/*

 * 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;

    int disconnectReason;

    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 (*onGameRecordedCb)(void *context, const uint8_t *record, size_t size, bool isSavegame);

    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) {

    flib_gameconn_onConnect(conn, NULL, NULL);

    flib_gameconn_onDisconnect(conn, NULL, NULL);

    flib_gameconn_onErrorMessage(conn, NULL, NULL);

    flib_gameconn_onChat(conn, NULL, NULL);

    flib_gameconn_onGameRecorded(conn, NULL, NULL);

    flib_gameconn_onEngineMessage(conn, NULL, NULL);

}

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;

            tempConn->disconnectReason = GAME_END_ERROR;

            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 *demoFileContent, size_t size) {

    if(log_badargs_if(demoFileContent==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, demoFileContent, size)) {

            result = tempConn;

            tempConn = NULL;

        }

    }

    flib_gameconn_destroy(tempConn);

    return result;

}

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

    if(log_badargs_if(saveFileContent==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, saveFileContent, 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;

}

int flib_gameconn_send_quit(flib_gameconn *conn) {

    return flib_gameconn_send_cmd(conn, "efinish");

}

int flib_gameconn_send_cmd(flib_gameconn *conn, const char *cmdString) {

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

        return -1;

    }

    int result = -1;

    uint8_t converted[256];

    size_t msglen = strlen(cmdString);

    if(!log_e_if(msglen>255, "Message too long: %s", cmdString)) {

        strcpy((char*)converted+1, cmdString);

        converted[0] = msglen;

        if(!flib_ipcbase_send_raw(conn->ipcBase, converted, msglen+1)) {

            demo_append(conn, converted, msglen+1);

            result = 0;

        }

    }

    return result;

}

/**

 * 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(onGameRecorded, (void *context, const uint8_t *record, size_t size, bool isSavegame));

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;

                    conn->disconnectReason = reason;

                    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;

                        }

                    }

                    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, conn->disconnectReason);

    }

}

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);

        }

    }

}