/*

 * Copyright (c) 2011, 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.

 *

 * 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.

 */

/*

 * @test

 * @bug 7062745

 * @summary  Regression: difference in overload resolution when two methods are maximally specific

 */

import com.sun.source.util.JavacTask;

import java.net.URI;

import java.util.Arrays;

import javax.tools.Diagnostic;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;

import javax.tools.SimpleJavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.ToolProvider;

public class GenericOverrideTest {

    static int checkCount = 0;

    enum SignatureKind {

        NON_GENERIC(""),

        GENERIC("<X>");

        String paramStr;

        private SignatureKind(String paramStr) {

            this.paramStr = paramStr;

        }

    }

    enum ReturnTypeKind {

        LIST("List"),

        ARRAYLIST("ArrayList");

        String retStr;

        private ReturnTypeKind(String retStr) {

            this.retStr = retStr;

        }

        boolean moreSpecificThan(ReturnTypeKind that) {

            switch (this) {

                case LIST:

                    return that == this;

                case ARRAYLIST:

                    return that == LIST || that == ARRAYLIST;

                default: throw new AssertionError("Unexpected ret kind: " + this);

            }

        }

    }

    enum TypeArgumentKind {

        NONE(""),

        UNBOUND("<?>"),

        INTEGER("<Number>"),

        NUMBER("<Integer>"),

        TYPEVAR("<X>");

        String typeargStr;

        private TypeArgumentKind(String typeargStr) {

            this.typeargStr = typeargStr;

        }

        boolean compatibleWith(SignatureKind sig) {

            switch (this) {

                case TYPEVAR: return sig != SignatureKind.NON_GENERIC;

                default: return true;

            }

        }

        boolean moreSpecificThan(TypeArgumentKind that, boolean strict) {

            switch (this) {

                case NONE:

                    return that == this || !strict;

                case UNBOUND:

                    return that == this || that == NONE;

                case INTEGER:

                case NUMBER:

                case TYPEVAR:

                    return that == this || that == NONE || that == UNBOUND;

                default: throw new AssertionError("Unexpected typearg kind: " + this);

            }

        }

        boolean assignableTo(TypeArgumentKind that, SignatureKind sig) {

            switch (this) {

                case NONE:

                    //this case needs to workaround to javac's impl of 15.12.2.8 being too strict

                    //ideally should be just 'return true' (see 7067746)

                    return sig == SignatureKind.NON_GENERIC || that == NONE;

                case UNBOUND:

                    return that == this || that == NONE;

                case INTEGER:

                case NUMBER:

                    return that == this || that == NONE || that == UNBOUND;

                case TYPEVAR:

                    return true;

                default: throw new AssertionError("Unexpected typearg kind: " + this);

            }

        }

    }

    public static void main(String... args) throws Exception {

        //create default shared JavaCompiler - reused across multiple compilations

        JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

        StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null);

        for (SignatureKind sig1 : SignatureKind.values()) {

            for (ReturnTypeKind rt1 : ReturnTypeKind.values()) {

                for (TypeArgumentKind ta1 : TypeArgumentKind.values()) {

                    if (!ta1.compatibleWith(sig1)) continue;

                    for (SignatureKind sig2 : SignatureKind.values()) {

                        for (ReturnTypeKind rt2 : ReturnTypeKind.values()) {

                            for (TypeArgumentKind ta2 : TypeArgumentKind.values()) {

                                if (!ta2.compatibleWith(sig2)) continue;

                                for (ReturnTypeKind rt3 : ReturnTypeKind.values()) {

                                    for (TypeArgumentKind ta3 : TypeArgumentKind.values()) {

                                        if (!ta3.compatibleWith(SignatureKind.NON_GENERIC)) continue;

                                        new GenericOverrideTest(sig1, rt1, ta1, sig2, rt2, ta2, rt3, ta3).run(comp, fm);

                                    }

                                }

                            }

                        }

                    }

                }

            }

        }

        System.out.println("Total check executed: " + checkCount);

    }

    SignatureKind sig1, sig2;

    ReturnTypeKind rt1, rt2, rt3;

    TypeArgumentKind ta1, ta2, ta3;

    JavaSource source;

    DiagnosticChecker diagChecker;

    GenericOverrideTest(SignatureKind sig1, ReturnTypeKind rt1, TypeArgumentKind ta1,

            SignatureKind sig2, ReturnTypeKind rt2, TypeArgumentKind ta2, ReturnTypeKind rt3, TypeArgumentKind ta3) {

        this.sig1 = sig1;

        this.sig2 = sig2;

        this.rt1 = rt1;

        this.rt2 = rt2;

        this.rt3 = rt3;

        this.ta1 = ta1;

        this.ta2 = ta2;

        this.ta3 = ta3;

        this.source = new JavaSource();

        this.diagChecker = new DiagnosticChecker();

    }

    class JavaSource extends SimpleJavaFileObject {

        String template = "import java.util.*;\n" +

                          "interface A { #S1 #R1#TA1 m(); }\n" +

                          "interface B { #S2 #R2#TA2 m(); }\n" +

                          "interface AB extends A, B {}\n" +

                          "class Test {\n" +

                          "  void test(AB ab) { #R3#TA3 n = ab.m(); }\n" +

                          "}";

        String source;

        public JavaSource() {

            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);

            source = template.replace("#S1", sig1.paramStr).

                    replace("#S2", sig2.paramStr).

                    replace("#R1", rt1.retStr).

                    replace("#R2", rt2.retStr).

                    replace("#R3", rt3.retStr).

                    replace("#TA1", ta1.typeargStr).

                    replace("#TA2", ta2.typeargStr).

                    replace("#TA3", ta3.typeargStr);

        }

        @Override

        public CharSequence getCharContent(boolean ignoreEncodingErrors) {

            return source;

        }

    }

    void run(JavaCompiler tool, StandardJavaFileManager fm) throws Exception {

        JavacTask ct = (JavacTask)tool.getTask(null, fm, diagChecker,

                null, null, Arrays.asList(source));

        try {

            ct.analyze();

        } catch (Throwable ex) {

            throw new AssertionError("Error thron when compiling the following code:\n" + source.getCharContent(true));

        }

        check();

    }

    void check() {

        checkCount++;

        boolean errorExpected = false;

        int mostSpecific = 0;

        //first check that either |R1| <: |R2| or |R2| <: |R1|

        if (rt1 != rt2) {

            if (!rt1.moreSpecificThan(rt2) &&

                    !rt2.moreSpecificThan(rt1)) {

                errorExpected = true;

            } else {

                mostSpecific = rt1.moreSpecificThan(rt2) ? 1 : 2;

            }

        }

        //check that either TA1 <= TA2 or TA2 <= TA1 (unless most specific return found above is raw)

        if (!errorExpected) {

            if (ta1 != ta2) {

                boolean useStrictCheck = ta1.moreSpecificThan(ta2, true) || ta2.moreSpecificThan(ta1, true);

                if (!ta1.moreSpecificThan(ta2, useStrictCheck) &&

                        !ta2.moreSpecificThan(ta1, useStrictCheck)) {

                    errorExpected = true;

                } else {

                    int mostSpecific2 = ta1.moreSpecificThan(ta2, useStrictCheck) ? 1 : 2;

                    if (mostSpecific != 0 && mostSpecific2 != mostSpecific) {

                        errorExpected = mostSpecific == 1 ? ta1 != TypeArgumentKind.NONE : ta2 != TypeArgumentKind.NONE;

                    } else {

                        mostSpecific = mostSpecific2;

                    }

                }

            } else if (mostSpecific == 0) {

                //when no signature is better than the other, an arbitrary choice

                //must be made - javac always picks the second signature

                mostSpecific = 2;

            }

        }

        //finally, check that most specific return type is compatible with expected type

        if (!errorExpected) {

            ReturnTypeKind msrt = mostSpecific == 1 ? rt1 : rt2;

            TypeArgumentKind msta = mostSpecific == 1 ? ta1 : ta2;

            SignatureKind mssig = mostSpecific == 1 ? sig1 : sig2;

            if (!msrt.moreSpecificThan(rt3) ||

                    !msta.assignableTo(ta3, mssig)) {

                errorExpected = true;

            }

        }

        if (errorExpected != diagChecker.errorFound) {

            throw new Error("invalid diagnostics for source:\n" +

                source.getCharContent(true) +

                "\nFound error: " + diagChecker.errorFound +

                "\nExpected error: " + errorExpected);

        }

    }

    static class DiagnosticChecker implements javax.tools.DiagnosticListener<JavaFileObject> {

        boolean errorFound;

        public void report(Diagnostic<? extends JavaFileObject> diagnostic) {

            if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {

                errorFound = true;

            }

        }

    }

}