/*

 * 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 "mapconn.h"

#include "ipcbase.h"

#include "ipcprotocol.h"

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

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

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

#include <stdlib.h>

typedef enum {

	AWAIT_CONNECTION,

	AWAIT_REPLY,

	AWAIT_CLOSE,

	FINISHED

} mapconn_state;

struct _flib_mapconn {

	uint8_t mapBuffer[IPCBASE_MAPMSG_BYTES];

	flib_ipcbase *ipcBase;

	flib_vector *configBuffer;

	mapconn_state progress;

	void (*onSuccessCb)(void*, const uint8_t*, int);

	void *onSuccessCtx;

	void (*onFailureCb)(void*, const char*);

	void *onFailureCtx;

	bool running;

	bool destroyRequested;

};

static void noop_handleSuccess(void *context, const uint8_t *bitmap, int numHedgehogs) {}

static void noop_handleFailure(void *context, const char *errormessage) {}

static void clearCallbacks(flib_mapconn *conn) {

	conn->onSuccessCb = &noop_handleSuccess;

	conn->onFailureCb = &noop_handleFailure;

}

static flib_vector *createConfigBuffer(const flib_map *mapdesc) {

	flib_vector *result = NULL;

	flib_vector *tempbuffer = flib_vector_create();

	if(tempbuffer) {

		bool error = false;

		error |= flib_ipc_append_mapconf(tempbuffer, mapdesc, true);

		error |= flib_ipc_append_message(tempbuffer, "!");

		if(!error) {

			result = tempbuffer;

			tempbuffer = NULL;

		}

	}

	flib_vector_destroy(tempbuffer);

	return result;

}

flib_mapconn *flib_mapconn_create(const flib_map *mapdesc) {

	if(log_badargs_if(mapdesc==NULL)) {

		return NULL;

	}

	flib_mapconn *result = NULL;

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

	if(tempConn) {

		tempConn->ipcBase = flib_ipcbase_create();

		tempConn->configBuffer = createConfigBuffer(mapdesc);

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

			tempConn->progress = AWAIT_CONNECTION;

			clearCallbacks(tempConn);

			result = tempConn;

			tempConn = NULL;

		}

	}

	flib_mapconn_destroy(tempConn);

	return result;

}

void flib_mapconn_destroy(flib_mapconn *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);

			free(conn);

		}

	}

}

int flib_mapconn_getport(flib_mapconn *conn) {

	if(log_badargs_if(conn==NULL)) {

		return 0;

	}

	return flib_ipcbase_port(conn->ipcBase);

}

void flib_mapconn_onSuccess(flib_mapconn *conn, void (*callback)(void* context, const uint8_t *bitmap, int numHedgehogs), void *context) {

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

		conn->onSuccessCb = callback ? callback : &noop_handleSuccess;

		conn->onSuccessCtx = context;

	}

}

void flib_mapconn_onFailure(flib_mapconn *conn, void (*callback)(void* context, const char *errormessage), void *context) {

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

		conn->onFailureCb = callback ? callback : &noop_handleFailure;

		conn->onFailureCtx = context;

	}

}

static void flib_mapconn_wrappedtick(flib_mapconn *conn) {

	if(conn->progress == 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->progress = FINISHED;

					conn->onFailureCb(conn->onFailureCtx, "Error sending map information to the engine.");

					return;

				} else {

					conn->progress = AWAIT_REPLY;

				}

			}

			break;

		case IPC_NOT_CONNECTED:

			conn->progress = FINISHED;

			conn->onFailureCb(conn->onFailureCtx, "Engine connection closed unexpectedly.");

			return;

		default:

			break;

		}

	}

	if(conn->progress == AWAIT_REPLY) {

		if(flib_ipcbase_recv_map(conn->ipcBase, conn->mapBuffer) >= 0) {

			conn->progress = AWAIT_CLOSE;

		} else if(flib_ipcbase_state(conn->ipcBase) != IPC_CONNECTED) {

			conn->progress = FINISHED;

			conn->onFailureCb(conn->onSuccessCtx, "Engine connection closed unexpectedly.");

			return;

		}

	}

	if(conn->progress == AWAIT_CLOSE) {

		// Just do throwaway reads so we find out when the engine disconnects

		uint8_t buf[256];

		flib_ipcbase_recv_message(conn->ipcBase, buf);

		if(flib_ipcbase_state(conn->ipcBase) != IPC_CONNECTED) {

			conn->progress = FINISHED;

			conn->onSuccessCb(conn->onSuccessCtx, conn->mapBuffer, conn->mapBuffer[IPCBASE_MAPMSG_BYTES-1]);

			return;

		}

	}

}

void flib_mapconn_tick(flib_mapconn *conn) {

	if(!log_badargs_if(conn==NULL)

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

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

		conn->running = true;

		flib_mapconn_wrappedtick(conn);

		conn->running = false;

		if(conn->destroyRequested) {

			flib_mapconn_destroy(conn);

		}

	}

}