/*
 * player.c
 *
 *  Created on: Nov 25, 2025
 *      Author: sowgro
 */

#include "endian_converters.h"
#include <stdint.h>
#include "endian_converters.h"
#include "hw8.h"
#include "activity4.h"
#include "song_info.h"

#define NOTE_OFF_EVENT (0)
#define NOTE_ON_EVENT (1)
#define KEY_PRESSURE (2)

typedef struct {
	uint8_t ev_type;
	uint32_t abs_time;
	uint8_t key_number;
	uint8_t value;
} note_event_t;

void parse_song(uint8_t *p_song) {
	header_t header;
	header = get_header(p_song);
	p_song += sizeof(header_t) - 2; // move pointer past header

	song_info_t song_info;
	p_song = get_song_info(p_song, &song_info);

	note_event_t trackEvents[header.ntrcks][1024];
	for(int i = 0; i < header.ntrcks; i++){
		p_song = parse_track(p_song, trackEvents[i]);
	}
}

uint8_t parse_track(uint8_t *p_song, note_event_t *events) {
	p_song += 4; // skip MTrk
	uint32_t MTrk_len = convert_to_uint32(p_song);
	p_song += 4;

	int curEvent = 0;
	uint32_t prev_abs_time = 0;

	for (uint8_t *p_end = p_song + MTrk_len; p_song != p_end; p_song++) {
		note_event_t note;

		parseDelay_result_t delay_result = parseDelay(p_song);
		uint32_t abs_time = prev_abs_time + delay_result.value;
		note.abs_time = abs_time;
		prev_abs_time = abs_time;
		p_song += delay_result.bytes_used;


		if (*p_song >> 4 == 0b1000) {
			note.ev_type = NOTE_OFF_EVENT;
		} else if (*p_song >> 4 == 0b1001) {
			note.ev_type = NOTE_ON_EVENT;
		} else if (*p_song >> 4 == 0b1010) {
			note.ev_type = KEY_PRESSURE;
		} else {
			continue;
		}

//		size_t channelNumber = *p_song && 0b00001111;
		p_song++;

		note.key_number = *p_song;
		p_song++;

		note.value = *p_song;
		p_song++;

		events[curEvent++] = note;
	}
	events[curEvent] = 0; // null terminate array

	return p_song;
}