/**************************************
  This class is a subclass of ImageLoopEditor.
  It implements a text-based image loop editor.
  Commands can be read interactively from standard input.
  If a file is named on the command line, editing commands are read from
  that file.

  This editor uses the pushXXX methods defined in ImageLoopEditor.

  There is no need to change this class (but pushXXX methods must be
  defined for this editor to work properly).

  Last updated on May 23, 2017 by Charles Fischer
**************************************/

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;


public class TextImageLoopEditor extends ImageLoopEditor  {

  // A text-based testing interface. Testing commands are read from a file

  public static void textInterface(String[] args) {
    Scanner in = null;
    if (args.length > 1){
      System.out.println("invalid command-line arguments");
      System.exit(1);
    }
    boolean useFile = (args.length == 1);

    if (useFile) {
      File inFile = new File(args[0]);
      if (!inFile.exists() || !inFile.canRead()) {
          System.out.println("problem with input file");
          System.exit(1);
       }
      try {
       in = new Scanner(inFile);
      } catch (FileNotFoundException e) {
          System.out.println("problem with input file");
          System.exit(1);
      }
    }
    else {
      in = new Scanner(System.in);
    }
    boolean done = false;
    String [] validCommands = {"save","load","add","insert","find","update",
                                 "edit","jump","display","show","test","remove",
                                 "forward","backward","quit","help"};
    //Map testing commands to their one character code

    HashMap<String,Character> commandSelect = new HashMap<String,Character>();
    commandSelect.put("save", 's');
    commandSelect.put("load", 'l');
    commandSelect.put("add", 'a');
    commandSelect.put("insert", 'i');
    commandSelect.put("find", 'c');
    commandSelect.put("update", 'u');
    commandSelect.put("edit", 'e');
    commandSelect.put("jump", 'j');
    commandSelect.put("display", 'd');
    commandSelect.put("show", 'p');
    commandSelect.put("test", 't');
    commandSelect.put("remove", 'r');
    commandSelect.put("forward", 'f');
    commandSelect.put("backward", 'b');
    commandSelect.put("quit", 'x');
    commandSelect.put("help", '?');

    while (!done) {
            System.out.print("Enter command: ");
            String input = in.nextLine();
            if (useFile)
               System.out.println(input);

            String[] tokens = input.split("[ ]+",2);
            String command = tokens[0];
            String parameter = "";
            if (tokens.length > 1)
                parameter = tokens[1];

            // only do something if the user enters at least one character
            if (command.length() > 0 ) {
                command = command.toLowerCase();
                char choice; // One character encoding command choice

                // Get a list of possible commands selected by command
                // (maybe a prefix)
                List<String> possibleCommands =
                     selectByPrefix(tokens[0], validCommands);
                if (possibleCommands.size() != 1) {
                  choice = '!'; // illegal command
                } else {
                  choice = commandSelect.get(possibleCommands.get(0));
                }

                switch (choice) {
                case '?':
                   System.out.print( pushHelpTextVersion());
                  break;

                case 's': // save
                   System.out.print( pushSave(parameter));
                  break;

                case 'l': // load
                   System.out.print( pushLoad(parameter));
                    break;

                case 'd': // display
                   System.out.print( pushDisplay());
                    break;

                case 't': // display
                   System.out.print( pushTest());
                    break;

                case 'f':
                   System.out.print( pushForward());
                   break;

                case 'b':
                   System.out.print( pushBack());
                    break;

                case 'j':
                   System.out.print( pushJump(parameter));
                    break;

                case 'r':
                   System.out.print( pushRemove());
                    break;

                case 'a':
                   System.out.print( pushAddImage(parameter));
                    break;

                case 'i':
                   System.out.print( pushInsertImage(parameter));
                    break;

                case 'c':
                   System.out.print( pushFind(parameter));
                    break;

                case 'u':
                   System.out.print( pushUpdate(parameter));
                    break;

                case 'e':
                   System.out.print( pushEdit(parameter));
                    break;

                case 'p':
                   System.out.print( pushShow());
                  break;

                case 'x':
                    done = true;
                    System.out.print( pushQuit());
                    break;

                default:  // ignore any unknown commands
                  System.out.println("invalid command");
                    break;

                } // end switch
            } // end if
            else {
              System.out.println("invalid command");
            }
        } // end while
    System.exit(1);
  }

static String pushHelpTextVersion(){
 String cmds = "";
 cmds +="Available commands\n" +
  "\tsave filename\t\t Save image loop into filename\n" +
  "\tload filename\t\t Load image loop from filename\n" +
  "\tadd filename\t\t Add image at filename after current image\n" +
  "\tinsert filename\t\t Insert image at filename before current image\n" +
  "\tcontains title\t\t Find image matching title\n" +
  "\tupdate time\t\t Update display time of current image\n" +
  "\tedit title\t\t Edit title of current image\n" +
  "\tjump count\t\t Jump count images (forward or back)\n" +
  "\tdisplay\t\t\t Display loop (in text form)\n" +
  "\tpicture\t\t\t Show current image in a window\n" +
  "\ttest\t\t\t Test image loop by showing all images\n" +
  "\tremove\t\t\t Remove current image from loop\n" +
  "\tforward\t\t\t Move current image forward one step\n" +
  "\tbackward\t\t Move current image back one step\n" +
  "\thelp\t\t\t Help on available commands\n" +
  "\tquit\t\t\t Treminate execution\n" ;
          return cmds;
  }

  // Return a list of commands that are prefixed by prefix
  static List<String> selectByPrefix(String prefix, String[] commands){
    List<String> results = new ArrayList<String>();

    for (String command : commands){
        if (prefix.length() <= command.length()){
            if (prefix.equals(command.substring(0,prefix.length()))) {
              results.add(command);
            }
        }
    }

    return results;
 }


  public static void main(String[] args) {
    textInterface(args);
  }
}