/*
    * Copyright 2007-2008 the original author or authors.
    * 
    * 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 org.gwe.utils.cmd;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.gwe.utils.StringUtils;
  import org.springframework.beans.BeanWrapper;
  import org.springframework.beans.BeanWrapperImpl;
  
  /**
   * @author Marco Ruiz
   * @since Jul 13, 2007
   */
  public class OptionableAppTemplate {
  	
  	public final OptionTemplate OPT_HELP = new OptionTemplate('h', "help", "Help. Displays command usage");
  	public final OptionTemplate OPT_INTERACT = new OptionTemplate("interactive", "Runs application in interactive mode, requesting the parameters to the user one by one.");
      
  	private List<OptionTemplate> templatesInOrder = new ArrayList<OptionTemplate>();
  	private Map<OptionTemplate, String> options = new HashMap<OptionTemplate, String>();
      
      public OptionableAppTemplate() {
      	options.put(OPT_HELP, null);
      	options.put(OPT_INTERACT, null);
  	}
      
      public OptionableAppTemplate(OptionTemplate... templates) {
      	this();
      	addOptions(templates);
  	}
      
  	public OptionableAppTemplate addOptions(OptionTemplate... options) {
  		for (OptionTemplate template : options)
  			addOption(template, template.getDefaultValue());
  
  		return this;
  	}
  	
  	public void resetArgs() {
  		addOptions(templatesInOrder.toArray(new OptionTemplate[]{}));
  	}
  	
  	public OptionTemplate addArg(OptionTemplate template) {
  		return addOption(template, template.getDefaultValue());
  	}
  	
  	public OptionTemplate addOption(OptionTemplate template, Object value) {
  		templatesInOrder.remove(template);
  		templatesInOrder.add(template);
  		String strVal = (value != null) ? value.toString() : null; 
  		options.put(template, strVal);
  		return template;
  	}
  	
  	public void removeOption(OptionTemplate template) {
  		templatesInOrder.remove(template);
  		options.remove(template);
  	}
  	
  	public String[] getInvocationArgs() {
  		List<String> result = new ArrayList<String>();
  		for (OptionTemplate template : templatesInOrder) {
  			result.add("-" + String.valueOf(template.getShortFlag()));
  			result.add(options.get(template));
  		}
  		return result.toArray(new String[]{});
  	}
      
  //	public String getInvocationArgsAsStr() { return StringUtils.getArrayAsAsStr(getInvocationArgs()); }
      
      public <APP_TYPE> APP_TYPE loadArgs(String[] args, APP_TYPE appObject) {
      	loadArgs(args);
      	return populateAppObject(appObject);
      }
      
      public void loadArgs(String[] args) {
      	resetArgs();
      	for (OptionTemplate option : options.keySet()) 
     		options.put(option, option.readOptionValue(args));
     	
     	if (getArg(OPT_HELP) != null) {
     		System.out.println(getUsage());
     		System.exit(0);
     	}
     	
     	if (getArg(OPT_INTERACT) != null) {
     		System.out.println("PLEASE ENTER THE PARAMETERS AS THEY ARE REQUESTED.\n" +
     				"To use a field's default value just leave it blank and press return.\n" +
     				"======================================================================");
         	for (OptionTemplate option : templatesInOrder) readOptionFromConsole(option);
     	}
     }
     
     public String[] getWithoutOptionsArgs(String[] args) {
     	for (OptionTemplate option : options.keySet()) 
     		args = option.removeOptionFromArray(args);
     	return args;
     }
     
     public String getWithoutOptionsArgsAsStr(String[] args) { return StringUtils.getArrayAsStr(getWithoutOptionsArgs(args)); }
     
 	private void readOptionFromConsole(OptionTemplate option) {
 		try {
 			String value = readNextField(option.getDescription() + "\n" + option.getLongFlag());
 			if (value == null || "".equals(value)) value = option.getDefaultValue();
 			options.put(option, value);
 		} catch (IOException e) {
 			System.out.print("There was an IO error trying to collect your information. " +
 					"The application will use the default value of " + option.getDefaultValue() + " for " + option.getLongFlag());
 		}
 	}
     
 	public String getArg(OptionTemplate key) { return options.get(key); }
 	
 	public Integer getArgAsInt(OptionTemplate key) {
 		try {
 			return Integer.parseInt(options.get(key));
 		} catch (Exception e) {
 			return null;
 		}
 	}
 	
 	public Long getArgAsLong(OptionTemplate key) {
 		try {
 			return Long.parseLong(options.get(key));
 		} catch (Exception e) {
 			return null;
 		}
 	}
 	
 	public <APP_TYPE> APP_TYPE populateAppObject(APP_TYPE appObject) {
 		BeanWrapper appObjectWrapper = new BeanWrapperImpl(appObject);
 		for (OptionTemplate template : templatesInOrder) 
 			template.setObjectProperty(appObjectWrapper, options.get(template));
 		return appObject;
 	}
 	
     public String getUsage() {
     	String usage;
     	usage = "Usage: java " + this.getClass().getName() + " [OPTION]\n\nOptions:\n";
 
     	int longFlagSize = 0;
     	for (OptionTemplate option : templatesInOrder) longFlagSize = Math.max(longFlagSize, option.getLongFlag().length());
     	for (OptionTemplate option : templatesInOrder) usage += option.toString(longFlagSize);
     	return usage; 
     }
     
     public String toString() {
     	return getUsage();
     }
     
     private String readNextField(String fieldName) throws IOException {
         System.out.print(fieldName + ": ");
 	    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
         String line = reader.readLine();
         if (line == null) return null;
 		return line;
     }
     
     public OptionableAppTemplate clone() {
     	OptionableAppTemplate result = new OptionableAppTemplate(templatesInOrder.toArray(new OptionTemplate[]{}));
    		result.options.putAll(options);
    		return result;
     }
 }