/*
 Copyright 2016 Google Inc. All Rights Reserved.
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

/* eslint-disable require-jsdoc */

const cookieParser = require('cookie-parser');
const express = require('express');
const fs = require('fs');
const glob = require('glob');
const handlebars = require('handlebars');
const path = require('path');
const serveIndex = require('serve-index');
const serveStatic = require('serve-static');

class ServerInstance {
  constructor() {
    this._server = null;
    this._sockets = [];

    this._app = express();
    this._app.use(cookieParser());

    // Test iframe is used by sw-testing-helpers to scope service workers
    this._app.get('/test/iframe/:random', function(req, res) {
      res.sendFile(path.join(__dirname, 'test-iframe.html'));
    });

    this._app.get('/__echo/filename/:file', function(req, res) {
      res.setHeader('Cache-Control', 'max-age=' + (24 * 60 * 60));
      res.send(req.params.file);
    });

    this._app.get('/__echo/date/:file', function(req, res) {
      res.setHeader('Cache-Control', 'max-age=' + (24 * 60 * 60));
      res.send(`${req.params.file}-${Date.now()}`);
    });

    this._app.all('/__echo/date-with-cors/:file', function(req, res) {
      res.setHeader('Access-Control-Allow-Methods',
        'POST, GET, PUT, DELETE, OPTIONS');
      res.setHeader('Cache-Control', 'max-age=' + (24 * 60 * 60));
      res.setHeader('Access-Control-Allow-Origin', '*');
      res.send(`${req.params.file}-${Date.now()}`);
    });

    this._app.get('/__test/404/', function(req, res) {
      res.status(404).send('404');
    });

    this._app.get('/__test/redirect/:statusCode/', function(req, res) {
      const statusCode = parseInt(req.params.statusCode, 10);
      res.redirect(
        statusCode,
        `/__echo/filename/${statusCode}`
      );
    });

    this._app.get('/__test/cookie/:id', function(req, res) {
      res.send(JSON.stringify(req.cookies));
    });

    // Harness to kick off all the in-browser tests for a given package.
    // It will pick up a list of all the top-level .js files and automatically
    // inject them into the HTML as <script> tags.
    this._app.get('/__test/mocha/browser/:pkg', function(req, res) {
      const pkg = req.params.pkg;
      const pattern = `packages/${pkg}/test/browser/*.js`;
      const repoRoot = path.join(__dirname, '..');
      const scripts = glob.sync(pattern, {
        cwd: repoRoot,
        root: repoRoot,
      }).map((script) => {
        // Converts packages/<pkg name>/test/sw/<filename>.js
        // to      /packages/<pkg name>/test/sw/<filename>.js
        return `/${script}`;
      });
      if (scripts.length === 0) {
        const errMsg = `No test scripts match the pattern '${pattern}'.`;
        /* eslint-disable no-console */
        console.log(errMsg);
        /* eslint-enable no-console */
        res.status(500).send(errMsg);
        return;
      }

      let config = {};
      try {
        // Read JSON file to avoid the require cache
        config =
          JSON.parse(
            fs.readFileSync(
              path.join(__dirname, '..', 'packages', pkg, 'test', 'config.json')
            , 'utf-8')
          );
      } catch (err) {
        // NOOP
      }

      const source = fs.readFileSync(path.join(
        __dirname, '..', 'templates', 'test-browser.hbs'), 'utf-8');
      const template = handlebars.compile(source);
      const html = template({
        scripts,
        config,
        pkg,
      });

      res.send(html);
    });

    this._app.get('/__test/mocha/sw/:pkg', function(req, res) {
      /* eslint-disable no-console */
      const pkg = req.params.pkg;
      const pattern = `packages/${pkg}/test/sw/*.js`;
      const scriptPaths = glob.sync(pattern).map((script) => {
        // Converts packages/<pkg name>/test/sw/<filename>.js
        // to      /packages/<pkg name>/test/sw/<filename>.js
        return `/${script}`;
      });

      const source = fs.readFileSync(path.join(
        __dirname, '..', 'templates', 'test-sw.hbs'), 'utf-8');
      const template = handlebars.compile(source);
      const html = template({scripts: scriptPaths, pkg});

      res.send(html);
    });

    // Redirect /packages/:pkg/test/browser/ to the /__test/mocha/:pkg templated
    // page, but only if there's no /packages/:pkg/test/browser/index.html
    this._app.get('/packages/:pkg/test/browser/', function(req, res, next) {
      const index = path.join(__dirname, '..', 'packages', req.params.pkg,
        'test', 'browser', 'index.html');
      if (fs.existsSync(index)) {
        next();
      } else {
        res.redirect(301, `/__test/mocha/${req.params.pkg}`);
      }
    });
  }

  start(rootDirectory, port) {
    if (typeof port === 'undefined') {
      port = 0;
    }

    if (this._server) {
      return Promise.reject(new Error('Server already started.'));
    }

    this._app.use('/', express.static(rootDirectory, {
      setHeaders: (res) => {
        res.append('Set-Cookie', `swtesting=${Date.now()}; Path=/;`);
        res.setHeader('Service-Worker-Allowed', '/');
      },
    }));

    this._app.use(serveStatic(rootDirectory));
    this._app.use(serveIndex(rootDirectory, {view: 'details'}));

    return new Promise((resolve, reject) => {
      this._server = this._app.listen(port, 'localhost', () => {
        if (process.env.TRAVIS) {
          /* eslint-disable no-console */
          console.log(`[Debug Info] Test Server: ` +
            `http://localhost:${this._server.address().port}`);
          console.log('');
          /* eslint-enable no-console */
        }
        resolve(this._server.address().port);
      });

      this._server.on('connection', (socket) => {
        this._sockets.push(socket);
      });
    });
  }

  stop() {
    return new Promise((resolve) => {
      this._sockets.forEach((socket) => {
        socket.destroy();
      });

      this._server.close(resolve);
      this._server = null;
    });
  }
}

module.exports = ServerInstance;