Refactor: Encapsulate MessageBubble colors

This commit refactors the `MessageBubble` composable by extracting the color logic into a private `messageBubbleColors` function. This function returns an immutable `MessageBubbleColors` data class, which holds the container, content, and reply container colors.

This change cleans up the main composable, improves readability, and centralizes color definitions for both incoming and outgoing messages. Additionally, the background color logic for attachments has been simplified to make it transparent for media types like stickers and videos.

feature/messageshistory/src/main/kotlin/dev/meloda/fast/messageshistory/presentation/MessageBubble.kt

@@ -16,6 +16,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.surfaceColorAtElevation
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableIntStateOf
@@ -68,22 +69,7 @@ fun MessageBubble(
     val currentOnLongClick by rememberUpdatedState(onLongClick)
 
     val theme = LocalThemeConfig.current
-    val backgroundColor = if (!isOut) {
-        MaterialTheme.colorScheme.surfaceColorAtElevation(2.dp)
-    } else {
-        MaterialTheme.colorScheme.primaryContainer
-    }
-    val replyBackgroundColor = if (!isOut) {
-        MaterialTheme.colorScheme.primaryContainer
-    } else {
-        MaterialTheme.colorScheme.inversePrimary
-    }
-
-    val contentColor = if (!isOut) {
-        MaterialTheme.colorScheme.onSurface
-    } else {
-        MaterialTheme.colorScheme.onPrimaryContainer
-    }
+    val colors = messageBubbleColors(isOut = isOut)
 
     val shouldShowBubble = !text.isNullOrEmpty()
 
@@ -117,7 +103,7 @@ fun MessageBubble(
         label = "dateContainerWidth"
     )
 
-    CompositionLocalProvider(LocalContentColor provides contentColor) {
+    CompositionLocalProvider(LocalContentColor provides colors.content) {
         Column(
             modifier = modifier
                 .wrapContentWidth()
@@ -140,8 +126,8 @@ fun MessageBubble(
                     onClick = onReplyClick,
                     title = replyTitle,
                     summary = replySummary,
-                    backgroundColor = backgroundColor,
-                    innerBackgroundColor = replyBackgroundColor
+                    backgroundColor = colors.container,
+                    innerBackgroundColor = colors.replyContainer
                 )
             }
 
@@ -163,7 +149,7 @@ fun MessageBubble(
                                 bottomEnd = if (attachments != null) 0.dp else 24.dp
                             )
                         )
-                        .background(backgroundColor)
+                        .background(colors.container)
                         .padding(
                             start = 8.dp,
                             end = 8.dp,
@@ -204,6 +190,15 @@ fun MessageBubble(
             }
 
             if (attachments != null) {
+                val firstAttachment = attachments.firstOrNull()
+                val isMediaAttachment = firstAttachment is VkStickerDomain ||
+                        firstAttachment is VkVideoMessageDomain
+                val attachmentBackgroundColor = if (isMediaAttachment) {
+                    Color.Transparent
+                } else {
+                    colors.container
+                }
+
                 Box(
                     modifier = Modifier
                         .onGloballyPositioned {
@@ -218,18 +213,7 @@ fun MessageBubble(
                                 topEnd = 0.dp
                             )
                         )
-                        .background(
-                            backgroundColor.copy(
-                                alpha = if ((attachments.firstOrNull()?.javaClass
-                                        ?: Nothing::class.java)
-                                    in listOf(
-                                        VkStickerDomain::class.java,
-                                        VkVideoMessageDomain::class.java
-                                    )
-                                ) 0f
-                                else 1f
-                            )
-                        )
+                        .background(attachmentBackgroundColor)
                 ) {
                     Attachments(
                         modifier = Modifier,
@@ -241,7 +225,7 @@ fun MessageBubble(
                     val dateStatusBackground = if (theme.darkMode) Color.Black.copy(alpha = 0.5f)
                     else Color.White.copy(alpha = 0.5f)
 
-                    CompositionLocalProvider(LocalContentColor provides contentColor) {
+                    CompositionLocalProvider(LocalContentColor provides colors.content) {
                         DateStatus(
                             modifier = Modifier
                                 .align(Alignment.BottomEnd)
@@ -266,6 +250,30 @@ fun MessageBubble(
     }
 }
 
+@Immutable
+private data class MessageBubbleColors(
+    val container: Color,
+    val content: Color,
+    val replyContainer: Color,
+)
+
+@Composable
+private fun messageBubbleColors(isOut: Boolean): MessageBubbleColors {
+    return if (isOut) {
+        MessageBubbleColors(
+            container = MaterialTheme.colorScheme.primaryContainer,
+            content = MaterialTheme.colorScheme.onPrimaryContainer,
+            replyContainer = MaterialTheme.colorScheme.inversePrimary
+        )
+    } else {
+        MessageBubbleColors(
+            container = MaterialTheme.colorScheme.surfaceColorAtElevation(2.dp),
+            content = MaterialTheme.colorScheme.onSurface,
+            replyContainer = MaterialTheme.colorScheme.primaryContainer
+        )
+    }
+}
+
 @Preview
 @Composable
 private fun Bubble() {