v1.2.4: реальная пауза скачивания с resume по Range

app/src/main/java/com/rosetta/messenger/data/ReleaseNotes.kt

@@ -52,6 +52,8 @@ object ReleaseNotes {
 
         Файлы и загрузки
         - Добавлена пауза и возобновление скачивания файлов прямо из пузырька (иконка pause/resume)
+        - Пауза скачивания теперь реальная: активный сетевой поток останавливается, а не только меняется UI-статус
+        - Resume продолжает загрузку с сохранённого места через HTTP Range (с безопасным fallback на полную перезагрузку, если сервер не поддерживает Range)
         - Устранено дёргание прогресса при быстрых тапах по скачивающемуся файлу
         - Прогресс скачивания стал стабильным и не откатывается назад после pause/resume
         - Обновлён экран активных загрузок: добавлен статус Paused

app/src/main/java/com/rosetta/messenger/network/FileDownloadManager.kt

@@ -52,6 +52,12 @@ object FileDownloadManager {
         val savedFile: File
     )
 
+    private fun encryptedPartFile(request: DownloadRequest): File {
+        val parent = request.savedFile.parentFile ?: request.savedFile.absoluteFile.parentFile
+        val safeId = request.attachmentId.take(32).replace(Regex("[^A-Za-z0-9._-]"), "_")
+        return File(parent, ".dl_${safeId}.part")
+    }
+
     // ─── helpers ───
 
     private fun isGroupStoredKey(value: String): Boolean = value.startsWith("group:")
@@ -161,6 +167,9 @@ object FileDownloadManager {
      * Отменяет скачивание
      */
     fun cancel(attachmentId: String) {
+        requests[attachmentId]?.let { req ->
+            encryptedPartFile(req).delete()
+        }
         pauseRequested.remove(attachmentId)
         resumeAfterPause.remove(attachmentId)
         requests.remove(attachmentId)
@@ -177,6 +186,7 @@ object FileDownloadManager {
         pauseRequested.remove(attachmentId)
 
         val savedPath = request.savedFile.absolutePath
+        val encryptedPart = encryptedPartFile(request)
         val resumeBase =
             (_downloads.value[attachmentId]
                 ?.takeIf { it.status == FileDownloadStatus.PAUSED }
@@ -205,19 +215,13 @@ object FileDownloadManager {
                 )
 
                 // Запускаем polling прогресса из TransportManager.
-                // При resume удерживаем плавный прогресс без визуального отката назад.
+                // Держим прогресс монотонным, чтобы он не дёргался вниз.
                 progressJob = launch {
                     TransportManager.downloading.collect { list ->
                         val entry = list.find { it.id == attachmentId } ?: return@collect
                         val rawCdn = (entry.progress / 100f) * 0.8f
-                        val mapped = if (resumeBase > 0f) {
-                            val normalized = (rawCdn / 0.8f).coerceIn(0f, 1f)
-                            resumeBase + (0.8f - resumeBase) * normalized
-                        } else {
-                            rawCdn
-                        }
                         val current = _downloads.value[attachmentId]?.progress ?: 0f
-                        val stable = maxOf(current, mapped).coerceIn(0f, 0.8f)
+                        val stable = maxOf(current, rawCdn).coerceIn(0f, 0.8f)
                         update(
                             attachmentId,
                             request.fileName,
@@ -238,6 +242,7 @@ object FileDownloadManager {
                             privateKey = request.privateKey,
                             fileName = request.fileName,
                             savedFile = request.savedFile,
+                            encryptedPartFile = encryptedPart,
                             accountPublicKey = request.accountPublicKey,
                             savedPath = savedPath
                         )
@@ -249,6 +254,7 @@ object FileDownloadManager {
                             privateKey = request.privateKey,
                             fileName = request.fileName,
                             savedFile = request.savedFile,
+                            encryptedPartFile = encryptedPart,
                             accountPublicKey = request.accountPublicKey,
                             savedPath = savedPath
                         )
@@ -264,6 +270,8 @@ object FileDownloadManager {
                         request.accountPublicKey,
                         savedPath
                     )
+                    encryptedPart.delete()
+                    requests.remove(attachmentId)
                 } else {
                     update(
                         attachmentId,
@@ -347,10 +355,21 @@ object FileDownloadManager {
         privateKey: String,
         fileName: String,
         savedFile: File,
+        encryptedPartFile: File,
         accountPublicKey: String,
         savedPath: String
     ): Boolean {
-        val encryptedContent = TransportManager.downloadFile(attachmentId, downloadTag)
+        val resumeBytes = if (encryptedPartFile.exists()) encryptedPartFile.length() else 0L
+        val encryptedFile =
+            TransportManager.downloadFileRawResumable(
+                id = attachmentId,
+                tag = downloadTag,
+                targetFile = encryptedPartFile,
+                resumeFromBytes = resumeBytes
+            )
+        val encryptedContent = withContext(Dispatchers.IO) {
+            encryptedFile.readText(Charsets.UTF_8)
+        }
         update(
             attachmentId,
             fileName,
@@ -405,11 +424,18 @@ object FileDownloadManager {
         privateKey: String,
         fileName: String,
         savedFile: File,
+        encryptedPartFile: File,
         accountPublicKey: String,
         savedPath: String
     ): Boolean {
-        // Streaming: скачиваем во temp file
+        val resumeBytes = if (encryptedPartFile.exists()) encryptedPartFile.length() else 0L
-        val tempFile = TransportManager.downloadFileRaw(attachmentId, downloadTag)
+        val tempFile =
+            TransportManager.downloadFileRawResumable(
+                id = attachmentId,
+                tag = downloadTag,
+                targetFile = encryptedPartFile,
+                resumeFromBytes = resumeBytes
+            )
         update(
             attachmentId,
             fileName,
@@ -438,7 +464,7 @@ object FileDownloadManager {
                     savedFile
                 )
             } finally {
-                tempFile.delete()
+                encryptedPartFile.delete()
             }
         }
         update(

app/src/main/java/com/rosetta/messenger/network/TransportManager.kt

@@ -4,9 +4,11 @@ import android.content.Context
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.ensureActive
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.isActive
 import kotlinx.coroutines.suspendCancellableCoroutine
 import kotlinx.coroutines.withContext
 import okhttp3.*
@@ -18,6 +20,7 @@ import java.util.concurrent.TimeUnit
 import kotlin.coroutines.resume
 import kotlin.coroutines.resumeWithException
 import kotlin.coroutines.suspendCoroutine
+import kotlin.coroutines.coroutineContext
 
 /**
  * Состояние загрузки/скачивания файла
@@ -157,6 +160,14 @@ object TransportManager {
             })
         }
 
+    private fun parseContentRangeTotal(value: String?): Long? {
+        if (value.isNullOrBlank()) return null
+        // Example: "bytes 100-999/12345"
+        val totalPart = value.substringAfter('/').trim()
+        if (totalPart.isEmpty() || totalPart == "*") return null
+        return totalPart.toLongOrNull()
+    }
+    
     /**
      * Загрузить файл на транспортный сервер с отслеживанием прогресса
      * @param id Уникальный ID файла
@@ -375,42 +386,97 @@ object TransportManager {
      * @return Временный файл с зашифрованным содержимым
      */
     suspend fun downloadFileRaw(id: String, tag: String): File = withContext(Dispatchers.IO) {
-        val server = getActiveServer()
+        val cacheDir = appContext?.cacheDir ?: throw IOException("No app context")
-        ProtocolManager.addLog("📥 Download raw start: id=${id.take(8)}, tag=${tag.take(10)}, server=$server")
+        val tempFile = File(cacheDir, "dlr_${id.take(16)}_${System.currentTimeMillis()}.tmp")
+        try {
+            downloadFileRawResumable(
+                id = id,
+                tag = tag,
+                targetFile = tempFile,
+                resumeFromBytes = 0L
+            )
+        } catch (e: Exception) {
+            tempFile.delete()
+            throw e
+        }
+    }
 
-        _downloading.value = _downloading.value + TransportState(id, 0)
+    /**
+     * Resumable download with HTTP Range support.
+     * If server supports range (206), continues from `targetFile.length()`.
+     * If not, safely restarts from zero and rewrites target file.
+     */
+    suspend fun downloadFileRawResumable(
+        id: String,
+        tag: String,
+        targetFile: File,
+        resumeFromBytes: Long = 0L
+    ): File = withContext(Dispatchers.IO) {
+        val server = getActiveServer()
+        ProtocolManager.addLog(
+            "📥 Download raw(resume) start: id=${id.take(8)}, tag=${tag.take(10)}, server=$server, resume=$resumeFromBytes"
+        )
+
+        _downloading.value = _downloading.value.filter { it.id != id } + TransportState(id, 0)
 
         try {
             withRetry {
-                val request = Request.Builder()
+                val existingBytes = if (targetFile.exists()) targetFile.length() else 0L
+                val startOffset = maxOf(existingBytes, resumeFromBytes.coerceAtLeast(0L))
+                    .coerceAtMost(existingBytes)
+
+                val requestBuilder = Request.Builder()
                     .url("$server/d/$tag")
                     .get()
-                    .build()
+                if (startOffset > 0L) {
-
+                    requestBuilder.addHeader("Range", "bytes=$startOffset-")
-                val response = awaitDownloadResponse(id, request)
+                }
 
+                val response = awaitDownloadResponse(id, requestBuilder.build())
                 if (!response.isSuccessful) {
                     throw IOException("Download failed: ${response.code}")
                 }
 
                 val body = response.body ?: throw IOException("Empty response body")
-                val contentLength = body.contentLength()
+                val rangeAccepted = response.code == 206
-                val cacheDir = appContext?.cacheDir ?: throw IOException("No app context")
+                val writeFromOffset = if (rangeAccepted) startOffset else 0L
-                val tempFile = File(cacheDir, "dlr_${id.take(16)}_${System.currentTimeMillis()}.tmp")
+                val incomingLength = body.contentLength().coerceAtLeast(0L)
+                val totalFromHeader = parseContentRangeTotal(response.header("Content-Range"))
+                val totalBytes = when {
+                    totalFromHeader != null && totalFromHeader > 0L -> totalFromHeader
+                    incomingLength > 0L -> writeFromOffset + incomingLength
+                    else -> -1L
+                }
 
-                try {
+                if (writeFromOffset == 0L && targetFile.exists()) {
-                    var totalRead = 0L
+                    targetFile.delete()
+                }
+                targetFile.parentFile?.mkdirs()
+
+                val append = writeFromOffset > 0L
+                var totalRead = writeFromOffset
                 val buffer = ByteArray(64 * 1024)
 
                 body.byteStream().use { inputStream ->
-                        tempFile.outputStream().use { outputStream ->
+                    java.io.FileOutputStream(targetFile, append).use { outputStream ->
                         while (true) {
-                                val bytesRead = inputStream.read(buffer)
+                            coroutineContext.ensureActive()
+                            val bytesRead = try {
+                                inputStream.read(buffer)
+                            } catch (e: IOException) {
+                                if (!coroutineContext.isActive) {
+                                    throw CancellationException("Download cancelled", e)
+                                }
+                                throw e
+                            }
                             if (bytesRead == -1) break
+
                             outputStream.write(buffer, 0, bytesRead)
                             totalRead += bytesRead
-                                if (contentLength > 0) {
+
-                                    val progress = ((totalRead * 100) / contentLength).toInt().coerceIn(0, 99)
+                            if (totalBytes > 0L) {
+                                val progress =
+                                    ((totalRead * 100L) / totalBytes).toInt().coerceIn(0, 99)
                                 _downloading.value = _downloading.value.map {
                                     if (it.id == id) it.copy(progress = progress) else it
                                 }
@@ -419,28 +485,26 @@ object TransportManager {
                     }
                 }
 
-                    if (contentLength > 0 && totalRead != contentLength) {
+                if (totalBytes > 0L && totalRead < totalBytes) {
-                        tempFile.delete()
+                    throw IOException(
-                        throw IOException("Incomplete download: expected=$contentLength, got=$totalRead")
+                        "Incomplete download: expected=$totalBytes, got=$totalRead"
+                    )
                 }
                 if (totalRead == 0L) {
-                        tempFile.delete()
                     throw IOException("Empty download: 0 bytes received")
                 }
 
                 _downloading.value = _downloading.value.map {
                     if (it.id == id) it.copy(progress = 100) else it
                 }
-                    ProtocolManager.addLog("✅ Download raw OK: id=${id.take(8)}, size=$totalRead")
+                ProtocolManager.addLog(
-                    tempFile
+                    "✅ Download raw(resume) OK: id=${id.take(8)}, size=$totalRead"
-                } catch (e: Exception) {
+                )
-                    tempFile.delete()
+                targetFile
-                    throw e
-                }
             }
         } catch (e: Exception) {
             ProtocolManager.addLog(
-                "❌ Download raw failed: id=${id.take(8)}, reason=${e.javaClass.simpleName}: ${e.message ?: "unknown"}"
+                "❌ Download raw(resume) failed: id=${id.take(8)}, reason=${e.javaClass.simpleName}: ${e.message ?: "unknown"}"
             )
             throw e
         } finally {