package org.impressive.artworx.android.filebrowser;

import java.io.File;
import java.util.ArrayList;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class AndroidFileBrowser extends ListActivity
{
     private enum DISPLAYMODE{ ABSOLUTE, RELATIVE};
     private final DISPLAYMODE mDisplayMode = DISPLAYMODE.ABSOLUTE;
     private ArrayList<String> mDirectoryEntries = new ArrayList<String>();
     private File mCurrentDirectory = new File("/");
     
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        // setContentView() gets called within the next line,
        // so we do not need it here.
        browseToRoot();
    }
   
    /**
     * This method browses to the root-directory of the file-system.
     */
    private void browseToRoot()
    {
     browseTo(new File("/"));
    }
   
    /**
     * Method browses to the given directory and either lists its files or asks the
     * user to open the file if it is not a directory but a file instead.
     *
     * @param dir the file or directory to browse to
     */
    private void browseTo(final File dir)
    {
     if(dir.isDirectory())
     {
          mCurrentDirectory = dir;
          fill(mCurrentDirectory.listFiles());
     }
     else
     {
          OnClickListener okButtonListener = new OnClickListener()
          {
               @Override
               public void onClick(DialogInterface arg0, int arg1)
               {
                    // Starts an intent to view the file that was clicked...
                    openFile(dir);
               }
          };
          OnClickListener cancelButtonListener = new OnClickListener(){
               @Override
               public void onClick(DialogInterface arg0, int arg1)
               {
                    // Do nothing
               }
          };
          new AlertDialog.Builder(this)
            .setTitle("Question")
            .setMessage("Do you want to open that file?\n"+ dir.getName())
            .setPositiveButton("OK", okButtonListener)
            .setNegativeButton("Cancel", cancelButtonListener)
            .show();
     }
    }
   
    /**
     * Fills the list view with the file path (relative or absolut).
     *
     * @param files the files to be shown
     */
    private void fill(File[] files)
    {
        this.mDirectoryEntries.clear();
       
        // Add the "." == "current directory"
        // and the ".." == 'Up one level'
        this.mDirectoryEntries.add(getString(R.string.current_level));      
        if(this.mCurrentDirectory.getParent() != null)
             this.mDirectoryEntries.add(getString(R.string.up_one_level));
       
        switch(this.mDisplayMode)
        {
             case ABSOLUTE:
                  for (File file : files)
                  {
                       this.mDirectoryEntries.add(file.getPath());
                  }
                  break;
             case RELATIVE: // On relative Mode, we have to substract the current-path from the beginning
                  int currentPathStringLenght = this.mCurrentDirectory.getAbsolutePath().length();
                  for (File file : files)
                  {
                       this.mDirectoryEntries.add(file.getAbsolutePath().substring(currentPathStringLenght));
                  }
                  break;
        }
       
        // create an array list adapter and set it as the view
        ArrayAdapter<String> directoryList = new ArrayAdapter<String>(this,
                R.layout.file_row, this.mDirectoryEntries);
        this.setListAdapter(directoryList);
    }
       
    /**
     * Sends an intent to open the given file.
     *
     * @param f the file to be opened
     */
    private void openFile(File f)
    {
     // Create an Intent
     Intent intent = new Intent();
     intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
     intent.setAction(android.content.Intent.ACTION_VIEW);
     
     // Category where the App should be searched
//        String category = new String("android.intent.category.DEFAULT");
     
     // Setting up the data and the type for the intent
     String type = getMIMEType(f);
     intent.setDataAndType(Uri.fromFile(f), type);
               
     // will start the activtiy found by android or show a dialog to select one
     startActivity(intent);
    }
   
    /**
     * Returns the MIME type for the given file.
     *
     * @param f the file for which you want to determine the MIME type
     * @return the detected MIME type
     */
    private String getMIMEType(File f)
    {
     String end = f.getName().substring(f.getName().lastIndexOf(".")+1, f.getName().length()).toLowerCase();
     String type = "";
     if(end.equals("mp3") || end.equals("aac") || end.equals("aac") || end.equals("amr") || end.equals("mpeg") || end.equals("mp4")) type = "audio";
     else if(end.equals("jpg") || end.equals("gif") || end.equals("png") || end.equals("jpeg")) type = "image";
     
     type += "/*";
     return type;
    }
   
    /**
     * This function browses up one level according to the field: mCurrentDirectory.
     */
    private void upOneLevel()
    {
         if(this.mCurrentDirectory.getParent() != null)
              this.browseTo(this.mCurrentDirectory.getParentFile());
    }
   
    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
     int selectionRowID = position;
        String selectedFileString = this.mDirectoryEntries.get(selectionRowID);
        if (selectedFileString.equals(getString(R.string.current_level)))
        {
             // Refresh
             this.browseTo(this.mCurrentDirectory);
        } else if(selectedFileString.equals(getString(R.string.up_one_level)))
        {
             this.upOneLevel();
        }
        else
        {
             File clickedFile = null;
             switch(this.mDisplayMode){
                  case RELATIVE:
                       clickedFile = new File(this.mCurrentDirectory.getAbsolutePath()
                                                          + this.mDirectoryEntries.get(selectionRowID));
                       break;
                  case ABSOLUTE:
                       clickedFile = new File(selectedFileString);
                       break;
             }
             if(clickedFile != null)
             {
                Log.d("AndroidFileBrowser", "File " + clickedFile + " exists? " +
                           clickedFile.exists());
                this.browseTo(clickedFile);
             }
        }
    }
}