namespace StoicGoose.Core.Sound
{
	/* Channel 1, no additional features */
	public sealed class SoundChannel1
	{
		const int counterReload = 2048;

		ushort counter;
		byte pointer;

		public byte OutputLeft { get; set; }
		public byte OutputRight { get; set; }

		readonly WaveTableReadDelegate waveTableReadDelegate;

		/* REG_SND_CH1_PITCH */
		public ushort Pitch { get; set; }
		/* REG_SND_CH1_VOL */
		public byte VolumeLeft { get; set; }
		public byte VolumeRight { get; set; }
		/* REG_SND_CTRL */
		public bool IsEnabled { get; set; }

		public SoundChannel1(WaveTableReadDelegate waveTableRead) => waveTableReadDelegate = waveTableRead;

		public void Reset()
		{
			counter = counterReload;
			pointer = 0;
			OutputLeft = OutputRight = 0;

			Pitch = 0;
			VolumeLeft = VolumeRight = 0;
			IsEnabled = false;
		}

		public void Step()
		{
			counter--;
			if (counter == Pitch)
			{
				var data = waveTableReadDelegate((ushort)(pointer >> 1));
				if ((pointer & 0b1) == 0b1) data >>= 4;
				data &= 0x0F;

				OutputLeft = (byte)(data * VolumeLeft);
				OutputRight = (byte)(data * VolumeRight);

				pointer++;
				pointer &= 0b11111;
				counter = counterReload;
			}
		}
	}
}