// Copyright (c) 2018, 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.

library kernel.text_serializer;

import '../ast.dart';

import 'serializer_combinators.dart';

import '../visitor.dart' show ExpressionVisitor;

abstract class Tagger<T extends Node> {
  String tag(T node);
}

class NameTagger implements Tagger<Name> {
  const NameTagger();

  String tag(Name name) => name.isPrivate ? "private" : "public";
}

TextSerializer<Name> publicName =
    new Wrapped(unwrapPublicName, wrapPublicName, const DartString());

String unwrapPublicName(Name name) => name.name;

Name wrapPublicName(String name) => new Name(name);

TextSerializer<Name> privateName = new Wrapped(unwrapPrivateName,
    wrapPrivateName, Tuple2Serializer(const DartString(), const DartString()));

Tuple2<String, String> unwrapPrivateName(Name name) {
  return new Tuple2(name.library.importUri.toString(), name.name);
}

Name wrapPrivateName(Tuple2<String, String> tuple) {
  // We need a map from import URI to libraries.  More generally, we will need
  // a way to map any 'named' node to the node's reference.
  throw UnimplementedError('deserialization of private names');
}

TextSerializer<Name> nameSerializer = new Case(const NameTagger(), [
  "public",
  "private",
], [
  publicName,
  privateName
]);

class ExpressionTagger extends ExpressionVisitor<String>
    implements Tagger<Expression> {
  const ExpressionTagger();

  String tag(Expression expression) => expression.accept(this);

  String visitStringLiteral(StringLiteral _) => "string";
  String visitIntLiteral(IntLiteral _) => "int";
  String visitDoubleLiteral(DoubleLiteral _) => "double";
  String visitBoolLiteral(BoolLiteral _) => "bool";
  String visitNullLiteral(NullLiteral _) => "null";
  String visitInvalidExpression(InvalidExpression _) => "invalid";
  String visitNot(Not _) => "not";
  String visitLogicalExpression(LogicalExpression expression) {
    return expression.operator;
  }

  String visitStringConcatenation(StringConcatenation _) => "concat";
  String visitSymbolLiteral(SymbolLiteral _) => "symbol";
  String visitThisExpression(ThisExpression _) => "this";
  String visitRethrow(Rethrow _) => "rethrow";
  String visitThrow(Throw _) => "throw";
  String visitAwaitExpression(AwaitExpression _) => "await";
  String visitConditionalExpression(ConditionalExpression _) => "cond";
  String visitIsExpression(IsExpression _) => "is";
  String visitAsExpression(AsExpression _) => "as";
  String visitTypeLiteral(TypeLiteral _) => "type";
  String visitListLiteral(ListLiteral expression) {
    return expression.isConst ? "const-list" : "list";
  }

  String visitSetLiteral(SetLiteral expression) {
    return expression.isConst ? "const-set" : "set";
  }

  String visitMapLiteral(MapLiteral expression) {
    return expression.isConst ? "const-map" : "map";
  }

  String visitLet(Let _) => "let";
}

TextSerializer<InvalidExpression> invalidExpressionSerializer = new Wrapped(
    unwrapInvalidExpression, wrapInvalidExpression, const DartString());

String unwrapInvalidExpression(InvalidExpression expression) {
  return expression.message;
}

InvalidExpression wrapInvalidExpression(String message) {
  return new InvalidExpression(message);
}

TextSerializer<Not> notSerializer =
    new Wrapped(unwrapNot, wrapNot, expressionSerializer);

Expression unwrapNot(Not expression) => expression.operand;

Not wrapNot(Expression operand) => new Not(operand);

TextSerializer<LogicalExpression> logicalAndSerializer = new Wrapped(
    unwrapLogicalExpression,
    wrapLogicalAnd,
    new Tuple2Serializer(expressionSerializer, expressionSerializer));

Tuple2<Expression, Expression> unwrapLogicalExpression(
    LogicalExpression expression) {
  return new Tuple2(expression.left, expression.right);
}

LogicalExpression wrapLogicalAnd(Tuple2<Expression, Expression> tuple) {
  return new LogicalExpression(tuple.first, '&&', tuple.second);
}

TextSerializer<LogicalExpression> logicalOrSerializer = new Wrapped(
    unwrapLogicalExpression,
    wrapLogicalOr,
    new Tuple2Serializer(expressionSerializer, expressionSerializer));

LogicalExpression wrapLogicalOr(Tuple2<Expression, Expression> tuple) {
  return new LogicalExpression(tuple.first, '||', tuple.second);
}

TextSerializer<StringConcatenation> stringConcatenationSerializer = new Wrapped(
    unwrapStringConcatenation,
    wrapStringConcatenation,
    new ListSerializer(expressionSerializer));

List<Expression> unwrapStringConcatenation(StringConcatenation expression) {
  return expression.expressions;
}

StringConcatenation wrapStringConcatenation(List<Expression> expressions) {
  return new StringConcatenation(expressions);
}

TextSerializer<StringLiteral> stringLiteralSerializer =
    new Wrapped(unwrapStringLiteral, wrapStringLiteral, const DartString());

String unwrapStringLiteral(StringLiteral literal) => literal.value;

StringLiteral wrapStringLiteral(String value) => new StringLiteral(value);

TextSerializer<IntLiteral> intLiteralSerializer =
    new Wrapped(unwrapIntLiteral, wrapIntLiteral, const DartInt());

int unwrapIntLiteral(IntLiteral literal) => literal.value;

IntLiteral wrapIntLiteral(int value) => new IntLiteral(value);

TextSerializer<DoubleLiteral> doubleLiteralSerializer =
    new Wrapped(unwrapDoubleLiteral, wrapDoubleLiteral, const DartDouble());

double unwrapDoubleLiteral(DoubleLiteral literal) => literal.value;

DoubleLiteral wrapDoubleLiteral(double value) => new DoubleLiteral(value);

TextSerializer<BoolLiteral> boolLiteralSerializer =
    new Wrapped(unwrapBoolLiteral, wrapBoolLiteral, const DartBool());

bool unwrapBoolLiteral(BoolLiteral literal) => literal.value;

BoolLiteral wrapBoolLiteral(bool value) => new BoolLiteral(value);

TextSerializer<NullLiteral> nullLiteralSerializer =
    new Wrapped(unwrapNullLiteral, wrapNullLiteral, const Nothing());

void unwrapNullLiteral(NullLiteral literal) {}

NullLiteral wrapNullLiteral(void ignored) => new NullLiteral();

TextSerializer<SymbolLiteral> symbolLiteralSerializer =
    new Wrapped(unwrapSymbolLiteral, wrapSymbolLiteral, const DartString());

String unwrapSymbolLiteral(SymbolLiteral expression) => expression.value;

SymbolLiteral wrapSymbolLiteral(String value) => new SymbolLiteral(value);

TextSerializer<ThisExpression> thisExpressionSerializer =
    new Wrapped(unwrapThisExpression, wrapThisExpression, const Nothing());

void unwrapThisExpression(ThisExpression expression) {}

ThisExpression wrapThisExpression(void ignored) => new ThisExpression();

TextSerializer<Rethrow> rethrowSerializer =
    new Wrapped(unwrapRethrow, wrapRethrow, const Nothing());

void unwrapRethrow(Rethrow expression) {}

Rethrow wrapRethrow(void ignored) => new Rethrow();

TextSerializer<Throw> throwSerializer =
    new Wrapped(unwrapThrow, wrapThrow, expressionSerializer);

Expression unwrapThrow(Throw expression) => expression.expression;

Throw wrapThrow(Expression expression) => new Throw(expression);

TextSerializer<AwaitExpression> awaitExpressionSerializer = new Wrapped(
    unwrapAwaitExpression, wrapAwaitExpression, expressionSerializer);

Expression unwrapAwaitExpression(AwaitExpression expression) =>
    expression.operand;

AwaitExpression wrapAwaitExpression(Expression operand) =>
    new AwaitExpression(operand);

TextSerializer<ConditionalExpression> conditionalExpressionSerializer =
    new Wrapped(
        unwrapConditionalExpression,
        wrapConditionalExpression,
        new Tuple4Serializer(expressionSerializer, dartTypeSerializer,
            expressionSerializer, expressionSerializer));

Tuple4<Expression, DartType, Expression, Expression>
    unwrapConditionalExpression(ConditionalExpression expression) {
  return new Tuple4(expression.condition, expression.staticType,
      expression.then, expression.otherwise);
}

ConditionalExpression wrapConditionalExpression(
    Tuple4<Expression, DartType, Expression, Expression> tuple) {
  return new ConditionalExpression(
      tuple.first, tuple.third, tuple.fourth, tuple.second);
}

TextSerializer<IsExpression> isExpressionSerializer = new Wrapped(
    unwrapIsExpression,
    wrapIsExpression,
    new Tuple2Serializer(expressionSerializer, dartTypeSerializer));

Tuple2<Expression, DartType> unwrapIsExpression(IsExpression expression) {
  return new Tuple2(expression.operand, expression.type);
}

IsExpression wrapIsExpression(Tuple2<Expression, DartType> tuple) {
  return new IsExpression(tuple.first, tuple.second);
}

TextSerializer<AsExpression> asExpressionSerializer = new Wrapped(
    unwrapAsExpression,
    wrapAsExpression,
    new Tuple2Serializer(expressionSerializer, dartTypeSerializer));

Tuple2<Expression, DartType> unwrapAsExpression(AsExpression expression) {
  return new Tuple2(expression.operand, expression.type);
}

AsExpression wrapAsExpression(Tuple2<Expression, DartType> tuple) {
  return new AsExpression(tuple.first, tuple.second);
}

TextSerializer<TypeLiteral> typeLiteralSerializer =
    new Wrapped(unwrapTypeLiteral, wrapTypeLiteral, dartTypeSerializer);

DartType unwrapTypeLiteral(TypeLiteral expression) => expression.type;

TypeLiteral wrapTypeLiteral(DartType type) => new TypeLiteral(type);

TextSerializer<ListLiteral> listLiteralSerializer = new Wrapped(
    unwrapListLiteral,
    wrapListLiteral,
    new Tuple2Serializer(
        dartTypeSerializer, new ListSerializer(expressionSerializer)));

Tuple2<DartType, List<Expression>> unwrapListLiteral(ListLiteral expression) {
  return new Tuple2(expression.typeArgument, expression.expressions);
}

ListLiteral wrapListLiteral(Tuple2<DartType, List<Expression>> tuple) {
  return new ListLiteral(tuple.second,
      typeArgument: tuple.first, isConst: false);
}

TextSerializer<ListLiteral> constListLiteralSerializer = new Wrapped(
    unwrapListLiteral,
    wrapConstListLiteral,
    new Tuple2Serializer(
        dartTypeSerializer, new ListSerializer(expressionSerializer)));

ListLiteral wrapConstListLiteral(Tuple2<DartType, List<Expression>> tuple) {
  return new ListLiteral(tuple.second,
      typeArgument: tuple.first, isConst: true);
}

TextSerializer<SetLiteral> setLiteralSerializer = new Wrapped(
    unwrapSetLiteral,
    wrapSetLiteral,
    new Tuple2Serializer(
        dartTypeSerializer, new ListSerializer(expressionSerializer)));

Tuple2<DartType, List<Expression>> unwrapSetLiteral(SetLiteral expression) {
  return new Tuple2(expression.typeArgument, expression.expressions);
}

SetLiteral wrapSetLiteral(Tuple2<DartType, List<Expression>> tuple) {
  return new SetLiteral(tuple.second,
      typeArgument: tuple.first, isConst: false);
}

TextSerializer<SetLiteral> constSetLiteralSerializer = new Wrapped(
    unwrapSetLiteral,
    wrapConstSetLiteral,
    new Tuple2Serializer(
        dartTypeSerializer, new ListSerializer(expressionSerializer)));

SetLiteral wrapConstSetLiteral(Tuple2<DartType, List<Expression>> tuple) {
  return new SetLiteral(tuple.second, typeArgument: tuple.first, isConst: true);
}

TextSerializer<MapLiteral> mapLiteralSerializer = new Wrapped(
    unwrapMapLiteral,
    wrapMapLiteral,
    new Tuple3Serializer(dartTypeSerializer, dartTypeSerializer,
        new ListSerializer(expressionSerializer)));

Tuple3<DartType, DartType, List<Expression>> unwrapMapLiteral(
    MapLiteral expression) {
  List<Expression> entries = new List(2 * expression.entries.length);
  for (int from = 0, to = 0; from < expression.entries.length; ++from) {
    MapEntry entry = expression.entries[from];
    entries[to++] = entry.key;
    entries[to++] = entry.value;
  }
  return new Tuple3(expression.keyType, expression.valueType, entries);
}

MapLiteral wrapMapLiteral(Tuple3<DartType, DartType, List<Expression>> tuple) {
  List<MapEntry> entries = new List(tuple.third.length ~/ 2);
  for (int from = 0, to = 0; to < entries.length; ++to) {
    entries[to] = new MapEntry(tuple.third[from++], tuple.third[from++]);
  }
  return new MapLiteral(entries,
      keyType: tuple.first, valueType: tuple.second, isConst: false);
}

TextSerializer<MapLiteral> constMapLiteralSerializer = new Wrapped(
    unwrapMapLiteral,
    wrapConstMapLiteral,
    new Tuple3Serializer(dartTypeSerializer, dartTypeSerializer,
        new ListSerializer(expressionSerializer)));

MapLiteral wrapConstMapLiteral(
    Tuple3<DartType, DartType, List<Expression>> tuple) {
  List<MapEntry> entries = new List(tuple.third.length ~/ 2);
  for (int from = 0, to = 0; to < entries.length; ++to) {
    entries[to] = new MapEntry(tuple.third[from++], tuple.third[from++]);
  }
  return new MapLiteral(entries,
      keyType: tuple.first, valueType: tuple.second, isConst: true);
}

TextSerializer<Let> letSerializer = new Wrapped(unwrapLet, wrapLet,
    new Tuple2Serializer(variableDeclarationSerializer, expressionSerializer));

Tuple2<VariableDeclaration, Expression> unwrapLet(Let expression) {
  return new Tuple2(expression.variable, expression.body);
}

Let wrapLet(Tuple2<VariableDeclaration, Expression> tuple) {
  return new Let(tuple.first, tuple.second);
}

Case<Expression> expressionSerializer =
    new Case.uninitialized(const ExpressionTagger());

class VariableDeclarationTagger implements Tagger<VariableDeclaration> {
  const VariableDeclarationTagger();

  String tag(VariableDeclaration decl) {
    if (decl.isCovariant) throw UnimplementedError("covariant declaration");
    if (decl.isFieldFormal) throw UnimplementedError("initializing formal");
    if (decl.isConst) {
      // It's not clear what invariants we assume about const/final.  For now
      // throw if we have both.
      if (decl.isFinal) throw UnimplementedError("const and final");
      return "const";
    }
    if (decl.isFinal) {
      return "final";
    }
    return "var";
  }
}

TextSerializer<VariableDeclaration> varDeclarationSerializer = new Wrapped(
    unwrapVariableDeclaration,
    wrapVarDeclaration,
    Tuple4Serializer(
        const DartString(),
        dartTypeSerializer,
        new Optional(expressionSerializer),
        new ListSerializer(expressionSerializer)));

Tuple4<String, DartType, Expression, List<Expression>>
    unwrapVariableDeclaration(VariableDeclaration declaration) {
  return new Tuple4(declaration.name ?? "", declaration.type,
      declaration.initializer, declaration.annotations);
}

VariableDeclaration wrapVarDeclaration(
    Tuple4<String, DartType, Expression, List<Expression>> tuple) {
  var result = new VariableDeclaration(tuple.first.isEmpty ? null : tuple.first,
      initializer: tuple.third, type: tuple.second);
  for (int i = 0; i < tuple.fourth.length; ++i) {
    result.addAnnotation(tuple.fourth[i]);
  }
  return result;
}

TextSerializer<VariableDeclaration> finalDeclarationSerializer = new Wrapped(
    unwrapVariableDeclaration,
    wrapFinalDeclaration,
    Tuple4Serializer(
        const DartString(),
        dartTypeSerializer,
        new Optional(expressionSerializer),
        new ListSerializer(expressionSerializer)));

VariableDeclaration wrapFinalDeclaration(
    Tuple4<String, DartType, Expression, List<Expression>> tuple) {
  var result = new VariableDeclaration(tuple.first.isEmpty ? null : tuple.first,
      initializer: tuple.third, type: tuple.second, isFinal: true);
  for (int i = 0; i < tuple.fourth.length; ++i) {
    result.addAnnotation(tuple.fourth[i]);
  }
  return result;
}

TextSerializer<VariableDeclaration> constDeclarationSerializer = new Wrapped(
    unwrapVariableDeclaration,
    wrapConstDeclaration,
    Tuple4Serializer(
        const DartString(),
        dartTypeSerializer,
        new Optional(expressionSerializer),
        new ListSerializer(expressionSerializer)));

VariableDeclaration wrapConstDeclaration(
    Tuple4<String, DartType, Expression, List<Expression>> tuple) {
  var result = new VariableDeclaration(tuple.first.isEmpty ? null : tuple.first,
      initializer: tuple.third, type: tuple.second, isConst: true);
  for (int i = 0; i < tuple.fourth.length; ++i) {
    result.addAnnotation(tuple.fourth[i]);
  }
  return result;
}

TextSerializer<VariableDeclaration> variableDeclarationSerializer =
    new Case(const VariableDeclarationTagger(), [
  "var",
  "final",
  "const",
], [
  varDeclarationSerializer,
  finalDeclarationSerializer,
  constDeclarationSerializer,
]);

class DartTypeTagger extends DartTypeVisitor<String>
    implements Tagger<DartType> {
  const DartTypeTagger();

  String tag(DartType type) => type.accept(this);

  String visitInvalidType(InvalidType _) => "invalid";
  String visitDynamicType(DynamicType _) => "dynamic";
  String visitVoidType(VoidType _) => "void";
  String visitBottomType(BottomType _) => "bottom";
}

TextSerializer<InvalidType> invalidTypeSerializer =
    new Wrapped(unwrapInvalidType, wrapInvalidType, const Nothing());

void unwrapInvalidType(InvalidType type) {}

InvalidType wrapInvalidType(void ignored) => const InvalidType();

TextSerializer<DynamicType> dynamicTypeSerializer =
    new Wrapped(unwrapDynamicType, wrapDynamicType, const Nothing());

void unwrapDynamicType(DynamicType type) {}

DynamicType wrapDynamicType(void ignored) => const DynamicType();

TextSerializer<VoidType> voidTypeSerializer =
    new Wrapped(unwrapVoidType, wrapVoidType, const Nothing());

void unwrapVoidType(VoidType type) {}

VoidType wrapVoidType(void ignored) => const VoidType();

TextSerializer<BottomType> bottomTypeSerializer =
    new Wrapped(unwrapBottomType, wrapBottomType, const Nothing());

void unwrapBottomType(BottomType type) {}

BottomType wrapBottomType(void ignored) => const BottomType();

Case<DartType> dartTypeSerializer =
    new Case.uninitialized(const DartTypeTagger());

void initializeSerializers() {
  expressionSerializer.tags.addAll([
    "string",
    "int",
    "double",
    "bool",
    "null",
    "invalid",
    "not",
    "&&",
    "||",
    "concat",
    "symbol",
    "this",
    "rethrow",
    "throw",
    "await",
    "cond",
    "is",
    "as",
    "type",
    "list",
    "const-list",
    "set",
    "const-set",
    "map",
    "const-map",
    "let",
  ]);
  expressionSerializer.serializers.addAll([
    stringLiteralSerializer,
    intLiteralSerializer,
    doubleLiteralSerializer,
    boolLiteralSerializer,
    nullLiteralSerializer,
    invalidExpressionSerializer,
    notSerializer,
    logicalAndSerializer,
    logicalOrSerializer,
    stringConcatenationSerializer,
    symbolLiteralSerializer,
    thisExpressionSerializer,
    rethrowSerializer,
    throwSerializer,
    awaitExpressionSerializer,
    conditionalExpressionSerializer,
    isExpressionSerializer,
    asExpressionSerializer,
    typeLiteralSerializer,
    listLiteralSerializer,
    constListLiteralSerializer,
    setLiteralSerializer,
    constSetLiteralSerializer,
    mapLiteralSerializer,
    constMapLiteralSerializer,
    letSerializer,
  ]);
  dartTypeSerializer.tags.addAll([
    "invalid",
    "dynamic",
    "void",
    "bottom",
  ]);
  dartTypeSerializer.serializers.addAll([
    invalidTypeSerializer,
    dynamicTypeSerializer,
    voidTypeSerializer,
    bottomTypeSerializer,
  ]);
}