#include <SDL.h>

#include <stdio.h>
#include <stdlib.h>

#include "pokey.h"

#define ROM_FILE "../jumpmanjr.rom"
#define ROM_SIZE 0x4000

#define FREQ 44100

#define PAL_BUF_SIZE 882
#define NTSC_BUF_SIZE 735

#define PAL_DELAY 20
#define NTSC_DELAY 17

unsigned char sndbuf[PAL_BUF_SIZE + 1];

int buf_size = NTSC_BUF_SIZE;
int delay = NTSC_DELAY;

unsigned char rom[ROM_SIZE];

void usage(void) {
	fprintf(stderr, "usage: playsnd [-p] 0xaddr\n");
	exit(1);
}

void load_rom(void) {
	int size;
	FILE *f;

	f = fopen(ROM_FILE, "rb");
	if(!f) {
		perror(ROM_FILE);
		usage();
	}

	size = fread(rom, 1, ROM_SIZE, f);
	if(size != ROM_SIZE) {
		fprintf(stderr, "file %s should be %d bytes long, not %d\n",
				ROM_FILE, ROM_SIZE, size);
		usage();
	}

	fprintf(stderr, "loaded ROM %s, %d bytes\n", ROM_FILE, size);
}

void play_frames(unsigned char count) {
	fprintf(stderr, "playing for %d frames\n", count);
	while(count--) {
		SDL_Delay(delay);
	}
}

void play_sfx(int addr) {
	unsigned char *p = rom + (addr - 0x8000);

	while(1) {
		fprintf(stderr, "$%04lx: $%02x\n", (p - rom + 0x8000), *p);
		switch(*p) {
			case 0:
				fprintf(stderr, "opcode 0 (snd_end)\n");
				return;
			case 1:
				fprintf(stderr, "opcode 1 (snd_audc)\n");
				Update_pokey_sound(audc1, *++p);
				play_frames(*++p);
				++p;
				break;
			case 2:
				fprintf(stderr, "opcode 2 (snd_jump)\n");
				addr = *++p;
				addr |= ( (*++p) << 8);
				addr -= 0x8000;
				p = rom + addr;
				break;
			case 3:
				fprintf(stderr, "opcode 3 (snd_rest)\n");
				Update_pokey_sound(audc1, 0);
				play_frames(*++p);
				++p;
				break;
			default:
				fprintf(stderr, "opcode $%02x (snd_note)\n", *p);
				Update_pokey_sound(audf1, *p);
				play_frames(*++p);
				++p;
				break;
		}
	}
}

void sdl_audio_callback(void *userdata, Uint8* stream, int len) {
	Pokey_process(stream, len);
}

void init_sdl_audio(void) {
	SDL_AudioSpec want, have;
	SDL_AudioDeviceID dev;

	if(SDL_Init(SDL_INIT_AUDIO) < 0) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(-1);
	}
	atexit(SDL_Quit);

	SDL_memset(&want, 0, sizeof(want));
	want.freq = FREQ;
	want.format = AUDIO_U8;
	want.channels = 1;
	want.samples = buf_size;
	want.callback = sdl_audio_callback;

	dev = SDL_OpenAudioDevice(0, 0, &want, &have, 0);
	if(!dev) {
		fprintf(stderr, "Failed to open audio: %s\n", SDL_GetError());
		exit(-1);
	}

	SDL_PauseAudioDevice(dev, 0);
}

int main(int argc, char **argv) {
	int addr;

	if(argc < 2 || argc > 3) usage();

	if(argc == 3) {
		buf_size = PAL_BUF_SIZE;
		delay = PAL_DELAY;
		addr = (int)strtol(argv[2], 0, 16);
	} else {
		addr = (int)strtol(argv[1], 0, 16);
	}

	if(addr < 0x8000 || addr > 0xbfff) {
		fprintf(stderr, "invalid address, must be 0x8fff thru 0xbfff\n");
		usage();
	}

	load_rom();

	fprintf(stderr, "playing sfx at $%04x, buf_size %d\n", addr, buf_size);

	Pokey_sound_init(FREQ_17_APPROX, FREQ);
	init_sdl_audio();
	play_sfx(addr);

	return(0);
}