// Copyright (c) 2013, 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:async' show Future;
import 'dart:convert' show JsonEncoder, json;
import 'dart:io' show File;

import 'package:path/path.dart' as p;
import 'package:pub/src/package_config.dart';
import 'package:pub_semver/pub_semver.dart';
import 'package:test/test.dart';
import 'package:test_descriptor/test_descriptor.dart';

/// Describes a `.dart_tools/package_config.json` file and its contents.
class PackageConfigFileDescriptor extends Descriptor {
  final String _generatorVersion;

  /// A map describing the packages in this `package_config.json` file.
  final List<PackageConfigEntry> _packages;

  PackageConfig get _config {
    return PackageConfig(
      configVersion: 2,
      packages: _packages,
      generatorVersion: Version.parse(_generatorVersion),
      generator: 'pub',
      generated: DateTime.now().toUtc(),
    );
  }

  /// Describes a `.packages` file with the given dependencies.
  ///
  /// [dependencies] maps package names to strings describing where the packages
  /// are located on disk.
  PackageConfigFileDescriptor(this._packages, this._generatorVersion)
      : super('.dart_tool/package_config.json');

  @override
  Future<void> create([String? parent]) async {
    final packageConfigFile = File(p.join(parent ?? sandbox, name));
    await packageConfigFile.parent.create();
    await packageConfigFile.writeAsString(
      '${const JsonEncoder.withIndent('  ').convert(_config.toJson())}\n',
    );
  }

  @override
  Future<void> validate([String? parent]) async {
    final packageConfigFile = p.join(parent ?? sandbox, name);
    if (!await File(packageConfigFile).exists()) {
      fail("File not found: '$packageConfigFile'.");
    }

    Map<String, dynamic> rawJson = json.decode(
      await File(packageConfigFile).readAsString(),
    );
    PackageConfig config;
    try {
      config = PackageConfig.fromJson(rawJson);
    } on FormatException catch (e) {
      fail('File "$packageConfigFile" is not valid: $e');
    }

    // Compare packages as sets to ignore ordering.
    expect(
      config.packages,
      _packages
          .map(
            (p) => isA<PackageConfigEntry>()
                .having((p0) => p0.name, 'name', p.name)
                .having(
                    (p0) => p0.languageVersion,
                    'languageVersion',
                    // If the expected entry has no language-version we don't check it.
                    p.languageVersion ?? anything)
                .having((p0) => p0.rootUri, 'rootUri', p.rootUri)
                .having((p0) => p0.packageUri, 'packageUri', p.packageUri),
          )
          .toSet(),
    );

    final expected = PackageConfig.fromJson(_config.toJson());
    // omit generated date-time and packages
    expected.generated = null; // comparing timestamps is unnecessary.
    config.generated = null;
    expected.packages = []; // Already compared packages (ignoring ordering)
    config.packages = [];
    expect(config.toJson(), equals(expected.toJson()),
        reason: '"$packageConfigFile" does not match expected values');
  }

  @override
  String describe() => name;
}