/*

 * Hedgewars, a free turn based strategy game

 * Copyright (C) 2012 Simeon Maxein <smaxein@googlemail.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 */

#include "netbase.h"

#include "../util/buffer.h"

#include "../util/logging.h"

#include "../util/util.h"

#include "../socket.h"

#include <string.h>

#include <stdbool.h>

#include <stdlib.h>

#include <stdio.h>

#define NET_READBUFFER_LIMIT (1024*1024)

struct _flib_netbase {

	flib_vector *readBuffer;

	flib_tcpsocket *sock;

};

flib_netbase *flib_netbase_create(const char *server, uint16_t port) {

	if(log_badargs_if2(server==NULL, port==0)) {

		return NULL;

	}

	flib_netbase *result = NULL;

	flib_netbase *newNet =  flib_calloc(1, sizeof(flib_netbase));

	if(newNet) {

		newNet->readBuffer = flib_vector_create();

		newNet->sock = flib_socket_connect(server, port);

		if(newNet->readBuffer && newNet->sock) {

			flib_log_i("Connected to server %s:%u", server, (unsigned)port);

			result = newNet;

			newNet = NULL;

		}

	}

	flib_netbase_destroy(newNet);

	return result;

}

void flib_netbase_destroy(flib_netbase *net) {

	if(net) {

		flib_socket_close(net->sock);

		flib_vector_destroy(net->readBuffer);

		free(net);

	}

}

bool flib_netbase_connected(flib_netbase *net) {

	if(!log_badargs_if(net==NULL) && net->sock) {

		return true;

	}

	return false;

}

/**

 * Parses and returns a message, and removes it from the vector.

 */

static flib_netmsg *parseMessage(flib_vector *vec) {

	const uint8_t *partStart = flib_vector_data(vec);

	const uint8_t *end = partStart+flib_vector_size(vec);

	flib_netmsg *result = flib_netmsg_create();

	if(!result) {

		return NULL;

	}

	while(1) {

		const uint8_t *partEnd = memchr(partStart, '\n', end-partStart);

		if(!partEnd) {

			// message incomplete

			flib_netmsg_destroy(result);

			return NULL;

		} else if(partEnd-partStart == 0) {

			// Zero-length part, message end marker. Remove the message from the vector.

			uint8_t *vectorStart = flib_vector_data(vec);

			size_t msgLen = partEnd+1-vectorStart;

			memmove(vectorStart, partEnd+1, flib_vector_size(vec)-msgLen);

			flib_vector_resize(vec, flib_vector_size(vec)-msgLen);

			return result;

		} else {

			if(flib_netmsg_append_part(result, partStart, partEnd-partStart)) {

				flib_netmsg_destroy(result);

				return NULL;

			}

			partStart = partEnd+1; // Skip the '\n'

		}

	}

	return NULL; // Never reached

}

/**

 * Receive some bytes and add them to the buffer.

 * Returns the number of bytes received.

 * Automatically closes the socket if an error occurs

 * and sets sock=NULL.

 */

static int receiveToBuffer(flib_netbase *net) {

	uint8_t buffer[256];

	if(!net->sock) {

		return 0;

	} else if(flib_vector_size(net->readBuffer) > NET_READBUFFER_LIMIT) {

		flib_log_e("Net connection closed: Net message too big");

		flib_socket_close(net->sock);

		net->sock = NULL;

		return 0;

	} else {

		int size = flib_socket_nbrecv(net->sock, buffer, sizeof(buffer));

		if(size>=0 && !flib_vector_append(net->readBuffer, buffer, size)) {

			return size;

		} else {

			flib_socket_close(net->sock);

			net->sock = NULL;

			return 0;

		}

	}

}

flib_netmsg *flib_netbase_recv_message(flib_netbase *net) {

	if(log_badargs_if(net==NULL)) {

		return NULL;

	}

	flib_netmsg *msg;

	while(!(msg=parseMessage(net->readBuffer))

			&& receiveToBuffer(net)) {}

	if(msg) {

		return msg;

	} else if(!net->sock && flib_vector_size(net->readBuffer)>0) {

		// Connection is down and we didn't get a complete message, just flush the rest.

		flib_vector_resize(net->readBuffer, 0);

	}

	return NULL;

}

static void logSentMsg(const uint8_t *data, size_t len) {

	if(flib_log_isActive(FLIB_LOGLEVEL_DEBUG)) {

		flib_log_d("[NET OUT][%03u]%*.*s",(unsigned)len, (unsigned)len, (unsigned)len, data);

	}

}

int flib_netbase_send_raw(flib_netbase *net, const void *data, size_t len) {

	if(log_badargs_if2(net==NULL, data==NULL && len>0)) {

		return -1;

	}

	if(!net->sock) {

		flib_log_w("flib_netbase_send_raw: Not connected.");

		return -1;

	}

	if(flib_socket_send(net->sock, data, len) == len) {

		logSentMsg(data, len);

		return 0;

	} else {

		flib_log_w("Failed or incomplete write: net connection lost.");

		flib_socket_close(net->sock);

		net->sock = NULL;

		return -1;

	}

}

int flib_netbase_send_message(flib_netbase *net, const flib_netmsg *msg) {

	if(log_badargs_if2(net==NULL, msg==NULL)) {

		return -1;

	}

	size_t totalSize = 0;

	for(int i=0; i<msg->partCount; i++) {

		totalSize += strlen(msg->parts[i]) + 1;

	}

	totalSize++; // Last part ends in two '\n' instead of one

	uint8_t *buffer = flib_malloc(totalSize);

	if(!buffer) {

		return -1;

	}

	size_t pos = 0;

	for(int i=0; i<msg->partCount; i++) {

		size_t partsize = strlen(msg->parts[i]);

		memcpy(buffer+pos, msg->parts[i], partsize);

		pos += partsize;

		buffer[pos++] = '\n';

	}

	buffer[pos++] = '\n';

	return flib_netbase_send_raw(net, buffer, pos);

}

int flib_netbase_sendf(flib_netbase *net, const char *format, ...) {

	int result = -1;

	if(!log_badargs_if2(net==NULL, format==NULL)) {

		va_list argp;

		va_start(argp, format);

		char *buffer = flib_vasprintf(format, argp);

		if(buffer) {

			result = flib_netbase_send_raw(net, buffer, strlen(buffer));

		}

		free(buffer);

		va_end(argp);

	}

	return result;

}

flib_netmsg *flib_netmsg_create() {

	flib_netmsg *result = flib_calloc(1, sizeof(flib_netmsg));

	if(result) {

		result->partCount = 0;

		result->parts = NULL;

		return result;

	} else {

		return NULL;

	}

}

void flib_netmsg_destroy(flib_netmsg *msg) {

	if(msg) {

		for(int i=0; i<msg->partCount; i++) {

			free(msg->parts[i]);

		}

		free(msg->parts);

		free(msg);

	}

}

int flib_netmsg_append_part(flib_netmsg *msg, const void *part, size_t partlen) {

	int result = -1;

	if(!log_badargs_if2(msg==NULL, part==NULL && partlen>0)) {

		char **newParts = realloc(msg->parts, (msg->partCount+1)*sizeof(*msg->parts));

		if(newParts) {

			msg->parts = newParts;

			msg->parts[msg->partCount] = flib_malloc(partlen+1);

			if(msg->parts[msg->partCount]) {

				memcpy(msg->parts[msg->partCount], part, partlen);

				msg->parts[msg->partCount][partlen] = 0;

				msg->partCount++;

				result = 0;

			}

		}

	}

	return result;

}