/*

 * Copyright 1998-2008 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.javadoc;

import com.sun.javadoc.*;

import static com.sun.javadoc.LanguageVersion.*;

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

import java.net.*;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.lang.reflect.InvocationTargetException;

import java.io.File;

import java.io.IOException;

import java.util.StringTokenizer;

/**

 * Class creates, controls and invokes doclets.

 * @author Neal Gafter (rewrite)

 */

public class DocletInvoker {

    private final Class<?> docletClass;

    private final String docletClassName;

    private final ClassLoader appClassLoader;

    private final Messager messager;

    private static class DocletInvokeException extends Exception {

        private static final long serialVersionUID = 0;

    }

    private String appendPath(String path1, String path2) {

        if (path1 == null || path1.length() == 0) {

            return path2 == null ? "." : path2;

        } else if (path2 == null || path2.length() == 0) {

            return path1;

        } else {

            return path1  + File.pathSeparator + path2;

        }

    }

    public DocletInvoker(Messager messager,

                         String docletClassName, String docletPath,

                         ClassLoader docletParentClassLoader) {

        this.messager = messager;

        this.docletClassName = docletClassName;

        // construct class loader

        String cpString = null;   // make sure env.class.path defaults to dot

        // do prepends to get correct ordering

        cpString = appendPath(System.getProperty("env.class.path"), cpString);

        cpString = appendPath(System.getProperty("java.class.path"), cpString);

        cpString = appendPath(docletPath, cpString);

        URL[] urls = pathToURLs(cpString);

        if (docletParentClassLoader == null)

            appClassLoader = new URLClassLoader(urls);

        else

            appClassLoader = new URLClassLoader(urls, docletParentClassLoader);

        // attempt to find doclet

        try {

            dc = appClassLoader.loadClass(docletClassName);

        } catch (ClassNotFoundException exc) {

            messager.error(null, "main.doclet_class_not_found", docletClassName);

            messager.exit();

        }

        docletClass = dc;

    }

    /**

     * Generate documentation here.  Return true on success.

     */

    public boolean start(RootDoc root) {

        Object retVal;

        String methodName = "start";

        Object[] params = new Object[1];

        paramTypes[0] = RootDoc.class;

        params[0] = root;

        try {

            retVal = invoke(methodName, null, paramTypes, params);

        } catch (DocletInvokeException exc) {

            return false;

        }

        if (retVal instanceof Boolean) {

            return ((Boolean)retVal).booleanValue();

        } else {

            messager.error(null, "main.must_return_boolean",

                           docletClassName, methodName);

            return false;

        }

    }

    /**

     * Check for doclet added options here. Zero return means

     * option not known.  Positive value indicates number of

     * arguments to option.  Negative value means error occurred.

     */

    public int optionLength(String option) {

        Object retVal;

        String methodName = "optionLength";

        Object[] params = new Object[1];

        paramTypes[0] = option.getClass();

        params[0] = option;

        try {

            retVal = invoke(methodName, new Integer(0), paramTypes, params);

        } catch (DocletInvokeException exc) {

            return -1;

        }

        if (retVal instanceof Integer) {

            return ((Integer)retVal).intValue();

        } else {

            messager.error(null, "main.must_return_int",

                           docletClassName, methodName);

            return -1;

        }

    }

    /**

     * Let doclet check that all options are OK. Returning true means

     * options are OK.  If method does not exist, assume true.

     */

    public boolean validOptions(List<String[]> optlist) {

        Object retVal;

        String options[][] = optlist.toArray(new String[optlist.length()][]);

        String methodName = "validOptions";

        DocErrorReporter reporter = messager;

        Object[] params = new Object[2];

        paramTypes[0] = options.getClass();

        paramTypes[1] = DocErrorReporter.class;

        params[0] = options;

        params[1] = reporter;

        try {

            retVal = invoke(methodName, Boolean.TRUE, paramTypes, params);

        } catch (DocletInvokeException exc) {

            return false;

        }

        if (retVal instanceof Boolean) {

            return ((Boolean)retVal).booleanValue();

        } else {

            messager.error(null, "main.must_return_boolean",

                           docletClassName, methodName);

            return false;

        }

    }

    /**

     * Return the language version supported by this doclet.

     * If the method does not exist in the doclet, assume version 1.1.

     */

    public LanguageVersion languageVersion() {

        try {

            Object retVal;

            String methodName = "languageVersion";

            Object[] params = new Object[0];

            try {

                retVal = invoke(methodName, JAVA_1_1, paramTypes, params);

            } catch (DocletInvokeException exc) {

                return JAVA_1_1;

            }

            if (retVal instanceof LanguageVersion) {

                return (LanguageVersion)retVal;

            } else {

                messager.error(null, "main.must_return_languageversion",

                               docletClassName, methodName);

                return JAVA_1_1;

            }

        } catch (NoClassDefFoundError ex) { // for boostrapping, no Enum class.

            return null;

        }

    }

    /**

     * Utility method for calling doclet functionality

     */

    private Object invoke(String methodName, Object returnValueIfNonExistent,

        throws DocletInvokeException {

            Method meth;

            try {

                meth = docletClass.getMethod(methodName, paramTypes);

            } catch (NoSuchMethodException exc) {

                if (returnValueIfNonExistent == null) {

                    messager.error(null, "main.doclet_method_not_found",

                                   docletClassName, methodName);

                    throw new DocletInvokeException();

                } else {

                    return returnValueIfNonExistent;

                }

            } catch (SecurityException exc) {

                messager.error(null, "main.doclet_method_not_accessible",

                               docletClassName, methodName);

                throw new DocletInvokeException();

            }

            if (!Modifier.isStatic(meth.getModifiers())) {

                messager.error(null, "main.doclet_method_must_be_static",

                               docletClassName, methodName);

                throw new DocletInvokeException();

            }

            try {

                Thread.currentThread().setContextClassLoader(appClassLoader);

                return meth.invoke(null , params);

            } catch (IllegalArgumentException exc) {

                messager.error(null, "main.internal_error_exception_thrown",

                               docletClassName, methodName, exc.toString());

                throw new DocletInvokeException();

            } catch (IllegalAccessException exc) {

                messager.error(null, "main.doclet_method_not_accessible",

                               docletClassName, methodName);

                throw new DocletInvokeException();

            } catch (NullPointerException exc) {

                messager.error(null, "main.internal_error_exception_thrown",

                               docletClassName, methodName, exc.toString());

                throw new DocletInvokeException();

            } catch (InvocationTargetException exc) {

                Throwable err = exc.getTargetException();

                if (err instanceof java.lang.OutOfMemoryError) {

                    messager.error(null, "main.out.of.memory");

                } else {

                messager.error(null, "main.exception_thrown",

                               docletClassName, methodName, exc.toString());

                    exc.getTargetException().printStackTrace();

                }

                throw new DocletInvokeException();

            }

    }

    /**

     * Utility method for converting a search path string to an array

     * of directory and JAR file URLs.

     *

     * @param path the search path string

     * @return the resulting array of directory and JAR file URLs

     */

    static URL[] pathToURLs(String path) {

        StringTokenizer st = new StringTokenizer(path, File.pathSeparator);

        URL[] urls = new URL[st.countTokens()];

        int count = 0;

        while (st.hasMoreTokens()) {

            URL url = fileToURL(new File(st.nextToken()));

            if (url != null) {

                urls[count++] = url;

            }

        }

        if (urls.length != count) {

            URL[] tmp = new URL[count];

            System.arraycopy(urls, 0, tmp, 0, count);

            urls = tmp;

        }

        return urls;

    }

    /**

     * Returns the directory or JAR file URL corresponding to the specified

     * local file name.

     *

     * @param file the File object

     * @return the resulting directory or JAR file URL, or null if unknown

     */

    static URL fileToURL(File file) {

        String name;

        try {

            name = file.getCanonicalPath();

        } catch (IOException e) {

            name = file.getAbsolutePath();

        }

        name = name.replace(File.separatorChar, '/');

        if (!name.startsWith("/")) {

            name = "/" + name;

        }

        // If the file does not exist, then assume that it's a directory

        if (!file.isFile()) {

            name = name + "/";

        }

        try {

            return new URL("file", "", name);

        } catch (MalformedURLException e) {

            throw new IllegalArgumentException("file");

        }

    }

}