/*

 * 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 7098660

 * @summary Write better overload resolution/inference tests

 * @library ../lib

 * @build JavacTestingAbstractProcessor ResolveHarness

 * @run main ResolveHarness

 */

import com.sun.source.util.JavacTask;

import com.sun.tools.javac.api.ClientCodeWrapper.DiagnosticSourceUnwrapper;

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

import com.sun.tools.javac.util.JCDiagnostic;

import java.io.File;

import java.util.Set;

import java.util.Arrays;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import javax.annotation.processing.AbstractProcessor;

import javax.annotation.processing.RoundEnvironment;

import javax.annotation.processing.SupportedAnnotationTypes;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.tools.Diagnostic;

import javax.tools.Diagnostic.Kind;

import javax.tools.DiagnosticListener;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.ToolProvider;

import static javax.tools.StandardLocation.*;

public class ResolveHarness implements javax.tools.DiagnosticListener<JavaFileObject> {

    static int nerrors = 0;

    static final JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

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

    public static void main(String[] args) throws Exception {

        fm.setLocation(SOURCE_PATH,

                Arrays.asList(new File(System.getProperty("test.src"), "tests")));

        for (JavaFileObject jfo : fm.list(SOURCE_PATH, "", Collections.singleton(JavaFileObject.Kind.SOURCE), true)) {

            new ResolveHarness(jfo).check();

        }

        if (nerrors > 0) {

            throw new AssertionError("Errors were found");

        }

    }

    JavaFileObject jfo;

    DiagnosticProcessor[] diagProcessors;

    Map<ElementKey, Candidate> candidatesMap = new HashMap<ElementKey, Candidate>();

    Set<String> declaredKeys = new HashSet<>();

    List<Diagnostic<? extends JavaFileObject>> diags = new ArrayList<>();

    List<ElementKey> seenCandidates = new ArrayList<>();

    protected ResolveHarness(JavaFileObject jfo) {

        this.jfo = jfo;

        this.diagProcessors = new DiagnosticProcessor[] {

            new VerboseResolutionNoteProcessor(),

            new VerboseDeferredInferenceNoteProcessor(),

            new ErrorProcessor()

        };

    }

    protected void check() throws Exception {

        String[] options = {

            "-XDshouldStopPolicy=ATTR",

            "-XDverboseResolution=success,failure,applicable,inapplicable,deferred-inference"

        };

        AbstractProcessor[] processors = { new ResolveCandidateFinder(), null };

        @SuppressWarnings("unchecked")

        DiagnosticListener<? super JavaFileObject>[] diagListeners =

                new DiagnosticListener[] { new DiagnosticHandler(false), new DiagnosticHandler(true) };

        for (int i = 0 ; i < options.length ; i ++) {

            JavacTask ct = (JavacTask)comp.getTask(null, fm, diagListeners[i],

                    Arrays.asList(options[i]), null, Arrays.asList(jfo));

            if (processors[i] != null) {

                ct.setProcessors(Collections.singleton(processors[i]));

            }

            ct.analyze();

        }

        //check diags

        for (Diagnostic<? extends JavaFileObject> diag : diags) {

            for (DiagnosticProcessor proc : diagProcessors) {

                if (proc.matches(diag)) {

                    proc.process(diag);

                    break;

                }

            }

        }

        //check all candidates have been used up

        for (Map.Entry<ElementKey, Candidate> entry : candidatesMap.entrySet()) {

            if (!seenCandidates.contains(entry.getKey())) {

                error("Redundant @Candidate annotation on method " + entry.getKey().elem);

            }

        }

    }

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

        diags.add(diagnostic);

    }

    Candidate getCandidateAtPos(Element methodSym, long line, long col) {

        Candidate c = candidatesMap.get(new ElementKey(methodSym));

        if (c != null) {

            Pos pos = c.pos();

            if (!pos.userDefined() ||

                    (pos.line() == line && pos.col() == col)) {

                seenCandidates.add(new ElementKey(methodSym));

                return c;

            }

        } else {

            error("Missing @Candidate annotation on method " + methodSym);

        }

        return null;

    }

    void checkSig(Candidate c, Element methodSym, MethodType mtype) {

        if (c.sig().length() > 0 && !c.sig().equals(mtype.toString())) {

            error("Inferred type mismatch for method: " + methodSym);

        }

    }

    protected void error(String msg) {

        nerrors++;

        System.err.printf("Error occurred while checking file: %s\nreason: %s\n", jfo.getName(), msg);

    }

    /**

     * Base class for diagnostic processor. It provides methods for matching and

     * processing a given diagnostic object (overridden by subclasses).

     */

    abstract class DiagnosticProcessor {

        List<String> codes;

        Diagnostic.Kind kind;

        public DiagnosticProcessor(Kind kind, String... codes) {

            this.codes = Arrays.asList(codes);

            this.kind = kind;

        }

        abstract void process(Diagnostic<? extends JavaFileObject> diagnostic);

        boolean matches(Diagnostic<? extends JavaFileObject> diagnostic) {

            return (codes.isEmpty() || codes.contains(diagnostic.getCode())) &&

                    diagnostic.getKind() == kind;

        }

        JCDiagnostic asJCDiagnostic(Diagnostic<? extends JavaFileObject> diagnostic) {

            if (diagnostic instanceof JCDiagnostic) {

                return (JCDiagnostic)diagnostic;

            } else if (diagnostic instanceof DiagnosticSourceUnwrapper) {

                return ((DiagnosticSourceUnwrapper)diagnostic).d;

            } else {

                throw new AssertionError("Cannot convert diagnostic to JCDiagnostic: " + diagnostic.getClass().getName());

            }

        }

        List<JCDiagnostic> subDiagnostics(Diagnostic<? extends JavaFileObject> diagnostic) {

            JCDiagnostic diag = asJCDiagnostic(diagnostic);

            if (diag instanceof JCDiagnostic.MultilineDiagnostic) {

                return ((JCDiagnostic.MultilineDiagnostic)diag).getSubdiagnostics();

            } else {

                throw new AssertionError("Cannot extract subdiagnostics: " + diag.getClass().getName());

            }

        }

    }

    /**

     * Processor for verbose resolution notes generated by javac. The processor

     * checks that the diagnostic is associated with a method declared by

     * a class annotated with the special @TraceResolve marker annotation. If

     * that's the case, all subdiagnostics (one for each resolution candidate)

     * are checked against the corresponding @Candidate annotations, using

     * a VerboseCandidateSubdiagProcessor.

     */

    class VerboseResolutionNoteProcessor extends DiagnosticProcessor {

        VerboseResolutionNoteProcessor() {

            super(Kind.NOTE,

                    "compiler.note.verbose.resolve.multi",

                    "compiler.note.verbose.resolve.multi.1");

        }

        @Override

        void process(Diagnostic<? extends JavaFileObject> diagnostic) {

            Element siteSym = getSiteSym(diagnostic);

            if (siteSym.getAnnotation(TraceResolve.class) == null) {

                return;

            }

            int candidateIdx = 0;

            for (JCDiagnostic d : subDiagnostics(diagnostic)) {

                boolean isMostSpecific = candidateIdx++ == mostSpecific(diagnostic);

                VerboseCandidateSubdiagProcessor subProc =

                        new VerboseCandidateSubdiagProcessor(isMostSpecific, phase(diagnostic), success(diagnostic));

                if (subProc.matches(d)) {

                    subProc.process(d);

                } else {

                    throw new AssertionError("Bad subdiagnostic: " + d.getCode());

                }

            }

        }

        Element getSiteSym(Diagnostic<? extends JavaFileObject> diagnostic) {

            return (Element)asJCDiagnostic(diagnostic).getArgs()[1];

        }

        int mostSpecific(Diagnostic<? extends JavaFileObject> diagnostic) {

            return success(diagnostic) ?

                    (Integer)asJCDiagnostic(diagnostic).getArgs()[2] : -1;

        }

        boolean success(Diagnostic<? extends JavaFileObject> diagnostic) {

            return diagnostic.getCode().equals("compiler.note.verbose.resolve.multi");

        }

        Phase phase(Diagnostic<? extends JavaFileObject> diagnostic) {

            return Phase.fromString(asJCDiagnostic(diagnostic).getArgs()[3].toString());

        }

    }

    /**

     * Processor for verbose resolution subdiagnostic notes generated by javac.

     * The processor checks that the details of the overload candidate

     * match against the info contained in the corresponding @Candidate

     * annotation (if any).

     */

    class VerboseCandidateSubdiagProcessor extends DiagnosticProcessor {

        boolean mostSpecific;

        Phase phase;

        boolean success;

        public VerboseCandidateSubdiagProcessor(boolean mostSpecific, Phase phase, boolean success) {

            super(Kind.OTHER,

                    "compiler.misc.applicable.method.found",

                    "compiler.misc.applicable.method.found.1",

                    "compiler.misc.not.applicable.method.found");

            this.mostSpecific = mostSpecific;

            this.phase = phase;

            this.success = success;

        }

        @Override

        void process(Diagnostic<? extends JavaFileObject> diagnostic) {

            Element methodSym = methodSym(diagnostic);

            Candidate c = getCandidateAtPos(methodSym,

                    asJCDiagnostic(diagnostic).getLineNumber(),

                    asJCDiagnostic(diagnostic).getColumnNumber());

            if (c == null) {

                return; //nothing to check

            }

            if (c.applicable().length == 0 && c.mostSpecific()) {

                error("Inapplicable method cannot be most specific " + methodSym);

            }

            if (isApplicable(diagnostic) != Arrays.asList(c.applicable()).contains(phase)) {

                error("Invalid candidate's applicability " + methodSym);

            }

            if (success) {

                for (Phase p : c.applicable()) {

                    if (phase.ordinal() < p.ordinal()) {

                        error("Invalid phase " + p + " on method " + methodSym);

                    }

                }

            }

            if (Arrays.asList(c.applicable()).contains(phase)) { //applicable

                if (c.mostSpecific() != mostSpecific) {

                    error("Invalid most specific value for method " + methodSym);

                }

                MethodType mtype = getSig(diagnostic);

                if (mtype != null) {

                    checkSig(c, methodSym, mtype);

                }

            }

        }

        boolean isApplicable(Diagnostic<? extends JavaFileObject> diagnostic) {

            return !diagnostic.getCode().equals("compiler.misc.not.applicable.method.found");

        }

        Element methodSym(Diagnostic<? extends JavaFileObject> diagnostic) {

            return (Element)asJCDiagnostic(diagnostic).getArgs()[1];

        }

        MethodType getSig(Diagnostic<? extends JavaFileObject> diagnostic) {

            JCDiagnostic details = (JCDiagnostic)asJCDiagnostic(diagnostic).getArgs()[2];

            if (details == null) {

                return null;

            } else if (details instanceof JCDiagnostic) {

                return details.getCode().equals("compiler.misc.full.inst.sig") ?

                        (MethodType)details.getArgs()[0] : null;

            } else {

                throw new AssertionError("Bad diagnostic arg: " + details);

            }

        }

    }

    /**

     * Processor for verbose deferred inference notes generated by javac. The

     * processor checks that the inferred signature for a given generic method

     * call corresponds to the one (if any) declared in the @Candidate annotation.

     */

    class VerboseDeferredInferenceNoteProcessor extends DiagnosticProcessor {

        public VerboseDeferredInferenceNoteProcessor() {

            super(Kind.NOTE, "compiler.note.deferred.method.inst");

        }

        @Override

        void process(Diagnostic<? extends JavaFileObject> diagnostic) {

            Element methodSym = methodSym(diagnostic);

            Candidate c = getCandidateAtPos(methodSym,

                    asJCDiagnostic(diagnostic).getLineNumber(),

                    asJCDiagnostic(diagnostic).getColumnNumber());

            MethodType sig = sig(diagnostic);

            if (c != null && sig != null) {

                checkSig(c, methodSym, sig);

            }

        }

        Element methodSym(Diagnostic<? extends JavaFileObject> diagnostic) {

            return (Element)asJCDiagnostic(diagnostic).getArgs()[0];

        }

        MethodType sig(Diagnostic<? extends JavaFileObject> diagnostic) {

            return (MethodType)asJCDiagnostic(diagnostic).getArgs()[1];

        }

    }

    /**

     * Processor for all error diagnostics; if the error key is not declared in

     * the test file header, the processor reports an error.

     */

    class ErrorProcessor extends DiagnosticProcessor {

        public ErrorProcessor() {

            super(Diagnostic.Kind.ERROR);

        }

        @Override

        void process(Diagnostic<? extends JavaFileObject> diagnostic) {

            if (!declaredKeys.contains(diagnostic.getCode())) {

                error("Unexpected compilation error key '" + diagnostic.getCode() + "'");

            }

        }

    }

    @SupportedAnnotationTypes({"Candidate","TraceResolve"})

    class ResolveCandidateFinder extends JavacTestingAbstractProcessor {

        @Override

        public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {

            if (roundEnv.processingOver())

                return true;

            TypeElement traceResolveAnno = elements.getTypeElement("TraceResolve");

            TypeElement candidateAnno = elements.getTypeElement("Candidate");

            if (!annotations.contains(traceResolveAnno)) {

                error("no @TraceResolve annotation found in test class");

            }

            if (!annotations.contains(candidateAnno)) {

                error("no @candidate annotation found in test class");

            }

            for (Element elem: roundEnv.getElementsAnnotatedWith(traceResolveAnno)) {

                TraceResolve traceResolve = elem.getAnnotation(TraceResolve.class);

                declaredKeys.addAll(Arrays.asList(traceResolve.keys()));

            }

            for (Element elem: roundEnv.getElementsAnnotatedWith(candidateAnno)) {

                candidatesMap.put(new ElementKey(elem), elem.getAnnotation(Candidate.class));

            }

            return true;

        }

    }

    class ElementKey {

        String key;

        Element elem;

        public ElementKey(Element elem) {

            this.elem = elem;

            this.key = computeKey(elem);

        }

        @Override

        public boolean equals(Object obj) {

            if (obj instanceof ElementKey) {

                ElementKey other = (ElementKey)obj;

                return other.key.equals(key);

            }

            return false;

        }

        @Override

        public int hashCode() {

            return key.hashCode();

        }

        String computeKey(Element e) {

            StringBuilder buf = new StringBuilder();

            while (e != null) {

                buf.append(e.toString());

                e = e.getEnclosingElement();

            }

            buf.append(jfo.getName());

            return buf.toString();

        }

        @Override

        public String toString() {

            return "Key{"+key+"}";

        }

    }

    class DiagnosticHandler implements DiagnosticListener<JavaFileObject> {

        boolean shouldRecordDiags;

        DiagnosticHandler(boolean shouldRecordDiags) {

            this.shouldRecordDiags = shouldRecordDiags;

        }

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

            if (shouldRecordDiags)

                diags.add(diagnostic);

        }

    }

}