import java.util.Hashtable;
import java.net.*;
import java.io.IOException;


public class AppletTag {

  String code;
  URL codebase;
  int width;
  int height;
  String name = null;
  Hashtable params;
  String alt = "";

  public AppletTag(String s) throws IOException {

    String temp;
    String at = s.substring(0, s.indexOf('>'));
    code = readParameter(at, "code");
    if (code.endsWith(".class")) code = code.substring(0,code.length()-6); 
    try {
      temp = readParameter(at, "codebase");
// need to handle relative URLs
      if (temp == null) codebase = null;
      else codebase = new URL(temp);
    }
    catch (MalformedURLException e) {
      codebase = null;
    }

    name = readParameter(at, "name");
    alt = readParameter(at, "alt");
    try {
      width = Integer.parseInt(readParameter(at, "width"));
      height = Integer.parseInt(readParameter(at, "height"));
    }
    catch (NumberFormatException e) {
      throw new IOException("The <APPLET> tag must have height and width parameters.");
    }
    catch (NullPointerException e) {
      throw new IOException("The <APPLET> tag must have height and width parameters.");
    }

    int nextParam = -1;
    String ucs = s.toUpperCase();
    while ((nextParam = ucs.indexOf("<PARAM ", nextParam+1)) != -1) {
      String name = readParameter(s.substring(nextParam, s.indexOf("\\>")), "name");
      String value = readParameter(s.substring(nextParam, s.indexOf("\\>")), "value");
      params.put(name, value);
    }

  }

  String readParameter(String tag, String key) {

    key = key.toLowerCase();
    String ltag = tag.toLowerCase();
    int e1;
    int k1 = ltag.indexOf(key + '=');
    if (k1 == -1) {
      k1 = ltag.indexOf(key + ' ');
      if (k1 == -1) return null;
      int k2 = ltag.indexOf(' ', k1);
      while (ltag.charAt(k2) == ' ') k2++;
      if (ltag.charAt(k2) != '=') return null;
      e1 = k2;
    }
    else {
      e1=ltag.indexOf('=', k1);
    }
    
    // e1 is now positioned on the equals sign
    // skip spaces, if any
    int v1 = e1+1;
    while (tag.charAt(v1) == ' ') v1++;

    int v2;
    try {
      char c = tag.charAt(v1);
      if (c == '"')  {
        v1 = v1 + 1;
        v2 = tag.indexOf('"', v1+1);
      }
      else  v2 = tag.indexOf(' ', v1);
      if (v2 == -1) v2 = tag.indexOf('>', v1);
      if (v2 == -1) return tag.substring(v1);
      return tag.substring(v1,v2);
    }
    catch (StringIndexOutOfBoundsException e) {
      System.err.println(key + "=" + tag.substring(v1));
      System.err.println(e);
      return null;
    }

  }

  public URL codebase() {
    return codebase;
  }

  public String code() {
    return code;
  }

  public int width() {
    return width;
  }

  public int height() {
    return height;
  }

  public String name() {
    return name;
  }

  public String alt() {
    return alt;
  }

  public Hashtable params() {
    return params;
  }

  public String toString() {

    String s = "<APPLET";
    if (code != null) s += " code=" + code;
    if (codebase != null) s += " codebase=" + codebase;
    s += " width=" + width;
    s += " height=" + height;
    if (name != null) s += " name=" + name;
    if (alt != null) s += " alt=" + alt;
    s += ">\n</APPLET>";
    return s;

  }

}