From dc596b4348109fd004584c75efba22672953e3d6 Mon Sep 17 00:00:00 2001
From: Rui Oliveira <ruimail24@gmail.com>
Date: Fri, 24 Jul 2026 15:35:43 +0100
Subject: [PATCH] Fix bugs in setting Rx frequency

---
 .../core/data/framework/Ic705Controller.kt    | 40 ++++++++++++++++---
 .../core/data/framework/IcomCivProtocol.kt    | 11 ++++-
 2 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ic705Controller.kt b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ic705Controller.kt
index 4641e11f..69d9cfe1 100644
--- a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ic705Controller.kt
+++ b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/Ic705Controller.kt
@@ -244,19 +244,25 @@ class Ic705Controller(
 
     /**
      * Drain whatever bytes the radio has buffered within a [timeoutMs] window.
-     * Uses non-blocking `available()` polling to avoid blocking indefinitely.
+     * Exits early as soon as a complete CI-V frame addressed to us is present
+     * in the buffer (i.e., FE FE E0 A4 … FD), so we don't waste the remaining
+     * timeout on responses that already arrived.
      */
     private suspend fun drainWithTimeout(timeoutMs: Long): ByteArray {
-        val result    = mutableListOf<Byte>()
-        val deadline  = System.currentTimeMillis() + timeoutMs
-        val stream    = inputStream ?: return ByteArray(0)
+        val result   = mutableListOf<Byte>()
+        val deadline = System.currentTimeMillis() + timeoutMs
+        val stream   = inputStream ?: return ByteArray(0)
         while (System.currentTimeMillis() < deadline) {
             try {
                 val available = stream.available()
                 if (available > 0) {
                     val chunk = ByteArray(available)
                     val read  = stream.read(chunk)
-                    if (read > 0) result.addAll(chunk.take(read))
+                    if (read > 0) {
+                        result.addAll(chunk.take(read))
+                        // Exit early once we have a complete frame for us
+                        if (hasCompleteFrameForUs(result)) break
+                    }
                 } else {
                     delay(POLL_INTERVAL_MS)
                 }
@@ -269,6 +275,30 @@ class Ic705Controller(
         return result.toByteArray()
     }
 
+    /**
+     * Returns true if [buf] contains a complete CI-V frame addressed to the
+     * controller (FE FE [ADDR_CTRL] [ADDR_IC705] … FD).
+     * CI-V data bytes cannot be 0xFD, so the first 0xFD after the header is
+     * always the frame terminator.
+     */
+    private fun hasCompleteFrameForUs(buf: List<Byte>): Boolean {
+        var i = 0
+        while (i < buf.size - 4) {
+            if (buf[i]     == IcomCivProtocol.PREAMBLE    &&
+                buf[i + 1] == IcomCivProtocol.PREAMBLE    &&
+                buf[i + 2] == IcomCivProtocol.ADDR_CTRL   &&
+                buf[i + 3] == IcomCivProtocol.ADDR_IC705
+            ) {
+                for (k in i + 4 until buf.size) {
+                    if (buf[k] == IcomCivProtocol.END_OF_MSG) return true
+                }
+                return false  // header found but no FD yet
+            }
+            i++
+        }
+        return false
+    }
+
     private fun write(bytes: ByteArray): Boolean {
         return try {
             outputStream?.write(bytes)
diff --git a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
index a851e3f5..73b25948 100644
--- a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
+++ b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
@@ -283,11 +283,18 @@ object IcomCivProtocol {
 
     /**
      * Parse TX status from a CMD_TX_STATUS reply payload.
+     *
+     * The IC-705 responds to a `1C 00` query with:
+     *   FE FE E0 A4  1C  00  <status>  FD
+     * After [parseResponse] strips the frame header the payload is:
+     *   payload[0] = 0x00  (sub-command echo)
+     *   payload[1] = status byte (0x00 = RX, 0x01 = TX)
+     *
      * Returns true if transmitting, false if receiving, null on error.
      */
     fun parseTxStatus(payload: ByteArray): Boolean? {
-        if (payload.isEmpty()) return null
-        return when (payload[0]) {
+        if (payload.size < 2) return null
+        return when (payload[1]) {
             0x00.toByte() -> false  // RX
             0x01.toByte() -> true   // TX
             else           -> null