#include "meta.h"
#include "../util.h"

/* VGS (from Guitar Hero Encore - Rocks the 80s) */
VGMSTREAM * init_vgmstream_vgs(STREAMFILE *streamFile) {
    VGMSTREAM * vgmstream = NULL;
    char filename[260];
    off_t start_offset;

    int loop_flag;
	int channel_flag;
	int channel_flag_offset;
	int channel_count;

    /* check extension, case insensitive */
    streamFile->get_name(streamFile,filename,sizeof(filename));
    if (strcasecmp("vgs",filename_extension(filename))) goto fail;

    /* check header */
    if (read_32bitBE(0x00,streamFile) != 0x56675321) /* "VgS!" */
        goto fail;

    loop_flag = 0;
    channel_flag_offset = get_streamfile_size(streamFile)-0x10;
	channel_flag = read_32bitBE(channel_flag_offset,streamFile);
	
	/* Only seen files up to 5 channels, but just
	to be sure we will look up to 8 chanels */
	switch (channel_flag) {
		case 0x00800000:
			channel_count = 1;
			break;
		case 0x00810000:
			channel_count = 2;
			break;
		case 0x00820000:
			channel_count = 3;
			break;
		case 0x00830000:
			channel_count = 4;
			break;
		case 0x00840000:
			channel_count = 5;
			break;
		case 0x00850000:
			channel_count = 6;
			break;
		case 0x00860000:
			channel_count = 7;
			break;
		case 0x00870000:
			channel_count = 8;
		break;
			default:
				goto fail;
		}

    
	/* build the VGMSTREAM */
    vgmstream = allocate_vgmstream(channel_count,loop_flag);
    if (!vgmstream) goto fail;

	/* fill in the vital statistics */
    start_offset = 0x80;
	vgmstream->channels = channel_count;
    vgmstream->sample_rate = read_32bitLE(0x08,streamFile);
    vgmstream->coding_type = coding_PSX_badflags;
    vgmstream->num_samples = (read_32bitLE(0x0C,streamFile)*channel_count*0x10)*28/16/channel_count;
    if (loop_flag) {
        vgmstream->loop_start_sample = 0;
        vgmstream->loop_end_sample = (read_32bitLE(0x0C,streamFile)*channel_count*0x10)*28/16/channel_count;
    }

    vgmstream->layout_type = layout_interleave;
    vgmstream->interleave_block_size = 0x10;
    vgmstream->meta_type = meta_VGS;

    /* open the file for reading */
    {
        int i;
        STREAMFILE * file;
        file = streamFile->open(streamFile,filename,STREAMFILE_DEFAULT_BUFFER_SIZE);
        if (!file) goto fail;
        for (i=0;i<channel_count;i++) {
            vgmstream->ch[i].streamfile = file;

            vgmstream->ch[i].channel_start_offset=
                vgmstream->ch[i].offset=start_offset+
                vgmstream->interleave_block_size*i;

        }
    }

    return vgmstream;

    /* clean up anything we may have opened */
fail:
    if (vgmstream) close_vgmstream(vgmstream);
    return NULL;
}
