/* libSoX MAUD file format handler, by Lutz Vieweg 1993
 *
 * supports: mono and stereo, linear, a-law and u-law reading and writing
 *
 * an IFF format; description at http://lclevy.free.fr/amiga/MAUDINFO.TXT
 *
 * Copyright 1998-2006 Chris Bagwell and SoX Contributors
 * This source code is freely redistributable and may be used for
 * any purpose.  This copyright notice must be maintained.
 * Lance Norskog And Sundry Contributors are not responsible for
 * the consequences of using this software.
 */

#include "sox_i.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

/* Private data for MAUD file */
typedef struct {
        uint32_t nsamples;
} priv_t;

static void maudwriteheader(sox_format_t *);

/*
 * Do anything required before you start reading samples.
 * Read file header.
 *      Find out sampling rate,
 *      size and encoding of samples,
 *      mono/stereo/quad.
 */
static int startread(sox_format_t * ft)
{
        priv_t * p = (priv_t *) ft->priv;

        char buf[12];
        char *chunk_buf;

        unsigned short bitpersam;
        uint32_t nom;
        unsigned short denom;
        unsigned short chaninf;

        uint32_t chunksize;
        uint32_t trash32;
        uint16_t trash16;
        int rc;

        /* Needed for rawread() */
        rc = lsx_rawstartread(ft);
        if (rc)
            return rc;

        /* read FORM chunk */
        if (lsx_reads(ft, buf, (size_t)4) == SOX_EOF || strncmp(buf, "FORM", (size_t)4) != 0)
        {
                lsx_fail_errno(ft,SOX_EHDR,"MAUD: header does not begin with magic word `FORM'");
                return (SOX_EOF);
        }

        lsx_readdw(ft, &trash32); /* totalsize */

        if (lsx_reads(ft, buf, (size_t)4) == SOX_EOF || strncmp(buf, "MAUD", (size_t)4) != 0)
        {
                lsx_fail_errno(ft,SOX_EHDR,"MAUD: `FORM' chunk does not specify `MAUD' as type");
                return(SOX_EOF);
        }

        /* read chunks until 'BODY' (or end) */

        while (lsx_reads(ft, buf, (size_t)4) == SOX_SUCCESS && strncmp(buf,"MDAT",(size_t)4) != 0) {

                /*
                buf[4] = 0;
                lsx_debug("chunk %s",buf);
                */

                if (strncmp(buf,"MHDR",(size_t)4) == 0) {

                        lsx_readdw(ft, &chunksize);
                        if (chunksize != 8*4)
                        {
                            lsx_fail_errno(ft,SOX_EHDR,"MAUD: MHDR chunk has bad size");
                            return(SOX_EOF);
                        }

                        /* number of samples stored in MDAT */
                        lsx_readdw(ft, &(p->nsamples));

                        /* number of bits per sample as stored in MDAT */
                        lsx_readw(ft, &bitpersam);

                        /* number of bits per sample after decompression */
                        lsx_readw(ft, &trash16);

                        lsx_readdw(ft, &nom);         /* clock source frequency */
                        lsx_readw(ft, &denom);       /* clock devide           */
                        if (denom == 0)
                        {
                            lsx_fail_errno(ft,SOX_EHDR,"MAUD: frequency denominator == 0, failed");
                            return (SOX_EOF);
                        }

                        ft->signal.rate = nom / denom;

                        lsx_readw(ft, &chaninf); /* channel information */
                        switch (chaninf) {
                        case 0:
                                ft->signal.channels = 1;
                                break;
                        case 1:
                                ft->signal.channels = 2;
                                break;
                        default:
                                lsx_fail_errno(ft,SOX_EFMT,"MAUD: unsupported number of channels in file");
                                return (SOX_EOF);
                        }

                        lsx_readw(ft, &chaninf); /* number of channels (mono: 1, stereo: 2, ...) */
                        if (chaninf != ft->signal.channels)
                        {
                                lsx_fail_errno(ft,SOX_EFMT,"MAUD: unsupported number of channels in file");
                            return(SOX_EOF);
                        }

                        lsx_readw(ft, &chaninf); /* compression type */

                        lsx_readdw(ft, &trash32); /* rest of chunk, unused yet */
                        lsx_readdw(ft, &trash32);
                        lsx_readdw(ft, &trash32);

                        if (bitpersam == 8 && chaninf == 0) {
                                ft->encoding.bits_per_sample = 8;
                                ft->encoding.encoding = SOX_ENCODING_UNSIGNED;
                        }
                        else if (bitpersam == 8 && chaninf == 2) {
                                ft->encoding.bits_per_sample = 8;
                                ft->encoding.encoding = SOX_ENCODING_ALAW;
                        }
                        else if (bitpersam == 8 && chaninf == 3) {
                                ft->encoding.bits_per_sample = 8;
                                ft->encoding.encoding = SOX_ENCODING_ULAW;
                        }
                        else if (bitpersam == 16 && chaninf == 0) {
                                ft->encoding.bits_per_sample = 16;
                                ft->encoding.encoding = SOX_ENCODING_SIGN2;
                        }
                        else
                        {
                                lsx_fail_errno(ft,SOX_EFMT,"MAUD: unsupported compression type detected");
                                return(SOX_EOF);
                        }

                        continue;
                }

                if (strncmp(buf,"ANNO",(size_t)4) == 0) {
                        lsx_readdw(ft, &chunksize);
                        if (chunksize & 1)
                                chunksize++;
                        chunk_buf = lsx_malloc(chunksize + (size_t)1);
                        if (lsx_readbuf(ft, chunk_buf, (size_t)chunksize)
                            != chunksize)
                        {
                                lsx_fail_errno(ft,SOX_EOF,"MAUD: Unexpected EOF in ANNO header");
                                return(SOX_EOF);
                        }
                        chunk_buf[chunksize] = '\0';
                        lsx_debug("%s",chunk_buf);
                        free(chunk_buf);

                        continue;
                }

                /* some other kind of chunk */
                lsx_readdw(ft, &chunksize);
                if (chunksize & 1)
                        chunksize++;
                lsx_seeki(ft, (off_t)chunksize, SEEK_CUR);
                continue;

        }

        if (strncmp(buf,"MDAT",(size_t)4) != 0)
        {
            lsx_fail_errno(ft,SOX_EFMT,"MAUD: MDAT chunk not found");
            return(SOX_EOF);
        }
        lsx_readdw(ft, &(p->nsamples));
        return(SOX_SUCCESS);
}

static int startwrite(sox_format_t * ft)
{
        priv_t * p = (priv_t *) ft->priv;
        int rc;

        /* Needed for rawwrite() */
        rc = lsx_rawstartwrite(ft);
        if (rc)
            return rc;

        /* If you have to seek around the output file */
        if (! ft->seekable)
        {
            lsx_fail_errno(ft,SOX_EOF,"Output .maud file must be a file, not a pipe");
            return (SOX_EOF);
        }
        p->nsamples = 0x7f000000;
        maudwriteheader(ft);
        p->nsamples = 0;
        return (SOX_SUCCESS);
}

static size_t write_samples(sox_format_t * ft, const sox_sample_t *buf, size_t len)
{
        priv_t * p = (priv_t *) ft->priv;

        p->nsamples += len;

        return lsx_rawwrite(ft, buf, len);
}

static int stopwrite(sox_format_t * ft)
{
        /* All samples are already written out. */

        priv_t *p = (priv_t*)ft->priv;
        uint32_t mdat_size; /* MDAT chunk size */
        mdat_size = p->nsamples * (ft->encoding.bits_per_sample >> 3);
        lsx_padbytes(ft, (size_t) (mdat_size%2));

        if (lsx_seeki(ft, (off_t)0, 0) != 0)
        {
            lsx_fail_errno(ft,errno,"can't rewind output file to rewrite MAUD header");
            return(SOX_EOF);
        }

        maudwriteheader(ft);
        return(SOX_SUCCESS);
}

#define MAUDHEADERSIZE (4+(4+4+32)+(4+4+19+1)+(4+4))
static void maudwriteheader(sox_format_t * ft)
{
        priv_t * p = (priv_t *) ft->priv;
        uint32_t mdat_size; /* MDAT chunk size */

        mdat_size = p->nsamples * (ft->encoding.bits_per_sample >> 3);

        lsx_writes(ft, "FORM");
        lsx_writedw(ft, MAUDHEADERSIZE + mdat_size + mdat_size%2);  /* size of file */
        lsx_writes(ft, "MAUD"); /* File type */

        lsx_writes(ft, "MHDR");
        lsx_writedw(ft,  8*4); /* number of bytes to follow */
        lsx_writedw(ft, p->nsamples);  /* number of samples stored in MDAT */

        switch (ft->encoding.encoding) {

        case SOX_ENCODING_UNSIGNED:
          lsx_writew(ft, 8); /* number of bits per sample as stored in MDAT */
          lsx_writew(ft, 8); /* number of bits per sample after decompression */
          break;

        case SOX_ENCODING_SIGN2:
          lsx_writew(ft, 16); /* number of bits per sample as stored in MDAT */
          lsx_writew(ft, 16); /* number of bits per sample after decompression */
          break;

        case SOX_ENCODING_ALAW:
        case SOX_ENCODING_ULAW:
          lsx_writew(ft, 8); /* number of bits per sample as stored in MDAT */
          lsx_writew(ft, 16); /* number of bits per sample after decompression */
          break;

        default:
          break;
        }

        lsx_writedw(ft, (unsigned)(ft->signal.rate + .5)); /* sample rate, Hz */
        lsx_writew(ft, (int) 1); /* clock devide */

        if (ft->signal.channels == 1) {
          lsx_writew(ft, 0); /* channel information */
          lsx_writew(ft, 1); /* number of channels (mono: 1, stereo: 2, ...) */
        }
        else {
          lsx_writew(ft, 1);
          lsx_writew(ft, 2);
        }

        switch (ft->encoding.encoding) {

        case SOX_ENCODING_UNSIGNED:
        case SOX_ENCODING_SIGN2:
          lsx_writew(ft, 0); /* no compression */
          break;

        case SOX_ENCODING_ULAW:
          lsx_writew(ft, 3);
          break;

        case SOX_ENCODING_ALAW:
          lsx_writew(ft, 2);
          break;

        default:
          break;
        }

        lsx_writedw(ft, 0); /* reserved */
        lsx_writedw(ft, 0); /* reserved */
        lsx_writedw(ft, 0); /* reserved */

        lsx_writes(ft, "ANNO");
        lsx_writedw(ft, 19); /* length of block */
        lsx_writes(ft, "file created by SoX");
        lsx_padbytes(ft, (size_t)1);

        lsx_writes(ft, "MDAT");
        lsx_writedw(ft, p->nsamples * (ft->encoding.bits_per_sample >> 3)); /* samples in file */
}

LSX_FORMAT_HANDLER(maud)
{
  static char const * const names[] = {"maud", NULL};
  static unsigned const write_encodings[] = {
    SOX_ENCODING_SIGN2, 16, 0,
    SOX_ENCODING_UNSIGNED, 8, 0,
    SOX_ENCODING_ULAW, 8, 0,
    SOX_ENCODING_ALAW, 8, 0,
    0};
  static sox_format_handler_t const handler = {SOX_LIB_VERSION_CODE,
    "Used with the ‘Toccata’ sound-card on the Amiga",
    names, SOX_FILE_BIG_END | SOX_FILE_MONO | SOX_FILE_STEREO,
    startread, lsx_rawread, lsx_rawstopread,
    startwrite, write_samples, stopwrite,
    NULL, write_encodings, NULL, sizeof(priv_t)
  };
  return &handler;
}