#extends Object
extends Node

var userroot := "user://" if OS.get_name() != "Android" else "/storage/emulated/0/RhythmGame/"
# The following would probably work. One huge caveat is that permission needs to be manually granted by the user in app settings as we can't use OS.request_permission("WRITE_EXTERNAL_STORAGE")
# "/storage/emulated/0/Android/data/au.ufeff.rhythmgame/"
# "/sdcard/Android/data/au.ufeff.rhythmgame/"

func directory_list(directory: String, hidden: bool) -> Dictionary:
	# Sadly there's no filelist sugar so we make our own
	var output = {folders=[], files=[], err=OK}
	var dir = Directory.new()
	output.err = dir.open(directory)
	if output.err != OK:
		print_debug('Failed to open directory: ' + directory + '(Error code '+output.err+')')
		return output
	output.err = dir.list_dir_begin(true, !hidden)
	if output.err != OK:
		print_debug('Failed to begin listing directory: ' + directory + '(Error code '+output.err+')')
		return output

	var item = dir.get_next()
	while (item != ''):
		if dir.current_is_dir():
			output['folders'].append(item)
		else:
			output['files'].append(item)
		item = dir.get_next()
	dir.list_dir_end()
	return output

func scan_library():
	print("Scanning library")
	var rootdir = userroot + "songs"
	var dir = Directory.new()
	var err = dir.make_dir_recursive(rootdir)
	if err != OK:
		print_debug("An error occurred while trying to create the songs directory: ", err)
		return err

	var songslist = directory_list(rootdir, false)
	if songslist.err != OK:
		print("An error occurred when trying to access the songs directory: ", songslist.err)
		return songslist.err

	var song_defs = {}
	var song_images = {}
	var genres = {}
	dir.open(rootdir)
	for key in songslist.folders:
		if dir.file_exists(key + "/song.json"):
			song_defs[key] = FileLoader.load_folder("%s/%s" % [rootdir, key])
			print("Loaded song directory: %s" % key)
			song_images[key] = FileLoader.load_image("%s/%s/%s" % [rootdir, key, song_defs[key]["tile_filename"]])
			if song_defs[key]["genre"] in genres:
				genres[song_defs[key]["genre"]].append(key)
			else:
				genres[song_defs[key]["genre"]] = [key]
		else:
			print("Found non-song directory: " + key)
	for file in songslist.files:
		print("Found file: " + file)

	return {song_defs=song_defs, song_images=song_images, genres=genres}



class SRT:
	const TAP_DURATION := 0.062500
	const ID_BREAK := 4
	const ID_HOLD := 2
	const ID_SLIDE_END := 128
	const ID3_SLIDE_CHORD := 0  # Straight line
	const ID3_SLIDE_ARC_CW := 1
	const ID3_SLIDE_ARC_ACW := 2

	static func load_file(filename):
		var file = File.new()
		var err = file.open(filename, File.READ)
		if err != OK:
			print(err)
			return err
		var notes = []
		var beats_per_measure := 4
		var length = file.get_len()
		var slide_idxs = {}
		while (file.get_position() < (length-2)):
			var noteline = file.get_csv_line()
			var time_hit := (float(noteline[0]) + (float(noteline[1]))-1.0) * beats_per_measure
			var duration := float(noteline[2]) * beats_per_measure
			var column := int(noteline[3])
			var id := int(noteline[4])
			var id2 := int(noteline[5])
			var id3 := int(noteline[6])

			match id:
				ID_HOLD:
					notes.push_back(Note.make_hold(time_hit, duration, column))
				ID_BREAK:
					notes.push_back(Note.make_break(time_hit, column))
				ID_SLIDE_END:
					# id2 is slide ID
					if id2 in slide_idxs:
						notes[slide_idxs[id2]].column_release = column
						notes[slide_idxs[id2]].update_slide_variables()
				_:
					if id2 == 0:
						notes.push_back(Note.make_tap(time_hit, column))
					else:
						# id2 is slide ID, id3 is slide pattern
						# In order to properly declare the slide, we need the paired endcap which may not be the next note
						slide_idxs[id2] = len(notes)
						var slide_type = Note.SlideType.CHORD
						match id3:
							ID3_SLIDE_CHORD:
								slide_type = Note.SlideType.CHORD
							ID3_SLIDE_ARC_CW:
								slide_type = Note.SlideType.ARC_CW
							ID3_SLIDE_ARC_ACW:
								slide_type = Note.SlideType.ARC_ACW
							_:
								print("Unknown slide type: ", id3)
						notes.push_back(Note.NoteSlide.new(time_hit, duration, column, -1, slide_type))
		return notes


class SRB:
	static func load_file(filename):
		pass


class SM:
	# Stepmania simfile

	const NOTE_VALUES = {
		'0': 'None',
		'1': 'Tap',
		'2': 'HoldStart',
		'3': 'HoldRollEnd',
		'4': 'RollStart',
		'M': 'Mine',
		# These three are less likely to show up anywhere, no need to implement
		'K': 'Keysound',
		'L': 'Lift',
		'F': 'Fake',
	}

	const CHART_DIFFICULTIES = {
		'Beginner': 0,
		'Easy': 1,
		'Medium': 2,
		'Hard': 3,
		'Challenge': 4,
		'Edit': 5,
		# Some will just write whatever for special difficulties, but we should at least color-code these standard ones
	}

	const TAG_TRANSLATIONS = {
		'#TITLE': 'title',
		'#SUBTITLE': 'subtitle',
		'#ARTIST': 'artist',
		'#TITLETRANSLIT': 'title_transliteration',
		'#SUBTITLETRANSLIT': 'subtitle_transliteration',
		'#ARTISTTRANSLIT': 'artist_transliteration',
		'#GENRE': 'genre',
		'#CREDIT': 'chart_author',
		'#BANNER': 'image_banner',
		'#BACKGROUND': 'image_background',
		'#LYRICSPATH': '',
		'#CDTITLE': 'image_cd_title',
		'#MUSIC': 'audio_filelist',
		'#OFFSET': 'audio_offsets',
		'#SAMPLESTART': 'audio_preview_times',
		'#SAMPLELENGTH': 'audio_preview_times',
		'#SELECTABLE': '',
		'#BPMS': 'bpm_values',
		'#STOPS': '',
		'#BGCHANGES': '',
		'#KEYSOUNDS': '',
	}

	static func load_chart(lines):
		var metadata = {}
		var notes = []

		assert(lines[0].begins_with('#NOTES:'))
		metadata['chart_type'] = lines[1].strip_edges().rstrip(':')
		metadata['description'] = lines[2].strip_edges().rstrip(':')
		metadata['difficulty_str'] = lines[3].strip_edges().rstrip(':')
		metadata['numerical_meter'] = lines[4].strip_edges().rstrip(':')
		metadata['groove_radar'] = lines[5].strip_edges().rstrip(':')

		# Measures are separated by lines that start with a comma
		# Each line has a state for each of the pads, e.g. '0000' for none pressed
		# The lines become even subdivisions of the measure, so if there's 4 lines everything represents a 1/4 beat, if there's 8 lines everything represents a 1/8 beat etc.
		# For this reason it's probably best to just have a float for beat-within-measure rather than integer beats.
		var measures = [[]]
		for i in range(6, len(lines)):
			var line = lines[i].strip_edges()
			if line.begins_with(','):
				measures.append([])
			elif line.begins_with(';'):
				break
			elif len(line) > 0:
				measures[-1].append(line)

		var ongoing_holds = {}
		var num_notes := 0
		var num_jumps := 0
		var num_hands := 0
		var num_holds := 0
		var num_rolls := 0
		var num_mines := 0

		for measure in range(len(measures)):
			var m_lines = measures[measure]
			var m_length = len(m_lines)  # Divide out all lines by this
			for beat in m_length:
				var line : String = m_lines[beat]
				# Jump check at a line-level (check for multiple 1/2/4s)
				var hits : int = line.count('1') + line.count('2') + line.count('4')
				# Hand/quad check more complex as need to check hold/roll state as well
				# TODO: are they exclusive? Does quad override hand override jump? SM5 doesn't have quads and has hands+jumps inclusive
				var total_pressed : int = hits + len(ongoing_holds)
				var jump : bool = hits >= 2
				var hand : bool = total_pressed >= 3
				# var quad : bool = total_pressed >= 4
				num_notes += hits
				num_jumps += int(jump)
				num_hands += int(hand)
				var time = measure + beat/float(m_length)
				for col in len(line):
					match line[col]:
						'1':
							notes.append(Note.make_tap(time, col))
						'2':  # Hold
							ongoing_holds[col] = len(notes)
							notes.append(Note.make_tap(time, col))
						'4':  # Roll
							ongoing_holds[col] = len(notes)
							notes.append(Note.make_tap(time, col))
						'3':  # End Hold/Roll
							assert(ongoing_holds.has(col))
							notes[ongoing_holds[col]].set_time_release(time)
						'M':  # Mine
							num_mines += 1
							pass
		metadata['num_notes'] = num_notes
		metadata['num_jumps'] = num_jumps
		metadata['num_hands'] = num_hands
		metadata['num_holds'] = num_holds
		metadata['num_rolls'] = num_rolls
		metadata['num_mines'] = num_mines
		return [metadata, notes]

	static func load_file(filename):
		# Technically, declarations end with a semicolon instead of a linebreak.
		# This is a PITA to do correctly in GDScript and the files in our collection are well-behaved with linebreaks anyway, so we won't bother.
		var file := File.new()
		var err := file.open(filename, File.READ)
		if err != OK:
			print(err)
			return err
		var length = file.get_len()
		var lines = [[]]  # First list will be header, then every subsequent one is a chart
		while (file.get_position() < (length-1)):  # Could probably replace this with file.eof_reached()
			var line : String = file.read_line()
			if line.begins_with('#NOTES'):  # Split to a new list for each chart definition
				lines.append([])
			lines[-1].append(line)
		file.close()

		var metadata = {}
		for line in lines[0]:
			var tokens = line.rstrip(';').split(':')
			if TAG_TRANSLATIONS.has(tokens[0]):
				metadata[TAG_TRANSLATIONS[tokens[0]]] = tokens[1]
		var charts = []

		for i in range(1, len(lines)):
			charts.append(load_chart(lines[i]))

		return charts


class Test:
	static func stress_pattern():
		var notes = []
		for bar in range(8):
			notes.push_back(Note.make_hold(bar*4, 1, bar%8))
			for i in range(1, 8):
				notes.push_back(Note.make_tap(bar*4 + (i/2.0), (bar + i)%8))
			notes.push_back(Note.make_tap(bar*4 + (7/2.0), (bar + 3)%8))
		for bar in range(8, 16):
			notes.push_back(Note.make_hold(bar*4, 2, bar%8))
			for i in range(1, 8):
				notes.push_back(Note.make_tap(bar*4 + (i/2.0), (bar + i)%8))
				notes.push_back(Note.make_tap(bar*4 + ((i+0.5)/2.0), (bar + i)%8))
				notes.push_back(Note.make_slide(bar*4 + ((i+1)/2.0), 1, (bar + i)%8, 0))
		for bar in range(16, 24):
			notes.push_back(Note.make_hold(bar*4, 2, bar%8))
			notes.push_back(Note.make_hold(bar*4, 1, (bar+1)%8))
			for i in range(2, 8):
				notes.push_back(Note.make_tap(bar*4 + (i/2.0), (bar + i)%8))
				notes.push_back(Note.make_hold(bar*4 + ((i+1)/2.0), 0.5, (bar + i)%8))
		for bar in range(24, 32):
			notes.push_back(Note.make_hold(bar*4, 1, bar%8))
			for i in range(1, 32):
				notes.push_back(Note.make_tap(bar*4 + (i/8.0), (bar + i)%8))
				if (i%2) > 0:
					notes.push_back(Note.make_tap(bar*4 + (i/8.0), (bar + i + 4)%8))
		for bar in range(32, 48):
			notes.push_back(Note.make_hold(bar*4, 1, bar%8))
			for i in range(1, 32):
				notes.push_back(Note.make_tap(bar*4 + (i/8.0), (bar + i)%8))
				notes.push_back(Note.make_tap(bar*4 + (i/8.0), (bar + i + 3)%8))
		return notes

func load_folder(folder):
	var file = File.new()
	var err = file.open("%s/song.json" % folder, File.READ)
	if err != OK:
		print(err)
		return err
	var result_json = JSON.parse(file.get_as_text())
	file.close()
	if result_json.error != OK:
		print("Error: ", result_json.error)
		print("Error Line: ", result_json.error_line)
		print("Error String: ", result_json.error_string)
		return result_json.error
	var result = result_json.result
	result.directory = folder
	return result


func load_ogg(filename) -> AudioStreamOGGVorbis:
	var audiostream = AudioStreamOGGVorbis.new()
	var oggfile = File.new()
	oggfile.open(filename, File.READ)
	audiostream.set_data(oggfile.get_buffer(oggfile.get_len()))
	oggfile.close()
	return audiostream

func load_image(filename) -> ImageTexture:
	var tex = ImageTexture.new()
	var img = Image.new()
	img.load(filename)
	tex.create_from_image(img)
	return tex