package hulp;

/**
 * Provides functions to read and write text to file
 *  where text is an ArrayList of strings 
 */
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.prefs.Preferences;

import javax.swing.JFileChooser;
import javax.swing.filechooser.FileFilter;

public class File2String {

	/**  EXAMPLE PROGRAM  **/
	public static void main(String s[]) {
		// *********************
		// *** WRITE TO FILE ***
		// *********************
		
		ArrayList<String> text = new ArrayList<String>();
		text.add("blabla");
		text.add("8.42");
		text.add("lalala;oef"); // we use the ';'-symbol to separate both items
		
		// write text to a given file
		File file = new File("D://test.txt");
		File2String.writeToFile(text, file);
		
		// let the user choose the file
//		 File2String.writeToFile(text, "Provide file for writing my text to");
		
		// **********************
		// *** READ FROM FILE ***
		// **********************
		
		// read content from a given file
		File file2 = new File("D://test.txt");
		ArrayList<String> linesOfFile = File2String.readFile(file2);
		
		// let the user choose the file
//		ArrayList<String> linesOfFile = File2String.readFile("Give the file you want to read");
		
		System.out.println("Contexts of file <"+File2String.lastFile+">:");
		System.out.println(linesOfFile);
		
		// ********************************
		// *** PARSING CONTENTS OF FILE ***
		// ********************************
		String line2 = linesOfFile.get(1);
		double x = Double.parseDouble(line2); // convert to double
		System.out.println("Value at line 2: "+x);
		
		String line3 = linesOfFile.get(2);
		int idx = line3.indexOf(";"); // we look for separator-symbol
		String item1 = line3.substring(0, idx);
		String item2 = line3.substring(idx+1);
		System.out.println("Item 1 of line 3: "+item1);
		System.out.println("Item 2 of line 3: "+item2);
    }
	
	
	public static File lastFile=null; // file of last read/write
	
	/************** METHODS TO READ FROM FILE ********************/
	public static ArrayList<String> readFile(){
		return readFile("Choose file");
    }
	 public static ArrayList<String> readFile(String text){
	    	return readFile(chooseFile(text, (FileFilter) null));
	    }
    public static ArrayList<String> readFile(String text, String fileSuffix){
    	return readFile(chooseFile(text, fileSuffix));
    }
    public static ArrayList<String> readFile(File file){
    	lastFile=file;
		if (file==null)
			return null;
		
		java.io.FileReader fr = null;
		try{
			fr = new java.io.FileReader(file);
		}
		catch( java.io.FileNotFoundException e){
			return null;
		}
	   	BufferedReader in = new BufferedReader(fr);
	   	try{
	   		saveFileLocation(file.getParent());
	   	}catch(Exception e){}
   	
	   	return readAllLines(in);
    }
    private static ArrayList<String> readAllLines(BufferedReader in) {
    	ArrayList<String> v = new ArrayList<String>();
    	String line=null;
    	int ctr=0;
    	try {
			while ((line = in.readLine()) != null) {
				line.trim();
				
				v.add(line);
				
				ctr++;
			}
		} catch (IOException e) {
				System.err.println("Error when reading line "+ctr+":"+line);
				e.printStackTrace();
	    }
		return v;
    }
    /************** METHODS TO WRITE TO FILE ********************/
    public static void writeToFile(ArrayList<String> lines){
		writeToFile(lines, "Choose file");
    }
	public static void writeToFile(ArrayList<String> lines, String text){
	    writeToFile(lines, chooseFile(text, (FileFilter) null));
	}
    public static void writeToFile(ArrayList<String> lines, String text, String fileSuffix){
    	writeToFile(lines, chooseFile(text, fileSuffix));
    }
    public static void writeToFile(ArrayList<String> lines, File file){
    	lastFile=file;
	    PrintWriter out;
	    try {
	        out = new PrintWriter(new FileOutputStream(file));
	    }
	    catch (IOException e) {
	        throw new IllegalArgumentException("Output file could not be opened: "+ file);
	    }
	    for(String line: lines){
	    	out.println(line);
	    }
	    out.close();
    }
    /************** METHODS TO OPEN FILES ********************/
    public static File chooseFile(String text){
    	return chooseFile(text, (FileFilter)null);
    }
    public static File chooseFile(String text, String fileSuffix){
    	return chooseFile(text, getFileFilter(new String[]{fileSuffix}));
    }
    public static File chooseFile(String text, String[] fileSuffices){
    	return chooseFile(text, getFileFilter(fileSuffices));
    }
    public static File chooseFile(String text, FileFilter fileFilter){
    	JFileChooser chooser = new JFileChooser();
        String sessionSaveLocation = getFileLocation();
        chooser.setCurrentDirectory(new File(sessionSaveLocation));
        if (fileFilter == null)
        	chooser.resetChoosableFileFilters();
        else
        	chooser.addChoosableFileFilter(fileFilter);
        chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
 		chooser.showDialog(null, text);
 		File file = chooser.getSelectedFile();
 		if (file != null)
 			saveFileLocation(file.getParent());
		return file;
    }
    /*********** METHODS TO REMEMBER LAST VISITED FILE LOCATION ********************/
    private static Preferences prefsData = Preferences.userRoot();
    private static String FILE_LOCATION = ""; // if preferences do not work
    public static String getFileLocation(){
    	String loc = prefsData.get("fileLocation", "");
    	if (loc.equals(""))
    		return FILE_LOCATION;
		else
			return loc;
    }
    public static void saveFileLocation(String fileLocation){
    	prefsData.put("fileLocation", fileLocation);
    	String loc = prefsData.get("fileLocation", "");
    	if (loc.equals("")) // if put did not succeed
    		FILE_LOCATION = fileLocation;
    }
    /************** METHODS TO CREATE FILE FILTERS ********************/
	// returns a file filter for a JFileChooser
    public static FileFilter getFileFilter(String[] s) {
		return getFileFilter(s,"");
	}
	public static FileFilter getFileFilter(String[] s, String d) {
		class CustomFileFilter extends FileFilter {
			private String[] ext;
			private String description;
			public CustomFileFilter(String[] ext, String desc) {
				this.ext = ext;
				description = desc;
			}

			public String getDescription() {
				return description;
			}

			public boolean accept(File f) {
			    if (f.isDirectory()) {
			    	return true;
			    }
			    String extension = getExtension(f);
			    boolean b = false;
			    if (extension != null) {
			    	for (int i=0; i<ext.length; i++) {
			    		b = b || extension.equals(ext[i]);
			    	}
			    }
			    return b;
			}
		}
		return new CustomFileFilter(s,d);
	}
	public static String getExtension(File f) {
        String ext = null;
        String s = f.getName();
        int i = s.lastIndexOf('.');

        if (i > 0 &&  i < s.length() - 1) {
            ext = s.substring(i+1).toLowerCase();
        }
        return ext;
    }
	/************************************************************************/
}