'use strict';

const config = require('config');
const fork = require('child_process').fork;
const log = require('./log');
const path = require('path');
const fs = require('fs-extra')
const crypto = require('crypto');

let zoneMtaProcess;

const zoneMtaDir = path.join(__dirname, '..', '..', 'zone-mta');
const zoneMtaBuiltingConfig = path.join(zoneMtaDir, 'config', 'builtin-zonemta.json');

const password = process.env.BUILTIN_ZONE_MTA_PASSWORD || crypto.randomBytes(20).toString('hex').toLowerCase();

function getUsername() {
    return 'mailtrain';
}

function getPassword() {
    return password;
}

async function createConfig() {
    const cnf = {    // This is the main config file
        name: 'ZoneMTA',

        // Process identifier
        ident: 'zone-mta',

        // Run as the following user. Only use this if the application starts up as root
        user: config.user,
        group: config.group,

        log: config.builtinZoneMTA.log,

        dbs: {
            // MongoDB connection string
            mongo: config.builtinZoneMTA.mongo,

            // Redis connection string
            redis: config.builtinZoneMTA.redis,

            // Database name for ZoneMTA data in MongoDB. In most cases it should be the same as in the connection string
            sender: 'zone-mta'
        },

        api: {
            maildrop: false,
            user: getUsername(),
            pass: getPassword()
        },

        smtpInterfaces: {
            // Default SMTP interface for accepting mail for delivery
            feeder: {
                enabled: true,

                // How many worker processes to spawn
                processes: 1,

                // Maximum allowed message size 30MB
                maxSize: 31457280,

                // Local IP and port to bind to
                host: config.builtinZoneMTA.host,
                port: config.builtinZoneMTA.port,

                // Set to true to require authentication
                // If authentication is enabled then you need to use a plugin with an authentication hook
                authentication: true,

                // How many recipients to allow per message
                maxRecipients: 1,

                // Set to true to enable STARTTLS. Do not forget to change default TLS keys
                starttls: false,

                // set to true to start in TLS mode if using port 465
                // this probably does not work as TLS support with 465 in ZoneMTA is a bit buggy
                secure: false,
            }
        },

        plugins: {
            "core/email-bounce": false,
            "core/http-bounce": {
                enabled: "main",
                url: `${config.www.trustedUrlBase}/webhooks/zone-mta`
            },
            "core/default-headers": {
                enabled: ["receiver", "main", "sender"],
                futureDate: false,
                xOriginatingIP: false
            },
            'mailtrain-main': {
                enabled: ['main']
            },
            'mailtrain-receiver': {
                enabled: ['receiver'],
                username: getUsername(),
                password: getPassword()
            }
        },

        zones: {
            default: {
                preferIPv6: false,
                ignoreIPv6: true,
                processes: 1,
                connections: 5,
                pool: 'default'
            }
        }
    };

    await fs.writeFile(zoneMtaBuiltingConfig, JSON.stringify(cnf, null, 2));
}

function spawn(callback) {
    if (config.builtinZoneMTA.enabled) {

        createConfig().then(() => {
            log.info('ZoneMTA', 'Starting built-in Zone MTA process');

            zoneMtaProcess = fork(
                path.join(zoneMtaDir, 'index.js'),
                ['--config=' + zoneMtaBuiltingConfig],
                {
                    cwd: zoneMtaDir,
                    env: {NODE_ENV: process.env.NODE_ENV}
                }
            );

            zoneMtaProcess.on('message', msg => {
                if (msg) {
                    if (msg.type === 'zone-mta-started') {
                        log.info('ZoneMTA', 'ZoneMTA process started');
                        return callback();
                    } else if (msg.type === 'entries-added') {
                        senders.scheduleCheck();
                    }
                }
            });

            zoneMtaProcess.on('close', (code, signal) => {
                log.error('ZoneMTA', 'ZoneMTA process exited with code %s signal %s', code, signal);
            });

        }).catch(err => callback(err));

    } else {
        callback();
    }
}

module.exports.spawn = spawn;
module.exports.getUsername = getUsername;
module.exports.getPassword = getPassword;