/*
 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.
 * Copyright (C) 2011, 2013-2024 The JavaParser Team.
 *
 * This file is part of JavaParser.
 *
 * JavaParser can be used either under the terms of
 * a) the GNU Lesser General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * b) the terms of the Apache License
 *
 * You should have received a copy of both licenses in LICENCE.LGPL and
 * LICENCE.APACHE. Please refer to those files for details.
 *
 * JavaParser is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 */
package com.github.javaparser.ast.body;

import static com.github.javaparser.ast.Modifier.Keyword.PUBLIC;
import static com.github.javaparser.utils.Utils.assertNotNull;

import com.github.javaparser.TokenRange;
import com.github.javaparser.ast.*;
import com.github.javaparser.ast.Modifier.Keyword;
import com.github.javaparser.ast.expr.AnnotationExpr;
import com.github.javaparser.ast.expr.SimpleName;
import com.github.javaparser.ast.nodeTypes.*;
import com.github.javaparser.ast.nodeTypes.modifiers.*;
import com.github.javaparser.ast.observer.ObservableProperty;
import com.github.javaparser.ast.stmt.BlockStmt;
import com.github.javaparser.ast.type.ClassOrInterfaceType;
import com.github.javaparser.ast.type.ReferenceType;
import com.github.javaparser.ast.type.Type;
import com.github.javaparser.ast.type.TypeParameter;
import com.github.javaparser.ast.visitor.CloneVisitor;
import com.github.javaparser.ast.visitor.GenericVisitor;
import com.github.javaparser.ast.visitor.VoidVisitor;
import com.github.javaparser.metamodel.JavaParserMetaModel;
import com.github.javaparser.metamodel.MethodDeclarationMetaModel;
import com.github.javaparser.metamodel.OptionalProperty;
import com.github.javaparser.resolution.Resolvable;
import com.github.javaparser.resolution.declarations.ResolvedMethodDeclaration;
import java.util.Arrays;
import java.util.Optional;
import java.util.function.Consumer;

/**
 * A method declaration. "public int abc() {return 1;}" in this example: {@code class X { public int abc() {return 1;}
 * }}
 * <p>
 * <br>All annotations preceding the return type will be set on this object, not on the return type.
 * JavaParser doesn't know if it they are applicable to the method or the type.
 *
 * @author Julio Vilmar Gesser
 */
public class MethodDeclaration extends CallableDeclaration<MethodDeclaration>
        implements NodeWithType<MethodDeclaration, Type>,
                NodeWithOptionalBlockStmt<MethodDeclaration>,
                NodeWithJavadoc<MethodDeclaration>,
                NodeWithDeclaration,
                NodeWithSimpleName<MethodDeclaration>,
                NodeWithParameters<MethodDeclaration>,
                NodeWithThrownExceptions<MethodDeclaration>,
                NodeWithTypeParameters<MethodDeclaration>,
                NodeWithAccessModifiers<MethodDeclaration>,
                NodeWithAbstractModifier<MethodDeclaration>,
                NodeWithStaticModifier<MethodDeclaration>,
                NodeWithFinalModifier<MethodDeclaration>,
                NodeWithStrictfpModifier<MethodDeclaration>,
                Resolvable<ResolvedMethodDeclaration> {

    private Type type;

    @OptionalProperty
    private BlockStmt body;

    public MethodDeclaration() {
        this(
                null,
                new NodeList<>(),
                new NodeList<>(),
                new NodeList<>(),
                new ClassOrInterfaceType(),
                new SimpleName(),
                new NodeList<>(),
                new NodeList<>(),
                new BlockStmt(),
                null);
    }

    public MethodDeclaration(final NodeList<Modifier> modifiers, final Type type, final String name) {
        this(
                null,
                modifiers,
                new NodeList<>(),
                new NodeList<>(),
                type,
                new SimpleName(name),
                new NodeList<>(),
                new NodeList<>(),
                new BlockStmt(),
                null);
    }

    public MethodDeclaration(
            final NodeList<Modifier> modifiers,
            final String name,
            final Type type,
            final NodeList<Parameter> parameters) {
        this(
                null,
                modifiers,
                new NodeList<>(),
                new NodeList<>(),
                type,
                new SimpleName(name),
                parameters,
                new NodeList<>(),
                new BlockStmt(),
                null);
    }

    public MethodDeclaration(
            final NodeList<Modifier> modifiers,
            final NodeList<AnnotationExpr> annotations,
            final NodeList<TypeParameter> typeParameters,
            final Type type,
            final SimpleName name,
            final NodeList<Parameter> parameters,
            final NodeList<ReferenceType> thrownExceptions,
            final BlockStmt body) {
        this(null, modifiers, annotations, typeParameters, type, name, parameters, thrownExceptions, body, null);
    }

    @AllFieldsConstructor
    public MethodDeclaration(
            final NodeList<Modifier> modifiers,
            final NodeList<AnnotationExpr> annotations,
            final NodeList<TypeParameter> typeParameters,
            final Type type,
            final SimpleName name,
            final NodeList<Parameter> parameters,
            final NodeList<ReferenceType> thrownExceptions,
            final BlockStmt body,
            ReceiverParameter receiverParameter) {
        this(
                null,
                modifiers,
                annotations,
                typeParameters,
                type,
                name,
                parameters,
                thrownExceptions,
                body,
                receiverParameter);
    }

    /**
     * This constructor is used by the parser and is considered private.
     */
    @Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator")
    public MethodDeclaration(
            TokenRange tokenRange,
            NodeList<Modifier> modifiers,
            NodeList<AnnotationExpr> annotations,
            NodeList<TypeParameter> typeParameters,
            Type type,
            SimpleName name,
            NodeList<Parameter> parameters,
            NodeList<ReferenceType> thrownExceptions,
            BlockStmt body,
            ReceiverParameter receiverParameter) {
        super(
                tokenRange,
                modifiers,
                annotations,
                typeParameters,
                name,
                parameters,
                thrownExceptions,
                receiverParameter);
        setType(type);
        setBody(body);
        customInitialization();
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.AcceptGenerator")
    public <R, A> R accept(final GenericVisitor<R, A> v, final A arg) {
        return v.visit(this, arg);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.AcceptGenerator")
    public <A> void accept(final VoidVisitor<A> v, final A arg) {
        v.visit(this, arg);
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public Optional<BlockStmt> getBody() {
        return Optional.ofNullable(body);
    }

    /**
     * Sets the body
     *
     * @param body the body, can be null
     * @return this, the MethodDeclaration
     */
    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public MethodDeclaration setBody(final BlockStmt body) {
        if (body == this.body) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.BODY, this.body, body);
        if (this.body != null) this.body.setParentNode(null);
        this.body = body;
        setAsParentNodeOf(body);
        return this;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public Type getType() {
        return type;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public MethodDeclaration setType(final Type type) {
        assertNotNull(type);
        if (type == this.type) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
        if (this.type != null) this.type.setParentNode(null);
        this.type = type;
        setAsParentNodeOf(type);
        return this;
    }

    @Override
    public MethodDeclaration setModifiers(final NodeList<Modifier> modifiers) {
        return super.setModifiers(modifiers);
    }

    @Override
    public MethodDeclaration setName(final SimpleName name) {
        return super.setName(name);
    }

    @Override
    public MethodDeclaration setParameters(final NodeList<Parameter> parameters) {
        return super.setParameters(parameters);
    }

    @Override
    public MethodDeclaration setThrownExceptions(final NodeList<ReferenceType> thrownExceptions) {
        return super.setThrownExceptions(thrownExceptions);
    }

    @Override
    public MethodDeclaration setTypeParameters(final NodeList<TypeParameter> typeParameters) {
        return super.setTypeParameters(typeParameters);
    }

    /**
     * The declaration returned has this schema:
     * <p>
     * [accessSpecifier] [static] [abstract] [final] [native]
     * [synchronized] returnType methodName ([paramType [paramName]])
     * [throws exceptionsList]
     *
     * @return method declaration as String
     */
    @Override
    public String getDeclarationAsString(
            boolean includingModifiers, boolean includingThrows, boolean includingParameterName) {
        StringBuilder sb = new StringBuilder();
        if (includingModifiers) {
            AccessSpecifier accessSpecifier = getAccessSpecifier();
            sb.append(accessSpecifier.asString()).append(" ");
            if (isStatic()) {
                sb.append("static ");
            }
            if (isAbstract()) {
                sb.append("abstract ");
            }
            if (isFinal()) {
                sb.append("final ");
            }
            if (isNative()) {
                sb.append("native ");
            }
            if (isSynchronized()) {
                sb.append("synchronized ");
            }
        }
        sb.append(getType().toString(prettyPrinterNoCommentsConfiguration));
        sb.append(" ");
        sb.append(getName().toString(prettyPrinterNoCommentsConfiguration));
        sb.append("(");
        boolean firstParam = true;
        for (Parameter param : getParameters()) {
            if (firstParam) {
                firstParam = false;
            } else {
                sb.append(", ");
            }
            if (includingParameterName) {
                sb.append(param.toString(prettyPrinterNoCommentsConfiguration));
            } else {
                sb.append(param.getType().toString(prettyPrinterNoCommentsConfiguration));
                if (param.isVarArgs()) {
                    sb.append("...");
                }
            }
        }
        sb.append(")");
        sb.append(appendThrowsIfRequested(includingThrows));
        return sb.toString();
    }

    /*
     * Returns the method descriptor (https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.3.3)
     * The method descriptor for the method: {@code Object m(int i, double d, Thread t) {...}}
     * is {@code (IDLjava/lang/Thread;)Ljava/lang/Object;}
     * Note that the internal forms of the binary names of Thread and Object are used.
     */
    public String toDescriptor() {
        StringBuilder sb = new StringBuilder();
        sb.append("(");
        for (int i = 0; i < getParameters().size(); i++) {
            sb.append(getParameter(i).getType().toDescriptor());
        }
        sb.append(")");
        sb.append(getType().toDescriptor());
        return sb.toString();
    }

    /*
     * A method in the body of an interface may be declared public or private
     * (§6.6). If no access modifier is given, the method is implicitly public.
     * https://docs.oracle.com/javase/specs/jls/se9/html/jls-9.html#jls-9.4
     */
    @Override
    public boolean isPublic() {
        return hasModifier(PUBLIC) || isImplicitlyPublic();
    }

    private boolean isImplicitlyPublic() {
        return getAccessSpecifier() == AccessSpecifier.NONE
                && hasParentNode()
                && getParentNode().get() instanceof ClassOrInterfaceDeclaration
                && ((ClassOrInterfaceDeclaration) getParentNode().get()).isInterface();
    }

    /*
     * An interface method lacking a private, default, or static modifier is implicitly abstract.
     * https://docs.oracle.com/javase/specs/jls/se9/html/jls-9.html#jls-9.4
     */
    @Override
    public boolean isAbstract() {
        return super.isAbstract() || isImplicitlyAbstract();
    }

    private boolean isImplicitlyAbstract() {
        return hasParentNode()
                && getParentNode().get() instanceof ClassOrInterfaceDeclaration
                && ((ClassOrInterfaceDeclaration) getParentNode().get()).isInterface()
                && Arrays.asList(Keyword.STATIC, Keyword.DEFAULT, Keyword.PRIVATE).stream()
                        .noneMatch(modifier -> hasModifier(modifier));
    }

    public boolean isNative() {
        return hasModifier(Modifier.Keyword.NATIVE);
    }

    public boolean isSynchronized() {
        return hasModifier(Modifier.Keyword.SYNCHRONIZED);
    }

    public boolean isDefault() {
        return hasModifier(Modifier.Keyword.DEFAULT);
    }

    public MethodDeclaration setNative(boolean set) {
        return setModifier(Modifier.Keyword.NATIVE, set);
    }

    public MethodDeclaration setSynchronized(boolean set) {
        return setModifier(Modifier.Keyword.SYNCHRONIZED, set);
    }

    public MethodDeclaration setDefault(boolean set) {
        return setModifier(Modifier.Keyword.DEFAULT, set);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")
    public boolean remove(Node node) {
        if (node == null) {
            return false;
        }
        if (body != null) {
            if (node == body) {
                removeBody();
                return true;
            }
        }
        return super.remove(node);
    }

    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")
    public MethodDeclaration removeBody() {
        return setBody((BlockStmt) null);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.CloneGenerator")
    public MethodDeclaration clone() {
        return (MethodDeclaration) accept(new CloneVisitor(), null);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.GetMetaModelGenerator")
    public MethodDeclarationMetaModel getMetaModel() {
        return JavaParserMetaModel.methodDeclarationMetaModel;
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.ReplaceMethodGenerator")
    public boolean replace(Node node, Node replacementNode) {
        if (node == null) {
            return false;
        }
        if (body != null) {
            if (node == body) {
                setBody((BlockStmt) replacementNode);
                return true;
            }
        }
        if (node == type) {
            setType((Type) replacementNode);
            return true;
        }
        return super.replace(node, replacementNode);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
    public boolean isMethodDeclaration() {
        return true;
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
    public MethodDeclaration asMethodDeclaration() {
        return this;
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
    public void ifMethodDeclaration(Consumer<MethodDeclaration> action) {
        action.accept(this);
    }

    @Override
    public ResolvedMethodDeclaration resolve() {
        return getSymbolResolver().resolveDeclaration(this, ResolvedMethodDeclaration.class);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")
    public Optional<MethodDeclaration> toMethodDeclaration() {
        return Optional.of(this);
    }
}
