#!/usr/bin/env dart
// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

//
// Compiles code with DDC and runs the resulting code with either node or
// chrome.
//
// The first script supplied should be the one with `main()`.
//
// Saves the output in the same directory as the sources for convenient
// inspection, modification or rerunning the code.

import 'dart:io';

import 'package:args/args.dart' show ArgParser;
import 'package:path/path.dart' as p;

void main(List<String> args) async {
  void printUsage() {
    print('Usage: ddb [options] <dart-script-file>\n');
    print('Compiles <dart-script-file> with the dev_compiler and runs it on a '
        'JS platform.\n');
  }

  // Parse flags.
  var parser = ArgParser()
    ..addFlag('help', abbr: 'h', help: 'Display this message.')
    ..addFlag('kernel',
        abbr: 'k', help: 'Compile with the new kernel-based front end.')
    ..addMultiOption('summary',
        abbr: 's',
        help: 'summary file(s) of imported libraries, optionally\n'
            'with module import path: -s path.sum=js/import/path')
    ..addFlag('debug',
        abbr: 'd',
        help: 'Use current source instead of built SDK.',
        defaultsTo: false)
    ..addFlag('observe',
        help:
            'Run the compiler in the Dart VM with --observe. Implies --debug.',
        defaultsTo: false)
    ..addOption('vm-service-port',
        help: 'Specify the observatory port. Implied --observe.')
    ..addFlag('summarize-text',
        help: 'Emit API summary in a .js.txt file.\n'
            'Ignored when not passed with --kernel.',
        defaultsTo: false)
    ..addOption('runtime',
        abbr: 'r',
        help: 'Platform to run on (node|d8|chrome).  Default is node.',
        allowed: ['node', 'd8', 'chrome'],
        defaultsTo: 'node')
    ..addOption('port',
        abbr: 'p',
        help: 'Run with the corresponding chrome/V8 debugging port open.',
        defaultsTo: '9222')
    ..addMultiOption('enable-experiment',
        help: 'Run with specified experiments enabled.')
    ..addOption('binary', abbr: 'b', help: 'Runtime binary path.')
    ..addOption('mode',
        help: 'Option to (compile|run|all).  Default is all (compile and run).',
        allowed: ['compile', 'run', 'all'],
        defaultsTo: 'all')
    ..addOption('compile-vm-options',
        help: 'DART_VM_OPTIONS for the compilation VM.')
    ..addOption('packages',
        help: 'Where to find a package spec file.')
    ..addOption('out',
        help: 'Output file.');

  var options = parser.parse(args);
  if (options['help'] as bool) {
    printUsage();
    print('Available options:');
    print(parser.usage);
    exit(0);
  }
  if (options.rest.length != 1) {
    print('Dart script file required.\n');
    printUsage();
    exit(1);
  }
  var debug = options['debug'] as bool ||
      options['observe'] as bool ||
      options.wasParsed('vm-service-port');
  var kernel = options['kernel'] as bool;
  var summarizeText = options['summarize-text'] as bool;
  var binary = options['binary'] as String;
  var experiments = options['enable-experiment'] as List;
  var summaries = options['summary'] as List;
  var port = int.parse(options['port'] as String);
  var mode = options['mode'] as String;
  var compile = mode == 'compile' || mode == 'all';
  var run = mode == 'run' || mode == 'all';

  var entry = p.canonicalize(options.rest.first);
  var out = (options['out'] as String) ?? p.setExtension(entry, '.js');
  var libRoot = p.dirname(entry);
  var basename = p.basenameWithoutExtension(entry);
  var libname = kernel
      ? p.relative(p.withoutExtension(entry)).replaceAll('/', '__')
      : basename;
  libname = libname.replaceAll('-', '_');

  // By default (no `-d`), we use the `dartdevc` binary on the user's path to
  // compute the SDK we use for execution.  I.e., we assume that `dart` is
  // under `$DART_SDK/bin/dart` and use that to find `dartdevc` and related
  // artifacts.  In this mode, this script can run against any installed SDK.
  // If you want to run against a freshly built SDK, that must be first on
  // your path.
  var dartBinary = Platform.resolvedExecutable;
  var dartSdk = p.dirname(p.dirname(dartBinary));

  // In debug mode (`-d`), we run from the `pkg/dev_compiler` sources.  We
  // determine the location via this actual script (i.e., `-d` assumes
  // this script remains under to `tool` sub-directory).
  var toolPath =
      Platform.script.normalizePath().toFilePath(windows: Platform.isWindows);
  var ddcPath = p.dirname(p.dirname(toolPath));
  var dartCheckoutPath = p.dirname(p.dirname(ddcPath));

  Future<void> runDdc(String command, List<String> args) async {
    if (debug) {
      // Use unbuilt script.  This only works from a source checkout.
      var vmServicePort = options.wasParsed('vm-service-port')
          ? '=${options['vm-service-port']}'
          : '';
      var observe =
          options.wasParsed('vm-service-port') || options['observe'] as bool;
      args.insertAll(0, [
        if (observe) ...[
          '--enable-vm-service$vmServicePort',
          '--pause-isolates-on-start',
        ],
        '--enable-asserts',
        p.join(ddcPath, 'bin', '$command.dart')
      ]);
      command = dartBinary;
    } else {
      // Use built snapshot.
      command = p.join(dartSdk, 'bin', command);
    }
    var process = await Process.start(command, args,
        mode: ProcessStartMode.inheritStdio,
        environment: <String, String>{
          if (options['compile-vm-options'] != null)
            'DART_VM_OPTIONS': options['compile-vm-options']
        });
    if (await process.exitCode != 0) exit(await process.exitCode);
  }

  String mod;
  bool chrome = false;
  bool node = false;
  bool d8 = false;
  switch (options['runtime'] as String) {
    case 'node':
      node = true;
      mod = 'common';
      break;
    case 'd8':
      d8 = true;
      mod = 'es6';
      break;
    case 'chrome':
      chrome = true;
      mod = 'amd';
      break;
  }

  String sdkJsPath;
  String requirePath;
  String ddcSdk;
  if (debug) {
    var sdkRoot = p.dirname(p.dirname(ddcPath));
    var buildDir = p.join(sdkRoot, Platform.isMacOS ? 'xcodebuild' : 'out');
    dartSdk = p.join(buildDir, 'ReleaseX64', 'dart-sdk');
  }
  var suffix = kernel ? p.join('kernel', mod) : mod;
  sdkJsPath = p.join(dartSdk, 'lib', 'dev_compiler', suffix);
  requirePath = sdkJsPath;
  ddcSdk = p.join(
      dartSdk, 'lib', '_internal', kernel ? 'ddc_sdk.dill' : 'ddc_sdk.sum');

  if (compile) {
    var ddcArgs = [
      if (kernel) '--kernel',
      if (kernel && summarizeText)
        '--summarize-text',
      '--modules=$mod',
      '--dart-sdk-summary=$ddcSdk',
      // TODO(nshahan) Cleanup when we settle on using or removing library-root.
      if (!kernel)
        '--library-root=$libRoot',
      for (var summary in summaries) '--summary=$summary',
      for (var experiment in experiments) '--enable-experiment=$experiment',
      if (options['packages'] != null) '--packages=${options['packages']}',
      '-o',
      out,
      entry
    ];

    await runDdc('dartdevc', ddcArgs);
  }

  if (run) {
    if (chrome) {
      String chromeBinary;
      if (binary != null) {
        chromeBinary = binary;
      } else if (Platform.isWindows) {
        chromeBinary =
            'C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe';
      } else if (Platform.isMacOS) {
        chromeBinary =
            '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome';
      } else {
        // Assume Linux
        chromeBinary = 'google-chrome';
      }

      var html = '''
<script src='$requirePath/require.js'></script>
<script>
  require.config({
    paths: {
        'dart_sdk': '$sdkJsPath/dart_sdk'
    },
    waitSeconds: 15
  });
  require(['dart_sdk', '$basename'],
        function(sdk, app) {
    'use strict';
    sdk._debugger.registerDevtoolsFormatter();
    app.$libname.main();
  });
</script>
''';
      var htmlFile = p.setExtension(out, '.html');
      File(htmlFile).writeAsStringSync(html);
      var tmp = p.join(Directory.systemTemp.path, 'ddc');

      var process = await Process.start(
          chromeBinary,
          [
            '--auto-open-devtools-for-tabs',
            '--allow-file-access-from-files',
            '--remote-debugging-port=$port',
            '--user-data-dir=$tmp',
            htmlFile
          ],
          mode: ProcessStartMode.inheritStdio);
      if (await process.exitCode != 0) exit(await process.exitCode);
    } else if (node) {
      var nodePath = '$sdkJsPath:$libRoot';
      var runjs = '''
let source_maps;
try {
  source_maps = require('source-map-support');
  source_maps.install();
} catch(e) {
}
let sdk = require(\"dart_sdk\");
let main = require(\"./$basename\").$libname.main;
try {
  sdk._isolate_helper.startRootIsolate(main, []);
} catch(e) {
  if (!source_maps) {
    console.log('For Dart source maps: npm install source-map-support');
  }
  sdk.core.print(sdk.dart.stackTrace(e));
  process.exit(1);
}
''';
      var nodeFile = p.setExtension(out, '.run.js');
      File(nodeFile).writeAsStringSync(runjs);
      var nodeBinary = binary ?? 'node';
      var process = await Process.start(
          nodeBinary, ['--inspect=localhost:$port', nodeFile],
          environment: {'NODE_PATH': nodePath},
          mode: ProcessStartMode.inheritStdio);
      if (await process.exitCode != 0) exit(await process.exitCode);
    } else if (d8) {
      // Fix SDK import.  `d8` doesn't let us set paths, so we need a full path
      // to the SDK.

      var jsFile = File(out);
      var jsContents = jsFile.readAsStringSync();
      jsContents = jsContents.replaceFirst(
          "from 'dart_sdk.js'", "from '$sdkJsPath/dart_sdk.js'");
      jsFile.writeAsStringSync(jsContents);

      var runjs = '''
import { dart, _isolate_helper } from '$sdkJsPath/dart_sdk.js';
import { $libname } from '$basename.js';
let main = $libname.main;
try {
  _isolate_helper.startRootIsolate(() => {}, []);
  main();
} catch(e) {
  console.error(e);
}
''';
      var d8File = p.setExtension(out, '.d8.js');
      File(d8File).writeAsStringSync(runjs);
      var d8Binary = binary ?? p.join(dartCheckoutPath, _d8executable);
      var process = await Process.start(d8Binary, ['--module', d8File],
          mode: ProcessStartMode.inheritStdio);
      if (await process.exitCode != 0) exit(await process.exitCode);
    }
  }
}

String get _d8executable {
  if (Platform.isWindows) {
    return p.join('third_party', 'd8', 'windows', 'd8.exe');
  } else if (Platform.isLinux) {
    return p.join('third_party', 'd8', 'linux', 'd8');
  } else if (Platform.isMacOS) {
    return p.join('third_party', 'd8', 'macos', 'd8');
  }
  throw UnsupportedError('Unsupported platform.');
}