/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2014 The libLTE Developers. See the
 * COPYRIGHT file at the top-level directory of this distribution.
 *
 * \section LICENSE
 *
 * This file is part of the libLTE library.
 *
 * libLTE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * libLTE is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * A copy of the GNU Lesser General Public License can be found in
 * the LICENSE file in the top-level directory of this distribution
 * and at http://www.gnu.org/licenses/.
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

#include "lte/io/filesource.h"

int filesource_init(filesource_t *q, char *filename, data_type_t type) {
	bzero(q, sizeof(filesource_t));
	q->f = fopen(filename, "r");
	if (!q->f) {
		perror("fopen");
		return -1;
	}
	q->type = type;
	return 0;
}

void filesource_free(filesource_t *q) {
	if (q->f) {
		fclose(q->f);
	}
	bzero(q, sizeof(filesource_t));
}

void filesource_seek(filesource_t *q, int pos) {
	fseek(q->f, pos, SEEK_SET);
}

int read_complex_f(FILE *f, _Complex float *y) {
	char in_str[64];
	_Complex float x;
	if (NULL == fgets(in_str, 64, f)) {
		return -1;
	} else {
		if (index(in_str, 'i') || index(in_str, 'j')) {
			sscanf(in_str,"%f%fi",&(__real__ x),&(__imag__ x));
		} else {
			__imag__ x = 0;
			sscanf(in_str,"%f",&(__real__ x));
		}
		*y = x;
		return 0;
	}
}

int filesource_read(filesource_t *q, void *buffer, int nsamples) {
	int i;
	float *fbuf = (float*) buffer;
	_Complex float *cbuf = (_Complex float*) buffer;
	_Complex short *sbuf = (_Complex short*) buffer;
	int size;

	switch(q->type) {
	case FLOAT:
		for (i=0;i<nsamples;i++) {
			if (EOF == fscanf(q->f,"%g\n",&fbuf[i]))
				break;
		}
		break;
	case COMPLEX_FLOAT:
		for (i=0;i<nsamples;i++) {
			if (read_complex_f(q->f, &cbuf[i])) {
				break;
			}
		}
		break;
	case COMPLEX_SHORT:
		for (i=0;i<nsamples;i++) {
			if (EOF == fscanf(q->f,"%hd%hdi\n",&(__real__ sbuf[i]),&(__imag__ sbuf[i])))
				break;
		}
		break;
	case FLOAT_BIN:
	case COMPLEX_FLOAT_BIN:
	case COMPLEX_SHORT_BIN:
		if (q->type == FLOAT_BIN) {
			size = sizeof(float);
		} else if (q->type == COMPLEX_FLOAT_BIN) {
			size = sizeof(_Complex float);
		} else if (q->type == COMPLEX_SHORT_BIN) {
			size = sizeof(_Complex short);
		}
		return fread(buffer, size, nsamples, q->f);
		break;
	default:
		i = -1;
		break;
	}
	return i;
}


int filesource_initialize(filesource_hl* h) {
	return filesource_init(&h->obj, h->init.file_name, h->init.data_type);
}

int filesource_work(filesource_hl* h) {
	h->out_len = filesource_read(&h->obj, h->output, h->ctrl_in.nsamples);
	if (h->out_len < 0) {
		return -1;
	}
	return 0;
}

int filesource_stop(filesource_hl* h) {
	filesource_free(&h->obj);
	return 0;
}