import threading
import pydub
import pygame
import math

class MusicFile:
    def __init__(self, filename, lock, channel_id, name = None, gain = 1):
        self.filename = filename
        self.channel_id = channel_id
        self.name = name or filename
        self.raw_data = None
        self.gain = gain

        self.loaded = False
        self.flag_paused = False
        threading.Thread(name = "MSMusicLoad", target = self.load_sound, args = [lock]).start()

    def load_sound(self, lock):
        lock.acquire()
        print("Loading « {} »".format(self.name))
        volume_factor = 20 * math.log10(self.gain)
        audio_segment = pydub.AudioSegment.from_file(self.filename).set_frame_rate(44100).apply_gain(volume_factor)
        self.sound_duration = audio_segment.duration_seconds
        self.raw_data = audio_segment.raw_data
        print("Loaded « {} »".format(self.name))
        self.loaded = True
        lock.release()

    def is_playing(self):
        return self.channel().get_busy()

    def is_paused(self):
        return self.flag_paused

    def play(self, fade_in = 0, volume = 100, start_at = 0):
        self.channel().set_endevent()
        self.channel().set_endevent(pygame.USEREVENT)
        self.set_volume(volume)

        if start_at > 0:
            raw_data_length = len(self.raw_data)
            start_offset = int((raw_data_length / self.sound_duration) * start_at)
            start_offset = start_offset - (start_offset % 2)
            sound = pygame.mixer.Sound(self.raw_data[start_offset:])
        else:
            sound = pygame.mixer.Sound(self.raw_data)

        self.channel().play(sound, fade_ms = int(fade_in * 1000))
        self.flag_paused = False

    def pause(self):
        self.channel().pause()
        self.flag_paused = True

    def unpause(self):
        self.channel().unpause()
        self.flag_paused = False

    def stop(self, fade_out = 0):
        if fade_out > 0:
            self.channel().fadeout(int(fade_out * 1000))
        else:
            self.channel().stop()

    def set_volume(self, value):
        if value < 0:
            value = 0
        if value > 100:
            value = 100
        self.channel().set_volume(value / 100)

    def wait_end(self):
        pass

    def channel(self):
        return pygame.mixer.Channel(self.channel_id)