android: compress images before media upload

android/app/src/main/java/ru/daemonlord/messenger/data/media/repository/NetworkMediaRepository.kt

@@ -1,5 +1,7 @@
 package ru.daemonlord.messenger.data.media.repository
 
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
 import okhttp3.MediaType.Companion.toMediaTypeOrNull
@@ -15,6 +17,8 @@ import ru.daemonlord.messenger.di.RefreshClient
 import ru.daemonlord.messenger.domain.common.AppError
 import ru.daemonlord.messenger.domain.common.AppResult
 import ru.daemonlord.messenger.domain.media.repository.MediaRepository
+import java.io.ByteArrayOutputStream
+import kotlin.math.roundToInt
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -32,15 +36,20 @@ class NetworkMediaRepository @Inject constructor(
         bytes: ByteArray,
     ): AppResult<Unit> = withContext(ioDispatcher) {
         try {
+            val uploadPayload = prepareUploadPayload(
+                fileName = fileName,
+                mimeType = mimeType,
+                bytes = bytes,
+            )
             val uploadInfo = mediaApiService.requestUploadUrl(
                 request = UploadUrlRequestDto(
-                    fileName = fileName,
-                    fileType = mimeType,
-                    fileSize = bytes.size.toLong(),
+                    fileName = uploadPayload.fileName,
+                    fileType = uploadPayload.mimeType,
+                    fileSize = uploadPayload.bytes.size.toLong(),
                 )
             )
 
-            val body = bytes.toRequestBody(mimeType.toMediaTypeOrNull())
+            val body = uploadPayload.bytes.toRequestBody(uploadPayload.mimeType.toMediaTypeOrNull())
             val uploadRequestBuilder = Request.Builder()
                 .url(uploadInfo.uploadUrl)
                 .put(body)
@@ -61,8 +70,8 @@ class NetworkMediaRepository @Inject constructor(
                 request = AttachmentCreateRequestDto(
                     messageId = messageId,
                     fileUrl = uploadInfo.fileUrl,
-                    fileType = mimeType,
-                    fileSize = bytes.size.toLong(),
+                    fileType = uploadPayload.mimeType,
+                    fileSize = uploadPayload.bytes.size.toLong(),
                 )
             )
             AppResult.Success(Unit)
@@ -70,4 +79,58 @@ class NetworkMediaRepository @Inject constructor(
             AppResult.Error(error.toAppError())
         }
     }
+
+    private fun prepareUploadPayload(
+        fileName: String,
+        mimeType: String,
+        bytes: ByteArray,
+    ): UploadPayload {
+        if (!mimeType.startsWith("image/", ignoreCase = true)) {
+            return UploadPayload(fileName = fileName, mimeType = mimeType, bytes = bytes)
+        }
+        if (mimeType.equals("image/gif", ignoreCase = true)) {
+            return UploadPayload(fileName = fileName, mimeType = mimeType, bytes = bytes)
+        }
+        val source = runCatching { BitmapFactory.decodeByteArray(bytes, 0, bytes.size) }.getOrNull()
+            ?: return UploadPayload(fileName = fileName, mimeType = mimeType, bytes = bytes)
+        val maxSide = 1920
+        val width = source.width
+        val height = source.height
+        val scale = (maxSide.toFloat() / maxOf(width, height).toFloat()).coerceAtMost(1f)
+        val targetWidth = (width * scale).roundToInt().coerceAtLeast(1)
+        val targetHeight = (height * scale).roundToInt().coerceAtLeast(1)
+
+        val scaled = if (targetWidth != width || targetHeight != height) {
+            Bitmap.createScaledBitmap(source, targetWidth, targetHeight, true)
+        } else {
+            source
+        }
+        val output = ByteArrayOutputStream()
+        val compressedOk = runCatching {
+            scaled.compress(Bitmap.CompressFormat.JPEG, 82, output)
+        }.getOrDefault(false)
+        if (scaled !== source) {
+            scaled.recycle()
+        }
+        source.recycle()
+        if (!compressedOk) {
+            return UploadPayload(fileName = fileName, mimeType = mimeType, bytes = bytes)
+        }
+        val compressedBytes = output.toByteArray()
+        if (compressedBytes.size >= bytes.size) {
+            return UploadPayload(fileName = fileName, mimeType = mimeType, bytes = bytes)
+        }
+        val baseName = fileName.substringBeforeLast('.').ifBlank { "image" }
+        return UploadPayload(
+            fileName = "$baseName-web.jpg",
+            mimeType = "image/jpeg",
+            bytes = compressedBytes,
+        )
+    }
+
+    private data class UploadPayload(
+        val fileName: String,
+        val mimeType: String,
+        val bytes: ByteArray,
+    )
 }