/*

 * Copyright (c) 2016, 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.

 */

package selectionresolution;

import java.io.File;

import java.io.FileWriter;

import java.util.HashMap;

/**

 * One individual test case.  This class also defines a builder, which

 * can be used to build up cases.

 */

public class SelectionResolutionTestCase {

    public enum InvokeInstruction {

        INVOKESTATIC,

        INVOKESPECIAL,

        INVOKEINTERFACE,

        INVOKEVIRTUAL;

    }

    /**

     * The class data (includes interface data).

     */

    public final HashMap<Integer, ClassData> classdata;

    /**

     * The hierarchy shape.

     */

    public final HierarchyShape hier;

    /**

     * The invoke instruction to use.

     */

    public final InvokeInstruction invoke;

    /**

     * Which class is the methodref (or interface methodref).

     */

    public final int methodref;

    /**

     * Which class is the objectref.

     */

    public final int objectref;

    /**

     * Which class is the callsite (this must be a class, not an interface.

     */

    public final int callsite;

    /**

     * The expected result.

     */

    public final Result result;

    private SelectionResolutionTestCase(final HashMap<Integer, ClassData> classdata,

                                        final HierarchyShape hier,

                                        final InvokeInstruction invoke,

                                        final int methodref,

                                        final int objectref,

                                        final int callsite,

                                        final int expected) {

        this.classdata = classdata;

        this.hier = hier;

        this.invoke = invoke;

        this.methodref = methodref;

        this.objectref = objectref;

        this.callsite = callsite;

        this.result = Result.is(expected);

    }

    private SelectionResolutionTestCase(final HashMap<Integer, ClassData> classdata,

                                        final HierarchyShape hier,

                                        final InvokeInstruction invoke,

                                        final int methodref,

                                        final int objectref,

                                        final int callsite,

                                        final Result result) {

        this.classdata = classdata;

        this.hier = hier;

        this.invoke = invoke;

        this.methodref = methodref;

        this.objectref = objectref;

        this.callsite = callsite;

        this.result = result;

    }

    private static int currError = 0;

    private String dumpClasses(final ClassConstruct[] classes)

        throws Exception {

        final String errorDirName = "error_" + currError++;

        final File errorDir = new File(errorDirName);

        errorDir.mkdirs();

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

            classes[i].writeClass(errorDir);

        }

        try (final FileWriter fos =

             new FileWriter(new File(errorDir, "description.txt"))) {

            fos.write(this.toString());

        }

        return errorDirName;

    }

    /**

     * Run this case, return an error message, or null.

     *

     * @return An error message, or null if the case succeeded.

     */

    public String run() {

        /* Uncomment this line to print EVERY case */

        //System.err.println("Running\n" + this);

        final ClassBuilder builder =

            new ClassBuilder(this, ClassBuilder.ExecutionMode.DIRECT);

        try {

            final ByteCodeClassLoader bcl = new ByteCodeClassLoader();

            final ClassConstruct[] classes = builder.build();

            try {

                bcl.addClasses(classes);

                bcl.loadAll();

                // Grab the callsite class.

                final Class testclass =

                    bcl.findClass(builder.getCallsiteClass().getDottedName());

                // Get the 'test' method out of it and call it.  The

                // return value tess which class that got selected.

                final java.lang.reflect.Method method =

                    testclass.getDeclaredMethod("test");

                final int actual = (Integer) method.invoke(null);

                // Check the result.

                if (!result.complyWith(actual)) {

                    final String dump = dumpClasses(classes);

                    return "Failed:\n" + this + "\nExpected " + result + " got " + actual + "\nClasses written to " + dump;

                }

            } catch (Throwable t) {

                // This catch block is handling exceptions that we

                // might expect to see.

                final Throwable actual = t.getCause();

                if (actual == null) {

                    final String dump = dumpClasses(classes);

                    System.err.println("Unexpected exception in test\n" + this + "\nClasses written to " + dump);

                    throw t;

                } else if (result == null) {

                    final String dump = dumpClasses(classes);

                    return "Failed:\n" + this + "\nUnexpected exception " + actual + "\nClasses written to " + dump;

                } else if (!result.complyWith(actual)) {

                    final String dump = dumpClasses(classes);

                    return "Failed:\n" + this + "\nExpected " + this.result + " got " + actual + "\nClasses written to " + dump;

                }

            }

        } catch(Throwable e) {

            throw new RuntimeException(e);

        }

        return null;

    }

    private static void addPackage(final StringBuilder sb,

                                  final ClassData cd) {

        switch (cd.packageId) {

        case SAME: sb.append("Same."); break;

        case DIFFERENT: sb.append("Different."); break;

        case OTHER: sb.append("Other."); break;

        case PLACEHOLDER: sb.append("_."); break;

        default: throw new RuntimeException("Impossible case");

        }

    }

    public String toString() {

        final StringBuilder sb = new StringBuilder();

        //sb.append("hierarchy:\n" + hier + "\n");

        sb.append("invoke:    " + invoke + "\n");

        if (methodref != -1) {

            if (hier.isClass(methodref)) {

                sb.append("methodref: C" + methodref + "\n");

            } else {

                sb.append("methodref: I" + methodref + "\n");

            }

        }

        if (objectref != -1) {

            if (hier.isClass(objectref)) {

                sb.append("objectref: C" + objectref + "\n");

            } else {

                sb.append("objectref: I" + objectref + "\n");

            }

        }

        if (callsite != -1) {

            if (hier.isClass(callsite)) {

                sb.append("callsite: C" + callsite + "\n");

            } else {

                sb.append("callsite: I" + callsite + "\n");

            }

        }

        sb.append("result: " + result + "\n");

        sb.append("classes:\n\n");

        for(int i = 0; classdata.containsKey(i); i++) {

            final ClassData cd = classdata.get(i);

            if (hier.isClass(i)) {

                sb.append("class ");

                addPackage(sb, cd);

                sb.append("C" + i);

            } else {

                sb.append("interface ");

                addPackage(sb, cd);

                sb.append("I" + i);

            }

            boolean first = true;

            for(final int j : hier.classes()) {

                if (hier.inherits(i, j)) {

                    if (first) {

                        sb.append(" extends C" + j);

                    } else {

                        sb.append(", C" + j);

                    }

                }

            }

            first = true;

            for(final int j : hier.interfaces()) {

                if (hier.inherits(i, j)) {

                    if (first) {

                        sb.append(" implements I" + j);

                    } else {

                        sb.append(", I" + j);

                    }

                }

            }

            sb.append(cd);

        }

        return sb.toString();

    }

    /**

     * A builder, facilitating building up test cases.

     */

    public static class Builder {

        /**

         * A map from class (or interface) id's to ClassDatas

         */

        public final HashMap<Integer, ClassData> classdata;

        /**

         * The hierarchy shape.

         */

        public final HierarchyShape hier;

        /**

         * Which invoke instruction to use.

         */

        public InvokeInstruction invoke;

        /**

         * The id of the methodref (or interface methodref).

         */

        public int methodref = -1;

        /**

         * The id of the object ref.  Note that for the generator

         * framework to work, this must be set to something.  If an

         * objectref isn't used, just set it to the methodref.

         */

        public int objectref = -1;

        /**

         * The id of the callsite.

         */

        public int callsite = -1;

        /**

         * The id of the expected result.  This is used to store the

         * expected resolution result.

         */

        public int expected;

        /**

         * The expected result.  This needs to be set before the final

         * test case is built.

         */

        public Result result;

        /**

         * Create an empty Builder object.

         */

        public Builder() {

            classdata = new HashMap<>();

            hier = new HierarchyShape();

        }

        private Builder(final HashMap<Integer, ClassData> classdata,

                        final HierarchyShape hier,

                        final InvokeInstruction invoke,

                        final int methodref,

                        final int objectref,

                        final int callsite,

                        final int expected,

                        final Result result) {

            this.classdata = classdata;

            this.hier = hier;

            this.invoke = invoke;

            this.methodref = methodref;

            this.objectref = objectref;

            this.callsite = callsite;

            this.expected = expected;

            this.result = result;

        }

        private Builder(final Builder other) {

            this((HashMap<Integer, ClassData>) other.classdata.clone(),

                 other.hier.copy(), other.invoke, other.methodref, other.objectref,

                 other.callsite, other.expected, other.result);

        }

        public SelectionResolutionTestCase build() {

            if (result != null) {

                return new SelectionResolutionTestCase(classdata, hier, invoke,

                                                       methodref, objectref,

                                                       callsite, result);

            } else {

                return new SelectionResolutionTestCase(classdata, hier, invoke,

                                                       methodref, objectref,

                                                       callsite, expected);

            }

        }

        /**

         * Set the expected result.

         */

        public void setResult(final Result result) {

            this.result = result;

        }

        /**

         * Add a class, and return its id.

         *

         * @return The new class' id.

         */

        public int addClass(final ClassData data) {

            final int id = hier.addClass();

            classdata.put(id, data);

            return id;

        }

        /**

         * Add an interface, and return its id.

         *

         * @return The new class' id.

         */

        public int addInterface(final ClassData data) {

            final int id = hier.addInterface();

            classdata.put(id, data);

            return id;

        }

        /**

         * Make a copy of this builder.

         */

        public Builder copy() {

            return new Builder(this);

        }

        public String toString() {

            final StringBuilder sb = new StringBuilder();

            //sb.append("hierarchy:\n" + hier + "\n");

            sb.append("invoke:    " + invoke + "\n");

            if (methodref != -1) {

                if (hier.isClass(methodref)) {

                    sb.append("methodref: C" + methodref + "\n");

                } else {

                    sb.append("methodref: I" + methodref + "\n");

                }

            }

            if (objectref != -1) {

                if (hier.isClass(objectref)) {

                    sb.append("objectref: C" + objectref + "\n");

                } else {

                    sb.append("objectref: I" + objectref + "\n");

                }

            }

            if (callsite != -1) {

                if (hier.isClass(callsite)) {

                    sb.append("callsite: C" + callsite + "\n");

                } else {

                    sb.append("callsite: I" + callsite + "\n");

                }

            }

            if (expected != -1) {

                if (hier.isClass(expected)) {

                    sb.append("expected: C" + expected + "\n");

                } else {

                    sb.append("expected: I" + expected + "\n");

                }

            }

            sb.append("result: " + result + "\n");

            sb.append("classes:\n\n");

            for(int i = 0; classdata.containsKey(i); i++) {

                final ClassData cd = classdata.get(i);

                if (hier.isClass(i)) {

                    sb.append("class ");

                    addPackage(sb, cd);

                    sb.append("C" + i);