// Copyright (c) 2012, 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';

import 'package:meta/meta.dart';
import 'package:path/path.dart' as p;
import 'package:pub_semver/pub_semver.dart';

import 'entrypoint.dart';
import 'log.dart' as log;
import 'sdk.dart';
import 'validator/changelog.dart';
import 'validator/compiled_dartdoc.dart';
import 'validator/dependency.dart';
import 'validator/dependency_override.dart';
import 'validator/deprecated_fields.dart';
import 'validator/directory.dart';
import 'validator/executable.dart';
import 'validator/flutter_constraint.dart';
import 'validator/flutter_plugin_format.dart';
import 'validator/gitignore.dart';
import 'validator/language_version.dart';
import 'validator/leak_detection.dart';
import 'validator/license.dart';
import 'validator/name.dart';
import 'validator/null_safety_mixed_mode.dart';
import 'validator/pubspec.dart';
import 'validator/pubspec_field.dart';
import 'validator/pubspec_typo.dart';
import 'validator/readme.dart';
import 'validator/relative_version_numbering.dart';
import 'validator/sdk_constraint.dart';
import 'validator/size.dart';
import 'validator/strict_dependencies.dart';

/// The base class for validators that check whether a package is fit for
/// uploading.
///
/// Each validator should override [errors], [warnings], or both to return
/// lists of errors or warnings to display to the user. Errors will cause the
/// package not to be uploaded; warnings will require the user to confirm the
/// upload.
abstract class Validator {
  /// The accumulated errors for this validator.
  ///
  /// Filled by calling [validate].
  final errors = <String>[];

  /// The accumulated warnings for this validator.
  ///
  /// Filled by calling [validate].
  final warnings = <String>[];

  /// The accumulated hints for this validator.
  ///
  /// Filled by calling [validate].
  final hints = <String>[];

  late ValidationContext context;
  Entrypoint get entrypoint => context.entrypoint;
  int get packageSize => context.packageSize;
  Uri get serverUrl => context.serverUrl;
  List<String> get files => context.files;

  /// Validates the entrypoint, adding any errors and warnings to [errors] and
  /// [warnings], respectively.
  Future<void> validate();

  /// Adds an error if the package's SDK constraint doesn't exclude Dart SDK
  /// versions older than [firstSdkVersion].
  @protected
  void validateSdkConstraint(Version firstSdkVersion, String message) {
    // If the SDK constraint disallowed all versions before [firstSdkVersion],
    // no error is necessary.
    if (entrypoint.root.pubspec.originalDartSdkConstraint
        .intersect(VersionRange(max: firstSdkVersion))
        .isEmpty) {
      return;
    }

    if (firstSdkVersion.isPreRelease &&
        !_isSamePreRelease(firstSdkVersion, sdk.version)) {
      // Unless the user is using a dev SDK themselves, suggest that they use a
      // non-dev SDK constraint, even if there were some dev versions that are
      // allowed.
      firstSdkVersion = firstSdkVersion.nextPatch;
    }

    var allowedSdks = VersionRange(
        min: firstSdkVersion,
        includeMin: true,
        max: firstSdkVersion.isPreRelease
            ? firstSdkVersion.nextPatch
            : firstSdkVersion.nextBreaking);

    var newSdkConstraint = entrypoint.root.pubspec.originalDartSdkConstraint
        .intersect(allowedSdks);
    if (newSdkConstraint.isEmpty) newSdkConstraint = allowedSdks;

    errors.add('$message\n'
        'Make sure your SDK constraint excludes old versions:\n'
        '\n'
        'environment:\n'
        '  sdk: "$newSdkConstraint"');
  }

  /// Returns whether [version1] and [version2] are pre-releases of the same version.
  bool _isSamePreRelease(Version version1, Version version2) =>
      version1.isPreRelease &&
      version2.isPreRelease &&
      version1.patch == version2.patch &&
      version1.minor == version2.minor &&
      version1.major == version2.major;

  /// Run all validators on the [entrypoint] package and print their results.
  ///
  /// [files] should be the result of `entrypoint.root.listFiles()`.
  ///
  /// When the future completes [hints] [warnings] amd [errors] will have been
  /// appended with the reported hints warnings and errors respectively.
  ///
  /// [packageSize], if passed, should complete to the size of the tarred
  /// package, in bytes. This is used to validate that it's not too big to
  /// upload to the server.
  static Future<void> runAll(Entrypoint entrypoint, Future<int> packageSize,
      Uri serverUrl, List<String> files,
      {required List<String> hints,
      required List<String> warnings,
      required List<String> errors}) async {
    var validators = [
      GitignoreValidator(),
      PubspecValidator(),
      LicenseValidator(),
      NameValidator(),
      PubspecFieldValidator(),
      DependencyValidator(),
      DependencyOverrideValidator(),
      DeprecatedFieldsValidator(),
      DirectoryValidator(),
      ExecutableValidator(),
      CompiledDartdocValidator(),
      ReadmeValidator(),
      ChangelogValidator(),
      SdkConstraintValidator(),
      StrictDependenciesValidator(),
      FlutterConstraintValidator(),
      FlutterPluginFormatValidator(),
      LanguageVersionValidator(),
      RelativeVersionNumberingValidator(),
      NullSafetyMixedModeValidator(),
      PubspecTypoValidator(),
      LeakDetectionValidator(),
      SizeValidator(),
    ];

    final context = ValidationContext(
      entrypoint,
      await packageSize,
      serverUrl,
      files,
    );
    return await Future.wait(validators.map((validator) async {
      validator.context = context;
      await validator.validate();
    })).then((_) {
      hints.addAll([for (final validator in validators) ...validator.hints]);
      warnings
          .addAll([for (final validator in validators) ...validator.warnings]);
      errors.addAll([for (final validator in validators) ...validator.errors]);

      if (errors.isNotEmpty) {
        final s = errors.length > 1 ? 's' : '';
        log.error('Package validation found the following error$s:');
        for (var error in errors) {
          log.error("* ${error.split('\n').join('\n  ')}");
        }
        log.error('');
      }

      if (warnings.isNotEmpty) {
        final s = warnings.length > 1 ? 's' : '';
        log.warning(
          'Package validation found the following potential issue$s:',
        );
        for (var warning in warnings) {
          log.warning("* ${warning.split('\n').join('\n  ')}");
        }
        log.warning('');
      }

      if (hints.isNotEmpty) {
        final s = hints.length > 1 ? 's' : '';
        log.warning(
          'Package validation found the following hint$s:',
        );
        for (var hint in hints) {
          log.warning("* ${hint.split('\n').join('\n  ')}");
        }
        log.warning('');
      }
    });
  }

  /// Returns the [files] that are inside [dir] (relative to the package
  /// entrypoint).
  // TODO(sigurdm): Consider moving this to a more central location.
  List<String> filesBeneath(String dir, {required bool recursive}) {
    final base = p.canonicalize(p.join(entrypoint.root.dir, dir));
    return files
        .where(
          recursive
              ? (file) => p.canonicalize(file).startsWith(base)
              : (file) => p.canonicalize(p.dirname(file)) == base,
        )
        .toList();
  }
}

class ValidationContext {
  final Entrypoint entrypoint;
  final int packageSize;
  final Uri serverUrl;
  final List<String> files;

  ValidationContext(
      this.entrypoint, this.packageSize, this.serverUrl, this.files);
}