/*
 * Copyright (c) 2009 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup netecho
 *  @{
 */

/** @file
 *  Network echo application.
 *  Answers received packets.
 */

#include <malloc.h>
#include <stdio.h>
#include <str.h>
#include <task.h>
#include <arg_parse.h>
#include <err.h>

#include <net/in.h>
#include <net/in6.h>
#include <net/inet.h>
#include <net/socket.h>
#include <net/socket_parse.h>

#include "print_error.h"

/** Network echo module name.
 */
#define NAME	"Network Echo"

/** Prints the application help.
 */
void echo_print_help(void);

/** Module entry point.
 *  Reads command line parameters and starts listenning.
 *  @param[in] argc The number of command line parameters.
 *  @param[in] argv The command line parameters.
 *  @returns EOK on success.
 */
int main(int argc, char * argv[]);

void echo_print_help(void){
	printf(
		"Network Echo aplication\n" \
		"Usage: echo [options]\n" \
		"Where options are:\n" \
		"-b backlog | --backlog=size\n" \
		"\tThe size of the accepted sockets queue. Only for SOCK_STREAM. The default is 3.\n" \
		"\n" \
		"-c count | --count=count\n" \
		"\tThe number of received messages to handle. A negative number means infinity. The default is infinity.\n" \
		"\n" \
		"-f protocol_family | --family=protocol_family\n" \
		"\tThe listenning socket protocol family. Only the PF_INET and PF_INET6 are supported.\n"
		"\n" \
		"-h | --help\n" \
		"\tShow this application help.\n"
		"\n" \
		"-p port_number | --port=port_number\n" \
		"\tThe port number the application should listen at. The default is 7.\n" \
		"\n" \
		"-r reply_string | --reply=reply_string\n" \
		"\tThe constant reply string. The default is the original data received.\n" \
		"\n" \
		"-s receive_size | --size=receive_size\n" \
		"\tThe maximum receive data size the application should accept. The default is 1024 bytes.\n" \
		"\n" \
		"-t socket_type | --type=socket_type\n" \
		"\tThe listenning socket type. Only the SOCK_DGRAM and the SOCK_STREAM are supported.\n" \
		"\n" \
		"-v | --verbose\n" \
		"\tShow all output messages.\n"
	);
}

int main(int argc, char * argv[]){
	ERROR_DECLARE;

	size_t size			= 1024;
	int verbose			= 0;
	char * reply		= NULL;
	sock_type_t type	= SOCK_DGRAM;
	int count			= -1;
	int family			= PF_INET;
	uint16_t port		= 7;
	int backlog			= 3;

	socklen_t max_length				= sizeof(struct sockaddr_in6);
	uint8_t address_data[max_length];
	struct sockaddr * address			= (struct sockaddr *) address_data;
	struct sockaddr_in * address_in		= (struct sockaddr_in *) address;
	struct sockaddr_in6 * address_in6	= (struct sockaddr_in6 *) address;
	socklen_t addrlen;
	char address_string[INET6_ADDRSTRLEN];
	uint8_t * address_start;
	int socket_id;
	int listening_id;
	char * data;
	size_t length;
	int index;
	size_t reply_length;
	int value;

	// parse the command line arguments
	for(index = 1; index < argc; ++ index){
		if(argv[index][0] == '-'){
			switch(argv[index][1]){
				case 'b':
					ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &backlog, 0));
					break;
				case 'c':
					ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &count, 0));
					break;
				case 'f':
					ERROR_PROPAGATE(arg_parse_name_int(argc, argv, &index, &family, 0, socket_parse_protocol_family));
					break;
				case 'h':
					echo_print_help();
					return EOK;
					break;
				case 'p':
					ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &value, 0));
					port = (uint16_t) value;
					break;
				case 'r':
					ERROR_PROPAGATE(arg_parse_string(argc, argv, &index, &reply, 0));
					break;
				case 's':
					ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &value, 0));
					size = (value >= 0) ? (size_t) value : 0;
					break;
				case 't':
					ERROR_PROPAGATE(arg_parse_name_int(argc, argv, &index, &value, 0, socket_parse_socket_type));
					type = (sock_type_t) value;
					break;
				case 'v':
					verbose = 1;
					break;
				// long options with the double minus sign ('-')
				case '-':
					if(str_lcmp(argv[index] + 2, "backlog=", 6) == 0){
						ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &backlog, 8));
					}else if(str_lcmp(argv[index] + 2, "count=", 6) == 0){
						ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &count, 8));
					}else if(str_lcmp(argv[index] + 2, "family=", 7) == 0){
						ERROR_PROPAGATE(arg_parse_name_int(argc, argv, &index, &family, 9, socket_parse_protocol_family));
					}else if(str_lcmp(argv[index] + 2, "help", 5) == 0){
						echo_print_help();
						return EOK;
					}else if(str_lcmp(argv[index] + 2, "port=", 5) == 0){
						ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &value, 7));
						port = (uint16_t) value;
					}else if(str_lcmp(argv[index] + 2, "reply=", 6) == 0){
						ERROR_PROPAGATE(arg_parse_string(argc, argv, &index, &reply, 8));
					}else if(str_lcmp(argv[index] + 2, "size=", 5) == 0){
						ERROR_PROPAGATE(arg_parse_int(argc, argv, &index, &value, 7));
						size = (value >= 0) ? (size_t) value : 0;
					}else if(str_lcmp(argv[index] + 2, "type=", 5) == 0){
						ERROR_PROPAGATE(arg_parse_name_int(argc, argv, &index, &value, 7, socket_parse_socket_type));
						type = (sock_type_t) value;
					}else if(str_lcmp(argv[index] + 2, "verbose", 8) == 0){
						verbose = 1;
					}else{
						echo_print_help();
						return EINVAL;
					}
					break;
				default:
					echo_print_help();
					return EINVAL;
			}
		}else{
			echo_print_help();
			return EINVAL;
		}
	}

	// check the buffer size
	if(size <= 0){
		fprintf(stderr, "Receive size too small (%d). Using 1024 bytes instead.\n", size);
		size = 1024;
	}
	// size plus the terminating null (\0)
	data = (char *) malloc(size + 1);
	if(! data){
		fprintf(stderr, "Failed to allocate receive buffer.\n");
		return ENOMEM;
	}

	// set the reply size if set
	reply_length = reply ? str_length(reply) : 0;

	// prepare the address buffer
	bzero(address_data, max_length);
	switch(family){
		case PF_INET:
			address_in->sin_family = AF_INET;
			address_in->sin_port = htons(port);
			addrlen = sizeof(struct sockaddr_in);
			break;
		case PF_INET6:
			address_in6->sin6_family = AF_INET6;
			address_in6->sin6_port = htons(port);
			addrlen = sizeof(struct sockaddr_in6);
			break;
		default:
			fprintf(stderr, "Protocol family is not supported\n");
			return EAFNOSUPPORT;
	}

	// get a listening socket
	listening_id = socket(family, type, 0);
	if(listening_id < 0){
		socket_print_error(stderr, listening_id, "Socket create: ", "\n");
		return listening_id;
	}

	// if the stream socket is used
	if(type == SOCK_STREAM){
		// check the backlog
		if(backlog <= 0){
			fprintf(stderr, "Accepted sockets queue size too small (%d). Using 3 instead.\n", size);
			backlog = 3;
		}
		// set the backlog
		if(ERROR_OCCURRED(listen(listening_id, backlog))){
			socket_print_error(stderr, ERROR_CODE, "Socket listen: ", "\n");
			return ERROR_CODE;
		}
	}

	// bind the listenning socket
	if(ERROR_OCCURRED(bind(listening_id, address, addrlen))){
		socket_print_error(stderr, ERROR_CODE, "Socket bind: ", "\n");
		return ERROR_CODE;
	}

	if(verbose){
		printf("Socket %d listenning at %d\n", listening_id, port);
	}

	socket_id = listening_id;

	// do count times
	// or indefinitely if set to a negative value
	while(count){

		addrlen = max_length;
		if(type == SOCK_STREAM){
			// acceept a socket if the stream socket is used
			socket_id = accept(listening_id, address, &addrlen);
			if(socket_id <= 0){
				socket_print_error(stderr, socket_id, "Socket accept: ", "\n");
			}else{
				if(verbose){
					printf("Socket %d accepted\n", socket_id);
				}
			}
		}

		// if the datagram socket is used or the stream socked was accepted
		if(socket_id > 0){

			// receive an echo request
			value = recvfrom(socket_id, data, size, 0, address, &addrlen);
			if(value < 0){
				socket_print_error(stderr, value, "Socket receive: ", "\n");
			}else{
				length = (size_t) value;
				if(verbose){
					// print the header

					// get the source port and prepare the address buffer
					address_start = NULL;
					switch(address->sa_family){
						case AF_INET:
							port = ntohs(address_in->sin_port);
							address_start = (uint8_t *) &address_in->sin_addr.s_addr;
							break;
						case AF_INET6:
							port = ntohs(address_in6->sin6_port);
							address_start = (uint8_t *) &address_in6->sin6_addr.s6_addr;
							break;
						default:
							fprintf(stderr, "Address family %d (0x%X) is not supported.\n", address->sa_family);
					}
					// parse the source address
					if(address_start){
						if(ERROR_OCCURRED(inet_ntop(address->sa_family, address_start, address_string, sizeof(address_string)))){
							fprintf(stderr, "Received address error %d\n", ERROR_CODE);
						}else{
							data[length] = '\0';
							printf("Socket %d received %d bytes from %s:%d\n%s\n", socket_id, length, address_string, port, data);
						}
					}
				}

				// answer the request either with the static reply or the original data
				if(ERROR_OCCURRED(sendto(socket_id, reply ? reply : data, reply ? reply_length : length, 0, address, addrlen))){
					socket_print_error(stderr, ERROR_CODE, "Socket send: ", "\n");
				}

			}

			// close the accepted stream socket
			if(type == SOCK_STREAM){
				if(ERROR_OCCURRED(closesocket(socket_id))){
					socket_print_error(stderr, ERROR_CODE, "Close socket: ", "\n");
				}
			}

		}

		// decrease the count if positive
		if(count > 0){
			-- count;
			if(verbose){
				printf("Waiting for next %d packet(s)\n", count);
			}
		}
	}

	if(verbose){
		printf("Closing the socket\n");
	}

	// close the listenning socket
	if(ERROR_OCCURRED(closesocket(listening_id))){
		socket_print_error(stderr, ERROR_CODE, "Close socket: ", "\n");
		return ERROR_CODE;
	}

	if(verbose){
		printf("Exiting\n");
	}

	return EOK;
}

/** @}
 */