/*

 * 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;

        }

    }

}