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

/* VGS (Phantom of Inferno) 

   This format is used in _many_ Princess Soft games.
*/
VGMSTREAM * init_vgmstream_ps2_vgs(STREAMFILE *streamFile) {
    VGMSTREAM * vgmstream = NULL;
    char filename[PATH_LIMIT];
    
    size_t fileLength;
    off_t readOffset = 0;
    off_t start_offset;
    off_t loop_start_offset = 0;
    off_t loop_end_offset = 0;

    uint8_t    testBuffer[0x10];
    int loop_flag = 0;
    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) != 0x56475300)
        goto fail;

    // get file length
    fileLength = get_streamfile_size(streamFile);

    // Find loop start
    do {
        readOffset += (off_t)read_streamfile(testBuffer, readOffset, 0x10, streamFile);

        // Loop Start ...
        if(testBuffer[0x01] == 0x06)
        {
            loop_start_offset = readOffset - 0x10;
            break;
        }

    } while (streamFile->get_offset(streamFile)<((int32_t)fileLength));

    // start at last line of file and move up
    readOffset = (int32_t)fileLength - 0x10;

    // Find loop end
    do {
        readOffset -= (off_t)read_streamfile(testBuffer, readOffset, 0x10, streamFile);

        // Loop End ...
        if((testBuffer[0x01]==0x03) && (testBuffer[0x03]!=0x77))
        {
            loop_end_offset = readOffset +  0x20;
            break;
        }
    } while (readOffset > 0);

    // setup loops
    if (loop_start_offset > 0)
    {
        loop_flag = 1;

        // if we have a start loop, use EOF if end loop is not found
        if (loop_end_offset == 0)
        {
            loop_end_offset = (int32_t)fileLength - 0x10;
        }
    }
    else
    {
        loop_flag = 0;
    }

    channel_count = 2;
    
    /* build the VGMSTREAM */
    vgmstream = allocate_vgmstream(channel_count,loop_flag);
    if (!vgmstream) goto fail;

    /* fill in the vital statistics */
    start_offset = 0x30;
    vgmstream->channels = channel_count;
    vgmstream->sample_rate = read_32bitBE(0x10,streamFile);
    vgmstream->coding_type = coding_PSX;
    vgmstream->num_samples = ((get_streamfile_size(streamFile)-0x30)/16/channel_count*28);
 
    if (loop_flag)
    {
        vgmstream->loop_start_sample = loop_start_offset/16/channel_count*28;
        vgmstream->loop_end_sample = loop_end_offset/16/channel_count*28;
    }

    vgmstream->layout_type = layout_interleave;
    vgmstream->interleave_block_size = read_32bitBE(0x04,streamFile)*0x1000;
    vgmstream->meta_type = meta_PS2_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;
}