/*
 * Concat all JS files before serving.
 */
import * as crypto from 'crypto';
import * as fs from 'fs';
import * as path from 'path';
import * as process from 'process';
import * as tmp from 'tmp';
///<reference types="lib.dom"/>

/**
 * Return SHA1 of data buffer.
 */
function sha1(data) {
  const hash = crypto.createHash('sha1');
  hash.update(data);
  return hash.digest('hex');
}

/**
 * Entry-point for the Karma plugin.
 */
function initConcatJs(logger, emitter, basePath) {
  const log = logger.create('framework.concat_js');

  // Create a tmp file for the concat bundle that is automatically cleaned up on
  // exit.
  const tmpFile = tmp.fileSync({keep: false, dir: process.env['TEST_TMPDIR']});

  emitter.on('file_list_modified', files => {
    const bundleFile = {
      path: '/concatjs_bundle.js',
      contentPath: tmpFile.name,
      isUrl: false,
      content: ''
    } as any;
    const included = [];

    files.included.forEach(file => {
      if (path.extname(file.originalPath) !== '.js') {
        // Preserve all non-JS that were there in the included list.
        included.push(file);
      } else {
        const relativePath =
            path.relative(basePath, file.originalPath).replace(/\\/g, '/');

        // Remove 'use strict'.
        let content = file.content.replace(/('use strict'|"use strict");?/,
                                           '');
        content = JSON.stringify(
            content + '\n//# sourceURL=http://concatjs/base/' +
            relativePath + '\n');
        content = `//${relativePath}\neval(${content});\n`;
        bundleFile.content += content;
      }
    });

    bundleFile.sha = sha1(Buffer.from(bundleFile.content));
    bundleFile.mtime = new Date();
    included.unshift(bundleFile);

    files.included = included;
    files.served.push(bundleFile);

    log.debug('Writing concatjs bundle to tmp file %s',
        bundleFile.contentPath);
    fs.writeFileSync(bundleFile.contentPath, bundleFile.content);
  });
}

(initConcatJs as any).$inject = ['logger', 'emitter', 'config.basePath'];

module.exports = {
  'framework:concat_js': ['factory', initConcatJs]
};