/*
 * TeamSpeak SDK server sample
 *
 * Copyright (c) TeamSpeak-Systems
 */

#ifdef _WINDOWS
#define _CRT_SECURE_NO_WARNINGS
#include <Windows.h>
#else
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#endif
#include <stdio.h>

#include <teamspeak/public_definitions.h>
#include <teamspeak/public_errors.h>
#include <teamspeak/serverlib_publicdefinitions.h>
#include <teamspeak/serverlib.h>

/*
 * Callback when client has connected.
 *
 * Parameter:
 *   serverID  - Virtual server ID
 *   clientID  - ID of connected client
 *   channelID - ID of channel the client joined
 */
void onClientConnected(uint64 serverID, anyID clientID, uint64 channelID, unsigned int* removeClientError) {
    printf("Client %u joined channel %llu on virtual server %llu\n", clientID, (unsigned long long)channelID, (unsigned long long)serverID);
}

/*
 * Callback when client has disconnected.
 *
 * Parameter:
 *   serverID  - Virtual server ID
 *   clientID  - ID of disconnected client
 *   channelID - ID of channel the client left
 */
void onClientDisconnected(uint64 serverID, anyID clientID, uint64 channelID) {
    printf("Client %u left channel %llu on virtual server %llu\n", clientID, (unsigned long long)channelID, (unsigned long long)serverID);
}

/*
 * Callback when client has moved.
 *
 * Parameter:
 *   serverID     - Virtual server ID
 *   clientID     - ID of moved client
 *   oldChannelID - ID of old channel the client left
 *   newChannelID - ID of new channel the client joined
 */
void onClientMoved(uint64 serverID, anyID clientID, uint64 oldChannelID, uint64 newChannelID) {
    printf("Client %u moved from channel %llu to channel %llu on virtual server %llu\n", clientID, (unsigned long long)oldChannelID, (unsigned long long)newChannelID, (unsigned long long)serverID);
}

/*
 * Callback when channel has been created.
 *
 * Parameter:
 *   serverID        - Virtual server ID
 *   invokerClientID - ID of the client who created the channel
 *   channelID       - ID of the created channel
 */
void onChannelCreated(uint64 serverID, anyID invokerClientID, uint64 channelID) {
    printf("Channel %llu created by %u on virtual server %llu\n", (unsigned long long)channelID, invokerClientID, (unsigned long long)serverID);
}

/*
 * Callback when channel has been edited.
 *
 * Parameter:
 *   serverID        - Virtual server ID
 *   invokerClientID - ID of the client who edited the channel
 *   channelID       - ID of the edited channel
 */
void onChannelEdited(uint64 serverID, anyID invokerClientID, uint64 channelID) {
    printf("Channel %llu edited by %u on virtual server %llu\n", (unsigned long long)channelID, invokerClientID, (unsigned long long)serverID);
}

/*
 * Callback when channel has been deleted.
 *
 * Parameter:
 *   serverID        - Virtual server ID
 *   invokerClientID - ID of the client who deleted the channel
 *   channelID       - ID of the deleted channel
 */
void onChannelDeleted(uint64 serverID, anyID invokerClientID, uint64 channelID) {
    printf("Channel %llu deleted by %u on virtual server %llu\n", (unsigned long long)channelID, invokerClientID, (unsigned long long)serverID);
}

/*
 * Callback for user-defined logging.
 *
 * Parameter:
 *   logMessage        - Log message text
 *   logLevel          - Severity of log message
 *   logChannel        - Custom text to categorize the message channel
 *   logID             - Virtual server ID giving the virtual server source of the log event
 *   logTime           - String with the date and time the log entry occured
 *   completeLogString - Verbose log message including all previous parameters for convinience
 */
void onUserLoggingMessageEvent(const char* logMessage, int logLevel, const char* logChannel, uint64 logID, const char* logTime, const char* completeLogString) {
    /* Your custom error display here... */
    /* printf("LOG: %s\n", completeLogString); */
    if(logLevel == LogLevel_CRITICAL) {
        exit(1);  /* Your custom handling of critical errors */
    }
}

/*
 * Callback triggered when the specified client starts talking.
 *
 * Parameters:
 *   serverID - ID of the virtual server sending the callback
 *   clientID - ID of the client which started talking
 */
void onClientStartTalkingEvent(uint64 serverID, anyID clientID) {
    printf("onClientStartTalkingEvent serverID=%llu, clientID=%u\n", (unsigned long long)serverID, clientID);
}

/*
 * Callback triggered when the specified client stops talking.
 *
 * Parameters:
 *   serverID - ID of the virtual server sending the callback
 *   clientID - ID of the client which stopped talking
 */
void onClientStopTalkingEvent(uint64 serverID, anyID clientID) {
    printf("onClientStopTalkingEvent serverID=%llu, clientID=%u\n", (unsigned long long)serverID, clientID);
}

/*
 * Callback triggered when a license error occurs.
 *
 * Parameters:
 *   serverID  - ID of the virtual server on which the license error occured. This virtual server will be automatically
 *               shutdown. If the parameter is zero, all virtual servers are affected and have been shutdown.
 *   errorCode - Code of the occured error. Use ts3server_getGlobalErrorMessage() to convert to a message string
 */
void onAccountingErrorEvent(uint64 serverID, unsigned int errorCode) {
    char* errorMessage;
    if(ts3server_getGlobalErrorMessage(errorCode, &errorMessage) == ERROR_ok) {
        printf("onAccountingErrorEvent serverID=%llu, errorCode=%u: %s\n", (unsigned long long)serverID, errorCode, errorMessage);
        ts3server_freeMemory(errorMessage);
    }

    /* Your custom handling here. In a real application, you wouldn't stop the whole process because the TS3 server part went down.
     * The whole idea of this callback is to let you gracefully handle the TS3 server failing to start and to continue your application. */
    exit(1);
}

/*
 * Read server key from file
 */
int readKeyPairFromFile(const char *fileName, char *keyPair) {
    FILE *file;

    file = fopen(fileName, "r");
    if(file == NULL) {
        printf("Could not open file '%s' for reading keypair\n", fileName);
        return -1;
    }

    fgets(keyPair, BUFSIZ, file);
    if(ferror(file) != 0) {
        fclose (file);
        printf("Error reading keypair from file '%s'.\n", fileName);
        return -1;
    }
    fclose (file);

    printf("Read keypair '%s' from file '%s'.\n", keyPair, fileName);
    return 0;
}

/*
 * Write server key to file
 */
int writeKeyPairToFile(const char *fileName, const char* keyPair) {
    FILE *file;

    file = fopen(fileName, "w");
    if(file == NULL) {
        printf("Could not open file '%s' for writing keypair\n", fileName);
        return -1;
    }

    fputs(keyPair, file);
    if(ferror(file) != 0) {
        fclose (file);
        printf("Error writing keypair to file '%s'.\n", fileName);
        return -1;
    }
    fclose (file);

    printf("Wrote keypair '%s' to file '%s'.\n", keyPair, fileName);
    return 0;
}

int main(int argc, char **argv) {
    char *version;
    uint64 serverID;
    unsigned int error;
    char buffer[BUFSIZ] = { 0 };
    char filename[BUFSIZ];
    char port_str[20];
    char *keyPair;

    /* Create struct for callback function pointers */
    struct ServerLibFunctions funcs;

    /* Initialize all callbacks with NULL */
    memset(&funcs, 0, sizeof(struct ServerLibFunctions));

    /* Now assign the used callback function pointers */
    funcs.onClientConnected         = onClientConnected;
    funcs.onClientDisconnected      = onClientDisconnected;
    funcs.onClientMoved              = onClientMoved;
    funcs.onChannelCreated          = onChannelCreated;
    funcs.onChannelEdited           = onChannelEdited;
    funcs.onChannelDeleted          = onChannelDeleted;
    funcs.onUserLoggingMessageEvent = onUserLoggingMessageEvent;
    funcs.onClientStartTalkingEvent = onClientStartTalkingEvent;
    funcs.onClientStopTalkingEvent  = onClientStopTalkingEvent;
    funcs.onAccountingErrorEvent    = onAccountingErrorEvent;

    /* Initialize server lib with callbacks */
    if((error = ts3server_initServerLib(&funcs, LogType_FILE | LogType_CONSOLE | LogType_USERLOGGING, NULL, argc, (const char* const *)argv)) != ERROR_ok) {
        char* errormsg;
        if(ts3server_getGlobalErrorMessage(error, &errormsg) == ERROR_ok) {
            printf("Error initialzing serverlib: %s\n", errormsg);
            ts3server_freeMemory(errormsg);
        }
        return 1;
    }

    /* Query and print server lib version */
    if((error = ts3server_getServerLibVersion(&version)) != ERROR_ok) {
        printf("Error querying server lib version: %d\n", error);
        return 1;
    }
    printf("Server lib version: %s\n", version);
    ts3server_freeMemory(version);  /* Release dynamically allocated memory */

    /* Attempt to load keypair from file */
    /* Assemble filename: keypair_<port>.txt */
    strcpy(filename, "keypair_");
    sprintf(port_str, "%d", 9987);  // Default port
    strcat(filename, port_str);
    strcat(filename, ".txt");

    /* Try reading keyPair from file */
    if(readKeyPairFromFile(filename, buffer) == 0) {
        keyPair = buffer;  /* Id read from file */
    } else {
        keyPair = "";  /* No Id saved, start virtual server with empty keyPair string */
    }

    /* Create virtual server using default port 9987 with max 10 slots */

    /* Create the virtual server with specified port, name, keyPair and max clients */
    printf("Create virtual server using keypair '%s'\n", keyPair);
    //listen on any address on ipv4 and ipv6 (it is also possible to enter multiple ipv4 and ipv6 addresses here)
    if((error = ts3server_createVirtualServer(9987, "0.0.0.0, ::", "TeamSpeak SDK Testserver", keyPair, 8, &serverID)) != ERROR_ok) {
        char* errormsg;
        if(ts3server_getGlobalErrorMessage(error, &errormsg) == ERROR_ok) {
            printf("Error creating virtual server: %s (%d)\n", errormsg, error);
            ts3server_freeMemory(errormsg);
        }
        return 1;
    }

    /* If we didn't load the keyPair before, query it from virtual server and save to file */
    if(!*buffer) {
        if((error = ts3server_getVirtualServerKeyPair(serverID, &keyPair)) != ERROR_ok) {
            char* errormsg;
            if(ts3server_getGlobalErrorMessage(error, &errormsg) == ERROR_ok) {
                printf("Error querying keyPair: %s\n\n", errormsg);
                ts3server_freeMemory(errormsg);
            }
            return 0;
        }

        /* Save keyPair to file "keypair_<port>.txt"*/
        if(writeKeyPairToFile(filename, keyPair) != 0) {
            ts3server_freeMemory(keyPair);
            return 0;
        }
        ts3server_freeMemory(keyPair);
    }

    /* Set welcome message */
    if((error = ts3server_setVirtualServerVariableAsString(serverID, VIRTUALSERVER_WELCOMEMESSAGE, "Hello TeamSpeak")) != ERROR_ok) {
        printf("Error setting server welcomemessage: %d\n", error);
        return 1;
    }

    /* Set server password */
    if((error = ts3server_setVirtualServerVariableAsString(serverID, VIRTUALSERVER_PASSWORD, "secret")) != ERROR_ok) {
        printf("Error setting server password: %d\n", error);
        return 1;
    }

    /* Flush above two changes to server */
    if((error = ts3server_flushVirtualServerVariable(serverID)) != ERROR_ok) {
        printf("Error flushing server variables: %d\n", error);
        return 1;
    }

    /* Set codec quality of channel(s) */
    uint64* channelList = NULL;
    if ((error = ts3server_getChannelList(serverID, &channelList)) != ERROR_ok) {
        printf("Couldn't get channel list: %d\n", error);
        return 1;
    }
    uint64* channelIDPtr = NULL;
    for (channelIDPtr = channelList; *channelIDPtr != (uint64)NULL; ++channelIDPtr) {
        if ((error = ts3server_setChannelVariableAsInt(serverID, *channelIDPtr, CHANNEL_CODEC_QUALITY, 10)) != ERROR_ok) {
            printf("Couldn't set channel codec quality: %d\n", error);
            ts3server_freeMemory(channelList);
            return 1;
        }
        if ((error = ts3server_flushChannelVariable(serverID, *channelIDPtr)) != ERROR_ok) {
            if (error != ERROR_ok_no_update) {
                printf("Error flushing channel variables: %d\n", error);
                ts3server_freeMemory(channelList);
                return 1;
            }
        }
    }
    ts3server_freeMemory(channelList);

    /* Wait for user input */
    printf("\n--- Press Return to shutdown server and exit ---\n");
    getchar();

    /* Stop virtual server */
    if((error = ts3server_stopVirtualServer(serverID)) != ERROR_ok) {
        printf("Error stopping virtual server: %d\n", error);
        return 1;
    }

    /* Shutdown server lib */
    if((error = ts3server_destroyServerLib()) != ERROR_ok) {
        printf("Error destroying server lib: %d\n", error);
        return 1;
    }

    return 0;
}