/**
 *
 * \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 <string.h>
#include <strings.h>
#include <unistd.h>

#include "lte.h"

char *input_file_name = NULL;
char *matlab_file_name = NULL;
int cell_id = 150;
lte_cp_t cp = CPNORM;
int nof_prb = 50;
int nof_ports = 2;
int flen;
int nof_ctrl_symbols = 1;
phich_resources_t phich_res = R_1;
phich_length_t phich_length = PHICH_NORM;
int numsubframe = 0;

FILE *fmatlab = NULL;

filesource_t fsrc;
cf_t *input_buffer, *fft_buffer, *ce[MAX_PORTS_CTRL];
phich_t phich;
regs_t regs;
lte_fft_t fft;
chest_t chest;

void usage(char *prog) {
	printf("Usage: %s [vcoe] -i input_file\n", prog);
	printf("\t-o output matlab file name [Default Disabled]\n");
	printf("\t-c cell_id [Default %d]\n", cell_id);
	printf("\t-p nof_ports [Default %d]\n", nof_ports);
	printf("\t-n nof_prb [Default %d]\n", nof_prb);
	printf("\t-f nof control symbols [Default %d]\n", nof_ctrl_symbols);
	printf("\t-g phich ng factor: 1/6, 1/2, 1, 2 [Default 1]\n");
	printf("\t-e phich extended length [Default normal]\n");
	printf("\t-l extended cyclic prefix [Default normal]\n");
	printf("\t-v [set verbose to debug, default none]\n");
}

void parse_args(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "iovcenpfgl")) != -1) {
		switch(opt) {
		case 'i':
			input_file_name = argv[optind];
			break;
		case 'o':
			matlab_file_name = argv[optind];
			break;
		case 'c':
			cell_id = atoi(argv[optind]);
			break;
		case 'f':
			nof_ctrl_symbols = atoi(argv[optind]);
			break;
		case 'g':
			if (!strcmp(argv[optind], "1/6")) {
				phich_res = R_1_6;
			} else if (!strcmp(argv[optind], "1/2")) {
				phich_res = R_1_2;
			} else if (!strcmp(argv[optind], "1")) {
				phich_res = R_1;
			} else if (!strcmp(argv[optind], "2")) {
				phich_res = R_2;
			} else {
				fprintf(stderr, "Invalid phich ng factor %s. Setting to default.\n", argv[optind]);
			}
			break;
		case 'e':
			phich_length = PHICH_EXT;
			break;
		case 'n':
			nof_prb = atoi(argv[optind]);
			break;
		case 'p':
			nof_ports = atoi(argv[optind]);
			break;
		case 'v':
			verbose++;
			break;
		case 'l':
			cp = CPEXT;
			break;
		default:
			usage(argv[0]);
			exit(-1);
		}
	}
	if (!input_file_name) {
		usage(argv[0]);
		exit(-1);
	}
}

int base_init() {
	int i;

	if (filesource_init(&fsrc, input_file_name, COMPLEX_FLOAT_BIN)) {
		fprintf(stderr, "Error opening file %s\n", input_file_name);
		exit(-1);
	}

	if (matlab_file_name) {
		fmatlab = fopen(matlab_file_name, "w");
		if (!fmatlab) {
			perror("fopen");
			return -1;
		}
	} else {
		fmatlab = NULL;
	}

	flen = SLOT_LEN(lte_symbol_sz(nof_prb), cp);

	input_buffer = malloc(flen * sizeof(cf_t));
	if (!input_buffer) {
		perror("malloc");
		exit(-1);
	}

	fft_buffer = malloc(CP_NSYMB(cp) * nof_prb * RE_X_RB * sizeof(cf_t));
	if (!fft_buffer) {
		perror("malloc");
		return -1;
	}

	for (i=0;i<MAX_PORTS_CTRL;i++) {
		ce[i] = malloc(CP_NSYMB(cp) * nof_prb * RE_X_RB * sizeof(cf_t));
		if (!ce[i]) {
			perror("malloc");
			return -1;
		}
	}

	if (chest_init(&chest, LINEAR, cp, nof_prb, nof_ports)) {
		fprintf(stderr, "Error initializing equalizer\n");
		return -1;
	}

	if (chest_ref_LTEDL(&chest, cell_id)) {
		fprintf(stderr, "Error initializing reference signal\n");
		return -1;
	}

	if (lte_fft_init(&fft, cp, nof_prb)) {
		fprintf(stderr, "Error initializing FFT\n");
		return -1;
	}

	if (regs_init(&regs, cell_id, nof_prb, nof_ports, phich_res, phich_length, cp)) {
		fprintf(stderr, "Error initiating regs\n");
		return -1;
	}

	if (phich_init(&phich, &regs, cell_id, nof_prb, nof_ports, cp)) {
		fprintf(stderr, "Error creating PBCH object\n");
		return -1;
	}

	DEBUG("Memory init OK\n",0);
	return 0;
}

void base_free() {
	int i;

	filesource_free(&fsrc);
	if (fmatlab) {
		fclose(fmatlab);
	}

	free(input_buffer);
	free(fft_buffer);

	filesource_free(&fsrc);
	for (i=0;i<MAX_PORTS_CTRL;i++) {
		free(ce[i]);
	}
	chest_free(&chest);
	lte_fft_free(&fft);

	phich_free(&phich);
	regs_free(&regs);
}

int main(int argc, char **argv) {
	int distance;
	int i, n;
	int ngroup, nseq, max_nseq;
	char ack_rx;

	if (argc < 3) {
		usage(argv[0]);
		exit(-1);
	}

	parse_args(argc,argv);

	max_nseq = CP_ISNORM(cp)?PHICH_NORM_NSEQUENCES:PHICH_EXT_NSEQUENCES;

	if (base_init()) {
		fprintf(stderr, "Error initializing memory\n");
		exit(-1);
	}

	n = filesource_read(&fsrc, input_buffer, flen);

	lte_fft_run(&fft, input_buffer, fft_buffer);

	if (fmatlab) {
		fprintf(fmatlab, "infft=");
		vec_fprint_c(fmatlab, input_buffer, flen);
		fprintf(fmatlab, ";\n");

		fprintf(fmatlab, "outfft=");
		vec_fprint_c(fmatlab, fft_buffer, CP_NSYMB(cp) * nof_prb * RE_X_RB);
		fprintf(fmatlab, ";\n");
	}

	/* Get channel estimates for each port */
	for (i=0;i<nof_ports;i++) {
		chest_ce_slot_port(&chest, fft_buffer, ce[i], 0, i);
		if (fmatlab) {
			chest_fprint(&chest, fmatlab, 0, i);
		}
	}

	INFO("Decoding PHICH\n", 0);

	/* Receive all PHICH groups and sequence numbers */
	for (ngroup=0;ngroup<phich_ngroups(&phich);ngroup++) {
		for (nseq=0;nseq<max_nseq;nseq++) {

			if (phich_decode(&phich, fft_buffer, ce, ngroup, nseq, numsubframe, &ack_rx, &distance)<0) {
				printf("Error decoding ACK\n");
				exit(-1);
			}

			INFO("%d/%d, ack_rx: %d, ns: %d, distance: %d\n",
					ngroup, nseq, ack_rx, numsubframe, distance);
		}
	}

	base_free();
	fftwf_cleanup();

	if (n < 0) {
		fprintf(stderr, "Error decoding phich\n");
		exit(-1);
	} else if (n == 0) {
		printf("Could not decode phich\n");
		exit(-1);
	} else {
		exit(0);
	}
}