#include "tracker_engine.h"

#include "../flizzer_tracker_hal.h"

#include <furi_hal.h>

void tracker_engine_init(TrackerEngine* tracker_engine, uint8_t rate, SoundEngine* sound_engine)
{
	furi_hal_interrupt_set_isr_ex(FuriHalInterruptIdTim1UpTim16, 14, tracker_engine_timer_isr, (void*)tracker_engine);
	tracker_engine_init_hardware(rate);

	tracker_engine->sound_engine = sound_engine;
}

void tracker_engine_deinit_song(TrackerSong* song)
{
	for(int i = 0; i < song->num_patterns; ++i)
	{
		if(song->pattern[i].step)
		{
			free(song->pattern[i].step);
		}
	}

	for(int i = 0; i < song->num_instruments; ++i)
	{
		if(song->instrument[i])
		{
			free(song->instrument[i]);
		}
	}

	free(song);
}

void tracker_engine_deinit(TrackerEngine* tracker_engine)
{
	tracker_engine_deinit_song(tracker_engine->song);

	furi_hal_interrupt_set_isr_ex(FuriHalInterruptIdTim1UpTim16, 13, NULL, NULL);
	tracker_engine_stop();
}

uint8_t tracker_engine_get_note(TrackerSongPatternStep* step)
{
	return (step->note & 0x7f);
}

uint8_t tracker_engine_get_instrument(TrackerSongPatternStep* step)
{
	return ((step->note & 0x80) >> 3) | ((step->inst_vol & 0xf0) >> 4);
}

uint8_t tracker_engine_get_volume(TrackerSongPatternStep* step)
{
	return (step->inst_vol & 0xf) | ((step->command & 0x8000) >> 11);
}

uint8_t tracker_engine_get_command(TrackerSongPatternStep* step)
{
	return (step->command & 0x7fff);
}

void tracker_engine_set_note(TrackerEngine* tracker_engine, uint8_t chan, uint16_t note, bool update_note)
{
	if(update_note) tracker_engine->channel[chan].note = note;

	sound_engine_set_channel_frequency(tracker_engine->sound_engine, &tracker_engine->sound_engine->channel[chan], note);
}

void tracker_engine_trigger_instrument_internal(TrackerEngine* tracker_engine, uint8_t chan, Instrument* pinst, uint16_t note)
{
	SoundEngineChannel* se_channel = &tracker_engine->sound_engine->channel[chan];
	TrackerEngineChannel* te_channel = &tracker_engine->channel[chan];

	te_channel->channel_flags = TEC_PLAYING | (te_channel->channel_flags & TEC_DISABLED);

	if(!(pinst->flags & TE_PROG_NO_RESTART) && pinst->program_period > 0)
	{
		te_channel->channel_flags |= TEC_PROGRAM_RUNNING;

		te_channel->program_counter = 0;
		te_channel->program_loop = 0;
		te_channel->program_period = 0;
		te_channel->program_tick = 0;
	}

	te_channel->program_period = pinst->program_period;

	te_channel->instrument = pinst;

	se_channel->waveform = pinst->waveform;
	se_channel->flags = pinst->sound_engine_flags;

	te_channel->flags = pinst->flags;

	te_channel->arpeggio_note = 0;
	te_channel->fixed_note = 0xffff;

	tracker_engine_set_note(tracker_engine, chan, note + (uint16_t)pinst->finetune, true);

	te_channel->last_note = te_channel->target_note = note + (uint16_t)pinst->finetune;

	if(pinst->sound_engine_flags & SE_ENABLE_KEYDOWN_SYNC)
	{
		te_channel->vibrato_position = te_channel->pwm_position = 0;
	}

	if(pinst->flags & TE_SET_CUTOFF)
	{
		te_channel->filter_cutoff = pinst->filter_cutoff;
		te_channel->filter_resonance = pinst->filter_resonance;

		sound_engine_filter_set_coeff(&se_channel->filter, te_channel->filter_cutoff, (te_channel->filter_resonance << 5));
	}

	if(pinst->flags & TE_SET_PW)
	{
		te_channel->pw = (pinst->pw << 4);
		se_channel->pw = (pinst->pw << 4);
	}

	te_channel->slide_speed = 0;

	se_channel->adsr.a = pinst->adsr.a;
	se_channel->adsr.d = pinst->adsr.d;
	se_channel->adsr.s = pinst->adsr.s;
	se_channel->adsr.r = pinst->adsr.r;
	se_channel->adsr.volume = pinst->adsr.volume;

	sound_engine_enable_gate(tracker_engine->sound_engine, &tracker_engine->sound_engine->channel[chan], true);
}

void tracker_engine_execute_track_command(TrackerEngine* tracker_engine, uint8_t chan, TrackerSongPatternStep* step, bool first_tick)
{
	UNUSED(first_tick);
	UNUSED(tracker_engine);
	UNUSED(chan);

	uint8_t vol = tracker_engine_get_volume(step);

	if(vol != MUS_NOTE_VOLUME_NONE)
	{
		//tracker_engine->sound_engine->channel[chan].adsr.volume = (int32_t)tracker_engine->sound_engine->channel[chan].adsr.volume * (int32_t)vol / (MUS_NOTE_VOLUME_NONE - 1);
	}

	//TODO: add actual big ass function that executes commands; add arpeggio commands there
}

void tracker_engine_advance_tick(TrackerEngine* tracker_engine)
{
	if(!(tracker_engine->playing)) return;

	if(!(tracker_engine->song)) return;

	if(!(tracker_engine->sound_engine)) return;

	TrackerSong* song = tracker_engine->song;

	for(int chan = 0; chan < SONG_MAX_CHANNELS; ++chan)
	{
		SoundEngineChannel* se_channel = &tracker_engine->sound_engine->channel[chan];
		TrackerEngineChannel* te_channel = &tracker_engine->channel[chan];

		uint8_t sequence_position = tracker_engine->sequence_position;
		uint8_t current_pattern = song->sequence.sequence_step[sequence_position].pattern_indices[chan];
		uint8_t pattern_step = tracker_engine->pattern_position;

		TrackerSongPattern* pattern = &song->pattern[current_pattern];

		uint8_t note_delay = 0; //TODO: add note delay command

		if(tracker_engine->current_tick == note_delay)
		{
			uint8_t note = tracker_engine_get_note(&pattern->step[pattern_step]);
			uint8_t inst = tracker_engine_get_instrument(&pattern->step[pattern_step]);

			Instrument* pinst = NULL;

			if(inst == MUS_NOTE_INSTRUMENT_NONE)
			{
				pinst = te_channel->instrument;
			}

			else
			{
				if(inst < song->num_instruments)
				{
					pinst = song->instrument[inst];
					te_channel->instrument = pinst;
				}
			}

			//TODO: add note cut command

			if(note == MUS_NOTE_RELEASE)
			{
				sound_engine_enable_gate(tracker_engine->sound_engine, se_channel, 0);
			}

			else if(pinst && note != MUS_NOTE_RELEASE && note != MUS_NOTE_CUT && note != MUS_NOTE_NONE)
			{
				te_channel->slide_speed = 0;

				//TODO: add setting slide speed if slide command is there

				uint8_t prev_adsr_volume = se_channel->adsr.volume;

				tracker_engine_trigger_instrument_internal(tracker_engine, chan, pinst, note << 8);
				te_channel->note = (note << 8);

				te_channel->target_note = (note << 8) + pinst->finetune;

				if(inst == MUS_NOTE_INSTRUMENT_NONE)
				{
					se_channel->adsr.volume = prev_adsr_volume;
				}
			}
		}

		tracker_engine_execute_track_command(tracker_engine, chan, &pattern->step[pattern_step], tracker_engine->current_tick == note_delay);

		if(te_channel->flags & TEC_PLAYING)
		{
			if(!(se_channel->flags & SE_ENABLE_GATE))
			{
				te_channel->flags &= ~(TEC_PLAYING);
			}

			if(te_channel->slide_speed != 0)
			{
				if(te_channel->target_note > te_channel->note)
				{
					te_channel->target_note += fmin(te_channel->slide_speed, te_channel->target_note - te_channel->note);
				}

				else if(te_channel->target_note < te_channel->note)
				{
					te_channel->target_note -= fmin(te_channel->slide_speed, te_channel->note - te_channel->target_note);
				}
			}

			//TODO: add instrument program execution

			//TODO: add PWM and vibrato execution
			uint8_t vib = 0;
			int32_t chn_note = (te_channel->fixed_note != 0xffff ? te_channel->fixed_note : te_channel->note) + vib + ((int16_t)te_channel->arpeggio_note << 8);

			if(chn_note < 0) chn_note = 0;
			if(chn_note > ((12 * 7 + 11) << 8)) chn_note = ((12 * 7 + 11) << 8); //highest note is B-7

			tracker_engine_set_note(tracker_engine, chan, (uint16_t)chn_note, false);
		}
	}

	tracker_engine->current_tick++;

	if(tracker_engine->current_tick >= song->speed)
	{
		//TODO: add pattern loop and pattern skip commands

		tracker_engine->pattern_position++;

		tracker_engine->current_tick = 0;

		if(tracker_engine->pattern_position >= song->pattern_length)
		{
			tracker_engine->pattern_position = 0;
			tracker_engine->sequence_position++;

			if(tracker_engine->sequence_position >= song->num_sequence_steps)
			{
				tracker_engine->playing = false; //TODO: add song loop handling
				tracker_engine->sequence_position--;
				tracker_engine->pattern_position = song->pattern_length - 1;
			}
		}
	}
}