const gulp = require('gulp');
const gutil = require('gulp-util');
const wrap = require('gulp-wrap');
const concat = require('gulp-concat');
const merge = require('merge-stream');
const print = require('gulp-print');
const runSequence = require('run-sequence');
const fs = require('fs-extra');
const webpack = require('webpack');
const WebpackDevServer = require('webpack-dev-server');
const exec = require('child_process').exec;
const path = require('path');

// Configuration

const isWindows = /^win/.test(process.platform);
const env = process.env.NODE_ENV ? process.env.NODE_ENV : 'development';

const langs = ['es', 'en'];
const srcDir = './client';
const servicesDir = './services';
const nginxDir = `${servicesDir}/nginx`;
const buildDir = `${nginxDir}/static`;

const modules = require('./client/modules.json');
const webpackConfig = require('./webpack.config.js');

let proxyConf = require(`${nginxDir}/config.json`);
let proxyEnvFile = `${nginxDir}/config.${env}.json`;

if (fs.existsSync(proxyEnvFile))
    Object.assign(proxyConf, require(proxyEnvFile));

const defaultService = proxyConf.main;
const defaultPort = proxyConf.defaultPort;
const devServerPort = proxyConf.devServerPort;

// Development

gulp.task('default', () => {
    return gulp.start('services', 'client');
});

gulp.task('client', ['clean'], () => {
    return gulp.start('watch', 'routes', 'locales', 'webpack-dev-server');
});

gulp.task('services', callback => {
    let command = isWindows
        ? 'docker inspect dblocal | findstr Status'
        : 'docker inspect dblocal | grep Status';

    exec(command, (err, stdout, stderr) => {
        if (err) return callback(err);
        let isNotRunning = !stdout.includes('running');
        if (isNotRunning)
            runSequence('docker-wait', 'services-run', callback);
        else
            runSequence('services-run', callback);
    });
});

gulp.task('services-run', async () => {
    const services = await getServices();
    for (let service of services)
        require(service.index).start(service.port);

    return gulp.start('nginx');
});

gulp.task('e2e', ['docker-wait'], () => {
    return gulp.start('e2e-run');
});

gulp.task('e2e-run', () => {
    const jasmine = require('gulp-jasmine');
    gulp.src('./e2e_tests.js')
    .pipe(jasmine({reporter: 'none'}));
});

gulp.task('clean', () => {
    const del = require('del');
    return del([`${buildDir}/*`, `${nginxDir}/temp/*`, `!${buildDir}/templates`, `!${buildDir}/images`], {force: true});
});

gulp.task('install', () => {
    const install = require('gulp-install');
    let jsonFile = [];
    let services = fs.readdirSync(servicesDir);
    services.push('..');
    services.forEach(service => {
        jsonFile.push(`${servicesDir}/${service}/package.json`);
    });
    return gulp.src(jsonFile)
        .pipe(print(filepath => {
            return `Installing packages in ${filepath}`;
        }))
        .pipe(install({
            npm: ['--no-package-lock']
        }));
});

// Deployment

gulp.task('build', ['clean'], () => {
    return gulp.start('routes', 'locales', 'webpack', 'build-conf');
});

gulp.task('build-conf', async () => {
    let compose = await fs.readFile('./docker-compose.tpl.yml', 'utf8');

    const yaml = require('js-yaml');
    let composeYml = yaml.safeLoad(compose);
    let services = await getServices();

    for (let service of services) {
        let dockerFile = `${__dirname}/Dockerfile`;

        if (await fs.exists(`./services/${service.name}/Dockerfile`))
            dockerFile = 'Dockerfile';

        composeYml.services[service.name] = {
            environment: ['NODE_ENV=${NODE_ENV}'],
            container_name: `\${BRANCH_NAME}-${service.name}`,
            image: `${service.name}:\${TAG}`,
            build: {
                context: `./services/${service.name}`,
                dockerfile: dockerFile
            },
            ports: [`${defaultPort}:${service.port}`]
        };
        composeYml.services.nginx.links.push(
            `${service.name}:\${BRANCH_NAME}-${service.name}`
        );
    }

    let ymlString = yaml.safeDump(composeYml);
    await fs.writeFile('./docker-compose.yml', ymlString);

    await buildNginxConf();
});

// Services

let services;

async function getServices() {
    if (services) return services;

    let startPort = defaultPort + 1;
    services = [];

    const serviceDirs = await fs.readdir(servicesDir);
    const exclude = ['loopback'];

    for (let service of serviceDirs) {
        let index = `${servicesDir}/${service}/server/server.js`;
        if (!await fs.exists(index) || exclude.indexOf(service) !== -1) continue;

        let port = service == defaultService ? defaultPort : startPort++;
        services.push({
            name: service,
            index: index,
            port: port
        });
    }

    return services;
}

// Nginx

gulp.task('nginx', async () => {
    await buildNginxConf();
    let command = isWindows ? 'start.cmd' : 'start.sh';
    command = path.join(`${nginxDir}/${command}`);
    return new Promise((resolve, reject) => {
        exec(command, (err, stdout, stderr) => {
            if (stderr) console.log(stderr);
            if (err) return reject(err);
            resolve();
        });
    });
});

async function buildNginxConf() {
    const mustache = require('mustache');

    let params = {
        services: await getServices(),
        defaultService: defaultService,
        defaultPort: defaultPort,
        devServerPort: devServerPort,
        port: proxyConf.port,
        host: proxyConf.host
    };

    let confFile = `${nginxDir}/nginx.${env}.mst`;

    if (!await fs.exists(confFile))
        confFile = `${nginxDir}/nginx.mst`;

    let template = await fs.readFile(confFile, 'utf8');
    let nginxConf = mustache.render(template, params);

    await fs.writeFile(`${nginxDir}/temp/nginx.conf`, nginxConf);
}

// Webpack

gulp.task('webpack', function(cb) {
    let configCopy = Object.create(webpackConfig);
    let compiler = webpack(configCopy);

    compiler.run(function(err, stats) {
        if (err) throw new gutil.PluginError('webpack', err);
        gutil.log('[webpack]', stats.toString({colors: true}));
        cb();
    });
});

gulp.task('webpack-dev-server', function() {
    let configCopy = Object.create(webpackConfig);

    for (let entry in configCopy.entry) {
        configCopy.entry[entry]
            .unshift(`webpack-dev-server/client?http://127.0.0.1:${devServerPort}/`);
    }

    let compiler = webpack(configCopy);
    new WebpackDevServer(compiler, {
        publicPath: '/',
        contentBase: buildDir,
        quiet: false,
        noInfo: false,
        // hot: true,
        stats: {
            assets: true,
            colors: true,
            version: false,
            hash: false,
            timings: true,
            chunks: false,
            chunkModules: false
        }
    }).listen(devServerPort, '127.0.0.1', function(err) {
        if (err) throw new gutil.PluginError('webpack-dev-server', err);
    });
});

// Locale

let localeFiles = `${srcDir}/**/locale/*.json`;

gulp.task('locales', function() {
    const extend = require('gulp-extend');
    let streams = [];

    for (let mod in modules)
        for (let lang of langs) {
            let localeFiles = `./client/${mod}/**/locale/${lang}.json`;
            streams.push(gulp.src(localeFiles)
                .pipe(extend(`${lang}.json`))
                .pipe(gulp.dest(`${buildDir}/locale/${mod}`)));
        }

    return merge(streams);
});

// Routes

let routeFiles = `${srcDir}/**/routes.json`;

gulp.task('routes', function() {
    return gulp.src(routeFiles)
        .pipe(concat('routes.js', {newLine: ','}))
        .pipe(wrap('var routes = [<%=contents%>\n];'))
        .pipe(gulp.dest(buildDir));
});

// Watch

gulp.task('watch', function() {
    gulp.watch(routeFiles, ['routes']);
    gulp.watch(localeFiles, ['locales']);
});

// Docker

gulp.task('docker', callback => {
    runSequence('docker-delete', 'docker-delete-image', 'docker-build', 'docker-run', callback);
});

gulp.task('docker-wait', ['docker'], callback => {
    let maxInterval = 30 * 60000;
    let interval = 1000;
    let timer = 0;
    console.log('Waiting for MySQL init process...');
    let waitForLocaldb = setInterval(() => {
        if (timer < maxInterval) {
            timer += interval;
            exec('docker logs --tail 4 dblocal', (err, stdout, stderr) => {
                if (stdout.includes('MySQL init process done. Ready for start up.')) {
                    clearInterval(waitForLocaldb);
                    callback(err);
                }
            });
        } else {
            console.log(`MySQL connection not established whithin ${maxInterval / 1000} secs!`);
            clearInterval(waitForLocaldb);
        }
    }, interval);
});

gulp.task('docker-run', callback => {
    exec('docker run -d --name dblocal -p 3306:3306 dblocal', (err, stdout, stderr) => {
        callback(err);
    });
});

gulp.task('docker-build', callback => {
    exec('docker build -t dblocal:latest ./services/db', (err, stdout, stderr) => {
        callback(err);
    });
});

gulp.task('docker-delete-image', callback => {
    exec('docker rmi dblocal:latest', (err, stdout, stderr) => {
        callback(err);
    });
});

gulp.task('docker-delete', callback => {
    exec('docker stop dblocal && docker wait dblocal && docker rm -f dblocal', (err, stdout, stderr) => {
        callback(err);
    });
});