Persist the Android call video bitrate range atomically

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoBitrateRange.kt

@@ -0,0 +1,19 @@
+package com.utun.chat.data
+
+/** Обе границы хранятся одной настройкой в десятичных кбит/с. */
+data class CallVideoBitrateRange(val minimum: Int = 300, val maximum: Int = 4000) {
+    init { require(minimum in 300..4000 && maximum in minimum..4000) }
+
+    fun encode(): String = "$minimum:$maximum"
+
+    companion object {
+        fun parse(value: String): CallVideoBitrateRange? {
+            val parts = value.split(':')
+            if (parts.size != 2 || parts.any { it.isEmpty() || it.any { digit -> digit !in '0'..'9' } }) return null
+            val minimum = parts[0].toIntOrNull() ?: return null
+            val maximum = parts[1].toIntOrNull() ?: return null
+            if (minimum !in 300..4000 || maximum !in minimum..4000) return null
+            return CallVideoBitrateRange(minimum, maximum)
+        }
+    }
+}

tools/chatgui-android/app/src/main/java/com/utun/chat/data/ConfigProvider.kt

@@ -55,6 +55,7 @@ class ConfigProvider(private val context: Context) {
     private val chatStorageMaxsizeGb = intPreferencesKey("chat_storage_maxsize_gb")
     private val chatOpusCodecPreset = intPreferencesKey("chat_opus_codec_preset")
     private val callJitterMaxReserveMs = intPreferencesKey("call_jitter_max_reserve_ms")
+    private val callVideoBitrateRange = stringPreferencesKey("call_video_bitrate_range_kbps")
     private val chatCompressorEnabled = intPreferencesKey("chat_compressor_enabled")
     private val chatCompressorMaxGainDb = intPreferencesKey("chat_compressor_max_gain_db")
     private val chatCompressorRiseRate = intPreferencesKey("chat_compressor_rise_rate")
@@ -141,6 +142,19 @@ class ConfigProvider(private val context: Context) {
         )
     }
 
+    fun getCallVideoBitrateRange(): CallVideoBitrateRange = runBlocking {
+        val value = context.dataStore.data.first()[callVideoBitrateRange] ?: return@runBlocking CallVideoBitrateRange()
+        CallVideoBitrateRange.parse(value) ?: run {
+            LogManager.addLog("WARN", "CallSettings", "Invalid video bitrate range '$value'; using 300:4000")
+            CallVideoBitrateRange()
+        }
+    }
+
+    suspend fun saveCallVideoBitrateRange(range: CallVideoBitrateRange) {
+        context.dataStore.edit { it[callVideoBitrateRange] = range.encode() }
+        LogManager.addLog("INFO", "CallSettings", "Video bitrate range saved: ${range.encode()} kbps")
+    }
+
     fun getString(key: String): String? = runBlocking {
         when {
             key == "node.private_key" -> readKeysFromFile()?.second ?: context.dataStore.data.first()[nodePrivateKey]
@@ -669,6 +683,7 @@ class ConfigProvider(private val context: Context) {
             appendLine("radio_compressor_enabled=$radioCompEnabled")
             appendLine("radio_compressor_max_gain_db=$radioCompMaxGain")
             appendLine("call_jitter_max_reserve_ms=${getInt("chat.call_jitter_max_reserve_ms")}")
+            appendLine("call_video_bitrate_range_kbps=${getCallVideoBitrateRange().encode()}")
             appendLine("compressor_enabled=$chatCompEnabled")
             appendLine("compressor_max_gain_db=$chatCompMaxGain")
             appendLine("compressor_rise_rate=$chatCompRiseRate")

tools/chatgui-android/app/src/test/java/com/utun/chat/data/CallVideoBitrateRangeTest.kt

@@ -0,0 +1,20 @@
+package com.utun.chat.data
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class CallVideoBitrateRangeTest {
+    @Test fun defaultsAndRoundTrip() {
+        assertEquals("300:4000", CallVideoBitrateRange().encode())
+        for (range in listOf(CallVideoBitrateRange(), CallVideoBitrateRange(500, 1500), CallVideoBitrateRange(300, 300))) {
+            assertEquals(range, CallVideoBitrateRange.parse(range.encode()))
+        }
+    }
+
+    @Test fun invalidPersistedRangeIsRejected() {
+        for (value in listOf("", "299:4000", "300:4001", "4000:300", "300", "300:4000x",
+            "-300:4000", "300:+4000", "300: 4000", "999999999999999999999999:4000")) {
+            assertNull(value, CallVideoBitrateRange.parse(value))
+        }
+    }
+}