/*

 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.lang.reflect.Modifier;

import com.sun.javadoc.*;

import com.sun.source.util.TreePath;

import com.sun.tools.javac.code.*;

import com.sun.tools.javac.code.Symbol.*;

import com.sun.tools.javac.code.Type;

import static com.sun.tools.javac.code.TypeTag.CLASS;

/**

 * Represents a method of a java class.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 *

 * @since 1.2

 * @author Robert Field

 * @author Neal Gafter (rewrite)

 */

public class MethodDocImpl

        extends ExecutableMemberDocImpl implements MethodDoc {

    /**

     * constructor.

     */

    public MethodDocImpl(DocEnv env, MethodSymbol sym) {

        super(env, sym);

    }

    /**

     * constructor.

     */

    public MethodDocImpl(DocEnv env, MethodSymbol sym, TreePath treePath) {

        super(env, sym, treePath);

    }

    /**

     * Return true if it is a method, which it is.

     * Note: constructors are not methods.

     * This method is overridden by AnnotationTypeElementDocImpl.

     *

     * @return true

     */

    public boolean isMethod() {

        return true;

    }

    /**

     * Return true if this method is default

     */

    public boolean isDefault() {

        return (sym.flags() & Flags.DEFAULT) != 0;

    }

    /**

     * Return true if this method is abstract

     */

    public boolean isAbstract() {

        return (Modifier.isAbstract(getModifiers()) && !isDefault());

    }

    /**

     * Get return type.

     *

     * @return the return type of this method, null if it

     * is a constructor.

     */

    public com.sun.javadoc.Type returnType() {

        return TypeMaker.getType(env, sym.type.getReturnType(), false);

    }

    /**

     * Return the class that originally defined the method that

     * is overridden by the current definition, or null if no

     * such class exists.

     *

     * @return a ClassDocImpl representing the superclass that

     * originally defined this method, null if this method does

     * not override a definition in a superclass.

     */

    public ClassDoc overriddenClass() {

        com.sun.javadoc.Type t = overriddenType();

        return (t != null) ? t.asClassDoc() : null;

    }

    /**

     * Return the type containing the method that this method overrides.

     * It may be a <code>ClassDoc</code> or a <code>ParameterizedType</code>.

     */

    public com.sun.javadoc.Type overriddenType() {

        if ((sym.flags() & Flags.STATIC) != 0) {

            return null;

        }

        ClassSymbol origin = (ClassSymbol)sym.owner;

        for (Type t = env.types.supertype(origin.type);

             t.hasTag(CLASS);

             t = env.types.supertype(t)) {

            ClassSymbol c = (ClassSymbol)t.tsym;

            for (Symbol sym2 : membersOf(c).getSymbolsByName(sym.name)) {

                if (sym.overrides(sym2, origin, env.types, true)) {

                    return TypeMaker.getType(env, t);

                }

            }

        }

        return null;

    }

    /**

     * Return the method that this method overrides.

     *

     * @return a MethodDoc representing a method definition

     * in a superclass this method overrides, null if

     * this method does not override.

     */

    public MethodDoc overriddenMethod() {

        // Real overriding only.  Static members are simply hidden.

        // Likewise for constructors, but the MethodSymbol.overrides

        // method takes this into account.

        if ((sym.flags() & Flags.STATIC) != 0) {

            return null;

        }

        // Derived from  com.sun.tools.javac.comp.Check.checkOverride .

        ClassSymbol origin = (ClassSymbol)sym.owner;

        for (Type t = env.types.supertype(origin.type);

             t.hasTag(CLASS);

             t = env.types.supertype(t)) {

            ClassSymbol c = (ClassSymbol)t.tsym;

            for (Symbol sym2 : membersOf(c).getSymbolsByName(sym.name)) {

                if (sym.overrides(sym2, origin, env.types, true)) {

                    return env.getMethodDoc((MethodSymbol)sym2);

                }

            }

        }

        return null;

    }

    /**Retrieve members of c, ignoring any CompletionFailures that occur. */

    private Scope membersOf(ClassSymbol c) {

        try {

            return c.members();

        } catch (CompletionFailure cf) {

            /* Quietly ignore completion failures and try again - the type

             * for which the CompletionFailure was thrown shouldn't be completed

             * again by the completer that threw the CompletionFailure.

             */

            return membersOf(c);

        }

    }

    /**

     * Tests whether this method overrides another.

     * The overridden method may be one declared in a superclass or

     * a superinterface (unlike {@link #overriddenMethod()}).

     *

     * <p> When a non-abstract method overrides an abstract one, it is

     * also said to <i>implement</i> the other.

     *

     * @param meth  the other method to examine

     * @return <tt>true</tt> if this method overrides the other

     */

    public boolean overrides(MethodDoc meth) {

        MethodSymbol overridee = ((MethodDocImpl) meth).sym;

        ClassSymbol origin = (ClassSymbol) sym.owner;

        return sym.name == overridee.name &&

               // not reflexive as per JLS

               sym != overridee &&

               // we don't care if overridee is static, though that wouldn't

               // compile

               !sym.isStatic() &&

               // sym, whose declaring type is the origin, must be

               // in a subtype of overridee's type

               env.types.asSuper(origin.type, overridee.owner) != null &&

               // check access and signatures; don't check return types

               sym.overrides(overridee, origin, env.types, false);

    }

    public String name() {

        if (name == null) {

            name = sym.name.toString();

        }

        return name;

    }

    private String name;

    public String qualifiedName() {

        if (qualifiedName == null) {

            qualifiedName =  sym.enclClass().getQualifiedName() + "." + sym.name;

        }

        return qualifiedName;

    }

    private String qualifiedName;

    /**

     * Returns a string representation of this method.  Includes the

     * qualified signature, the qualified method name, and any type

     * parameters.  Type parameters follow the class name, as they do

     * in the syntax for invoking methods with explicit type parameters.

     */

    public String toString() {

        return sym.enclClass().getQualifiedName() +

                "." + typeParametersString() + name() + signature();

    }

}