// Copyright (c) 2015, 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 'package:analyzer/error/error.dart';
import 'package:analyzer/src/generated/engine.dart';
import 'package:analyzer/src/generated/utilities_general.dart';
import 'package:analyzer/src/task/options.dart';
import 'package:analyzer/src/util/yaml.dart';
import 'package:yaml/yaml.dart';

/// String identifiers mapped to associated severities.
const Map<String, ErrorSeverity> severityMap = {
  'error': ErrorSeverity.ERROR,
  'info': ErrorSeverity.INFO,
  'warning': ErrorSeverity.WARNING
};

/// Error processor configuration derived from analysis (or embedder) options.
class ErrorConfig {
  /// The processors in this config.
  final List<ErrorProcessor> processors = <ErrorProcessor>[];

  /// Create an error config for the given error code map.
  /// For example:
  ///     new ErrorConfig({'missing_return' : 'error'});
  /// will create a processor config that turns `missing_return` warnings into
  /// errors.
  ErrorConfig(YamlNode? codeMap) {
    _processMap(codeMap);
  }

  void _process(String? code, Object action) {
    code = toUpperCase(code);
    var actionStr = toLowerCase(action);
    if (AnalyzerOptions.ignoreSynonyms.contains(actionStr)) {
      processors.add(ErrorProcessor.ignore(code!));
    } else {
      var severity = _toSeverity(actionStr);
      if (severity != null) {
        processors.add(ErrorProcessor(code!, severity));
      }
    }
  }

  void _processMap(YamlNode? codes) {
    if (codes is YamlMap) {
      codes.nodes.forEach((k, v) {
        if (k is YamlScalar && v is YamlScalar) {
          _process(k.value as String?, v.valueOrThrow);
        }
      });
    }
  }

  ErrorSeverity? _toSeverity(String? severity) => severityMap[severity];
}

/// Process errors by filtering or changing associated [ErrorSeverity].
class ErrorProcessor {
  /// The code name of the associated error.
  final String code;

  /// The desired severity of the processed error.
  ///
  /// If `null`, this processor will "filter" the associated error code.
  final ErrorSeverity? severity;

  /// Create an error processor that assigns errors with this [code] the
  /// given [severity].
  ///
  /// If [severity] is `null`, matching errors will be filtered.
  ErrorProcessor(this.code, [this.severity]);

  /// Create an error processor that ignores the given error by [code].
  factory ErrorProcessor.ignore(String code) => ErrorProcessor(code);

  /// The string that unique describes the processor.
  String get description => '$code -> ${severity?.name}';

  /// Check if this processor applies to the given [error].
  ///
  /// Note: [code] is normalized to uppercase; `errorCode.name` for regular
  /// analysis issues uses uppercase; `errorCode.name` for lints uses lowercase.
  bool appliesTo(AnalysisError error) =>
      code == error.errorCode.name ||
      code == error.errorCode.name.toUpperCase();

  /// Return an error processor associated in the [analysisOptions] for the
  /// given [error], or `null` if none is found.
  static ErrorProcessor? getProcessor(
      AnalysisOptions? analysisOptions, AnalysisError error) {
    if (analysisOptions == null) {
      return null;
    }

    // Let the user configure how specific errors are processed.
    List<ErrorProcessor> processors = analysisOptions.errorProcessors;

    // Add the strong mode processor.
    processors = processors.toList();
    for (var processor in processors) {
      if (processor.appliesTo(error)) {
        return processor;
      }
    }
    return null;
  }
}