# Used to play sound, best suited for sounds effects in apps or games
class SoundPool

	# Latest error on this sound pool
	var error: nullable Error = null

	private var nsoundpool: NativeSoundPool is noinit

	# The maximum number of simultaneous streams for this SoundPool
	var max_streams = 10 is writable

	# The audio stream type, 3 is STREAM_MUSIC, default for game application
	var stream_type = 3 is writable

	# The sample-rate converter quality, currently has no effect
	var src_quality = 0 is writable

	# Left volume value, range 0.0 to 1.0
	var left_volume = 1.0 is writable

	# Right volume value, range 0.0 to 1.0
	var right_volume = 1.0 is writable

	# Playback rate, 1.0 = normal playback, range 0.5 to 2.0
	var rate = 1.0 is writable

	# Loop mode, 0 = no loop, -1 = loop forever
	var looping = 0 is writable

	# Stream priority
	private var priority = 1

	init do self.nsoundpool = (new NativeSoundPool(max_streams, stream_type, src_quality)).new_global_ref

	# Load the sound from an asset file descriptor
	# this function is for advanced use
	private fun load_asset_fd(afd: NativeAssetFileDescriptor): Sound do
		var resval = nsoundpool.load_asset_fd(afd, self.priority)
		if  resval == -1 then
			self.error = new Error("Unable to load sound from assets")
			return new Sound.priv_init(null, -1, self, self.error)
		else
			return new Sound.priv_init(null, resval, self, null)
		end
	end

	# Returns only the id corresponding to the soundpool where the sound is loaded.
	# Needed by `load` of `Sound`.
	private fun load_asset_fd_rid(afd: NativeAssetFileDescriptor): Int do
		return nsoundpool.load_asset_fd(afd, self.priority)
	end

	# Load the sound from its resource id
	fun load_id(context: NativeActivity, id:Int): Sound do
		var resval = nsoundpool.load_id(context, id, priority)
			if  resval == -1 then
			self.error = new Error("Unable to load sound from assets")
			return new Sound.priv_init(null, -1, self, self.error)
		else
			return new Sound.priv_init(null, resval, self, null)
		end
	end

	# Returns only the id corresponding to the soundpool where the sound is loaded.
	private fun load_id_rid(context: NativeActivity, id: Int): Int do
		return nsoundpool.load_id(context, id, priority)
	end

	# Load the sound from the specified path
	fun load_path(path: String): Sound do
		sys.jni_env.push_local_frame(1)
		var resval = nsoundpool.load_path(path.to_java_string, priority)
		sys.jni_env.pop_local_frame
		if  resval == -1 then
			self.error = new Error("Unable to load sound from path: " + path)
			return new Sound.priv_init(null, -1, self, self.error)
		else
			return new Sound.priv_init(null, resval, self, null)
		end
	end

	# Play a sound from a sound ID
	# return non-zero streamID if successful, zero if failed
	fun play(id: Int): Int do
		return nsoundpool.play(id, left_volume, right_volume, priority, looping, rate)
	end

	# Load a sound by its `name` in the resources, the sound must be in the `res/raw` folder
	fun load_name(resource_manager: ResourcesManager, context: NativeActivity, name: String): Sound do
		var id = resource_manager.raw_id(name)
		var resval = nsoundpool.load_id(context, id, priority)
		if  resval == -1 then
			self.error = new Error("Unable to load sound from resources: " + name)
			return new Sound.priv_init(null, -1, self, self.error)
		else
			return new Sound.priv_init(null, resval, self, null)
		end
	end

	# Returns only the id corresponding to the soundpool where the sound is loaded.
	private fun load_name_rid(resource_manager: ResourcesManager, context: NativeActivity, sound: String): Int do
		var id = resource_manager.raw_id(sound)
		return nsoundpool.load_id(context, id, priority)
	end

	# Pause a playback stream
	fun pause_stream(stream_id: Int) do nsoundpool.pause(stream_id)

	# Pause all active_streams
	fun auto_pause do nsoundpool.auto_pause

	# Resume all previously active streams
	fun auto_resume do nsoundpool.auto_resume

	# Resume a playback stream
	fun resume(stream_id: Int) do nsoundpool.resume(stream_id)

	# Set loop mode on a stream
	fun stream_loop=(stream_id, looping: Int) do nsoundpool.set_loop(stream_id, looping)

	# Change stream priority
	fun stream_priority=(stream_id, priority: Int) do nsoundpool.set_priority(stream_id, priority)

	# Change playback rate
	fun stream_rate=(stream_id: Int, rate: Float) do nsoundpool.set_rate(stream_id, rate)

	# Set stream volume
	fun stream_volume(stream_id: Int, left_volume, right_volume: Float) do
		nsoundpool.set_volume(stream_id, left_volume, right_volume)
	end

	# Stop a playback stream
	fun stop_stream(stream_id: Int) do nsoundpool.stop(stream_id)

	# Unload a sound from a sound ID
	fun unload(sound: Sound): Bool do return nsoundpool.unload(sound.soundpool_id)

	# Destroys the object
	fun destroy do nsoundpool.release
end