refactor(chat): unify media types and viewer (#1328, #1329) (#1353)

app/src/main/java/com/m57/hermescontrol/ui/chat/ImageBytesResolver.kt

@@ -114,15 +114,12 @@ object ImageBytesResolver {
         }.getOrElse { e -> Result.Error(e.message ?: "Could not download image") }
     }
 
+    /** Image-only view of the shared MIME table: anything that isn't `image/` saves as `.img`. */
     fun extensionForMime(mime: String): String =
-        when (mime.substringBefore(';').trim().lowercase()) {
-            "image/jpeg", "image/jpg" -> "jpg"
-            "image/png" -> "png"
-            "image/gif" -> "gif"
-            "image/webp" -> "webp"
-            "image/bmp" -> "bmp"
-            "image/heic", "image/heif" -> "heic"
-            "image/svg+xml" -> "svg"
-            else -> "img"
+        if (mime.trim().startsWith("image/", ignoreCase = true)) {
+            com.m57.hermescontrol.ui.chat
+                .extensionForMime(mime)
+        } else {
+            "img"
         }
 }

app/src/main/java/com/m57/hermescontrol/ui/chat/MediaTypes.kt

@@ -140,67 +140,41 @@ fun normalizeFrameworkMime(mime: String?): String =
         ?.takeIf { it.isNotBlank() }
         ?: "application/octet-stream"
 
+/**
+ * MIME aliases and preferred extensions that [MEDIA_BY_EXT] can't express
+ * (it's keyed by extension, so `image/jpeg` would otherwise resolve to its
+ * first entry, `jpeg`). HEIC is save-only here: it isn't classified as inline media.
+ */
+private val EXT_BY_MIME_ALIAS: Map<String, String> =
+    mapOf(
+        "image/jpeg" to "jpg",
+        "image/jpg" to "jpg",
+        "image/heic" to "heic",
+        "image/heif" to "heic",
+        "audio/mp3" to "mp3",
+        "audio/x-m4a" to "m4a",
+        "audio/x-wav" to "wav",
+        "audio/wave" to "wav",
+        "application/x-flac" to "flac",
+        "application/ogg" to "ogg",
+    )
+
 /** Returns the canonical file extension for a given MIME type. */
 fun extensionForMime(mime: String): String {
     val clean = mime.substringBefore(';').trim().lowercase()
-    for ((ext, pair) in MEDIA_BY_EXT) {
-        if (pair.second
+    EXT_BY_MIME_ALIAS[clean]?.let { return it }
+    MEDIA_BY_EXT.entries
+        .firstOrNull { (_, pair) ->
+            pair.second
                 .substringBefore(';')
                 .trim()
                 .lowercase() == clean
-        ) {
-            return ext
-        }
-    }
-    return when (clean) {
-        "image/jpeg", "image/jpg" -> {
-            "jpg"
-        }
-
-        "video/mp4" -> {
-            "mp4"
-        }
-
-        "video/x-matroska" -> {
-            "mkv"
-        }
-
-        "video/quicktime" -> {
-            "mov"
-        }
-
-        "audio/mpeg", "audio/mp3" -> {
-            "mp3"
-        }
-
-        "audio/mp4", "audio/x-m4a" -> {
-            "m4a"
-        }
-
-        "audio/wav", "audio/x-wav", "audio/wave" -> {
-            "wav"
-        }
-
-        "audio/flac", "application/x-flac" -> {
-            "flac"
-        }
-
-        "audio/ogg", "application/ogg" -> {
-            "ogg"
-        }
-
-        "audio/aac" -> {
-            "aac"
-        }
-
-        else -> {
-            when {
-                clean.startsWith("video/") -> "mp4"
-                clean.startsWith("audio/") -> "mp3"
-                clean.startsWith("image/") -> "img"
-                else -> "bin"
-            }
-        }
+        }?.let { return it.key }
+    return when {
+        clean.startsWith("video/") -> "mp4"
+        clean.startsWith("audio/") -> "mp3"
+        clean.startsWith("image/") -> "img"
+        else -> "bin"
     }
 }
 

app/src/test/java/com/m57/hermescontrol/ui/chat/ImageBytesResolverTest.kt

@@ -35,6 +35,11 @@ class ImageBytesResolverTest {
         assertEquals("heic", ImageBytesResolver.extensionForMime("image/heic"))
         assertEquals("svg", ImageBytesResolver.extensionForMime("image/svg+xml"))
         assertEquals("img", ImageBytesResolver.extensionForMime("image/unknown"))
+        assertEquals("heic", ImageBytesResolver.extensionForMime("image/heif"))
+        assertEquals("bmp", ImageBytesResolver.extensionForMime("image/bmp"))
+        // Non-image content types stay `.img`, not `.bin`/`.pdf`.
+        assertEquals("img", ImageBytesResolver.extensionForMime("application/pdf"))
+        assertEquals("img", ImageBytesResolver.extensionForMime("text/html"))
     }
 
     @Test

app/src/test/java/com/m57/hermescontrol/ui/chat/MediaTypesTest.kt

@@ -30,6 +30,30 @@ class MediaTypesTest {
         assertEquals("application/octet-stream", mediaMimeForPath("/tmp/x.weird"))
     }
 
+    @Test
+    fun `extension for mime uses one table plus aliases`() {
+        // Table entries, including params and case.
+        assertEquals("png", extensionForMime("image/png"))
+        assertEquals("png", extensionForMime(" IMAGE/PNG; charset=binary"))
+        assertEquals("ogg", extensionForMime("audio/ogg; codecs=opus"))
+        assertEquals("mkv", extensionForMime("video/x-matroska"))
+        assertEquals("pdf", extensionForMime("application/pdf"))
+        // Aliases win over first-table-match.
+        assertEquals("jpg", extensionForMime("image/jpeg"))
+        assertEquals("jpg", extensionForMime("image/jpg"))
+        assertEquals("heic", extensionForMime("image/heif"))
+        assertEquals("mp3", extensionForMime("audio/mp3"))
+        assertEquals("m4a", extensionForMime("audio/x-m4a"))
+        assertEquals("wav", extensionForMime("audio/wave"))
+        assertEquals("flac", extensionForMime("application/x-flac"))
+        assertEquals("ogg", extensionForMime("application/ogg"))
+        // Family fallbacks.
+        assertEquals("mp4", extensionForMime("video/unknown"))
+        assertEquals("mp3", extensionForMime("audio/unknown"))
+        assertEquals("img", extensionForMime("image/unknown"))
+        assertEquals("bin", extensionForMime("application/unknown"))
+    }
+
     @Test
     fun `name extraction handles urls and paths`() {
         assertEquals("report.pdf", mediaNameFromPath("https://gw/api/files/download?path=%2Ftmp%2Freport.pdf"))