#include <stdio.h>
#include <time.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <toml.h>

#include "settings.h"
#include "ansicolor.h"
#include "connlist.h"
#include "utils.h"
#include "help.h"
#include "dbutil.h"
#include "chat.h"

// config values
unsigned short configPort;
unsigned int configConnlimit;
char *configCertfile, *configKeyfile, *configPassword, sslInUse;

// return value: 0 = succeeded ; 1 = failed
uint8_t initConfigFromFile(const char* configPath) {
    FILE* configFile = fopen(configPath, "r");
    if (configFile == NULL) {logMessage(error, "Config file does not exist."); return 1;}
    char errbuf[256];
    toml_table_t* conf = toml_parse_file(configFile, errbuf, sizeof(errbuf));
    fclose(configFile);
    if (!conf) {logMessage(error, "Config parsing error: %s", errbuf); return 1;}

    toml_table_t* server = toml_table_in(conf, "listen");
    if (!server) {logMessage(error, "Config parsing error: missing [listen]"); return 1;}

    toml_datum_t confPort = toml_int_in(server, "port");
    if (!confPort.ok) {logMessage(error, "Config parsing error: missing 'port' field"); return 1;}
    if (confPort.u.b > USHRT_MAX) {logMessage(error, "Config parsing error: port out of range"); return 1;}
    configPort = confPort.u.b;

    toml_table_t* ssl = toml_table_in(conf, "ssl");
    if (ssl) {
      toml_datum_t confCertfile = toml_string_in(ssl, "certfile");
      if (!confCertfile.ok) {logMessage(error, "Config parsing error: missing 'certfile' field"); return 1;}
      configCertfile = confCertfile.u.s;

      toml_datum_t confKeyfile = toml_string_in(ssl, "keyfile");
      if (!confKeyfile.ok) {logMessage(error, "Config parsing error: missing 'keyfile' field"); return 1;}
      configKeyfile = confKeyfile.u.s;

      toml_datum_t confPassword = toml_string_in(ssl, "password");
      if (!confPassword.ok) {logMessage(error, "Config parsing error: missing 'password' field"); return 1;}
      configPassword = confPassword.u.s;
    }

    toml_table_t* bbs = toml_table_in(conf, "bbs");
    if (!bbs) {logMessage(error, "Config parsing error: missing [bbs]"); return 1;}

    toml_array_t* confChannels = toml_array_in(bbs, "channelList");
    if (!confChannels) {logMessage(error, "Config parsing error: missing 'channelList' field"); return 1;}
    unsigned int channelCount = toml_array_nelem(confChannels);

    if (channelCount == 0) {logMessage(error, "Config parsing error: empty 'channelList' field"); return 1;}
    toml_datum_t confConnlimit = toml_int_in(bbs, "connlimit");
    if (!confConnlimit.ok) {logMessage(error, "Config parsing error: missing 'connlimit' field"); return 1;}
    configConnlimit = confConnlimit.u.b;
    initChat(channelCount);

    for (int i = 0; i < channelCount; ++i) {
        toml_datum_t channelName = toml_string_at(confChannels, i);
        if (!channelName.ok) {logMessage(error, "Config parsing error: invalid 'channelList' field"); return 1;}
        char* channelNameStr = channelName.u.s;
        trimWhitespace(channelNameStr);
        unsigned int newLength = sanitizeString(channelNameStr, strlen(channelNameStr));
        if (newLength == 0) {
            logMessage(error, "Config parsing error: 'channelList' field contains an empty entry");
            return 1;
        }
        if (newLength >= CHANNEL_NAME_LEN) {
            logMessage(error, "Config parsing error: 'channelList' field contains an entry that is longer than "STR(CHANNEL_NAME_LEN)" characters.");
            return 1;
        }
        setChannelName(i, channelNameStr);
        free(channelNameStr);
    }
    toml_free(conf);
    return 0;
}

int askCredentials(struct LemonClientSocket *socket, char* username, char* password, int bufLength) {
    while (1) {
        lolib_writeSocket(socket, METASTRING(ANSI_YELLOW"\n Username: "ANSI_RESET));
        int read = lolib_readSocket(socket, username, bufLength-1);
        if (read < 1) return -1; // IO error
        if (username[0] == 'q') return 0; // cancelled
        username[read] = 0; // null-terminator
        trimWhitespace(username);
        if (sanitizeString(username, read) == 0) {
            lolib_writeSocket(socket, METASTRING(ANSI_RED"\n Error: Username empty."));
            continue;
        }
        lolib_writeSocket(socket, METASTRING(ANSI_YELLOW" Password: "ANSI_RESET));
        read = lolib_readSocket(socket, password, bufLength-1);
        if (read < 1) return -1; // IO error
        password[read] = 0; // null-terminator
        trimWhitespace(password);
        if (sanitizeString(password, read) == 0) {
            lolib_writeSocket(socket, METASTRING(ANSI_RED"\n Error: Password empty."));
            continue;
        }
        return 1;
    }
}

int channelSelector(struct LemonClientSocket *socket) {
    lolib_writeSocket(socket, METASTRING(ANSI_RED"\n +--------+\n |  "ANSI_GREEN"Chat"ANSI_RED"  |\n +--------+\n"ANSI_YELLOW" WARNING: Chat feature is EXPERIMENTAL and may not work correctly.\n\n"));
    for (size_t i = 0; i < getChannelCount(); ++i) {
        char line[128];
        int toWrite = snprintf(line, 128, ANSI_RED"  %lu. "ANSI_GREEN"#%s "ANSI_CYAN"[%d/%d online]\n", i + 1, getChannelName(i), countUsers(i), USERS_PER_CHANNEL);
        lolib_writeSocket(socket, line, toWrite);
    }
    while (1) {
        char answer[8];
        lolib_writeSocket(socket, METASTRING(ANSI_YELLOW"\n Pick a channel ['q' to cancel]: "ANSI_RESET));
        int read = lolib_readSocket(socket, answer, 7);
        if (read < 1) return -1; // IO error
        if (answer[0] == 'q') return -2; // cancelled
        if (sanitizeString(answer, read) == 0) continue;
        int channelSelected = strtol(answer, NULL, 10);
        if (!inRange(channelSelected, 1, getChannelCount())) {
            lolib_writeSocket(socket, METASTRING(ANSI_YELLOW" No channel with given ID exists."));
        } else {
            return channelSelected-1;
        }
    }
}

int chatWindow(struct Connection* cta, size_t channelId) {
    char inbuf[400], outbuf[500];
    while (1) {
        int read = lolib_readSocket(&cta->socket, inbuf, sizeof(inbuf)-1);
        if (read < 1) return -1; // IO error
        inbuf[read] = 0;
        trimWhitespace(inbuf);
        if (sanitizeString(inbuf, read) == 0) {
            continue;
        }
        if (inbuf[0] == '/') {
            if (strcmp(inbuf+1, "help") == 0) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_CYAN"Available commands:\n  = /help - displays this help screen\n  = /quit - leaves the text channel\n  = /info - info about the text channel\n"ANSI_RESET));
            }
            else if (strcmp(inbuf+1, "info") == 0) {
                int toWrite = snprintf(outbuf, sizeof(outbuf), ANSI_GREEN"#%s "ANSI_CYAN"[%d/%d users]\n"ANSI_RESET, getChannelName(channelId), countUsers(channelId), USERS_PER_CHANNEL);
                lolib_writeSocket(&cta->socket, outbuf, toWrite);
            }
            else if (strcmp(inbuf+1, "quit") == 0) {
                return 0;
            }
        } else {
            int toWrite = snprintf(outbuf, sizeof(outbuf), ANSI_YELLOW" <%s>:"ANSI_RESET" %s\n", cta->username, inbuf);
            broadcastString(channelId, outbuf, toWrite);
        }
    }
}

void* connectionHandler(struct Connection* cta) {
    {
        char writebuf[256];
        time_t timeNow = time(0);
        int toWrite = snprintf(writebuf, sizeof(writebuf), ANSI_RED"\n +----------+ +--------------------------+\n | "ANSI_GREEN"LemonBBS"ANSI_RED" |-|"ANSI_GREEN" %.24s "ANSI_RED"|\n +----------+ +--------------------------+\n"ANSI_CYAN" * Made by ./lemon.sh\n * Recommended text mode: 80x25\n", ctime(&timeNow));
        lolib_writeSocket(&cta->socket, writebuf, toWrite);
    }
    cta->userId = -1;
    while (1) {
        char readbuf[256];
        loopStart:
        lolib_writeSocket(&cta->socket, METASTRING(ANSI_YELLOW"\n > "ANSI_RESET));
        int sslRead = lolib_readSocket(&cta->socket, readbuf, sizeof(readbuf)-1);
        if (sslRead < 1) goto end;
        readbuf[sslRead] = 0;
        trimWhitespace(readbuf);
        if (strcmp(readbuf, "chat") == 0) {
            if (cta->userId == -1) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED" You're not logged in!"));
                goto loopStart;
            }
            int32_t channelSelected = channelSelector(&cta->socket);
            switch (channelSelected) {
                case -1:
                    goto end;
                case -2:
                    goto loopStart;
                default:
                    break;
            }
            if (isUserInChat(channelSelected, cta->userId)) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED" You're already in this channel on a different session."));
                goto loopStart;
            }
            if (addChatUser(channelSelected, cta) == 0) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_YELLOW" This chat room is full. Try again later."));
                goto loopStart;
            }
            char lvenMessage[128];
            int toWrite = snprintf(lvenMessage, sizeof(lvenMessage), "\n %s joined the chat.\n", cta->username);
            broadcastString(channelSelected, lvenMessage, toWrite);
            int chatWindowResult = chatWindow(cta, channelSelected);
            removeChatUser(channelSelected, cta->userId);
            toWrite = snprintf(lvenMessage, sizeof(lvenMessage), "\n %s left the chat.\n", cta->username);
            broadcastString(channelSelected, lvenMessage, toWrite);
            if (chatWindowResult == -1) goto end;
        } else if (strcmp(readbuf, "register") == 0) {
            if (cta->userId != -1) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_GREEN" You're already logged in!"));
                goto loopStart;
            }
            lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n +---------------+\n |  "ANSI_GREEN"New Account"ANSI_RED"  |\n +---------------+\n \n  "ANSI_CYAN"Welcome to LemonBBS!\n  To register, type your desired username and password below. ['q' to cancel].\n"));
            char username[64], password[64];
            while (1) {
                switch (askCredentials(&cta->socket, username, password, 64)) {
                    case -1:
                        goto end;
                    case 0:
                        goto loopStart;
                }
                switch (dbUsernameTaken(username)) {
                    case -1:
                        lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n An error has occurred while processing your request. Please try again later."));
                        goto loopStart;
                    case 1:
                        lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n Error: Username already taken."));
                        continue;
                }
                char writebuf[256];
                int toWrite = snprintf(writebuf, 256, ANSI_CYAN"\n Is this correct?\n  "ANSI_RESET"Username: %s\n  Password: %s\n "ANSI_YELLOW"[y/n] > ", username, password);
                lolib_writeSocket(&cta->socket, writebuf, toWrite);
                char answer[8];
                if (lolib_readSocket(&cta->socket, answer, 8) < 1) goto end;
                if (answer[0] != 'y') continue;
                switch (dbInsertUser(username, password)) {
                    case -1:
                        lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n An error has occurred while processing your request. Please try again later."));
                        break;
                    case 1:
                        lolib_writeSocket(&cta->socket, METASTRING(ANSI_GREEN"\n Account successfully created! Use 'login' to log in."));
                }
                goto loopStart;
            }
        } else if (strcmp(readbuf, "login") == 0) {
            if (cta->userId != -1) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_YELLOW" You're already logged in!"));
                goto loopStart;
            }
            char username[64], password[64];
            switch (askCredentials(&cta->socket, username, password, 64)) {
                case -1:
                    goto end;
                case 0:
                    goto loopStart;
            }
            int64_t verifyResult = dbVerifyLogin(username, password);
            switch (verifyResult) {
                case -1:
                    lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n An error has occurred while processing your request. Please try again later.")); break;
                case -2:
                    lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n No account with this username exists. Create a new account using 'register'.")); break;
                case -3:
                    lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED"\n Invalid password.")); break;
                default:
                    strcpy(cta->username, username);
                    cta->userId = verifyResult;
                    lolib_writeSocket(&cta->socket, METASTRING(ANSI_GREEN"\n Logged in successfully!"));
            }
        } else if (strcmp(readbuf, "logout") == 0) {
            if (cta->userId == -1) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_YELLOW" You're not logged in!"));
                goto loopStart;
            }
            cta->userId = -1;
            lolib_writeSocket(&cta->socket, METASTRING(ANSI_GREEN" You have been logged out."));
        } else if (strcmp(readbuf, "help") == 0) {
            lolib_writeSocket(&cta->socket, help_txt, sizeof(help_txt));
        } else if (strcmp(readbuf, "mail") == 0) {
            lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED" Error: LemonMail service is not available right now."));
        } else if (strcmp(readbuf, "disconnect") == 0) {
            lolib_writeSocket(&cta->socket, METASTRING(ANSI_RESET"Thanks for using LemonBBS!\n"));
            goto end;
        } else if (strcmp(readbuf, "account") == 0) {
            if (cta->userId == -1) {
                lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED" You're not logged in!"));
                goto loopStart;
            }
            char outbuf[256];
            int toWrite = snprintf(outbuf, sizeof(outbuf), " User ID: %ld | Username: %s", cta->userId, cta->username);
            lolib_writeSocket(&cta->socket, outbuf, toWrite);
        } else {
            lolib_writeSocket(&cta->socket, METASTRING(ANSI_RED" Unknown command!"));
        }
    }
    end:
    lolib_finalize(&cta->socket);
    deallocateConnection(cta);
    return NULL;
}

#ifdef _WIN32
void enableVT() {
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hOut == INVALID_HANDLE_VALUE) return;
    DWORD dwMode = 0;
    if (!GetConsoleMode(hOut, &dwMode)) return;
    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    SetConsoleMode(hOut, dwMode);
}
#endif

int main(/*int argc, char *argv[]*/)
{
#ifdef unix
    signal(SIGPIPE, SIG_IGN);
#endif
#ifdef _WIN32
    enableVT();
#endif
    lolib_init();
    printf(ANSI_CYAN "\n  LemonBBS Server v0.3a\n -----------------------\n"ANSI_RESET);
    logMessage(debug, "Initializing...");
    if (initConfigFromFile(CONFIG_PATH) == 1) exit(1);
    switch (dbInit()) {
        case -1:
            logMessage(error, "Couldn't open file '"DB_PATH"'.");
            exit(1);
        case -2:
            logMessage(error, "Couldn't initialize the database.");
            exit(1);
    }
    initConnList(configConnlimit);

    LemonServerSocket serverSocket;
    if (lolib_createServerSocket("127.0.0.1", 3333, &serverSocket) != 0) {
        logMessage(error, "Couldn't initialize the socket.");
        exit(1);
    }

    logMessage(debug, "Done! Listening on "ANSI_BLUE"%d"ANSI_RESET".", configPort);

    while (1) {
        struct LemonClientSocket connSock;
        if (lolib_acceptTcpSocket(serverSocket, &connSock)) {
            logMessage(warning, "A client failed to connect.");
            continue;
        }
        struct Connection* newConnection = allocateConnection();
        if (newConnection == NULL) {
            lolib_writeSocket(&connSock, METASTRING("Sorry, all slots are currently in use. Try again later.\n"));
            lolib_finalize(&connSock);
            continue;
        }
        newConnection->socket = connSock;
        pthread_t connThread;
        pthread_create(&connThread, NULL, (void *(*)(void *)) connectionHandler, newConnection);
        pthread_detach(connThread);
    }
}