport: String = "",
+    val receivedReport: String = "",
+    val txFrequencyHz: Long? = null,
+    val rxFrequencyHz: Long? = null,
+    val band: String = "",
+    val rxBand: String = "",
+    val mode: String = "MFSK",
+    val submode: String = "FT4",
+    val satelliteName: String = "",
+    val transponderName: String = "",
+    val satelliteMode: String = "",
+    val passAosUtcMillis: Long? = null,
+    val automatic: Boolean = false,
+    val status: QsoStatus = QsoStatus.DRAFT,
+    val propagationMode: String = if (satelliteName.isNotBlank()) "SAT" else "",
+    val lotwConfirmed: Boolean = false,
+    val lotwReceived: Boolean = false,
+    val lotwQslDate: String = "",
+    val vuccGrids: List<String> = emptyList(),
+    val dxcc: Int? = null,
+    val country: String = "",
+    val cqZone: Int? = null,
+    val region: String = "",
+    val comment: String = ""
+)
+
+data class AdifImportResult(val imported: Int, val skipped: Int, val updated: Int = 0)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ILoTWUploadRepository.kt

@@ -0,0 +1,74 @@
+package com.rtbishop.look4sat.core.domain.repository
+
+import com.rtbishop.look4sat.core.domain.logbook.QsoRecord
+
+interface ILoTWUploadRepository {
+    suspend fun certificate(): LoTWCertificate?
+    suspend fun station(): LoTWStation?
+    suspend fun importCertificate(data: ByteArray, password: CharArray): LoTWCertificate
+    suspend fun saveCertificatePassword(password: CharArray): LoTWCertificate
+    suspend fun saveStation(station: LoTWStation): LoTWStation
+    suspend fun removeCertificate()
+    suspend fun audit(records: List<QsoRecord>): LoTWUploadAudit
+    suspend fun prepare(records: List<QsoRecord>, resubmit: Boolean): LoTWUploadPreview
+    suspend fun upload(previewId: String): LoTWUploadResult
+    fun discardPreview()
+}
+
+data class LoTWCertificate(
+    val callsign: String,
+    val dxcc: Int,
+    val serial: String,
+    val expires: String,
+    val firstQsoDate: String,
+    val lastQsoDate: String,
+    val passwordSaved: Boolean = false
+)
+
+/** The location is explicitly confirmed for the selected contacts, not inferred from today's GPS. */
+data class LoTWStation(
+    val grid: String = "",
+    val cqZone: String = "",
+    val ituZone: String = "",
+    val region: String = "",
+    val county: String = "",
+    val iota: String = ""
+)
+
+data class LoTWUploadPreview(
+    val id: String,
+    val callsign: String,
+    val dxcc: Int,
+    val grid: String,
+    val count: Int,
+    val skipped: Int,
+    val firstUtc: String,
+    val lastUtc: String,
+    val contacts: List<String>,
+    val unknownSkipped: Int = 0
+)
+
+/** Local comparison against downloaded LoTW receipt flags and this app's durable upload receipts. */
+data class LoTWUploadAudit(
+    val total: Int,
+    val pending: Int,
+    val uploaded: Int,
+    val unknown: Int,
+    val unavailable: Int
+)
+
+sealed interface LoTWUploadResult {
+    data class Accepted(val count: Int) : LoTWUploadResult
+    data class Rejected(val message: String = "") : LoTWUploadResult
+    /** May have reached LoTW. Do not retry automatically. */
+    data object Unknown : LoTWUploadResult
+    data object ExpiredPreview : LoTWUploadResult
+}
+
+class LoTWOperationException(val reason: LoTWProblem, val detail: String = "") : Exception(reason.name)
+
+enum class LoTWProblem {
+    CERTIFICATE_PASSWORD, CERTIFICATE_INVALID, CERTIFICATE_EXPIRED, CERTIFICATE_MISSING,
+    STORAGE, EMPTY_SELECTION, CALLSIGN_MISMATCH, QSO_DATE, STATION_GRID, STATION_REGION,
+    STATION_ZONE, STATION_IOTA, MODE, BAND, SATELLITE, INVALID_CONTACT, LOCATION_MISMATCH, TOO_MANY_CONTACTS
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IMainContainer.kt

@@ -16,6 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 package com.rtbishop.look4sat.core.domain.repository
+import com.rtbishop.look4sat.core.domain.logbook.IQsoRepository
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
 import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
@@ -34,6 +35,8 @@ interface IMainContainer {
     val updateRepo: IUpdateRepository
     val wavelogRepo: IWavelogRepository
     val lotwRepo: com.rtbishop.look4sat.core.domain.repository.ILoTWRepository
+    val qsoRepository: IQsoRepository
+    val lotwUploadRepository: ILoTWUploadRepository
     val radioTrackingService: IRadioTrackingService
     val mutualPassData: StateFlow<MutualPassData>
     fun setMutualPassData(data: MutualPassData)

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ISettingsRepo.kt

@@ -89,6 +89,12 @@ interface ISettingsRepo {
     fun setSatelliteOffset(catnum: Int, offset: String)
     //endregion
 
+    //region # Per-satellite logbook mode preset settings
+    /** Last selected logbook mode (CW/SSB/FT4) for a satellite; empty when unset. */
+    fun getSatelliteMode(catnum: Int): String
+    fun setSatelliteMode(catnum: Int, mode: String)
+    //endregion
+
     //region # AMSAT status report settings
     fun getAmSatCallsign(): String
     fun setAmSatCallsign(callsign: String)

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/logbook/AdifCodecTest.kt

@@ -0,0 +1,86 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class AdifCodecTest {
+
+    @Test
+    fun encodeDecode_roundTrip() {
+        val record = QsoRecord(
+            startUtcMillis = 1_700_000_000_000L,
+            endUtcMillis = 1_700_000_000_100L,
+            theirCallsign = "BG5JVM",
+            myCallsign = "BA7OPF",
+            theirGrid = "OM60",
+            myGrid = "OL62TI",
+            sentReport = "59",
+            receivedReport = "59",
+            txFrequencyHz = 145_850_000L,
+            rxFrequencyHz = 436_805_000L,
+            band = "2M",
+            rxBand = "70CM",
+            mode = "FM",
+            satelliteName = "SO-50",
+            satelliteMode = "FM",
+            propagationMode = "SAT",
+            status = QsoStatus.COMPLETE,
+            lotwConfirmed = true,
+            lotwQslDate = "2026-09-20",
+            vuccGrids = listOf("OM60", "OM50")
+        )
+        val decoded = AdifCodec.decode(AdifCodec.encode(listOf(record))).single()
+        assertEquals(record.startUtcMillis, decoded.startUtcMillis)
+        assertEquals(record.theirCallsign, decoded.theirCallsign)
+        assertEquals(record.myCallsign, decoded.myCallsign)
+        assertEquals(record.satelliteName, decoded.satelliteName)
+        assertEquals("2M", decoded.band)
+        assertEquals("70CM", decoded.rxBand)
+        assertTrue(decoded.lotwConfirmed)
+        assertEquals(listOf("OM60", "OM50"), decoded.vuccGrids)
+    }
+
+    @Test
+    fun decode_lotwStyleReportFields() {
+        // LoTW report subset: lowercase eor, alphabetical fields, VUCC_GRIDS list.
+        val adi = """
+            <EOH>
+            <CALL:6>BH6RJD
+            <QSO_DATE:8>20260916
+            <TIME_ON:6>051300
+            <MODE:2>FM
+            <SAT_NAME:5>SO-50
+            <PROP_MODE:3>SAT
+            <BAND:3>2M
+            <BAND_RX:4>70CM
+            <GRIDSQUARE:4>OM60
+            <MY_GRIDSQUARE:8>OM60IL70
+            <VUCC_GRIDS:9>OM60,OM50
+            <STATION_CALLSIGN:6>BH6RJD
+            <DXCC:3>318
+            <COUNTRY:5>China
+            <LOTW_QSL_RCVD:1>Y
+            <eor>
+        """.trimIndent()
+        val records = AdifCodec.decode(adi)
+        assertEquals(1, records.size)
+        val record = records.single()
+        assertEquals("BH6RJD", record.theirCallsign)
+        assertEquals("SO-50", record.satelliteName)
+        assertEquals("FM", record.displayMode)
+        assertEquals("OM60IL70", record.myGrid)
+        assertEquals(listOf("OM60", "OM50"), record.vuccGrids)
+        assertTrue(record.lotwConfirmed)
+        assertTrue(record.isSatellite)
+    }
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/logbook/LogbookMergeTest.kt

@@ -0,0 +1,126 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+package com.rtbishop.look4sat.core.domain.logbook
+
+import com.rtbishop.look4sat.core.domain.model.GridQso
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class LogbookMergeTest {
+
+    private val local = QsoRecord(
+        startUtcMillis = 1_700_000_000_000L,
+        theirCallsign = "bg5jvm",
+        myCallsign = "ba7opf",
+        txFrequencyHz = 145_850_000L,
+        mode = "FM",
+        submode = "",
+        satelliteName = "SO-50 (SaudiOSCAR 50)",
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE
+    )
+
+    private val confirmed = QsoRecord(
+        startUtcMillis = 1_700_000_000_000L,
+        theirCallsign = "BG5JVM",
+        myCallsign = "BA7OPF",
+        mode = "FM",
+        submode = "",
+        satelliteName = "SO-50",
+        propagationMode = "SAT",
+        status = QsoStatus.COMPLETE,
+        lotwConfirmed = true,
+        vuccGrids = listOf("OM60", "OM50")
+    )
+
+    @Test
+    fun satMatchKey_stripsParenthetical() {
+        assertEquals("SO-50", satMatchKey("SO-50 (SaudiOSCAR 50)"))
+        assertEquals("SO-50", satMatchKey("SO-50"))
+        assertEquals("AO-91", satMatchKey("AO-91 (FUNcube-1)"))
+        assertEquals("IO-86", satMatchKey("IO-86"))
+    }
+
+    @Test
+    fun sameConfirmedContact_matchesAcrossSatNOGSAndOfficialName() {
+        assertTrue(sameConfirmedContact(local, confirmed))
+    }
+
+    @Test
+    fun sameConfirmedContact_rejectsDifferentSatellite() {
+        val other = confirmed.copy(satelliteName = "AO-91")
+        assertFalse(sameConfirmedContact(local, other))
+    }
+
+    @Test
+    fun sameConfirmedContact_rejectsTimeSkew() {
+        val skewed = confirmed.copy(startUtcMillis = confirmed.startUtcMillis + 120_000L)
+        assertFalse(sameConfirmedContact(local, skewed))
+    }
+
+    @Test
+    fun confirmationLookupKey_usesNormalizedSatellite() {
+        assertEquals(local.confirmationLookupKey(), confirmed.confirmationLookupKey())
+    }
+
+    @Test
+    fun withConfirmation_marksConfirmedAndMergesVuccGrids() {
+        val merged = local.withConfirmation(confirmed)
+        assertTrue(merged.lotwConfirmed)
+        assertTrue(merged.lotwReceived)
+        assertEquals(listOf("OM60", "OM50"), merged.vuccGrids)
+        // Local myCallsign is kept when present; only blanks are backfilled.
+        assertEquals("ba7opf", merged.myCallsign)
+    }
+
+    @Test
+    fun toConfirmedRecord_mapsGridQso() {
+        val qso = GridQso(
+            call = "BH6RJD",
+            epochMs = 1_700_000_000_000L,
+            satName = "SO-50",
+            mode = "FM",
+            bandUp = "70CM",
+            bandDown = "2M",
+            dxcc = 318,
+            country = "China",
+            cqz = 24,
+            state = "GD",
+            myGrid = "OM60",
+            myGrids = setOf("OM60", "OM50")
+        )
+        val record = qso.toConfirmedRecord("ba7opf")
+        assertEquals("BH6RJD", record.theirCallsign)
+        assertEquals("BA7OPF", record.myCallsign)
+        assertEquals("OM60", record.myGrid)
+        assertEquals(listOf("OM60", "OM50"), record.vuccGrids)
+        assertTrue(record.lotwConfirmed)
+        assertTrue(record.isSatellite)
+        assertEquals("70CM", record.band)
+        assertEquals("2M", record.rxBand)
+    }
+
+    @Test
+    fun frequencyBand_edges() {
+        assertEquals("2M", frequencyBand(144_000_000L))
+        assertEquals("70CM", frequencyBand(450_000_000L))
+        assertEquals("10M", frequencyBand(29_000_000L))
+        assertEquals("", frequencyBand(null))
+    }
+
+    @Test
+    fun displayMode_prefersSubmode() {
+        val ft4 = QsoRecord(startUtcMillis = 0, theirCallsign = "x", myCallsign = "y", mode = "MFSK", submode = "FT4")
+        assertEquals("FT4", ft4.displayMode)
+        assertEquals("FM", local.displayMode)
+    }
+}

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/repository/LoTWGridSyncTest.kt

@@ -285,6 +285,8 @@ class LoTWGridSyncTest {
         override fun updateDataSourcesStatus(status: Map<String, Int>) = TODO()
         override fun updateRadioControlSettings(settings: RadioControlSettings) = TODO()
         override fun getSatelliteOffset(catnum: Int): String = ""
+        override fun getSatelliteMode(catnum: Int): String = ""
+        override fun setSatelliteMode(catnum: Int, mode: String) {}
         override fun setSatelliteOffset(catnum: Int, offset: String) = TODO()
         override fun getAmSatCallsign(): String = ""
         override fun setAmSatCallsign(callsign: String) = TODO()

core/presentation/src/main/res/values-zh/strings.xml

@@ -191,6 +191,24 @@
     <string name="lotw_sync_progress_qso">本次同步 %1$d 条 QSO，预计还需 %2$d 秒</string>
     <string name="prefs_locator_text">使用梅登黑德网格设置站点位置</string>
 
+    <string name="prefs_logbook_title">日志本</string>
+    <string name="prefs_logbook_count">%1$d 条记录 — 本地通联与 LoTW 确认</string>
+    <string name="prefs_logbook_empty">暂无记录 — 在雷达页 Log 标签记录通联</string>
+    <string name="prefs_logbook_close">关闭</string>
+    <string name="prefs_lotw_upload_title">LoTW 上传</string>
+    <string name="prefs_lotw_upload_configured">证书已导入 · 台址网格 %1$s</string>
+    <string name="prefs_lotw_upload_not_configured">未配置 — 导入 TrustedQSL 证书后即可上传通联</string>
+    <string name="prefs_lotw_upload_busy">处理中…</string>
+    <string name="prefs_lotw_upload_cert_hint">导入你的 TrustedQSL .p12 证书（与 TQSL 同款）用于签名上传通联。密码仅加密保存在手机本地。</string>
+    <string name="prefs_lotw_upload_password">证书密码</string>
+    <string name="prefs_lotw_upload_import">选择 .p12 文件</string>
+    <string name="prefs_lotw_upload_cert_info">%1$s · DXCC %2$d · 有效期至 %3$s</string>
+    <string name="prefs_lotw_upload_remove">移除证书</string>
+    <string name="prefs_lotw_upload_station_title">台址</string>
+    <string name="prefs_lotw_upload_grid">网格（逗号分隔，可多格）</string>
+    <string name="prefs_lotw_upload_save">保存</string>
+    <string name="prefs_lotw_upload_close">关闭</string>
+
     <string name="prefs_data_title">卫星数据更新</string>
     <string name="prefs_data_entries">卫星：%s</string>
     <string name="prefs_data_radios">收发器：%s</string>

core/presentation/src/main/res/values/strings.xml

@@ -222,6 +222,24 @@
     <string name="lotw_sync_progress_qso">Syncing %1$d QSOs, ~%2$d s remaining</string>
     <string name="prefs_locator_text">Set station\'s position using locator</string>
 
+    <string name="prefs_logbook_title">Logbook</string>
+    <string name="prefs_logbook_count">%1$d records — local QSOs and LoTW confirmations</string>
+    <string name="prefs_logbook_empty">No records yet — record QSOs from the Radar Log tab</string>
+    <string name="prefs_logbook_close">Close</string>
+    <string name="prefs_lotw_upload_title">LoTW upload</string>
+    <string name="prefs_lotw_upload_configured">Certificate imported · station grid %1$s</string>
+    <string name="prefs_lotw_upload_not_configured">Not configured — import your TrustedQSL certificate to upload QSOs</string>
+    <string name="prefs_lotw_upload_busy">Working…</string>
+    <string name="prefs_lotw_upload_cert_hint">Import your TrustedQSL .p12 certificate (same one you use in TQSL) to sign and upload QSOs. The password is stored encrypted on this device only.</string>
+    <string name="prefs_lotw_upload_password">Certificate password</string>
+    <string name="prefs_lotw_upload_import">Choose .p12 file</string>
+    <string name="prefs_lotw_upload_cert_info">%1$s · DXCC %2$d · expires %3$s</string>
+    <string name="prefs_lotw_upload_remove">Remove certificate</string>
+    <string name="prefs_lotw_upload_station_title">Station location</string>
+    <string name="prefs_lotw_upload_grid">Grid(s), comma-separated</string>
+    <string name="prefs_lotw_upload_save">Save</string>
+    <string name="prefs_lotw_upload_close">Close</string>
+
     <string name="prefs_data_title">Satellite data</string>
     <string name="prefs_data_entries">Satellites: %s</string>
     <string name="prefs_data_radios">Transceivers: %s</string>