/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 *
 * Copyright (C) 2009 Mohamed Tarek
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include <string.h>

#include "logf.h"
#include "codeclib.h"
#include "libatrac/atrac3.h"

CODEC_HEADER

#define FRAMESIZE ci->id3->bytesperframe
#define BITRATE   ci->id3->bitrate

static ATRAC3Context q IBSS_ATTR;

/* this is the codec entry point */
enum codec_status codec_main(enum codec_entry_call_reason reason)
{
    /* Nothing to do */
    return CODEC_OK;
    (void)reason;
}

/* this is called for each file to process */
enum codec_status codec_run(void)
{
    static size_t buff_size;
    int datasize, res, frame_counter, total_frames, seek_frame_offset;
    uint8_t *bit_buffer;
    int elapsed = 0;
    size_t resume_offset;
    intptr_t param;
    long action;

    if (codec_init()) {
        DEBUGF("codec init failed\n");
        return CODEC_ERROR;
    }

    action = CODEC_ACTION_NULL;
    param = ci->id3->elapsed;
    resume_offset = ci->id3->offset;

    codec_set_replaygain(ci->id3);
    ci->memset(&q,0,sizeof(ATRAC3Context));
 
    ci->configure(DSP_SET_FREQUENCY, ci->id3->frequency);
    ci->configure(DSP_SET_SAMPLE_DEPTH, 17); /* Remark: atrac3 uses s15.0 by default, s15.2 was hacked. */
    const uint8_t channels = 2;
    ci->configure(DSP_SET_STEREO_MODE, channels == 1 ?
        STEREO_MONO : STEREO_NONINTERLEAVED);

    ci->seek_buffer(0);

    /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
    /* ATRAC3 expects and extra-data size of 14 bytes for wav format, and *
     * looks for that in the id3v2buf.                                    */
    res = atrac3_decode_init(&q, ci->id3, channels, 14);
    if(res < 0) {
        DEBUGF("failed to initialize OMA atrac decoder\n");
        return CODEC_ERROR;
    }

    total_frames = (ci->id3->filesize - ci->id3->first_frame_offset) / FRAMESIZE;
    frame_counter = 0;
    
    /* check for a mid-track resume and force a seek time accordingly */
    if (resume_offset) {
        resume_offset -= MIN(resume_offset, ci->id3->first_frame_offset);
        /* calculate resume_offset in frames */
        param = (resume_offset/FRAMESIZE) * ((FRAMESIZE * 8)/BITRATE);
    }

    if ((unsigned long)param) {
        action = CODEC_ACTION_SEEK_TIME;
    }
    else {
        ci->set_elapsed(0);
        ci->seek_buffer(ci->id3->first_frame_offset);
    }

    /* The main decoder loop */  
    while(frame_counter < total_frames)
    {
        if (action == CODEC_ACTION_NULL)
            action = ci->get_command(&param);

        if (action == CODEC_ACTION_HALT)
            break;

        if (action == CODEC_ACTION_SEEK_TIME) {
            /* Do not allow seeking beyond the file's length */
            if ((unsigned long) param > ci->id3->length) {
                ci->set_elapsed(ci->id3->length);
                ci->seek_complete();
                break;
            }       

            /* Seek to the start of the track */
            if (param == 0) {
                elapsed = 0;
                ci->set_elapsed(0);
                ci->seek_buffer(ci->id3->first_frame_offset);
                ci->seek_complete();
                action = CODEC_ACTION_NULL;
                continue;           
            }                                                                

            seek_frame_offset = (param * BITRATE) / (8 * FRAMESIZE);
            frame_counter = seek_frame_offset;
            ci->seek_buffer(ci->id3->first_frame_offset + seek_frame_offset* FRAMESIZE);
            elapsed = param;
            ci->set_elapsed(elapsed);
            ci->seek_complete(); 
        }

        action = CODEC_ACTION_NULL;

        bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, FRAMESIZE);

        res = atrac3_decode_frame(FRAMESIZE, &q, &datasize, bit_buffer, FRAMESIZE);

        if(res != (int)FRAMESIZE) {
            DEBUGF("codec error\n");
            return CODEC_ERROR;
        }

        if(datasize)
            ci->pcmbuf_insert(q.outSamples, q.outSamples + 1024,
                              q.samples_per_frame / channels);

        elapsed += (FRAMESIZE * 8) / BITRATE;
        ci->set_elapsed(elapsed);

        ci->advance_buffer(FRAMESIZE);
        frame_counter++;
    }

    return CODEC_OK;    
}