Media View showcase - Overview and local media handling

• The MediaStoreQueryBuilder class constructs queries for retrieving media files based on specified filters (MediaFilter) and sort options (MediaSortBy).
• The buildSelection method dynamically generates selection clauses for the MediaStore query, allowing for flexible filtering based on media types and other criteria.
• The buildSortOrder method constructs the sort order clause based on the selected MediaSortBy option, allowing users to organize their media by date, size, or name.

• The MediaStoreFileDto class represents a media file retrieved from the MediaStore. It includes logic to determine the type of media based on file properties like mime type, aspect ratio, dimensions, and bit rate.
• Methods like isPanorama, isRayban, is360, and isSpatial use heuristics to categorize media files. For example, panoramas are identified based on their aspect ratio exceeding a certain threshold, while 360-degree media are detected based on a 2:1 aspect ratio.
• Based on these detection methods, the mediaType and mediaFilter properties of MediaStoreFileDto are set, facilitating filtering and presentation in the UI.

• The DeviceGalleryService class handles the process of saving new media files to the device. The saveMediaFile method utilizes ContentValues to create a new entry in the MediaStore, specifying properties like display name, mime type, and relative path.
• The method also opens a file descriptor for the new MediaStore entry, allowing data to be written to the associated file using a FileOutputStream. The IS_PENDING flag is used to indicate that the file is still being written. Once the write is complete, the flag is cleared, signifying that the file is available.

• The UserRepository class provides a centralized way to access and modify user preferences.
• The UserPreferencesService interacts with SharedPreferences to store and retrieve preferences. The isSampleMediaSaved method checks whether the user has previously saved the sample media.

• The PermissionViewModel handles the process of loading sample assets from the assets folder. This occurs after the user grants storage permissions.
• Before saving assets, the code checks if a sample media folder exists from a previous installation. If found, it is deleted to avoid conflicts or duplicates.
• The saveAssetDirectory and saveAssetFile methods recursively iterate through the sample assets in the assets folder, saving each file to the device using the DeviceGalleryService. The setSampleMediaSaved method in UserRepository is called after successful asset saving to update the user’s preference.

fun buildSelection(filter: MediaFilter?): Pair<String?, Array<String>?> {
    return Pair(
        "${MediaStore.Files.FileColumns.MEDIA_TYPE} = ? OR ${MediaStore.Files.FileColumns.MEDIA_TYPE} = ?",
        arrayOf(
            "${MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE}",
            "${MediaStore.Files.FileColumns.MEDIA_TYPE_VIDEO}"
        ),
    ) // ... Add support for other MediaFilters
}

private fun isPanorama(): Boolean {
    return aspectRatio?.let { it > MediaType.panoramaAspectRatioMin } ?: false
}

suspend fun saveMediaFile(
    displayFileName: String?,
    mimeType: String?,
    relativeSubPath: String?,
    onWrite: (FileOutputStream) -> Unit
): Boolean {
    // ... ContentValues setup and MediaStore insertion
    contentResolver.openFileDescriptor(mediaUri, "w", null).use { file ->
        // ... Writing data to the FileOutputStream
    }
    // ... Update MediaStore entry to clear IS_PENDING flag
}

fun isSampleMediaSaved(): Boolean {
    return userPreferencesService.isSampleMediaSaved()
}