#include "eburn_private.h"

static int audio_source_read(Burn_Source *src, unsigned char *buffer, int size);
static off_t audio_source_get_size(Burn_Source *src);
static void audio_source_free(Burn_Source *src);


Burn_Source *audio_source_new(const char *path)
{
        Burn_Source *src;
        Audio_Source *as;
        int ret;
        FILE *file;
        
        if (!path)
                return NULL;

        as = calloc(1, sizeof(Audio_Source));
        
        if (!as)
                return NULL;

        src = calloc(1, sizeof(Burn_Source));
        
        if (!src) {
                free(as);
                return NULL;
        }
        
        /*
         * setup the source structure
         */
        src->refcount = 1;
        src->read = audio_source_read;
        src->read_sub = NULL;
        src->get_size = audio_source_get_size;
        src->free_data = audio_source_free;
        src->data = as;

        /*
         * setup the audiofile
         */
        if (!file) {
                fprintf(stderr, "Error: could not open %s\n",
                        path);
                free(as);
                free(src);
                return NULL;
        }
        ret = ov_open(file, as->vf, NULL, 0);
        if (ret < 0) {
                fprintf(stderr, "Error %i: %s is not a ogg-file\n",
                        ret, path);
                
                fclose(file);
                free(as);
                free(src);
                return NULL;
        }

        return src;
}

static int audio_source_read(Burn_Source *src, unsigned char *buffer, int size)
{
        Audio_Source *as;
        int ret, sum = 0;

        as = src->data;
        /* take care that the actually read buffer isn't smaller */
        while (sum >= size) {
                ret = ov_read(as->vf, buffer + sum, size - sum,
                                0, 2, 1, &as->current_section);
                /*
                 * if it occured an error, return this immediately
                 */
                if (ret < 0) {
                        fprintf(stderr, "Error in audio_source_read %i\n",
                                ret);
                        return ret;
                }
                /*
                 * break the loop, if we reached the eof
                 */
                else if (ret == 0)
                        break;

                sum += ret;
        }
        
        return sum;
}

static off_t audio_source_get_size(Burn_Source *src)
{
        Audio_Source *as;

        as = src->data;

        if (!as) {
                fprintf(stderr, "in audio_source_get_size: \n\t"
                                "data == NULL, this should not happen\n");
                return -1;
        }
        
        return ov_pcm_total(as->vf, -1) * 4;
}

static void audio_source_free(Burn_Source *src)
{
        Audio_Source *as;

        as = src->data;
        if (!as)
                return;
        
        ov_clear(as->vf);
        free(as->vf);
        free(as);
}