/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dalvik.system;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import libcore.io.Streams;
import junit.framework.TestCase;

/**
 * Tests for the class {@link DexClassLoader}.
 */
public class DexClassLoaderTest extends TestCase {
    private static final File TMP_DIR =
        new File(System.getProperty("java.io.tmpdir"), "loading-test");
    private static final String PACKAGE_PATH = "dalvik/system/";
    private static final String JAR_NAME = "loading-test.jar";
    private static final String DEX_NAME = "loading-test.dex";
    private static final String JAR2_NAME = "loading-test2.jar";
    private static final String DEX2_NAME = "loading-test2.dex";
    private static final File JAR_FILE = new File(TMP_DIR, JAR_NAME);
    private static final File DEX_FILE = new File(TMP_DIR, DEX_NAME);
    private static final File JAR2_FILE = new File(TMP_DIR, JAR2_NAME);
    private static final File DEX2_FILE = new File(TMP_DIR, DEX2_NAME);
    private static final File OPTIMIZED_DIR = new File(TMP_DIR, "optimized");

    private static enum Configuration {
        /** just one classpath element, a raw dex file */
        ONE_DEX(1),

        /** just one classpath element, a jar file */
        ONE_JAR(1),

        /** two classpath elements, both raw dex files */
        TWO_DEX(2),

        /** two classpath elements, both jar files */
        TWO_JAR(2);

        public final int expectedFiles;

        Configuration(int expectedFiles) {
            this.expectedFiles = expectedFiles;
        }
    }

    protected void setUp() throws IOException {
        TMP_DIR.mkdirs();

        ClassLoader cl = DexClassLoaderTest.class.getClassLoader();
        copyResource(cl, JAR_NAME, JAR_FILE);
        copyResource(cl, DEX_NAME, DEX_FILE);
        copyResource(cl, JAR2_NAME, JAR2_FILE);
        copyResource(cl, DEX2_NAME, DEX2_FILE);

        OPTIMIZED_DIR.mkdirs();
        File[] files = OPTIMIZED_DIR.listFiles();
        for (File file : files) {
            file.delete();
        }
    }

    /**
     * Copy a resource in the package directory to the indicated
     * target file, but only if the target file doesn't exist.
     */
    private static void copyResource(ClassLoader loader, String resourceName,
            File destination) throws IOException {
        if (destination.exists()) {
            return;
        }

        InputStream in =
            loader.getResourceAsStream(PACKAGE_PATH + resourceName);
        FileOutputStream out = new FileOutputStream(destination);
        Streams.copy(in, out);
        in.close();
        out.close();
    }

    /**
     * Helper to construct an instance to test.
     *
     * @param config how to configure the classpath
     */
    private static DexClassLoader createInstance(Configuration config) {
        File file1;
        File file2;

        switch (config) {
            case ONE_DEX: file1 = DEX_FILE; file2 = null;      break;
            case ONE_JAR: file1 = JAR_FILE; file2 = null;      break;
            case TWO_DEX: file1 = DEX_FILE; file2 = DEX2_FILE; break;
            case TWO_JAR: file1 = JAR_FILE; file2 = JAR2_FILE; break;
            default: throw new AssertionError("shouldn't happen");
        }

        String path = file1.getAbsolutePath();
        if (file2 != null) {
            path += File.pathSeparator + file2.getAbsolutePath();
        }

        return new DexClassLoader(
            path, OPTIMIZED_DIR.getAbsolutePath(), null,
            ClassLoader.getSystemClassLoader());
    }

    /**
     * Helper to construct an instance to test, using the jar file as
     * the source, and call a named no-argument static method on a
     * named class.
     *
     * @param config how to configure the classpath
     */
    public static Object createInstanceAndCallStaticMethod(
            Configuration config, String className, String methodName)
            throws ClassNotFoundException, NoSuchMethodException,
            IllegalAccessException, InvocationTargetException {
        DexClassLoader dcl = createInstance(config);
        Class c = dcl.loadClass(className);
        Method m = c.getMethod(methodName, (Class[]) null);
        return m.invoke(null, (Object[]) null);
    }

    /*
     * Tests that are parametric with respect to whether to use a jar
     * file or a dex file as the source of the code
     */

    /**
     * Just a trivial test of construction. This one merely makes
     * sure that a valid construction doesn't fail. It doesn't try
     * to verify anything about the constructed instance, other than
     * checking for the existence of optimized dex files.
     */
    private static void test_init(Configuration config) {
        createInstance(config);

        int expectedFiles = config.expectedFiles;
        int actualFiles = OPTIMIZED_DIR.listFiles().length;

        assertEquals(expectedFiles, actualFiles);
    }

    /**
     * Check that a class in the jar/dex file may be used successfully. In this
     * case, a trivial static method is called.
     */
    private static void test_simpleUse(Configuration config) throws Exception {
        String result = (String)
            createInstanceAndCallStaticMethod(config, "test.Test1", "test");

        assertSame("blort", result);
    }

    /*
     * All the following tests are just pass-throughs to test code
     * that lives inside the loading-test dex/jar file.
     */

    private static void test_constructor(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_constructor");
    }

    private static void test_callStaticMethod(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_callStaticMethod");
    }

    private static void test_getStaticVariable(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_getStaticVariable");
    }

    private static void test_callInstanceMethod(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_callInstanceMethod");
    }

    private static void test_getInstanceVariable(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_getInstanceVariable");
    }

    private static void test_diff_constructor(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_diff_constructor");
    }

    private static void test_diff_callStaticMethod(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_diff_callStaticMethod");
    }

    private static void test_diff_getStaticVariable(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_diff_getStaticVariable");
    }

    private static void test_diff_callInstanceMethod(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_diff_callInstanceMethod");
    }

    private static void test_diff_getInstanceVariable(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_diff_getInstanceVariable");
    }

    /*
     * These methods are all essentially just calls to the
     * parametrically-defined tests above.
     */

    // ONE_JAR

    public void test_oneJar_init() throws Exception {
        test_init(Configuration.ONE_JAR);
    }

    public void test_oneJar_simpleUse() throws Exception {
        test_simpleUse(Configuration.ONE_JAR);
    }

    public void test_oneJar_constructor() throws Exception {
        test_constructor(Configuration.ONE_JAR);
    }

    public void test_oneJar_callStaticMethod() throws Exception {
        test_callStaticMethod(Configuration.ONE_JAR);
    }

    public void test_oneJar_getStaticVariable() throws Exception {
        test_getStaticVariable(Configuration.ONE_JAR);
    }

    public void test_oneJar_callInstanceMethod() throws Exception {
        test_callInstanceMethod(Configuration.ONE_JAR);
    }

    public void test_oneJar_getInstanceVariable() throws Exception {
        test_getInstanceVariable(Configuration.ONE_JAR);
    }

    // ONE_DEX

    public void test_oneDex_init() throws Exception {
        test_init(Configuration.ONE_DEX);
    }

    public void test_oneDex_simpleUse() throws Exception {
        test_simpleUse(Configuration.ONE_DEX);
    }

    public void test_oneDex_constructor() throws Exception {
        test_constructor(Configuration.ONE_DEX);
    }

    public void test_oneDex_callStaticMethod() throws Exception {
        test_callStaticMethod(Configuration.ONE_DEX);
    }

    public void test_oneDex_getStaticVariable() throws Exception {
        test_getStaticVariable(Configuration.ONE_DEX);
    }

    public void test_oneDex_callInstanceMethod() throws Exception {
        test_callInstanceMethod(Configuration.ONE_DEX);
    }

    public void test_oneDex_getInstanceVariable() throws Exception {
        test_getInstanceVariable(Configuration.ONE_DEX);
    }

    // TWO_JAR

    public void test_twoJar_init() throws Exception {
        test_init(Configuration.TWO_JAR);
    }

    public void test_twoJar_simpleUse() throws Exception {
        test_simpleUse(Configuration.TWO_JAR);
    }

    public void test_twoJar_constructor() throws Exception {
        test_constructor(Configuration.TWO_JAR);
    }

    public void test_twoJar_callStaticMethod() throws Exception {
        test_callStaticMethod(Configuration.TWO_JAR);
    }

    public void test_twoJar_getStaticVariable() throws Exception {
        test_getStaticVariable(Configuration.TWO_JAR);
    }

    public void test_twoJar_callInstanceMethod() throws Exception {
        test_callInstanceMethod(Configuration.TWO_JAR);
    }

    public void test_twoJar_getInstanceVariable() throws Exception {
        test_getInstanceVariable(Configuration.TWO_JAR);
    }

    public static void test_twoJar_diff_constructor() throws Exception {
        test_diff_constructor(Configuration.TWO_JAR);
    }

    public static void test_twoJar_diff_callStaticMethod() throws Exception {
        test_diff_callStaticMethod(Configuration.TWO_JAR);
    }

    public static void test_twoJar_diff_getStaticVariable() throws Exception {
        test_diff_getStaticVariable(Configuration.TWO_JAR);
    }

    public static void test_twoJar_diff_callInstanceMethod()
            throws Exception {
        test_diff_callInstanceMethod(Configuration.TWO_JAR);
    }

    public static void test_twoJar_diff_getInstanceVariable()
            throws Exception {
        test_diff_getInstanceVariable(Configuration.TWO_JAR);
    }

    // TWO_DEX

    public void test_twoDex_init() throws Exception {
        test_init(Configuration.TWO_DEX);
    }

    public void test_twoDex_simpleUse() throws Exception {
        test_simpleUse(Configuration.TWO_DEX);
    }

    public void test_twoDex_constructor() throws Exception {
        test_constructor(Configuration.TWO_DEX);
    }

    public void test_twoDex_callStaticMethod() throws Exception {
        test_callStaticMethod(Configuration.TWO_DEX);
    }

    public void test_twoDex_getStaticVariable() throws Exception {
        test_getStaticVariable(Configuration.TWO_DEX);
    }

    public void test_twoDex_callInstanceMethod() throws Exception {
        test_callInstanceMethod(Configuration.TWO_DEX);
    }

    public void test_twoDex_getInstanceVariable() throws Exception {
        test_getInstanceVariable(Configuration.TWO_DEX);
    }

    public static void test_twoDex_diff_constructor() throws Exception {
        test_diff_constructor(Configuration.TWO_DEX);
    }

    public static void test_twoDex_diff_callStaticMethod() throws Exception {
        test_diff_callStaticMethod(Configuration.TWO_DEX);
    }

    public static void test_twoDex_diff_getStaticVariable() throws Exception {
        test_diff_getStaticVariable(Configuration.TWO_DEX);
    }

    public static void test_twoDex_diff_callInstanceMethod()
            throws Exception {
        test_diff_callInstanceMethod(Configuration.TWO_DEX);
    }

    public static void test_twoDex_diff_getInstanceVariable()
            throws Exception {
        test_diff_getInstanceVariable(Configuration.TWO_DEX);
    }

    /*
     * Tests specifically for resource-related functionality.  Since
     * raw dex files don't contain resources, these test only work
     * with jar files. The first couple methods here are helpers,
     * and they are followed by the tests per se.
     */

    /**
     * Check that a given resource (by name) is retrievable and contains
     * the given expected contents.
     */
    private static void test_directGetResourceAsStream(Configuration config,
            String resourceName, String expectedContents)
            throws Exception {
        DexClassLoader dcl = createInstance(config);
        InputStream in = dcl.getResourceAsStream(resourceName);
        byte[] contents = Streams.readFully(in);
        String s = new String(contents, "UTF-8");

        assertEquals(expectedContents, s);
    }

    /**
     * Check that a resource in the jar file is retrievable and contains
     * the expected contents.
     */
    private static void test_directGetResourceAsStream(Configuration config)
            throws Exception {
        test_directGetResourceAsStream(
            config, "test/Resource1.txt", "Muffins are tasty!\n");
    }

    /**
     * Check that a resource in the jar file can be retrieved from
     * a class within that jar file.
     */
    private static void test_getResourceAsStream(Configuration config)
            throws Exception {
        createInstanceAndCallStaticMethod(
            config, "test.TestMethods", "test_getResourceAsStream");
    }

    public void test_oneJar_directGetResourceAsStream() throws Exception {
        test_directGetResourceAsStream(Configuration.ONE_JAR);
    }

    public void test_oneJar_getResourceAsStream() throws Exception {
        test_getResourceAsStream(Configuration.ONE_JAR);
    }

    public void test_twoJar_directGetResourceAsStream() throws Exception {
        test_directGetResourceAsStream(Configuration.TWO_JAR);
    }

    public void test_twoJar_getResourceAsStream() throws Exception {
        test_getResourceAsStream(Configuration.TWO_JAR);
    }

    /**
     * Check that a resource in the second jar file is retrievable and
     * contains the expected contents.
     */
    public void test_twoJar_diff_directGetResourceAsStream()
            throws Exception {
        test_directGetResourceAsStream(
            Configuration.TWO_JAR, "test2/Resource2.txt",
            "Who doesn't like a good biscuit?\n");
    }

    /**
     * Check that a resource in a jar file can be retrieved from
     * a class within the other jar file.
     */
    public void test_twoJar_diff_getResourceAsStream()
            throws Exception {
        createInstanceAndCallStaticMethod(
            Configuration.TWO_JAR, "test.TestMethods",
            "test_diff_getResourceAsStream");
    }
}