#include "library.h"
#include "plat.h"
#include <string.h>
#include <stdio.h>

#include "dr_flac.h"

static unsigned hash(const char* s) {
	const unsigned char* p = (const unsigned char*)s;
	unsigned h = 2166136261;
	while (*p)
		h = (h ^ *p++) * 16777619;
	return h;
}

Song* find_song(Library* l, const char* path) {
	int i = hash(path) % l->cap;
	int c;
	Song* s;
	for (c = 0; c < l->cap; c++) {
		s = &l->songs[i];
		if (!s->path[0] || !strcmp(path, s->path))
			return s;
		i++;
		i %= l->cap;
	}
	return 0;
}

static void cap_iter(
	void* uptr,
	const char* path
) {
	Library* lib = uptr;
	(void)path;
	lib->cap++;
}

static void adder_iter(
	void* uptr,
	const char* path
) {
	Song* s;
	Library* lib = uptr;
	s = find_song(lib, path);
	if (get_song_meta(path, s)) {
		strcpy(s->path, path);
		lib->indices[lib->cnt++] = s - lib->songs;
	}
}

void build_library(
	Arena* a,
	Library* lib,
	const char* path
) {
	int i;
	lib->cnt = lib->cap = 0;
	iter_dir(path, cap_iter, lib);
	lib->cap += 16;
	lib->songs = arena_alloc(
		a,
		lib->cap * sizeof *lib->songs
	);
	lib->indices = arena_alloc(
		a,
		lib->cap * sizeof *lib->indices
	);
	for (i = 0; i < lib->cap; i++)
		lib->songs[i].path[0] = 0;
	iter_dir(path, adder_iter, lib);
}

void parse_vorbis_comment(
	Song* s,
	const char* com,
	int len
) {
	/* this is not safe xDDDD idrc */
	if (len > 64) {
		len = 64;
	}
	if (!memcmp(com, "ARTIST=", 7)) {
		len -= 7;
		memcpy(s->artist, com + 7, len);
		s->artist[len] = 0;
	} else if (!memcmp(com, "TITLE=", 6)) {
		len -= 6;
		memcpy(s->name, com + 6, len);
		s->name[len] = 0;
	} else if (!memcmp(com, "ALBUM=", 6)) {
		len -= 6;
		memcpy(s->album, com + 6, len);
		s->album[len] = 0;
	}
}

void flac_meta(
	void* uptr,
	drflac_metadata* m
) {
	Song* s = uptr;
	drflac_vorbis_comment_iterator i;
	drflac_uint32 len;
	const char* c;
	int size;
	switch (m->type) {
		case DRFLAC_METADATA_BLOCK_TYPE_VORBIS_COMMENT:
			drflac_init_vorbis_comment_iterator(
				&i,
				m->data.vorbis_comment.commentCount,
				m->data.vorbis_comment.pComments
			);
			while ((c = drflac_next_vorbis_comment(
				&i,
				&len
			))) {
				parse_vorbis_comment(s, c, len);
			}
			break;
	}
}

int get_song_meta(const char* path, Song* s) {
	drflac* f;
	f = drflac_open_file_with_metadata(
		path,
		flac_meta,
		s,
		0
	);
	if (f) {
		drflac_close(f);
		return 1;
	}
	s->path[0] = 0;
	return 0;
}

#define DR_FLAC_IMPLEMENTATION
#include "dr_flac.h"