/*

 * 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 "gameconn.h"

#include "ipcbase.h"

#include "ipcprotocol.h"

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

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

#include "../hwconsts.h"

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

typedef enum {

	AWAIT_CONNECTION,

	CONNECTED,

	FINISHED

} gameconn_state;

struct _flib_gameconn {

	flib_ipcbase *ipcBase;

	flib_vector *configBuffer;

	flib_vector *demoBuffer;

	char *playerName;

	gameconn_state state;

	bool netgame;

	void (*onConnectCb)(void* context);

	void *onConnectCtx;

	void (*onDisconnectCb)(void* context, int reason);

	void *onDisconnectCtx;

	void (*onErrorMessageCb)(void* context, const char *msg);

	void *onErrorMessageCtx;

	void (*onChatCb)(void* context, const char *msg, bool teamchat);

	void *onChatCtx;

	void *onGameRecordedCtx;

	void (*onEngineMessageCb)(void *context, const uint8_t *em, size_t size);

	void *onEngineMessageCtx;

	bool running;

	bool destroyRequested;

};

static void defaultCallback_onErrorMessage(void* context, const char *msg) {

	flib_log_w("Error from engine (no callback set): %s", msg);

}

static void clearCallbacks(flib_gameconn *conn) {

}

static flib_gameconn *flib_gameconn_create_partial(bool record, const char *playerName, bool netGame) {

	flib_gameconn *result = NULL;

	flib_gameconn *tempConn = flib_calloc(1, sizeof(flib_gameconn));

	if(tempConn) {

		tempConn->ipcBase = flib_ipcbase_create();

		tempConn->configBuffer = flib_vector_create();

		tempConn->playerName = flib_strdupnull(playerName);

		if(tempConn->ipcBase && tempConn->configBuffer && tempConn->playerName) {

			if(record) {

				tempConn->demoBuffer = flib_vector_create();

			}

			tempConn->state = AWAIT_CONNECTION;

			tempConn->netgame = netGame;

			clearCallbacks(tempConn);

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_gameconn_destroy(tempConn);

	return result;

}

flib_gameconn *flib_gameconn_create(const char *playerName, const flib_gamesetup *setup, bool netgame) {

	if(log_badargs_if2(playerName==NULL, setup==NULL)) {

		return NULL;

	}

	flib_gameconn *result = NULL;

	flib_gameconn *tempConn = flib_gameconn_create_partial(true, playerName, netgame);

	if(tempConn) {

		if(flib_ipc_append_fullconfig(tempConn->configBuffer, setup, netgame)) {

			flib_log_e("Error generating full game configuration for the engine.");

		} else {

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_gameconn_destroy(tempConn);

	return result;

}

flib_gameconn *flib_gameconn_create_playdemo(const uint8_t *demo, size_t size) {

	if(log_badargs_if(demo==NULL && size>0)) {

		return NULL;

	}

	flib_gameconn *result = NULL;

	flib_gameconn *tempConn = flib_gameconn_create_partial(false, "Player", false);

	if(tempConn) {

		if(!flib_vector_append(tempConn->configBuffer, demo, size)) {

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_gameconn_destroy(tempConn);

	return result;

}

flib_gameconn *flib_gameconn_create_loadgame(const char *playerName, const uint8_t *save, size_t size) {

	if(log_badargs_if(save==NULL && size>0)) {

		return NULL;

	}

	flib_gameconn *result = NULL;

	flib_gameconn *tempConn = flib_gameconn_create_partial(true, playerName, false);

	if(tempConn) {

		if(!flib_vector_append(tempConn->configBuffer, save, size)) {

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_gameconn_destroy(tempConn);

	return result;

}

flib_gameconn *flib_gameconn_create_campaign(const char *playerName, const char *seed, const char *script) {

	if(log_badargs_if3(playerName==NULL, seed==NULL, script==NULL)) {

		return NULL;

	}

	flib_gameconn *result = NULL;

	flib_gameconn *tempConn = flib_gameconn_create_partial(true, playerName, false);

	if(tempConn) {

		if(!flib_ipc_append_message(tempConn->configBuffer, "TL")

				&& !flib_ipc_append_seed(tempConn->configBuffer, seed)

				&& !flib_ipc_append_script(tempConn->configBuffer, script)

				&& !flib_ipc_append_message(tempConn->configBuffer, "!")) {

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_gameconn_destroy(tempConn);

	return result;

}

void flib_gameconn_destroy(flib_gameconn *conn) {

	if(conn) {

		if(conn->running) {

			/*

			 * The function was called from a callback, so the tick function is still running

			 * and we delay the actual destruction. We ensure no further callbacks will be

			 * sent to prevent surprises.

			 */

			clearCallbacks(conn);

			conn->destroyRequested = true;

		} else {

			flib_ipcbase_destroy(conn->ipcBase);

			flib_vector_destroy(conn->configBuffer);

			flib_vector_destroy(conn->demoBuffer);

			free(conn->playerName);

			free(conn);

		}

	}

}

int flib_gameconn_getport(flib_gameconn *conn) {

	if(log_badargs_if(conn==NULL)) {

		return 0;

	}

	return flib_ipcbase_port(conn->ipcBase);

}

static void demo_append(flib_gameconn *conn, const void *data, size_t len) {

	if(conn->demoBuffer) {

		if(flib_vector_append(conn->demoBuffer, data, len)) {

			flib_log_e("Error recording demo: Out of memory.");

			flib_vector_destroy(conn->demoBuffer);

			conn->demoBuffer = NULL;

		}

	}

}

static int format_chatmessage(uint8_t buffer[257], const char *playerName, const char *message) {

	size_t msglen = strlen(message);

	// If the message starts with /me, it will be displayed differently.

	bool meMessage = msglen >= 4 && !memcmp(message, "/me ", 4);

	const char *template = meMessage ? "s\x02* %s %s  " : "s\x01%s: %s  ";

	int size = snprintf((char*)buffer+1, 256, template, playerName, meMessage ? message+4 : message);

	if(log_e_if(size<=0, "printf error")) {

		return -1;

	} else {

		buffer[0] = size>255 ? 255 : size;

		return 0;

	}

}

static void demo_append_chatmessage(flib_gameconn *conn, const char *message) {

	// Chat messages are reformatted to make them look as if they were received, not sent.

	uint8_t converted[257];

	if(!format_chatmessage(converted, conn->playerName, message)) {

		demo_append(conn, converted, converted[0]+1);

	}

}

static void demo_replace_gamemode(flib_buffer buf, char gamemode) {

	size_t msgStart = 0;

	uint8_t *data = (uint8_t*)buf.data;

	while(msgStart+2 < buf.size) {

		if(!memcmp(data+msgStart, "\x02T", 2)) {

			data[msgStart+2] = gamemode;

		}

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

	}

}

int flib_gameconn_send_enginemsg(flib_gameconn *conn, const uint8_t *data, size_t len) {

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

		return -1;

	}

	int result = flib_ipcbase_send_raw(conn->ipcBase, data, len);

	if(!result) {

		demo_append(conn, data, len);

	}

	return result;

}

int flib_gameconn_send_textmsg(flib_gameconn *conn, int msgtype, const char *msg) {

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

		return -1;

	}

	int result = -1;

	uint8_t converted[257];

	int size = snprintf((char*)converted+1, 256, "s%c%s", (char)msgtype, msg);

	if(size>0) {

		converted[0] = size>255 ? 255 : size;

		if(!flib_ipcbase_send_raw(conn->ipcBase, converted, converted[0]+1)) {

			demo_append(conn, converted, converted[0]+1);

			result = 0;

		}

	}

	return result;

}

int flib_gameconn_send_chatmsg(flib_gameconn *conn, const char *playername, const char *msg) {

	if(log_badargs_if3(conn==NULL, playername==NULL, msg==NULL)) {

		return -1;

	}

	uint8_t converted[257];

	if(!format_chatmessage(converted, playername, msg)

			&& !flib_ipcbase_send_raw(conn->ipcBase, converted, converted[0]+1)) {

		demo_append(conn, converted, converted[0]+1);

		return 0;

	}

	return -1;

}

/**

 * This macro generates a callback setter function. It uses the name of the callback to

 * automatically generate the function name and the fields to set, so a consistent naming

 * convention needs to be enforced (not that that is a bad thing). If null is passed as

 * callback to the generated function, the defaultCb will be set instead (with conn

 * as the context).

 */

#define GENERATE_CB_SETTER(cbName, cbParameterTypes, defaultCb) \

	void flib_gameconn_##cbName(flib_gameconn *conn, void (*callback)cbParameterTypes, void *context) { \

		if(!log_badargs_if(conn==NULL)) { \

			conn->cbName##Cb = callback ? callback : &defaultCb; \

			conn->cbName##Ctx = callback ? context : conn; \

		} \

	}

/**

 * Generate a callback setter function like GENERATE_CB_SETTER, and automatically generate a

 * no-op callback function as well that is used as default.

 */

#define GENERATE_CB_SETTER_AND_DEFAULT(cbName, cbParameterTypes) \

	static void _noop_callback_##cbName cbParameterTypes {} \

	GENERATE_CB_SETTER(cbName, cbParameterTypes, _noop_callback_##cbName)

GENERATE_CB_SETTER_AND_DEFAULT(onConnect, (void *context));

GENERATE_CB_SETTER_AND_DEFAULT(onDisconnect, (void* context, int reason));

GENERATE_CB_SETTER(onErrorMessage, (void* context, const char *msg), defaultCallback_onErrorMessage);

GENERATE_CB_SETTER_AND_DEFAULT(onChat, (void* context, const char *msg, bool teamchat));

GENERATE_CB_SETTER_AND_DEFAULT(onEngineMessage, (void *context, const uint8_t *em, size_t size));

#undef GENERATE_CB_SETTER_AND_DEFAULT

#undef GENERATE_CB_SETTER

static void flib_gameconn_wrappedtick(flib_gameconn *conn) {

	if(conn->state == AWAIT_CONNECTION) {

		flib_ipcbase_accept(conn->ipcBase);

		switch(flib_ipcbase_state(conn->ipcBase)) {

		case IPC_CONNECTED:

			{

				flib_constbuffer configBuffer = flib_vector_as_constbuffer(conn->configBuffer);

				if(flib_ipcbase_send_raw(conn->ipcBase, configBuffer.data, configBuffer.size)) {

					conn->state = FINISHED;

					conn->onDisconnectCb(conn->onDisconnectCtx, GAME_END_ERROR);

					return;

				} else {

					demo_append(conn, configBuffer.data, configBuffer.size);

					conn->state = CONNECTED;

					conn->onConnectCb(conn->onConnectCtx);

					if(conn->destroyRequested) {

						return;

					}

				}

			}

			break;

		case IPC_NOT_CONNECTED:

			conn->state = FINISHED;

			conn->onDisconnectCb(conn->onDisconnectCtx, GAME_END_ERROR);

			return;

		default:

			break;

		}

	}

	if(conn->state == CONNECTED) {

		uint8_t msgbuffer[257];

		int len;

		while(!conn->destroyRequested && (len = flib_ipcbase_recv_message(conn->ipcBase, msgbuffer))>=0) {

			if(len<2) {

				flib_log_w("Received short message from IPC (<2 bytes)");

				continue;

			}

			switch(msgbuffer[1]) {

			case '?':	// Ping

				// The pong is already part of the config message

				break;

			case 'C':	// Config query

				// And we already send the config message on connecting.

				break;

			case 'E':	// Error message

				if(len>=3) {

					msgbuffer[len-2] = 0;

					conn->onErrorMessageCb(conn->onErrorMessageCtx, (char*)msgbuffer+2);

				}

				break;

			case 'i':	// Statistics

				// TODO stats

				break;

			case 'Q':	// Game interrupted

			case 'H':	// Game halted

			case 'q':	// game finished

				{

					int reason = msgbuffer[1]=='Q' ? GAME_END_INTERRUPTED : msgbuffer[1]=='H' ? GAME_END_HALTED : GAME_END_FINISHED;

					bool savegame = (reason != GAME_END_FINISHED) && !conn->netgame;

					if(conn->demoBuffer) {

						flib_buffer demoBuffer = flib_vector_as_buffer(conn->demoBuffer);

						demo_replace_gamemode(demoBuffer, savegame ? 'S' : 'D');

						conn->onGameRecordedCb(conn->onGameRecordedCtx, demoBuffer.data, demoBuffer.size, savegame);

						if(conn->destroyRequested) {

							return;

						}

					}

					conn->state = FINISHED;

					conn->onDisconnectCb(conn->onDisconnectCtx, reason);

					return;

				}

			case 's':	// Chat message

				if(len>=3) {

					msgbuffer[len-2] = 0;

					demo_append_chatmessage(conn, (char*)msgbuffer+2);

					conn->onChatCb(conn->onChatCtx, (char*)msgbuffer+2, false);

				}

				break;

			case 'b':	// Teamchat message

				if(len>=3) {

					msgbuffer[len-2] = 0;

					conn->onChatCb(conn->onChatCtx, (char*)msgbuffer+2, true);

				}

				break;

			default:	// Engine message

				demo_append(conn, msgbuffer, len);

				conn->onEngineMessageCb(conn->onEngineMessageCtx, msgbuffer, len);

				break;

			}

		}

	}

	if(flib_ipcbase_state(conn->ipcBase) == IPC_NOT_CONNECTED) {

		conn->state = FINISHED;

		conn->onDisconnectCb(conn->onDisconnectCtx, GAME_END_ERROR);

	}

}

void flib_gameconn_tick(flib_gameconn *conn) {

	if(!log_badargs_if(conn == NULL)

			&& !log_w_if(conn->running, "Call to flib_gameconn_tick from a callback")

			&& !log_w_if(conn->state == FINISHED, "We are already done.")) {

		conn->running = true;

		flib_gameconn_wrappedtick(conn);

		conn->running = false;

		if(conn->destroyRequested) {

			flib_gameconn_destroy(conn);

		}

	}

}