/* jslint node: true */
'use strict';

const { MenuModule }    = require('./menu_module.js');
const { resetScreen }   = require('./ansi_term.js');
const { Errors }        = require('./enig_error.js');
const {
    trackDoorRunBegin,
    trackDoorRunEnd
}                       = require('./door_util.js');

//  deps
const async         = require('async');
const http          = require('http');
const net           = require('net');
const crypto        = require('crypto');

const packageJson   = require('../package.json');

/*
    Expected configuration block:

    {
        module: bbs_link
        ...
        config: {
            sysCode: XXXXX
            authCode: XXXXX
            schemeCode: XXXX
            door: lord

            //  default hoss: games.bbslink.net
            host: games.bbslink.net

            //  defualt port: 23
            port: 23
        }
    }
*/

//  :TODO: BUG: When a client disconnects, it's not handled very well -- the log is spammed with tons of errors
//  :TODO: ENH: Support nodeMax and tooManyArt

exports.moduleInfo = {
    name    : 'BBSLink',
    desc    : 'BBSLink Access Module',
    author  : 'NuSkooler',
};

exports.getModule = class BBSLinkModule extends MenuModule {
    constructor(options) {
        super(options);

        this.config         = options.menuConfig.config;
        this.config.host    = this.config.host || 'games.bbslink.net';
        this.config.port    = this.config.port || 23;
    }

    initSequence() {
        let token;
        let randomKey;
        let clientTerminated;
        const self = this;

        async.series(
            [
                function validateConfig(callback) {
                    return self.validateConfigFields(
                        {
                            host        : 'string',
                            sysCode     : 'string',
                            authCode    : 'string',
                            schemeCode  : 'string',
                            door        : 'string',
                            port        : 'number',
                        },
                        callback
                    );
                },
                function acquireToken(callback) {
                    //
                    //  Acquire an authentication token
                    //
                    crypto.randomBytes(16, function rand(ex, buf) {
                        if(ex) {
                            callback(ex);
                        } else {
                            randomKey = buf.toString('base64').substr(0, 6);
                            self.simpleHttpRequest('/token.php?key=' + randomKey, null, function resp(err, body) {
                                if(err) {
                                    callback(err);
                                } else {
                                    token = body.trim();
                                    self.client.log.trace( { token : token }, 'BBSLink token');
                                    callback(null);
                                }
                            });
                        }
                    });
                },
                function authenticateToken(callback) {
                    //
                    //  Authenticate the token we acquired previously
                    //
                    const headers = {
                        'X-User'    : self.client.user.userId.toString(),
                        'X-System'  : self.config.sysCode,
                        'X-Auth'    : crypto.createHash('md5').update(self.config.authCode + token).digest('hex'),
                        'X-Code'    : crypto.createHash('md5').update(self.config.schemeCode + token).digest('hex'),
                        'X-Rows'    : self.client.term.termHeight.toString(),
                        'X-Key'     : randomKey,
                        'X-Door'    : self.config.door,
                        'X-Token'   : token,
                        'X-Type'    : 'enigma-bbs',
                        'X-Version' : packageJson.version,
                    };

                    self.simpleHttpRequest('/auth.php?key=' + randomKey, headers, function resp(err, body) {
                        var status = body.trim();

                        if('complete' === status) {
                            return callback(null);
                        }
                        return callback(Errors.AccessDenied(`Bad authentication status: ${status}`));
                    });
                },
                function createTelnetBridge(callback) {
                    //
                    //  Authentication with BBSLink successful. Now, we need to create a telnet
                    //  bridge from us to them
                    //
                    const connectOpts = {
                        port    : self.config.port,
                        host    : self.config.host,
                    };

                    let clientTerminated;
                    let dataOut;

                    self.client.term.write(resetScreen());
                    self.client.term.write(`  Connecting to ${self.config.host}, please wait...\n`);

                    const doorTracking = trackDoorRunBegin(self.client, `bbslink_${self.config.door}`);

                    const bridgeConnection = net.createConnection(connectOpts, function connected() {
                        self.client.log.info(connectOpts, 'BBSLink bridge connection established');

                        dataOut = (data) => {
                            return bridgeConnection.write(data);
                        };

                        self.client.term.output.on('data', dataOut);

                        self.client.once('end', function clientEnd() {
                            self.client.log.info('Connection ended. Terminating BBSLink connection');
                            clientTerminated = true;
                            bridgeConnection.end();
                        });
                    });

                    const restore = () => {
                        if(dataOut && self.client.term.output) {
                            self.client.term.output.removeListener('data', dataOut);
                            dataOut = null;
                        }

                        trackDoorRunEnd(doorTracking);
                    };

                    bridgeConnection.on('data', function incomingData(data) {
                        //  pass along
                        //  :TODO: just pipe this as well
                        self.client.term.rawWrite(data);
                    });

                    bridgeConnection.on('end', function connectionEnd() {
                        restore();
                        return callback(clientTerminated ? Errors.General('Client connection terminated') : null);
                    });

                    bridgeConnection.on('error', function error(err) {
                        self.client.log.info('BBSLink bridge connection error: ' + err.message);
                        restore();
                        return callback(err);
                    });
                }
            ],
            function complete(err) {
                if(err) {
                    self.client.log.warn( { error : err.toString() }, 'BBSLink connection error');
                }

                if(!clientTerminated) {
                    self.prevMenu();
                }
            }
        );
    }

    simpleHttpRequest(path, headers, cb) {
        const getOpts = {
            host    : this.config.host,
            path    : path,
            headers : headers,
        };

        const req = http.get(getOpts, function response(resp) {
            let data = '';

            resp.on('data', function chunk(c) {
                data += c;
            });

            resp.on('end', function respEnd() {
                cb(null, data);
                req.end();
            });
        });

        req.on('error', function reqErr(err) {
            cb(err);
        });
    }
};