// Copyright (c) 2014, 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.

/// Tools for Java code generation.
library;

import 'package:analyzer_utilities/html_dom.dart' as dom;
import 'package:analyzer_utilities/tools.dart';

import 'api.dart';
import 'from_html.dart';
import 'to_html.dart';

/// Create a [GeneratedFile] that creates Java code and outputs it to [path].
/// [path] uses Posix-style path separators regardless of the OS.
GeneratedFile javaGeneratedFile(
  String path,
  CodegenJavaVisitor Function(Api api) createVisitor,
) {
  return GeneratedFile(path, (pkgRoot) async {
    var visitor = createVisitor(readApi(pkgRoot));
    return visitor.collectCode(visitor.visitApi);
  });
}

/// Iterate through the values in [map] in the order of increasing keys.
Iterable<String> _valuesSortedByKey(Map<String, String> map) {
  var entries = map.entries.toList();
  entries.sort((a, b) => a.key.compareTo(b.key));
  return entries.map((e) => e.value);
}

/// Common code for all Java code generation.
class CodegenJavaVisitor extends HierarchicalApiVisitor with CodeGenerator {
  /// Variable names which must be changed in order to avoid conflict with
  /// reserved words in Java.
  static const Map<String, String> _variableRenames = {'default': 'defaultSdk'};

  /// Type references in the spec that are named something else in Java.
  static const Map<String, String> _typeRenames = {
    'bool': 'boolean',
    'double': 'double',
    'int': 'int',
    'AvailableSuggestionRelevanceTag': 'String',
    'ExecutionContextId': 'String',
    'FilePath': 'String',
    'DebugContextId': 'String',
    'object': 'Object',
    'Override': 'OverrideMember',
  };

  _CodegenJavaState _state = _CodegenJavaState();

  /// Visitor used to produce doc comments.
  final ToHtmlVisitor toHtmlVisitor;

  new(super.api) : toHtmlVisitor = ToHtmlVisitor(api);

  /// Create a constructor, using [callback] to create its contents.
  void constructor(String name, void Function() callback) {
    _state.constructors[name] = collectCode(callback);
  }

  /// Get the name of the consumer class for responses to this request.
  String consumerName(Request request) {
    return camelJoin([request.method, 'consumer'], doCapitalize: true);
  }

  /// Return true iff the passed [TypeDecl] will represent an array in Java.
  bool isArray(TypeDecl type) {
    return type is TypeList && isPrimitive(type.itemType);
  }

  /// Return true iff the passed [TypeDecl] is a type declared in the
  /// spec_input.
  bool isDeclaredInSpec(TypeDecl type) {
    //    TypeReference resolvedType = super.resolveTypeReferenceChain(type);
    //    if(resolvedType is TypeObject) {
    //      return true;
    //    }
    if (type is TypeReference) {
      return api.types.containsKey(type.typeName) && javaType(type) != 'String';
    }
    return false;
  }

  /// Return true iff the passed [TypeDecl] will represent an array in Java.
  bool isList(TypeDecl type) {
    return type is TypeList && !isPrimitive(type.itemType);
  }

  /// Return true iff the passed [TypeDecl] will represent a Map in type.
  bool isMap(TypeDecl type) {
    return type is TypeMap;
  }

  /// Return true iff the passed [TypeDecl] will be represented as Object in
  /// Java.
  bool isObject(TypeDecl type) {
    var typeStr = javaType(type);
    return typeStr == 'Object';
  }

  /// Return true iff the passed [TypeDecl] will represent a primitive Java
  /// type.
  bool isPrimitive(TypeDecl type) {
    if (type is TypeReference) {
      var typeStr = javaType(type);
      return typeStr == 'boolean' ||
          typeStr == 'double' ||
          typeStr == 'int' ||
          typeStr == 'long';
    }
    return false;
  }

  /// Convenience method for subclasses for calling docComment.
  void javadocComment(List<dom.Node> docs) {
    docComment(docs);
  }

  /// Return a Java type for the given [TypeObjectField].
  String javaFieldType(TypeObjectField field) {
    return javaType(field.type, field.optional);
  }

  /// Return a suitable representation of [name] as the name of a Java variable.
  String javaName(String name) {
    return _variableRenames[name] ?? name;
  }

  /// Convert the given [TypeDecl] to a Java type.
  String javaType(TypeDecl type, [bool optional = false]) {
    if (type is TypeReference) {
      var resolvedType = resolveTypeReferenceChain(type) as TypeReference;
      var typeName = resolvedType.typeName;
      var renameTo = _typeRenames[typeName];
      if (renameTo != null) {
        typeName = renameTo;
        if (optional) {
          if (typeName == 'boolean') {
            typeName = 'Boolean';
          } else if (typeName == 'double') {
            typeName = 'Double';
          } else if (typeName == 'int') {
            typeName = 'Integer';
          }
        }
      }
      return typeName;
    } else if (type is TypeList) {
      if (isPrimitive(type.itemType)) {
        return '${javaType(type.itemType)}[]';
      } else {
        return 'List<${javaType(type.itemType)}>';
      }
    } else if (type is TypeMap) {
      return 'Map<${javaType(type.keyType)}, ${javaType(type.valueType)}>';
    } else if (type is TypeUnion) {
      return 'Object';
    } else {
      throw Exception("Can't make type buildable");
    }
  }

  /// Execute [callback], collecting any methods that are output using
  /// [privateMethod] or [publicMethod], and insert the class (with methods
  /// sorted).  [header] is the part of the class declaration before the
  /// opening brace.
  void makeClass(String header, void Function() callback) {
    var oldState = _state;
    try {
      _state = _CodegenJavaState();
      callback();
      writeln('$header {');
      indent(() {
        // fields
        var allFields = _state.publicFields.values.toList();
        allFields.addAll(_state.privateFields.values.toList());
        for (var field in allFields) {
          writeln();
          write(field);
        }

        // constructors
        var allConstructors = _state.constructors.values.toList();
        for (var constructor in allConstructors) {
          writeln();
          write(constructor);
        }

        // methods (ordered by method name)
        var allMethods = _valuesSortedByKey(_state.publicMethods).toList();
        allMethods.addAll(_valuesSortedByKey(_state.privateMethods));
        for (var method in allMethods) {
          writeln();
          write(method);
        }
        writeln();
      });
      writeln('}');
    } finally {
      _state = oldState;
    }
  }

  /// Create a private field, using [callback] to create its contents.
  void privateField(String fieldName, void Function() callback) {
    _state.privateFields[fieldName] = collectCode(callback);
  }

  /// Create a private method, using [callback] to create its contents.
  void privateMethod(String methodName, void Function() callback) {
    _state.privateMethods[methodName] = collectCode(callback);
  }

  /// Create a public field, using [callback] to create its contents.
  void publicField(String fieldName, void Function() callback) {
    _state.publicFields[fieldName] = collectCode(callback);
  }

  /// Create a public method, using [callback] to create its contents.
  void publicMethod(String methodName, void Function() callback) {
    _state.publicMethods[methodName] = collectCode(callback);
  }

  @override
  TypeDecl resolveTypeReferenceChain(TypeDecl type) {
    var typeDecl = super.resolveTypeReferenceChain(type);
    if (typeDecl is TypeEnum) {
      return TypeReference('String', null);
    }
    return type;
  }
}

/// State used by [CodegenJavaVisitor].
class _CodegenJavaState {
  /// Temporary storage for public methods.
  Map<String, String> publicMethods = <String, String>{};

  /// Temporary storage for private methods.
  Map<String, String> privateMethods = <String, String>{};

  /// Temporary storage for public fields.
  Map<String, String> publicFields = <String, String>{};

  /// Temporary storage for private fields.
  Map<String, String> privateFields = <String, String>{};

  /// Temporary storage for constructors.
  Map<String, String> constructors = <String, String>{};
}
