package edu.jsu.leathrum.mathlets.shared;
import javax.swing.*;
import java.awt.event.*;
import java.util.Locale;
import java.util.ResourceBundle;
import java.text.DecimalFormat;
import java.util.PropertyResourceBundle;
import java.util.MissingResourceException;

abstract public class AMathlet extends JApplet {
// abstract method:  draw(), localinit(), localclear()
// call setHandler() to set up field handling
// register buttons with registerButtonAction()
// some standard button actions with registerGraphButton(), registerClearButton()

  ButtonList bb = new ButtonList();

  class ClearAction implements ActionWrapper {
      public void doThis() {
        clear();
        draw();
      }
  }

  class GraphAction implements ActionWrapper {
      public void doThis() {
        draw();
      }
  }

  public void registerButtonAction(AbstractButton item, ActionWrapper act) {
    bb.registerButtonAction(item, act);
  }

  // must be called in localinit(), not constructor, because of getProperty()
  public void registerClearButton(JButton item) {
    item.setText(getProperty("clear"));
    bb.registerButtonAction(item, new ClearAction());
  }

  // must be called in localinit(), not constructor, because of getProperty()
  public void registerGraphButton(JButton item) {
    item.setText(getProperty("graph"));
    bb.registerButtonAction(item, new GraphAction());
  }

  KeyHandlerSequence kseq = new KeyHandlerSequence();

  public void registerInputSet(InputSet item, ActionWrapper act) {
    kseq.registerKeyHandler(item, act);
    bb.registerButtonAction(item.getCheckBox(), act);
  }

  public void registerInputSet(InputSet item) {
    registerInputSet(item, new GraphAction());
  }
  
  public abstract void draw();

  public void jsDraw() {
    draw();
  }

  final static int FIELDS = 10;
  static String[] fields = new String[FIELDS];
  static FieldHandler[] handlers = new FieldHandler[FIELDS];
  static int numfields = 0;

  public static void setHandler(String name, FieldHandler obj) {
    // static so that it can be called anywhere to register defaults
    while (numfields>=fields.length) {
      String[] tmp1 = new String[fields.length+2*FIELDS];
      FieldHandler[] tmp2 = new FieldHandler[handlers.length+2*FIELDS];
      for (int i=0; i<numfields; i++) {
        tmp1[i]=fields[i];
        tmp2[i]=handlers[i];
      }
      fields=tmp1;
      handlers=tmp2;
    }
    fields[numfields]=name;
    handlers[numfields]=obj;
    numfields++;
  }

  public void jsSetField(String name, String value) {
    int j = -1;
      for (int i=0; i<numfields; i++)
        if (name.compareTo(fields[i]) == 0) {
	  j = i;
        }
    if (j>-1)
      handlers[j].setField(value);
  }

  public void localclear() {}
  // often overridden to clear graph objects and such
  // but some applets don't need this method, so it isn't abstract

  public void clear() {
      for (int i=0; i<numfields; i++) handlers[i].setToDefault();
      localclear();
  }
  
  public void jsClear() {
    clear();
  }

  public String jsGetField(String name) {
    int j = -1;
      for (int i=0; i<numfields; i++)
        if (name.compareTo(fields[i]) == 0) {
	  j = i;
        }
    if (j>-1) return handlers[j].getField();
    else return "";
  }

  private static Locale currentLocale = Locale.ENGLISH;

  public static Locale getLoc() {
    return currentLocale;
  }

  private static DecimalFormat nf = 
          (DecimalFormat) DecimalFormat.getNumberInstance(currentLocale);

  public static DecimalFormat getNumberFormat() {
    return nf;
  }

  private static final int MAXFILES = 20;
  private static PropertyResourceBundle properties[] 
      = new PropertyResourceBundle[MAXFILES];

  private void checkForLocaleParams() {
    try { // parameters to determine locale checked here
      // get NullPointerExceptions from calls to getParameter()
      // when running as application rather than applet
      // if so, catch them, do nothing
      String lang = getParameter("language");
      String ctry = getParameter("country");
      if (lang != null) { 
        if (ctry != null) currentLocale = new Locale(lang,ctry);
        else currentLocale = new Locale(lang);
      }
    }
    catch (NullPointerException e) {}

    // open ALL properties files, using locale info
    // MathletsB can override MathletsA, C can override B, etc.
    // and can skip filenames in the sequence
    // but no further down than MathletsT (based on MAXFILES value)
    int i = 0;
    for (int n=0; n<MAXFILES; n++) {
      try {
        properties[n] = (PropertyResourceBundle)
            ResourceBundle.getBundle(
	        "edu.jsu.leathrum.mathlets.locales.Mathlets"
	           +((char) ('A'+n)),
	        currentLocale);
      }
      catch (MissingResourceException e) {i++;}
    }
    if (i==MAXFILES) throw new MissingResourceException(
            "No valid Mathlets properties file for this locale","Mathlets*","");

    nf = (DecimalFormat) DecimalFormat.getNumberInstance(currentLocale);
    nf.setMinimumFractionDigits(1);
    nf.setMaximumFractionDigits(100);
  }

  private void checkParams() {
    try { // all other parameters handled here by registered handlers
      // get NullPointerExceptions from calls to getParameter()
      // when running as application rather than applet
      // if so, catch them, do nothing
    
      String value;
      for (int i=0; i<numfields; i++) {
        value = null;
        value = getParameter(fields[i]);
        if (value != null)
          handlers[i].setField(value);
      }
    } catch (NullPointerException e) {}
  }

  public static String getProperty(String name) {
    // managing many properties files
    // properties from files later in list override those earlier
    // also need to watch out for nonexistent properties files (null pointers)

    String val = "";
    int i=0;
    for (int n=0; n<MAXFILES; n++) {
      if (properties[n]!=null)
        try {val=properties[n].getString(name);}
        catch (MissingResourceException e) {i++;}
      else i++;
    }
    if (i==MAXFILES) throw new MissingResourceException(
            "No such property in Mathlets properties files","Mathlets*",name);
    return val;
  }

  abstract public void localinit();

  public void init() {
    checkForLocaleParams();
    localinit();
    clear();
    checkParams();
    draw();
  }
}