import { Socket } from 'net';
import { IRCUser } from './IRCUser.js';
import { IRCMessage, parseIRCMessage } from './Message.js';
import numerics from './numerics.js';
import { Server } from './Server.js';

export class Client {
    user: IRCUser|null
    capVersion: string
    enabledCaps: Map<string, string>
    allCaps: Map<string, string>
    localNick: string
    localUsername: string
    localRealname: string
    constructor(private socket: Socket, public server: Server) {
        this.user = null;
        this.capVersion = '301';
        this.enabledCaps = new Map();
        this.allCaps = new Map([
            ["account-tag", ""],
            ["batch", ""],
            ["draft/chathistory", ""],
            ["echo-message", ""],
            ["draft/event-playback", ""],
            ["invite-notify", ""],
            ["message-tags", ""],
            ["sasl", "PLAIN"],
            ["server-time", ""],
        ]);
        this.localNick = 'none';
        this.localUsername = 'none';
        this.localRealname = 'none';
        this.socket.on('data', (data) => this.receiveData(data));
        //this.socket.on('close', (e) => {if (this.user) this.user.handleClientClose(this, e)});
    }

    receiveData(data: Buffer|String) {
        const dataArray = data.toString().split('\r\n');
        dataArray.forEach(m => {
            const trimmedMsg = m.replace('\r', '').replace('\n', '');
            if (trimmedMsg !== '')
                this.routeMessage(trimmedMsg);
        });
    }

    routeMessage(data: string) {
        const message = parseIRCMessage(data);
        switch (message.command.toUpperCase()) {
            case 'AUTHENTICATE': {
                this.doAUTHENTICATE(message);
                break;
            }
            case 'CAP': {
                this.doCAP(message);
                break;
            }
        }
    }
    
    getCapString(capVersion: string) {
        let capArray = [];
        for (const [key, value] of this.allCaps.entries()) {
            if (capVersion === '301' || value.length === 0) {
                capArray.push(key);
            }
            else {
                capArray.push(`${key}=${value}`);
            }
        }
        return capArray.join(' ');
    }

    doCAP(message: IRCMessage) {
        switch (message.params[0]) {
            case 'LS': {
                if (message.params.length === 2) {
                    this.capVersion = message.params[1];
                }
                this.sendMessage(this.server.name, "CAP", ["*", "LS", this.getCapString(this.capVersion)], message.tags);
                break;
            }
            case 'LIST': {
                this.sendMessage(this.server.name, "CAP", ["*", "LIST", this.getCapString(this.capVersion)], message.tags);
                break;
            }
            case 'REQ': {
                const capsToChange = (message.params[1].indexOf(' ') === -1) ? [message.params[1]] : message.params[1].split(' ');
                const capsEnabled: string[] = [];
                capsToChange.forEach(cap => {
                    if (cap in this.allCaps) {
                        this.enabledCaps.set(cap, '');
                        capsEnabled.push(cap);
                    }
                });
                this.sendMessage(this.server.name, "CAP", ["*", "ACK", capsEnabled.join(' ')], message.tags);
                break;
            }
            case 'END': {
                if (this.user !== null) {
                    this.doRegistration(message);
                }
                else {
                    this.closeConnectionWithError("You must use SASL to connect to this server");
                }
            }
        }
    }

    doAUTHENTICATE(message: IRCMessage) {
        if (message.params[0] === "PLAIN") {
            this.sendMessage("", "AUTHENTICATE", ["+"], message.tags);
        }
        else {
            const authArray = Buffer.from(message.params[0], 'base64').toString('utf-8').split('\0');
            if (!authArray || authArray.length !== 3) {
                this.sendMessage(this.server.name, '904', numerics['904']('*'), message.tags)
                this.closeConnectionWithError('Invalid authentication')
            }
            const mxid = authArray[1];
            const accessToken = authArray[2];
            const thisIRCUser = this.server.ircUsers.get(mxid) || new IRCUser(this, mxid, accessToken);
            if (thisIRCUser.isAuthed) {
                if (!thisIRCUser.verifyCredentials(accessToken)) {
                    this.sendMessage(this.server.name, '904', numerics['904']('*'), message.tags)
                    this.closeConnectionWithError('Invalid authentication')
                }
                else {
                    this.user = thisIRCUser;
                }
            }
        }
    }

    doRegistration(message: IRCMessage) {
        if (this.user === null) {
            this.closeConnectionWithError('Authentication failed');
            return;
        }
        this.sendMessage(this.server.name, '001', numerics['001'](this.user.nick, this.server.name), message.tags);
        this.sendMessage(this.server.name, '002', numerics['002'](this.user.nick, this.server.name, '0.0.1'), message.tags);
        this.sendMessage(this.server.name, '003', numerics['003'](this.user.nick, 'yesterday'), message.tags);
        this.sendMessage(this.server.name, '004', numerics['004'](this.user.nick, this.server.name, '0.0.1', 'i', 'Lhionpsv'), message.tags);
        const iSupportArray = [
            'CASEMAPPING=ascii',
            'CHANMODES=,,,Linps',
            'CHANTYPES=#&!',
            'MAXTARGETS=1',
            'PREFIX=(ohv)@%+',
        ]
        if (this.enabledCaps.has('draft/chathistory')) {
            iSupportArray.push('CHATHISTORY=50');
        }
        this.sendMessage(this.server.name, '005', numerics['005'](this.user.nick, iSupportArray), message.tags);

        this.sendMessage(this.server.name, '375', numerics['375'](this.user.nick), message.tags);
        this.sendMessage(this.server.name, '372', numerics['372'](this.user.nick, "It's an MOTD"), message.tags);
        this.sendMessage(this.server.name, '376', numerics['376'](this.user.nick), message.tags);

        this.sendMessage(this.user.nick, 'MODE', [this.user.nick, '+i'], message.tags);
    }

    sendMessage(prefix: string, command: string, params: string[], tags: Map<string, string>) {
        const capTagMapping = new Map([
            ['account', 'account-tag'],
            ['label', 'labeled-response'],
            ['msgid', 'message-tags'],
            ['reflectionircd.chat/delete-message', 'reflectionircd.chat/delete-message'],
            ['reflectionircd.chat/edit-message', 'reflectionircd.chat/edit-message'],
            ['time', 'server-time'],
        ])
        const ourTags: Map<string, string> = new Map();
        if (this.enabledCaps.has('server-time') && !tags.has('time'))
            ourTags.set('time', new Date().toISOString());

        tags.forEach((v, k) => {
            if (k.startsWith('+')) {
                if (this.enabledCaps.has('message-tags')) {
                    ourTags.set(k, v);
                }
            }
            else {
                const capToCheck = capTagMapping.get(k) || '';
                if (this.enabledCaps.has(capToCheck)) {
                    ourTags.set(k, v);
                }
            }
        })
        const newMsg = new IRCMessage(ourTags, prefix, command, params);
        const msgToSend = newMsg.toString();
        console.log(`SENT: ${msgToSend}`);
        this.socket.write(`${msgToSend}\r\n`);
    }

    closeConnectionWithError(message: string) {
        this.sendMessage(this.server.name, 'ERROR', [message], new Map());
        this.socket.destroy();
    }
}