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

/* WAV+DCS

	2008-12-06 - manakoAT : Evil Twin - Cypriens Chronicles...
	2008-12-07 - manakoAT : Added a function to read the Header file and for 
							retrieving the channels/frequency, Frequency starts
							always at a "data" chunk - 0x0C bytes, Channels
							always - 0x0E bytes...
*/

VGMSTREAM * init_vgmstream_dc_wav_dcs(STREAMFILE *streamFile) {

	VGMSTREAM * vgmstream = NULL;
    STREAMFILE * streamFileWAV = NULL;
    char filename[260];
	char filenameWAV[260];
	int i;
	int channel_count;
	int loop_flag;
	int frequency;
	int dataBuffer = 0;
	int Founddata = 0;
	size_t file_size;
	off_t current_chunk;
	
	/* check extension, case insensitive */
    streamFile->get_name(streamFile,filename,sizeof(filename));
    if (strcasecmp("dcs",filename_extension(filename))) goto fail;

	/* Getting the Header file name... */
	strcpy(filenameWAV,filename);
	strcpy(filenameWAV+strlen(filenameWAV)-3,"WAV");
	
	/* Look if the Header file is present, else cancel vgmstream */
	streamFileWAV = streamFile->open(streamFile,filenameWAV,STREAMFILE_DEFAULT_BUFFER_SIZE);
	if (!streamFileWAV) goto fail;

    /* check header */
    if (read_32bitBE(0x00,streamFileWAV) != 0x52494646 || /* "RIFF" */
        read_32bitBE(0x08,streamFileWAV) != 0x57415645 || /* "WAVE" */
        read_32bitBE(0x0C,streamFileWAV) != 0x34582E76 || /* 0x34582E76 */
        read_32bitBE(0x3C,streamFileWAV) != 0x406E616D) /* "@nam" */
    goto fail;

    /* scan file until we find a "data" string */
    file_size = get_streamfile_size(streamFileWAV);
	{
		current_chunk = 0;
		/* Start at 0 and loop until we reached the
		file size, or until we found a "data string */
		while (!Founddata && current_chunk < file_size) {
		dataBuffer = (read_32bitBE(current_chunk,streamFileWAV));
			if (dataBuffer == 0x64617461) { /* "data" */
				/* if "data" string found, retrieve the needed infos */
				Founddata = 1;
				/* We will cancel the search here if we have a match */
			break;	
			}
			/* else we will increase the search offset by 1 */
			current_chunk = current_chunk + 1;
		}
	}
	
	if (Founddata == 0) {
		goto fail;
	} else if (Founddata == 1) {
		channel_count = (uint16_t)read_16bitLE(current_chunk-0x0E,streamFileWAV);
        frequency = read_32bitLE(current_chunk-0x0C,streamFileWAV);
	}
	
	loop_flag = 0;

    /* Seems we're dealing with a vaild file+header,
	now we can finally build the VGMSTREAM */
    vgmstream = allocate_vgmstream(channel_count,loop_flag);
    if (!vgmstream) goto fail;

    /* fill in the vital statistics */
	vgmstream->channels = channel_count;
	vgmstream->sample_rate = frequency;
	vgmstream->num_samples=(get_streamfile_size(streamFile))*2/channel_count;
	
	if(loop_flag) {
		vgmstream->loop_start_sample = 0;
		vgmstream->loop_end_sample = (get_streamfile_size(streamFile))*2/channel_count;
	}	

	switch (channel_count) {
		case 1:
			vgmstream->layout_type = layout_none;
			break;
		case 2:
			vgmstream->layout_type = layout_interleave;
			vgmstream->interleave_block_size = 0x4000;
			break;
		default:
	goto fail;
	}

	vgmstream->coding_type = coding_AICA;
    vgmstream->meta_type = meta_DC_WAV_DCS;
	
    /* open the file for reading */
    {
        for (i=0;i<channel_count;i++) {
            vgmstream->ch[i].streamfile = streamFile->open(streamFile,filename,0x8000);
            vgmstream->ch[i].offset = 0;
            vgmstream->ch[i].adpcm_step_index = 0x7f;   /* AICA */
            if (!vgmstream->ch[i].streamfile) goto fail;
        }
    }

	close_streamfile(streamFileWAV); streamFileWAV=NULL;
	
    return vgmstream;

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