/*
 * 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 opennlp.tools.similarity.apps.utils;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.log4j.Logger;


/**
 *This class responsible to save data to files as well as read out!
 *It is capable to handle text and binary files. 
 */
public class FileHandler {
	
	private static Logger LOG = Logger.getLogger("opennlp.tools.similarity.apps.utils.FileHandler");
       
	
	public  void writeToTextFile(String data,String filepath,boolean append) throws IOException {
		try{
			BufferedWriter out = new BufferedWriter(new FileWriter(filepath, append));
			out.write(data + "\n");
            out.close();
            } catch (IOException e) {
                	LOG.error(e);
                	e.printStackTrace();
            }
	}
	/**
	 * Writes data from an arrayList<String> to a text-file where each line of the text represented by an element in the list.
	 * @param list
	 * @param filePath
	 * @param append
	 * @throws Exception
	 */
	public  void writeToTextFile(ArrayList<String> list, String filePath, boolean append)	throws Exception {
		FileWriter outFile = null;
		Iterator<String> it = list.iterator();
		if (!append) {
			outFile = new FileWriter(filePath);
			PrintWriter out = new PrintWriter(outFile);
			while (it.hasNext()) {
				out.println((String) it.next());
			}
			outFile.close();
		} else {
			int tmp = 0;
			while (it.hasNext()) {
				if (tmp == 0) {
					appendtofile("\n" + (String) it.next(), filePath);
				} else {
					appendtofile((String) it.next(), filePath);
				}
				tmp++;
			}
		}
	}

     public  void writeObjectToFile(Object obj, String filepath, boolean append) {
    	 	if(!isFileOrDirectoryExists(getDirPathfromFullPath(filepath))){
    	 		createFolder(getDirPathfromFullPath(filepath));
    	 	}
    	 	ObjectOutputStream outputStream = null;
         try {
        	 outputStream = new ObjectOutputStream(new FileOutputStream(filepath));
             outputStream.writeObject(obj);
             } catch (IOException e) {
            	 LOG.error(e);
             }
    }
    public  Object readObjectfromFile(String filePath){
    	ObjectInputStream inputStream = null;
    	try {
    		//Construct the ObjectInputStream object
            inputStream = new ObjectInputStream(new FileInputStream(filePath));
            Object obj = null;
            while ((obj = inputStream.readObject()) != null) {
            	return  obj;
            }
        } catch (EOFException ex) { //This exception will be caught when EOF is reached
        	LOG.error("End of file reached.",ex);
        } catch (ClassNotFoundException ex) {
        	LOG.error(ex);
        } catch (FileNotFoundException ex) {
        	LOG.error(ex);
        } catch (IOException ex) {
        	LOG.error(ex);
        } finally {
            //Close the ObjectInputStream
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
            } catch (IOException ex) {
            	LOG.error(ex);
            }
        }
             return null;
         }
    /**
     * Creates a byte array from any object.
     * 
     * I wanted to use it when I write out object to files! (This is not in use right now, I may move it into other class)
     * 
     * @param obj
     * @return
     * @throws java.io.IOException
     */
    public  byte[] getBytes(Object obj) throws java.io.IOException{
    	ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        oos.writeObject(obj);
        oos.flush();
        oos.close();
        bos.close();
        byte [] data = bos.toByteArray();
        return data;
    }

	/**
	 * Fetches all content from a text file, and return it as a String.
	 * @return
	 */
	 public String readFromTextFile(String filePath) {
		StringBuilder contents = new StringBuilder();
		// ...checks on aFile are edited
		File aFile = new File(filePath);

		try {
			// use buffering, reading one line at a time
			// FileReader always assumes default encoding is OK!
			// TODO be sure that the default encoding is OK!!!!! Otherwise
			// change it

			BufferedReader input = new BufferedReader(new FileReader(aFile));
			try {
				String line = null; // not declared within while loop
				/*
				 * readLine is a bit quirky : it returns the content of a line
				 * MINUS the newline. it returns null only for the END of the
				 * stream. it returns an empty String if two newlines appear in
				 * a row.
				 */
				while ((line = input.readLine()) != null) {
					contents.append(line);
					contents.append(System.getProperty("line.separator"));
				}
			} finally {
				input.close();
			}
		} catch (IOException ex) {
			LOG.error("fileName: "+filePath,ex);
		}
		return contents.toString();
	}
	/**
	 * Reads text file line-wise each line will be an element in the resulting list
	 * @param filePath
	 * @return
	 */
	public  List<String> readLinesFromTextFile(String filePath){
		List<String> lines= new ArrayList<String>();
		// ...checks on aFile are edited
		File aFile = new File(filePath);
		try {
			// use buffering, reading one line at a time
			// FileReader always assumes default encoding is OK!
			// TODO be sure that the default encoding is OK!!!!! Otherwise
			// change it

			BufferedReader input = new BufferedReader(new FileReader(aFile));
			try {
				String line = null; // not declared within while loop
				/*
				 * readLine is a bit quirky : it returns the content of a line
				 * MINUS the newline. it returns null only for the END of the
				 * stream. it returns an empty String if two newlines appear in
				 * a row.
				 */
				while ((line = input.readLine()) != null) {
					lines.add(line);
				}
			} finally {
				input.close();
			}
		} catch (IOException ex) {
			LOG.error(ex);
		}
		return lines;
	}

	

	private  void appendtofile(String data, String filePath) {
		try {
			BufferedWriter out = new BufferedWriter(new FileWriter(filePath,true));
			out.write(data + "\n");
			out.close();
		} catch (IOException e) {
		}
	}
	public  void  createFolder(String path){
		if(!isFileOrDirectoryExists(path)){
			File file = new File(path);
	    	 try{
	    	 file.mkdirs();
	    	 }catch (Exception e) {
				LOG.error("Directory already exists or the file-system is read only",e);
			}	
		} 
	}
	public  boolean isFileOrDirectoryExists(String path){
		File file=new File(path);
		boolean exists = file.exists();
		return exists;
	}
	/**
	 * Separates the directory-path from a full file-path
	 * @param filePath
	 * @return
	 */
	private  String getDirPathfromFullPath(String filePath){
		String dirPath="";
		if(filePath!=null){
			if(filePath!=""&&filePath.contains("\\"))
			dirPath =filePath.substring(0,filePath.lastIndexOf("\\"));
		}
		return dirPath;
	}
	/**
	 * Returns the file-names of the files in a folder (not paths only names) (Not recursive)
	 * @param dirPath
	 * @return
	 */
	public  ArrayList<String> getFileNamesInFolder(String dirPath){
		ArrayList<String> fileNames= new ArrayList<String>();
			
			File folder = new File(dirPath);
		    File[] listOfFiles = folder.listFiles();

		    for (int i = 0; i < listOfFiles.length; i++) {
		      if (listOfFiles[i].isFile()) {
		        fileNames.add(listOfFiles[i].getName());
		      } else if (listOfFiles[i].isDirectory()) {
		        //TODO if I want to use it recursive I should handle this case
		      }
			}
		return fileNames;
	}
	
	public void deleteAllfilesinDir(String dirName){
		ArrayList<String> fileNameList=getFileNamesInFolder(dirName);
		if(fileNameList!=null){
		for(int i=0; i<fileNameList.size();i++){
		try{
			deleteFile(dirName+fileNameList.get(i));
			}catch(IllegalArgumentException e){
				LOG.error("No way to delete file: "+dirName+fileNameList.get(i),e);
			}
		}
		}
	}
	public  void deleteFile(String filePath) throws IllegalArgumentException{
		// A File object to represent the filename
	    File f = new File(filePath);
	    // Make sure the file or directory exists and isn't write protected
	    if (!f.exists())
	      throw new IllegalArgumentException(
	          "Delete: no such file or directory: " + filePath);

	    if (!f.canWrite())
	      throw new IllegalArgumentException("Delete: write protected: "
	          + filePath);
	    // If it is a directory, make sure it is empty
	    if (f.isDirectory()) {
	      String[] files = f.list();
	      if (files.length > 0)
	        throw new IllegalArgumentException(
	            "Delete: directory not empty: " + filePath);
	    }
	    // Attempt to delete it
	    boolean success = f.delete();
	    if (!success)
	      throw new IllegalArgumentException("Delete: deletion failed");
	}
	
	public boolean deleteDirectory(File path) {
	    if( path.exists() ) {
	      File[] files = path.listFiles();
	      for(int i=0; i<files.length; i++) {
	         if(files[i].isDirectory()) {
	           deleteDirectory(files[i]);
	         }
	         else {
	           files[i].delete();
	         }
	      }
	    }
	    return( path.delete() );
	  }
	
	/**
	 * Returns the absolute-file-paths of the files in a directory (not recursive)
	 * @param dirPath
	 * @return
	 */
	public  ArrayList<String> getFilePathsInFolder(String dirPath){
		ArrayList<String> filePaths= new ArrayList<String>();
			
			File folder = new File(dirPath);
		    File[] listOfFiles = folder.listFiles();
		    if(listOfFiles==null)
		    	return null;
		    for (int i = 0; i < listOfFiles.length; i++) {
		      if (listOfFiles[i].isFile()) {
		    	  filePaths.add(listOfFiles[i].getAbsolutePath());
		      } else if (listOfFiles[i].isDirectory()) {
		        //TODO if I want to use it recursive I should handle this case
		      }
			}
		return filePaths;
	}
	/**
	 * Returns the number of individual files in a directory (Not ercursive)
	 * @param dirPath
	 * @return
	 */
	public  int getFileNumInFolder(String dirPath){
		int num=0;
		try{
			num=getFileNamesInFolder(dirPath).size();
		}catch (Exception e) {
			num=0;
		}
		return num;
	}

}