src/plugins/android/src/com/motorola/studio/android/obfuscate/ObfuscatorManager.java

/*
 * Copyright (C) 2012 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 com.motorola.studio.android.obfuscate;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Scanner;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubMonitor;
import org.osgi.framework.Bundle;

import com.motorola.studio.android.AndroidPlugin;
import com.motorola.studio.android.common.log.StudioLogger;
import com.motorola.studio.android.common.utilities.AndroidUtils;

/**
 * Manager to set Proguard files inside project 
 * Manipulates the file on <project_root>/default.properties
 * Copy proguard.cfg
 */
public class ObfuscatorManager
{

    private static final String PROGUARD_PATH = "/files/proguard.cfg";

    private static final String PROGUARD_SDK_PATH = "tools/lib/proguard.cfg";

    private static final String PROGUARD_FILENAME = "proguard.cfg";

    private static final String PROGUARD_CONFIG_STATEMENT = "proguard.config=proguard.cfg";

    private static final String DEFAULT_PROPERTIES_FILENAME = "default.properties";

    private static final String PROJECT_PROPERTIES_FILENAME = "project.properties";

    private static final String NL = System.getProperty("line.separator");

    /**
     * Prepares the project with the Proguard settings 
     * to obfuscate when the project is exported in release mode
     * @param project
     * @param monitor
     * @return
     */
    public static IStatus obfuscate(IProject project, IProgressMonitor monitor)
    {
        IStatus status = Status.OK_STATUS;

        /*
         * Project properties file is the new filename for ADT
         */
        File projectPropertiesFile =
                project.getFile(PROJECT_PROPERTIES_FILENAME).getLocation().toFile();
        File defaultPropertiesFile =
                project.getFile(DEFAULT_PROPERTIES_FILENAME).getLocation().toFile();
        if (projectPropertiesFile.canWrite())
        {
            defaultPropertiesFile = projectPropertiesFile;
        }

        File proguardFile = project.getFile(PROGUARD_FILENAME).getLocation().toFile();

        try
        {
            addProguardLine(defaultPropertiesFile);
            if (!fileExists(proguardFile))
            {
                copyProguardFile(project, monitor);
            }
            try
            {
                project.refreshLocal(IResource.DEPTH_ONE, null);
            }
            catch (CoreException e)
            {
                // Do nothing, user just have to press F5 
            }
        }
        catch (Exception e)
        {
            StudioLogger.error(ObfuscatorManager.class,
                    "Error while setting Proguard to obfuscate", e);
            status =
                    new Status(IStatus.ERROR, AndroidPlugin.PLUGIN_ID,
                            "Could not set Proguard to obfuscate", e);
        }

        StudioLogger.collectUsageData(StudioLogger.WHAT_OBFUSCATE, StudioLogger.KIND_OBFUSCATE,
                StudioLogger.DESCRIPTION_DEFAULT, AndroidPlugin.PLUGIN_ID, AndroidPlugin
                        .getDefault().getBundle().getVersion().toString());

        return status;
    }

    /**
     * Removes Proguard settings 
     * (Project will not be obfuscated when the is exported in release mode)
     * @param project
     * @return
     */
    public static IStatus unobfuscate(IProject project)
    {
        IStatus status = Status.OK_STATUS;

        try
        {
            File projectPropertiesFile =
                    project.getFile(PROJECT_PROPERTIES_FILENAME).getLocation().toFile();
            File defaultPropertiesFile =
                    project.getFile(DEFAULT_PROPERTIES_FILENAME).getLocation().toFile();
            if (isProguardSet(defaultPropertiesFile))
            {
                removeProguardLine(defaultPropertiesFile);
            }
            if (isProguardSet(projectPropertiesFile))
            {
                removeProguardLine(projectPropertiesFile);
            }
            try
            {
                project.refreshLocal(IResource.DEPTH_ONE, null);
            }
            catch (CoreException e)
            {
                // Do nothing, user just have to press F5 
            }
        }
        catch (Exception e)
        {
            StudioLogger
                    .error(ObfuscatorManager.class, "Error while removing Proguard settings", e);
            status =
                    new Status(IStatus.ERROR, AndroidPlugin.PLUGIN_ID,
                            "Could not remove Proguard settings", e);
        }

        StudioLogger.collectUsageData(StudioLogger.WHAT_OBFUSCATE, StudioLogger.KIND_DESOBFUSCATE,
                StudioLogger.DESCRIPTION_DEFAULT, AndroidPlugin.PLUGIN_ID, AndroidPlugin
                        .getDefault().getBundle().getVersion().toString());

        return status;
    }

    /*
     * @param propertiesFile file to write
     * @param newContent content to write (replaces entire file)
     * @throws IOException
     */
    private static void write(File propertiesFile, String newContent) throws IOException
    {
        Writer out = new OutputStreamWriter(new FileOutputStream(propertiesFile));
        try
        {
            out.write(newContent);
        }
        finally
        {
            if (out != null)
            {
                out.close();
            }
        }
    }

    /*
     * @param ignoreProguardStatement true it does not return the line with proguard.config=proguard.cfg 
     * @return
     * @throws IOException
     */
    private static String read(File propertiesFile, boolean ignoreProguardStatement)
            throws IOException
    {
        StringBuilder text = new StringBuilder();
        Scanner scanner = null;
        FileInputStream stream = null;
        try
        {
            stream = new FileInputStream(propertiesFile);
            scanner = new Scanner(stream);
            while (scanner.hasNextLine())
            {
                String line = scanner.nextLine();
                if (!ignoreProguardStatement || !line.contains(PROGUARD_CONFIG_STATEMENT))
                {
                    text.append(line + NL);
                }
            }
        }
        finally
        {
            try
            {
                if (scanner != null)
                {
                    scanner.close();
                }
                if (stream != null)
                {
                    stream.close();
                }
            }
            catch (IOException e)
            {
                StudioLogger
                        .info("Could not close stream while reading obfuscator properties file. "
                                + e.getMessage());
            }
        }
        return text.toString();
    }

    private static boolean fileExists(File proguardFile)
    {
        return (proguardFile != null) && proguardFile.exists();
    }

    /**
     * Checks if default.properties have Proguard statement
     * and if the proguard.cfg exists in the project
     * @param project
     * @return
     */
    public static boolean isProguardSet(IProject project)
    {
        File projectPropertiesFile =
                project.getFile(PROJECT_PROPERTIES_FILENAME).getLocation().toFile();
        File defaultPropertiesFile =
                project.getFile(DEFAULT_PROPERTIES_FILENAME).getLocation().toFile();
        File proguardFile = project.getFile(PROGUARD_FILENAME).getLocation().toFile();

        return (isProguardSet(projectPropertiesFile) || isProguardSet(defaultPropertiesFile))
                && fileExists(proguardFile);
    }

    /**
     * Checks if default.properties have the Proguard statement
     * @param propertiesFile
     * @return
     */
    private static boolean isProguardSet(File propertiesFile)
    {
        String defaultPropertiesContent = null;
        try
        {
            defaultPropertiesContent = read(propertiesFile, false);
        }
        catch (IOException e)
        {
            StudioLogger.error(ObfuscatorManager.class, e.getMessage(), e);
        }
        return ((defaultPropertiesContent != null) && defaultPropertiesContent
                .contains(PROGUARD_CONFIG_STATEMENT));
    }

    /**
     * Add the following line to file 
     * proguard.config=proguard.cfg
     * if it does not exist yet
     * @param project
     * @throws IOException 
     */
    private static void addProguardLine(File propertiesFile) throws IOException
    {
        String currentContent = null;
        currentContent = read(propertiesFile, false);
        if (!currentContent.toString().contains(PROGUARD_CONFIG_STATEMENT))
        {
            String newContent =
                    currentContent.endsWith(NL) ? currentContent + PROGUARD_CONFIG_STATEMENT
                            : currentContent + NL + PROGUARD_CONFIG_STATEMENT;
            write(propertiesFile, newContent);
        }
    }

    /**
     * Remove the following line to file 
     * proguard.config=proguard.cfg
     * if it exists
     * @param project
     * @throws IOException 
     */
    private static void removeProguardLine(File propertiesFile) throws IOException
    {
        String contentWithoutProguardStatement = null;
        contentWithoutProguardStatement = read(propertiesFile, true);
        write(propertiesFile, contentWithoutProguardStatement);
    }

    private static void copyProguardFile(IProject project, IProgressMonitor monitor)
            throws IOException, CoreException
    {
        SubMonitor subMonitor = SubMonitor.convert(monitor);

        URL proguardURL = getProguardFileURL();
        if (proguardURL != null)
        {
            InputStream is = null;
            try
            {
                is = proguardURL.openStream();
                IFile destFile = project.getFile(PROGUARD_FILENAME);
                destFile.create(is, IResource.NONE, subMonitor);
            }
            finally
            {
                if (is != null)
                {
                    is.close();
                }
            }
        }
    }

    /**
     * Get the most suitable proguard file, either from SDK or our plug-in
     * @return the URL of the best proguard file found
     */
    private static URL getProguardFileURL()
    {
        String sdkPath = AndroidUtils.getSDKPathByPreference();
        File sdkPathFile = sdkPath.isEmpty() ? new File(sdkPath) : null;
        File proguardFromSDK = null;
        if (sdkPathFile != null)
        {
            proguardFromSDK = new File(sdkPathFile, PROGUARD_SDK_PATH);
        }

        URL fileURL = null;
        // copy newest proguard file from SDK
        if ((proguardFromSDK != null) && proguardFromSDK.canRead())
        {
            try
            {
                fileURL = proguardFromSDK.toURI().toURL();
            }
            catch (MalformedURLException e)
            {
                StudioLogger.warn(ObfuscatorManager.class,
                        "Exception converting proguard template file to URL", e);
            }
        }
        //copy file bundled with android plugin
        else
        {
            Bundle bundle = AndroidPlugin.getDefault().getBundle();
            fileURL = bundle.getEntry(PROGUARD_PATH);
        }

        return fileURL;
    }
}