#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sysexits.h>
#include <fcntl.h>
#include <math.h>

#include <xas/audio.h>
#include <xas/mixer.h>
#include <xas/riff.h>
#include <xas/vox.h>

static void usage(int argc, char **argv, const char *message, ...) {
    va_list args;

    va_start(args, message);

    if (message) {
        vfprintf(stderr, message, args);
        fputc('\n', stderr);
    }

    va_end(args);

    fprintf(stderr, "usage: %s output.wav\n", argv[0]);

    exit(EX_USAGE);
}

int main(int argc, char **argv) {
    xas_mixer *mixer;

    xas_audio_stream *input,
                       *output;

    xas_vox *vox;

    size_t sample_rate = 44100,
           buffer_size =  4096,
           duration_s  =    60,
           i;

    if (argc != 2) {
        usage(argc, argv, "No output file provided");
    }

    if ((output = xas_riff_new_file(argv[1],
                                      XAS_AUDIO_STREAM_PCM_16_BIT,
                                      sample_rate,
                                      XAS_AUDIO_STREAM_STEREO,
                                      O_WRONLY | O_CREAT | O_TRUNC)) == NULL) {
        goto error_riff_new_file;
    }

    if ((vox = xas_vox_new("/usr/bin/text2wave",
                             XAS_AUDIO_STREAM_PCM_16_BIT,
                             sample_rate,
                             buffer_size,
                             NULL)) == NULL) {
        goto error_vox_new;
    }

    if ((input = xas_vox_stream_new(vox)) == NULL) {
        goto error_vox_stream_new;
    }

    if ((mixer = xas_mixer_new(XAS_AUDIO_STREAM_PCM_16_BIT,
                                 sample_rate,
                                 XAS_AUDIO_STREAM_STEREO,
                                 buffer_size)) == NULL) {
        goto error_mixer_new;
    }

    if (xas_mixer_input_add(mixer, input, 1.0, -1.0) == NULL) {
        goto error_mixer_input_add;
    }

    xas_vox_say(vox, "I want to eat your soul.  You don't understand.  I really want to eat your soul.\n");

    for (i=0; i<duration_s; i++) {
        void *buf;
        ssize_t readlen;

        if ((readlen = xas_audio_stream_read(mixer->output,
                                               &buf,
                                               buffer_size)) < 0) {
            goto error_audio_stream_read;
        }

        if (xas_audio_stream_write(output, buf, readlen) < 0) {
            goto error_audio_stream_write;
        }
    }

    xas_audio_stream_flush(output);

    xas_mixer_destroy(mixer);
    xas_audio_stream_destroy(input);
    xas_audio_stream_destroy(output);

    return EX_OK;

error_audio_stream_write:
error_audio_stream_read:
error_mixer_input_add:
    xas_mixer_destroy(mixer);

error_mixer_new:
    xas_audio_stream_destroy(input);

error_vox_stream_new:
    xas_vox_destroy(vox);

error_vox_new:
    xas_audio_stream_destroy(output);

error_riff_new_file:
    return EX_OSERR;
}