/*

 * Copyright (c) 2012, 2013, 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

 *

 * 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 org.openjdk.tests.separate;

import org.testng.ITestResult;

import org.testng.annotations.AfterMethod;

import java.lang.reflect.InvocationTargetException;

import java.util.Arrays;

import java.util.HashSet;

import java.util.List;

import static org.openjdk.tests.separate.SourceModel.Class;

import static org.openjdk.tests.separate.SourceModel.*;

import static org.testng.Assert.*;

public class TestHarness {

    /**

     * Creates a per-thread persistent compiler object to allow as much

     * sharing as possible, but still allows for parallel execution of tests.

     */

    protected ThreadLocal<Compiler> compilerLocal = new ThreadLocal<Compiler>(){

         protected synchronized Compiler initialValue() {

             return new Compiler();

         }

    };

    protected ThreadLocal<Boolean> verboseLocal = new ThreadLocal<Boolean>() {

         protected synchronized Boolean initialValue() {

             return Boolean.FALSE;

         }

    };

    protected boolean verbose;

    protected boolean canUseCompilerCache;

    public static final String stdMethodName = SourceModel.stdMethodName;

    private TestHarness() {

    }

    protected TestHarness(boolean verbose, boolean canUseCompilerCache) {

        this.verbose = verbose;

        this.canUseCompilerCache = canUseCompilerCache;

    }

    public void setTestVerbose() {

        verboseLocal.set(Boolean.TRUE);

    }

    @AfterMethod

    public void reset() {

        if (!this.verbose) {

            verboseLocal.set(Boolean.FALSE);

        }

    }

    public Compiler.Flags[] compilerFlags() {

        HashSet<Compiler.Flags> flags = new HashSet<>();

        if (verboseLocal.get() == Boolean.TRUE) {

            flags.add(Compiler.Flags.VERBOSE);

        }

        if (this.canUseCompilerCache) {

            flags.add(Compiler.Flags.USECACHE);

        }

        return flags.toArray(new Compiler.Flags[0]);

    }

    @AfterMethod

    public void printError(ITestResult result) {

        if (result.getStatus() == ITestResult.FAILURE) {

            String clsName = result.getTestClass().getName();

            clsName = clsName.substring(clsName.lastIndexOf(".") + 1);

            System.out.println("Test " + clsName + "." +

                               result.getName() + " FAILED");

        }

    }

    private static final ConcreteMethod stdCM = ConcreteMethod.std("-1");

    private static final AbstractMethod stdAM =

            new AbstractMethod("int", stdMethodName);

    /**

     * Returns a class which has a static method with the same name as

     * 'method', whose body creates an new instance of 'specimen' and invokes

     * 'method' upon it via an invokevirtual instruction with 'args' as

     * function call parameters.

     *

     * 'returns' is a dummy return value that need only match 'methods'

     * return type (it is only used in the dummy class when compiling IV).

     */

    private Class invokeVirtualHarness(

            Class specimen, ConcreteMethod method,

            String returns, String ... args) {

        Method cm = new ConcreteMethod(

            method.getReturnType(), method.getName(),

            "return " + returns + ";",  method.getElements());

        Class stub = new Class(specimen.getName(), cm);

        String params = toJoinedString(args, ", ");

        ConcreteMethod sm = new ConcreteMethod(

            method.getReturnType(), method.getName(),

            String.format("return (new %s()).%s(%s);",

                          specimen.getName(), method.getName(), params),

            new AccessFlag("public"), new AccessFlag("static"));

        Class iv = new Class("IV_" + specimen.getName(), sm);

        iv.addCompilationDependency(stub);

        iv.addCompilationDependency(cm);

        return iv;

    }

    /**

     * Returns a class which has a static method with the same name as

     * 'method', whose body creates an new instance of 'specimen', casts it

     * to 'iface' (including the type parameters)  and invokes

     * 'method' upon it via an invokeinterface instruction with 'args' as

     * function call parameters.

     */

    private Class invokeInterfaceHarness(Class specimen, Extends iface,

            AbstractMethod method, String ... args) {

        Interface istub = new Interface(

            iface.getType().getName(), iface.getType().getAccessFlags(),

            iface.getType().getParameters(),

            null, Arrays.asList((Method)method));

        Class cstub = new Class(specimen.getName());

        String params = toJoinedString(args, ", ");

        ConcreteMethod sm = new ConcreteMethod(

            "int", SourceModel.stdMethodName,

            String.format("return ((%s)(new %s())).%s(%s);", iface.toString(),

                specimen.getName(), method.getName(), params),

            new AccessFlag("public"), new AccessFlag("static"));

        sm.suppressWarnings();

        Class ii = new Class("II_" + specimen.getName() + "_" +

            iface.getType().getName(), sm);

        ii.addCompilationDependency(istub);

        ii.addCompilationDependency(cstub);

        ii.addCompilationDependency(method);

        return ii;

    }

    /**

     * Uses 'loader' to load class 'clzz', and calls the static method

     * 'method'.  If the return value does not equal 'value' (or if an

     * exception is thrown), then a test failure is indicated.

     *

     * If 'value' is null, then no equality check is performed -- the assertion

     * fails only if an exception is thrown.

     */

    protected void assertStaticCallEquals(

            ClassLoader loader, Class clzz, String method, Object value) {

        java.lang.Class<?> cls = null;

        try {

            cls = java.lang.Class.forName(clzz.getName(), true, loader);

        } catch (ClassNotFoundException e) {}

        assertNotNull(cls);

        java.lang.reflect.Method m = null;

        try {

            m = cls.getMethod(method);

        } catch (NoSuchMethodException e) {}

        assertNotNull(m);

        try {

            Object res = m.invoke(null);

            assertNotNull(res);

            if (value != null) {

                assertEquals(res, value);

            }

        } catch (InvocationTargetException | IllegalAccessException e) {

            fail("Unexpected exception thrown: " + e.getCause(), e.getCause());

        }

    }

    /**

     * Creates a class which calls target::method(args) via invokevirtual,

     * compiles and loads both the new class and 'target', and then invokes

     * the method.  If the returned value does not match 'value' then a

     * test failure is indicated.

     */

    public void assertInvokeVirtualEquals(

            Object value, Class target, ConcreteMethod method,

            String returns, String ... args) {

        Compiler compiler = compilerLocal.get();

        compiler.setFlags(compilerFlags());

        Class iv = invokeVirtualHarness(target, method, returns, args);

        ClassLoader loader = compiler.compile(iv, target);

        assertStaticCallEquals(loader, iv, method.getName(), value);

        compiler.cleanup();

    }

    /**

     * Convenience method for above, which assumes stdMethodName,

     * a return type of 'int', and no arguments.

     */

    public void assertInvokeVirtualEquals(int value, Class target) {

        assertInvokeVirtualEquals(value, target, stdCM, "-1");

    }

    /**

     * Creates a class which calls target::method(args) via invokeinterface

     * through 'iface', compiles and loads both it and 'target', and

     * then invokes the method.  If the returned value does not match

     * 'value' then a test failure is indicated.

     */

    public void assertInvokeInterfaceEquals(Object value, Class target,

            Extends iface, AbstractMethod method, String ... args) {

        Compiler compiler = compilerLocal.get();

        compiler.setFlags(compilerFlags());

        Class ii = invokeInterfaceHarness(target, iface, method, args);

        ClassLoader loader = compiler.compile(ii, target);

        assertStaticCallEquals(loader, ii, method.getName(), value);

        compiler.cleanup();

    }

    /**

     * Convenience method for above, which assumes stdMethodName,

     * a return type of 'int', and no arguments.

     */

    public void assertInvokeInterfaceEquals(

            int value, Class target, Interface iface) {

        Compiler compiler = compilerLocal.get();

        compiler.setFlags(compilerFlags());

        assertInvokeInterfaceEquals(value, target, new Extends(iface), stdAM);

        compiler.cleanup();

    }

    protected void assertInvokeInterfaceThrows(java.lang.Class<? extends Throwable> errorClass,

                                               Class target, Extends iface, AbstractMethod method,

                                               String... args) {

        try {

            assertInvokeInterfaceEquals(0, target, iface, method, args);

            fail("Expected exception: " + errorClass);

        }

        catch (AssertionError e) {

            Throwable cause = e.getCause();

            if (cause == null)

                throw e;

            else if ((errorClass.isAssignableFrom(cause.getClass()))) {

                // this is success

                return;

            }

            else

                throw e;

        }

    }

    /**

     * Creates a class which calls target::method(args) via invokevirtual,

     * compiles and loads both the new class and 'target', and then invokes

     * the method.  If an exception of type 'exceptionType' is not thrown,

     * then a test failure is indicated.

     */

    public void assertThrows(java.lang.Class<?> exceptionType, Class target,

            ConcreteMethod method, String returns, String ... args) {

        Compiler compiler = compilerLocal.get();

        compiler.setFlags(compilerFlags());

        Class iv = invokeVirtualHarness(target, method, returns, args);

        ClassLoader loader = compiler.compile(iv, target);

        java.lang.Class<?> cls = null;

        try {

            cls = java.lang.Class.forName(iv.getName(), true, loader);

        } catch (ClassNotFoundException e) {}

        assertNotNull(cls);

        java.lang.reflect.Method m = null;

        try {

            m = cls.getMethod(method.getName());

        } catch (NoSuchMethodException e) {}

        assertNotNull(m);

        try {

            m.invoke(null);

            fail("Exception should have been thrown");

        } catch (InvocationTargetException | IllegalAccessException e) {

            if (verboseLocal.get() == Boolean.TRUE) {

                System.out.println(e.getCause());

            }

            assertTrue(exceptionType.isAssignableFrom(e.getCause().getClass()));

        }

        compiler.cleanup();

    }

    /**

     * Convenience method for above, which assumes stdMethodName,

     * a return type of 'int', and no arguments.

     */

    public void assertThrows(java.lang.Class<?> exceptionType, Class target) {

        assertThrows(exceptionType, target, stdCM, "-1");

    }

    private static <T> String toJoinedString(T[] a, String... p) {

        return toJoinedString(Arrays.asList(a), p);

    }

    private static <T> String toJoinedString(List<T> list, String... p) {

        StringBuilder sb = new StringBuilder();

        String sep = "";

        String init = "";

        String end = "";

        String empty = null;

        switch (p.length) {

            case 4:

                empty = p[3];

            /*fall-through*/

            case 3:

                end = p[2];

            /*fall-through*/

            case 2:

                init = p[1];

            /*fall-through*/

            case 1:

                sep = p[0];

                break;

        }

        if (empty != null && list.isEmpty()) {

            return empty;

        } else {

            sb.append(init);

            for (T x : list) {

                if (sb.length() != init.length()) {

                    sb.append(sep);

                }

                sb.append(x.toString());

            }

            sb.append(end);

            return sb.toString();

        }

    }

}