// Copyright (c) 2016, 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.

import 'dart:io';
import 'dart:math';

import 'package:args/args.dart';
import 'package:boolean_selector/boolean_selector.dart';
import 'package:test_api/src/backend/runtime.dart'; // ignore: implementation_imports
import 'package:test_api/src/frontend/timeout.dart'; // ignore: implementation_imports

import '../../util/io.dart';
import '../configuration.dart';
import '../runtime_selection.dart';
import 'reporters.dart';
import 'values.dart';

/// The parser used to parse the command-line arguments.
final ArgParser _parser = (() {
  var parser = ArgParser(allowTrailingOptions: true);

  var allRuntimes = Runtime.builtIn.toList()..remove(Runtime.vm);
  if (!Platform.isMacOS) allRuntimes.remove(Runtime.safari);
  if (!Platform.isWindows) allRuntimes.remove(Runtime.internetExplorer);

  parser.addFlag('help',
      abbr: 'h', negatable: false, help: 'Show this usage information.');
  parser.addFlag('version',
      negatable: false, help: 'Show the package:test version.');

  // Note that defaultsTo declarations here are only for documentation purposes.
  // We pass null instead of the default so that it merges properly with the
  // config file.

  parser.addSeparator('Selecting Tests:');
  parser.addMultiOption('name',
      abbr: 'n',
      help: 'A substring of the name of the test to run.\n'
          'Regular expression syntax is supported.\n'
          'If passed multiple times, tests must match all substrings.',
      splitCommas: false);
  parser.addMultiOption('plain-name',
      abbr: 'N',
      help: 'A plain-text substring of the name of the test to run.\n'
          'If passed multiple times, tests must match all substrings.',
      splitCommas: false);
  parser.addMultiOption('tags',
      abbr: 't',
      help: 'Run only tests with all of the specified tags.\n'
          'Supports boolean selector syntax.');
  parser.addMultiOption('tag', hide: true);
  parser.addMultiOption('exclude-tags',
      abbr: 'x',
      help: "Don't run tests with any of the specified tags.\n"
          'Supports boolean selector syntax.');
  parser.addMultiOption('exclude-tag', hide: true);
  parser.addFlag('run-skipped',
      help: 'Run skipped tests instead of skipping them.');

  parser.addSeparator('Running Tests:');

  // The UI term "platform" corresponds with the implementation term "runtime".
  // The [Runtime] class used to be called [TestPlatform], but it was changed to
  // avoid conflicting with [SuitePlatform]. We decided not to also change the
  // UI to avoid a painful migration.
  parser.addMultiOption('platform',
      abbr: 'p',
      help: 'The platform(s) on which to run the tests.\n'
          '[vm (default), '
          '${allRuntimes.map((runtime) => runtime.identifier).join(", ")}]');
  parser.addMultiOption('preset',
      abbr: 'P', help: 'The configuration preset(s) to use.');
  parser.addOption('concurrency',
      abbr: 'j',
      help: 'The number of concurrent test suites run.',
      defaultsTo: defaultConcurrency.toString(),
      valueHelp: 'threads');
  parser.addOption('total-shards',
      help: 'The total number of invocations of the test runner being run.');
  parser.addOption('shard-index',
      help: 'The index of this test runner invocation (of --total-shards).');
  parser.addOption('pub-serve',
      help: 'The port of a pub serve instance serving "test/".',
      valueHelp: 'port');
  parser.addOption('timeout',
      help: 'The default test timeout. For example: 15s, 2x, none',
      defaultsTo: '30s');
  parser.addFlag('pause-after-load',
      help: 'Pause for debugging before any tests execute.\n'
          'Implies --concurrency=1, --debug, and --timeout=none.\n'
          'Currently only supported for browser tests.',
      negatable: false);
  parser.addFlag('debug',
      help: 'Run the VM and Chrome tests in debug mode.', negatable: false);
  parser.addOption('coverage',
      help: 'Gather coverage and output it to the specified directory.\n'
          'Implies --debug.',
      valueHelp: 'directory');
  parser.addFlag('chain-stack-traces',
      help: 'Use chained stack traces to provide greater exception details\n'
          'especially for asynchronous code. It may be useful to disable\n'
          'to provide improved test performance but at the cost of\n'
          'debuggability.',
      defaultsTo: false);
  parser.addFlag('no-retry',
      help: "Don't rerun tests that have retry set.",
      defaultsTo: false,
      negatable: false);
  parser.addOption('test-randomize-ordering-seed',
      help: 'Use the specified seed to randomize the execution order of test'
          ' cases.\n'
          'Must be a 32bit unsigned integer or "random".\n'
          'If "random", pick a random seed to use.\n'
          'If not passed, do not randomize test case execution order.');

  var reporterDescriptions = <String, String>{};
  for (var reporter in allReporters.keys) {
    reporterDescriptions[reporter] = allReporters[reporter]!.description;
  }

  parser.addSeparator('Output:');
  parser.addOption('reporter',
      abbr: 'r',
      help: 'Set how to print test results.',
      defaultsTo: defaultReporter,
      allowed: reporterDescriptions.keys.toList(),
      allowedHelp: reporterDescriptions);
  parser.addOption('file-reporter',
      help: 'Set the reporter used to write test results to a file.\n'
          'Should be in the form <reporter>:<filepath>, '
          'Example: "json:reports/tests.json"');
  parser.addFlag('verbose-trace',
      negatable: false, help: 'Emit stack traces with core library frames.');
  parser.addFlag('js-trace',
      negatable: false,
      help: 'Emit raw JavaScript stack traces for browser tests.');
  parser.addFlag('color',
      help: 'Use terminal colors.\n(auto-detected by default)');

  /// The following options are used only by the internal Google test runner.
  /// They're hidden and not supported as stable API surface outside Google.

  parser.addOption('configuration',
      help: 'The path to the configuration file.', hide: true);
  parser.addOption('dart2js-path',
      help: 'The path to the dart2js executable.', hide: true);
  parser.addMultiOption('dart2js-args',
      help: 'Extra arguments to pass to dart2js.', hide: true);

  // If we're running test/dir/my_test.dart, we'll look for
  // test/dir/my_test.dart.html in the precompiled directory.
  parser.addOption('precompiled',
      help: 'The path to a mirror of the package directory containing HTML '
          'that points to precompiled JS.',
      hide: true);

  return parser;
})();

/// The usage string for the command-line arguments.
String get usage => _parser.usage;

/// Parses the configuration from [args].
///
/// Throws a [FormatException] if [args] are invalid.
Configuration parse(List<String> args) => _Parser(args).parse();

/// A class for parsing an argument list.
///
/// This is used to provide access to the arg results across helper methods.
class _Parser {
  /// The parsed options.
  final ArgResults _options;

  _Parser(List<String> args) : _options = _parser.parse(args);

  /// Returns the parsed configuration.
  Configuration parse() {
    var patterns = (_options['name'] as List<String>)
        .map<Pattern>(
            (value) => _wrapFormatException('name', () => RegExp(value)))
        .toList()
          ..addAll(_options['plain-name'] as List<String>);

    var includeTagSet = Set.from(_options['tags'] as Iterable? ?? [])
      ..addAll(_options['tag'] as Iterable? ?? []);

    var includeTags = includeTagSet.fold(BooleanSelector.all,
        (BooleanSelector selector, tag) {
      var tagSelector = BooleanSelector.parse(tag as String);
      return selector.intersection(tagSelector);
    });

    var excludeTagSet = Set.from(_options['exclude-tags'] as Iterable? ?? [])
      ..addAll(_options['exclude-tag'] as Iterable? ?? []);

    var excludeTags = excludeTagSet.fold(BooleanSelector.none,
        (BooleanSelector selector, tag) {
      var tagSelector = BooleanSelector.parse(tag as String);
      return selector.union(tagSelector);
    });

    var shardIndex = _parseOption('shard-index', int.parse);
    var totalShards = _parseOption('total-shards', int.parse);
    if ((shardIndex == null) != (totalShards == null)) {
      throw FormatException(
          '--shard-index and --total-shards may only be passed together.');
    } else if (shardIndex != null) {
      if (shardIndex < 0) {
        throw FormatException('--shard-index may not be negative.');
      } else if (shardIndex >= totalShards!) {
        throw FormatException(
            '--shard-index must be less than --total-shards.');
      }
    }

    var testRandomizeOrderingSeed =
        _parseOption('test-randomize-ordering-seed', (value) {
      var seed = value == 'random'
          ? Random().nextInt(4294967295)
          : int.parse(value).toUnsigned(32);
      print('Shuffling test order with --test-randomize-ordering-seed=$seed');

      return seed;
    });

    var color = _ifParsed<bool>('color') ?? canUseSpecialChars;

    var platform = _ifParsed<List<String>>('platform')
        ?.map((runtime) => RuntimeSelection(runtime))
        .toList();
    if (platform
            ?.any((runtime) => runtime.name == Runtime.phantomJS.identifier) ??
        false) {
      var yellow = color ? '\u001b[33m' : '';
      var noColor = color ? '\u001b[0m' : '';
      print('${yellow}Warning:$noColor '
          'PhatomJS is deprecated and will be removed in version ^2.0.0');
    }

    return Configuration(
        help: _ifParsed('help'),
        version: _ifParsed('version'),
        verboseTrace: _ifParsed('verbose-trace'),
        chainStackTraces: _ifParsed('chain-stack-traces'),
        jsTrace: _ifParsed('js-trace'),
        pauseAfterLoad: _ifParsed('pause-after-load'),
        debug: _ifParsed('debug'),
        color: color,
        configurationPath: _ifParsed('configuration'),
        dart2jsPath: _ifParsed('dart2js-path'),
        dart2jsArgs: _ifParsed('dart2js-args'),
        precompiledPath: _ifParsed('precompiled'),
        reporter: _ifParsed('reporter'),
        fileReporters: _parseFileReporterOption(),
        coverage: _ifParsed('coverage'),
        pubServePort: _parseOption('pub-serve', int.parse),
        concurrency: _parseOption('concurrency', int.parse),
        shardIndex: shardIndex,
        totalShards: totalShards,
        timeout: _parseOption('timeout', (value) => Timeout.parse(value)),
        patterns: patterns,
        runtimes: platform,
        runSkipped: _ifParsed('run-skipped'),
        chosenPresets: _ifParsed('preset'),
        paths: _options.rest.isEmpty ? null : _options.rest,
        includeTags: includeTags,
        excludeTags: excludeTags,
        noRetry: _ifParsed('no-retry'),
        testRandomizeOrderingSeed: testRandomizeOrderingSeed);
  }

  /// Returns the parsed option for [name], or `null` if none was parsed.
  ///
  /// If the user hasn't explicitly chosen a value, we want to pass null values
  /// to [new Configuration] so that it considers those fields unset when
  /// merging with configuration from the config file.
  T? _ifParsed<T>(String name) =>
      _options.wasParsed(name) ? _options[name] as T : null;

  /// Runs [parse] on the value of the option [name], and wraps any
  /// [FormatException] it throws with additional information.
  T? _parseOption<T>(String name, T Function(String) parse) {
    if (!_options.wasParsed(name)) return null;

    var value = _options[name];
    if (value == null) return null;

    return _wrapFormatException(name, () => parse(value as String));
  }

  Map<String, String>? _parseFileReporterOption() =>
      _parseOption('file-reporter', (value) {
        if (!value.contains(':')) {
          throw FormatException(
              'option must be in the form <reporter>:<filepath>, e.g. '
              '"json:reports/tests.json"');
        }
        final sep = value.indexOf(':');
        final reporter = value.substring(0, sep);
        if (!allReporters.containsKey(reporter)) {
          throw FormatException('"$reporter" is not a supported reporter');
        }
        return {reporter: value.substring(sep + 1)};
      });

  /// Runs [parse], and wraps any [FormatException] it throws with additional
  /// information.
  T _wrapFormatException<T>(String name, T Function() parse) {
    try {
      return parse();
    } on FormatException catch (error) {
      throw FormatException('Couldn\'t parse --$name "${_options[name]}": '
          '${error.message}');
    }
  }
}