/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You 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 org.apache.any23.cli;

 import org.apache.any23.plugin.Any23PluginManager;

 import java.io.File;

 import java.io.IOException;

 import java.lang.annotation.ElementType;

 import java.lang.annotation.Retention;

 import java.lang.annotation.RetentionPolicy;

 import java.lang.annotation.Target;

 /**

  * This class is the main class responsible to provide a uniform command-line

  * access points to all the others tools like {@link Rover}.

  *

  * @see ExtractorDocumentation

  * @see Rover

  */

 @ToolRunner.Skip

 public class ToolRunner {

     public static final File HOME_PLUGIN_DIR = new File(

             new File(System.getProperty("user.home")),

             ".any23/plugins"

     );

     private static final String USAGE = String.format(

             "Usage: %s <utility> [options...]",

             ToolRunner.class.getSimpleName()

     );

     public static void main(String[] args) throws IOException {

         //Generate automatically the cli.

         final Class<Tool>[] tools = getToolsInClasspath();

         try {

             if (args.length < 1) {

                 usage(null, tools);

             }

             final String toolName = args[0];

             Class<Tool> targetTool = null;

             for(Class<Tool> tool : tools) {

                 if(tool.getSimpleName().equals(toolName)) {

                     targetTool = tool;

                     break;

                 }

             }

             if(targetTool == null) {

                 usage( String.format("[%s] is not a valid tool name.", toolName), tools);

                 throw new IllegalStateException();

             }

             String[] mainArgs = new String[args.length - 1];

             System.arraycopy(args, 1, mainArgs, 0, mainArgs.length);

             final Tool targetToolInstance = targetTool.newInstance();

             targetToolInstance.run(mainArgs);

         } catch (Throwable e) {

             e.printStackTrace();

             Throwable cause = e.getCause();

             if(cause != null) cause.printStackTrace();

             usage(e.toString(), null);

         }

     }

     public static Class<Tool>[] getToolsInClasspath() throws IOException {

         final Any23PluginManager pluginManager =  Any23PluginManager.getInstance();

         if(HOME_PLUGIN_DIR.exists()) {

             pluginManager.loadJARDir(HOME_PLUGIN_DIR);

         }

         return pluginManager.getTools();

     }

     private static String padLeft(String s, int n) {

         return String.format("%1$#" + n + "s", s);

     }

     private static String getUtilitiesMessage(Class<Tool>[] toolClasses) {

         StringBuffer sb = new StringBuffer();

         sb.append(" where <utility> is one of:\n");

         Description description;

         String utilityName;

         int padding;

         for (Class<Tool> toolClass :  toolClasses) {

             utilityName = toolClass.getSimpleName();

             sb.append("\t").append(utilityName);

             description = toolClass.getAnnotation(Description.class);

             padding = 100 - utilityName.length();

             if (description != null) {

                 sb.append( padLeft( description.value(), padding >= 0 ? padding : 0) );

             }

             sb.append('\n');

         }

         return sb.toString();

     }

     private static void usage(String msg, Class<Tool>[] utilities) {

         if(msg != null) {

             System.err.println("*** ERROR: " + msg);

             System.err.println();

         }

         System.err.println(USAGE);

         if(utilities != null) {

             System.err.println( getUtilitiesMessage(utilities) );

         }

         System.exit(1);

     }

     @Retention(RetentionPolicy.RUNTIME)

     @Target(ElementType.TYPE)

     public @interface Skip {}

     @Retention(RetentionPolicy.RUNTIME)

     @Target(ElementType.TYPE)

     public @interface Description { String value();  }

 }