/*

 * 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 "ipcbase.h"

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

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

#include "../socket.h"

#include <string.h>

#include <stdbool.h>

#include <stdlib.h>

#include <stdio.h>

/*

 * The receive buffer has to be able to hold any message that might be received. Normally

 * the messages are at most 256 bytes, but the map preview contains 4097 bytes (4096 for a

 * bitmap, 1 for the number of hogs which fit on the map).

 *

 * We don't need to worry about wasting a few kb though, and I like powers of two...

 */

struct _flib_ipcbase {

	uint8_t readBuffer[8192];

	int readBufferSize;

	flib_acceptor *acceptor;

	uint16_t port;

	flib_tcpsocket *sock;

};

flib_ipcbase *flib_ipcbase_create() {

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

	flib_acceptor *acceptor = flib_acceptor_create(0);

	if(!result || !acceptor) {

		free(result);

		flib_acceptor_close(acceptor);

		return NULL;

	}

	result->acceptor = acceptor;

	result->sock = NULL;

	result->readBufferSize = 0;

	result->port = flib_acceptor_listenport(acceptor);

	flib_log_i("Started listening for IPC connections on port %u", (unsigned)result->port);

	return result;

}

uint16_t flib_ipcbase_port(flib_ipcbase *ipc) {

	if(log_badargs_if(ipc==NULL)) {

		return 0;

	}

	return ipc->port;

}

void flib_ipcbase_destroy(flib_ipcbase *ipc) {

	if(ipc) {

		flib_acceptor_close(ipc->acceptor);

		flib_socket_close(ipc->sock);

		if(ipc->sock) {

			flib_log_d("IPC connection closed.");

		}

		free(ipc);

	}

}

IpcState flib_ipcbase_state(flib_ipcbase *ipc) {

	if(log_badargs_if(ipc==NULL)) {

		return IPC_NOT_CONNECTED;

	} else if(ipc->sock) {

		return IPC_CONNECTED;

	} else if(ipc->acceptor) {

		return IPC_LISTENING;

	} else {

		return IPC_NOT_CONNECTED;

	}

}

static void receiveToBuffer(flib_ipcbase *ipc) {

	if(ipc->sock) {

		int size = flib_socket_nbrecv(ipc->sock, ipc->readBuffer+ipc->readBufferSize, sizeof(ipc->readBuffer)-ipc->readBufferSize);

		if(size>=0) {

			ipc->readBufferSize += size;

		} else {

			flib_log_d("IPC connection lost.");

			flib_socket_close(ipc->sock);

			ipc->sock = NULL;

		}

	}

}

static bool isMessageReady(flib_ipcbase *ipc) {

	return ipc->readBufferSize >= ipc->readBuffer[0]+1;

}

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

	if(flib_log_isActive(FLIB_LOGLEVEL_DEBUG)) {

		size_t msgStart = 0;

		while(msgStart < len) {

			uint8_t msglen = data[msgStart];

			if(msgStart+msglen < len) {

				flib_log_d("[IPC OUT][%03u]%*.*s",(unsigned)msglen, (unsigned)msglen, (unsigned)msglen, data+msgStart+1);

			} else {

				uint8_t msglen2 = len-msgStart-1;

				flib_log_d("[IPC OUT][%03u/%03u]%*.*s",(unsigned)msglen2, (unsigned)msglen, (unsigned)msglen2, (unsigned)msglen2, data+msgStart+1);

			}

			msgStart += (uint8_t)data[msgStart]+1;

		}

	}

}

static void logRecvMsg(const uint8_t *data) {

	if(flib_log_isActive(FLIB_LOGLEVEL_DEBUG)) {

		uint8_t msglen = data[0];

		flib_log_d("[IPC IN][%03u]%*.*s",(unsigned)msglen, (unsigned)msglen, (unsigned)msglen, data+1);

	}

}

static void popFromReadBuffer(flib_ipcbase *ipc, uint8_t *outbuf, size_t size) {

	memcpy(outbuf, ipc->readBuffer, size);

	memmove(ipc->readBuffer, ipc->readBuffer+size, ipc->readBufferSize-size);

	ipc->readBufferSize -= size;

}

int flib_ipcbase_recv_message(flib_ipcbase *ipc, void *data) {

	if(log_badargs_if2(ipc==NULL, data==NULL)) {

		return -1;

	}

	if(!isMessageReady(ipc)) {

		receiveToBuffer(ipc);

	}

	if(isMessageReady(ipc)) {

		int msgsize = ipc->readBuffer[0]+1;

		popFromReadBuffer(ipc, data, msgsize);

		logRecvMsg(data);

		return msgsize;

	} else if(!ipc->sock && ipc->readBufferSize>0) {

		flib_log_w("Last message from engine data stream is incomplete (received %u of %u bytes)", (unsigned)ipc->readBufferSize, (unsigned)(ipc->readBuffer[0])+1);

		ipc->readBufferSize = 0;

		return -1;

	} else {

		return -1;

	}

}

int flib_ipcbase_recv_map(flib_ipcbase *ipc, void *data) {

	if(log_badargs_if2(ipc==NULL, data==NULL)) {

		return -1;

	}

	receiveToBuffer(ipc);

	if(ipc->readBufferSize >= IPCBASE_MAPMSG_BYTES) {

		popFromReadBuffer(ipc, data, IPCBASE_MAPMSG_BYTES);

		return IPCBASE_MAPMSG_BYTES;

	} else {

		return -1;

	}

}

int flib_ipcbase_send_raw(flib_ipcbase *ipc, const void *data, size_t len) {

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

			|| log_w_if(!ipc->sock, "flib_ipcbase_send_raw: Not connected.")) {

		return -1;

	}

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

		logSentMsg(data, len);

		return 0;

	} else {

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

		flib_socket_close(ipc->sock);

		ipc->sock = NULL;

		return -1;

	}

}

int flib_ipcbase_send_message(flib_ipcbase *ipc, void *data, size_t len) {

	if(log_badargs_if3(ipc==NULL, data==NULL && len>0, len>255)) {

		return -1;

	}

	uint8_t sendbuf[256];

	sendbuf[0] = len;

	memcpy(sendbuf+1, data, len);

	return flib_ipcbase_send_raw(ipc, sendbuf, len+1);

}

void flib_ipcbase_accept(flib_ipcbase *ipc) {

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

		ipc->sock = flib_socket_accept(ipc->acceptor, true);

		if(ipc->sock) {

			flib_log_d("IPC connection accepted.");

			flib_acceptor_close(ipc->acceptor);

			ipc->acceptor = NULL;

		}

	}

}