//
// AirLook.java - defines top level applet class for Airport Lookup Tool
//
//  Copyright (c) 1996 by Philip Garnatz, Garnatz and Grovender, Inc.
//  All Rights Reserved
//
import java.awt.*;      // references to Java packages used
import java.net.*;
import java.io.*;
import java.lang.*;
import java.util.*;
import java.applet.Applet;
//
   public class AirLook2 extends Applet {

        // member data
        TextField       _textField;
        TextArea        _outField;
        Button          _button;
        Button          cty_button;
        Button          clr_button;

        // only works in appletviewer
        final static int _width=550, _height=350;

        int i = 0;
        int ix = 0;
        int ixm = 0;
        int lflag = 1;
        StringBuffer data1 = new StringBuffer(8000);
        StringBuffer data3 = new StringBuffer(8000);
        String master_i;
        String data_blk;
        String data_blk3;
        String file2_sav = " ";
        String file3_sav = " ";
	Color ltgreen = new Color(128, 255, 153);
	Color ltgold = new Color(255, 255, 204);

        public void init(){
           resize(_width, _height);                // size the app window
           _textField=new TextField();             // input field
           _textField.setText("msp");              // sample start
           Font f = new Font("Courier", Font.BOLD, 14);
           setFont(f);
	   Color gold = new Color(255, 222, 173);
           Panel buttonbar = new Panel();
           buttonbar.setLayout(new GridLayout(2,1));
           Panel topbar = new Panel();
           GridBagLayout gbl = new GridBagLayout();
           GridBagConstraints gbc = new GridBagConstraints();
           topbar.setLayout(gbl);
           topbar.setBackground(Color.white);
              // text field
           gbc.weightx = 1;
           gbc.ipadx = 5;
           gbc.fill = GridBagConstraints.HORIZONTAL;
           gbl.setConstraints(_textField, gbc);
           topbar.add(_textField);
              // lookup code button
           _button=new Button("lookup airport code");
           _button.setBackground(ltgreen);
           buttonbar.add(_button);
              // lookup city
           cty_button=new Button("lookup city name");
           cty_button.setBackground(ltgold);
           buttonbar.add(cty_button);
              // add buttonbar to topbar
           gbc.weightx = 0;
           gbc.fill = GridBagConstraints.NONE;
           gbl.setConstraints(_button, gbc);
           gbl.setConstraints(buttonbar, gbc);
           topbar.add(buttonbar);
              // clear button
           clr_button = new Button("Clear");
           clr_button.setBackground(gold);
           gbc.gridwidth = GridBagConstraints.REMAINDER;
           gbl.setConstraints(clr_button, gbc);
           topbar.add(clr_button);

           setLayout(new BorderLayout());          // create a layout mgr
           // setBackground(Color.white);
           setBackground(gold);
           add("North", topbar);

           _outField=new TextArea(7,80);           // output lines
           _outField.setEditable(false);
           _outField.setBackground(ltgold);

           data1 = ReadFileURL("air/air.ix", 11);
           master_i = new String(data1.toString());
           lookIt();
           add("Center", _outField);

        } // end of init

        // called to look up a new code
        public void lookIt(){
           String s=_textField.getText().toUpperCase();  // get user input
           ixm = BinarySearch(master_i, s, 11, 3, 0);
           String file2 = "air/air." +
                           master_i.substring(ixm*11+5,ixm*11+7);
           if(!file2.equals(file2_sav)) {
              data1 = ReadFileURL(file2, 80);
              data_blk = new String(data1.toString());
              file2_sav = file2;
           }
           ixm = BinarySearch(data_blk, s, 80, 3, 0);

           if(StrComp (data_blk.substring(ixm*80,ixm*80+3), s) == 0) {
              _outField.appendText
                 (" Here is the airport for the code " + s +"\n");
              _outField.appendText
                 (data_blk.substring(ixm*80,ixm*80+80)+"\n");
           } else {

              _outField.appendText
                 (" No exact match found for "+ s +", here are the closest:\n");
              int ixl = ixm-2; if(ixl<0) ixl = 0;
              int ixh = ixm+3;
              if(ixh > data_blk.length()/80) ixh = data_blk.length()/80;
              for(ix=ixl; ix<ixh; ix++){
                 _outField.appendText
                    (data_blk.substring(ix*80,ix*80+80)+"\n");
              }
           }
        }

        public void lookName(){
           String s=_textField.getText().toUpperCase();  // get user input
           char ch1;
           try {ch1 = s.charAt(0);}
           catch(StringIndexOutOfBoundsException e) { ch1 = ' ';}
           if ( ch1 < 'A' || ch1 > 'Z' ) {
              _outField.appendText
              (" Lookup city name - first letter must be [A-Z] " + ch1 + "\n");
              return;
           }
           String file3 = "air/cty." + ch1;
           if(!file3.equals(file3_sav)) {
              data3 = ReadFileURL(file3, 40);
              data_blk3 = new String(data3.toString().toUpperCase());
              file3_sav = file3;
           }
           ixm = BinarySearch(data_blk3, s, 40, 32, 8);
           int ixl = ixm-2; if(ixl<0) ixl = 0;
           int ixh = ixm+4;
           if(ixh > data_blk3.length()/40) ixh = data_blk3.length()/40;

           if(StrComp (data_blk3.substring(ixm*40+8,ixm*40+40), s) == 0) {
              _outField.appendText
                 (" Here is an airport or city code for city name: " + s +"\n");
              ixl = ixm;
              ixh = ixm;
              for (ix=ixm-1; ix>0; ix-- ) { 
                 if(Math.abs(StrComp(data_blk3.substring(ix*40+8,ix*40+40), s))
                     == 2) break;
              }
              if( ix+1 < ixl ) ixl = ix+1;
              for (ix=ixm+1; ix<data_blk3.length()/40; ix++ ) { 
                 if(Math.abs(StrComp(data_blk3.substring(ix*40+8,ix*40+40), s))
                     == 2) break;
              }
              if( ix > ixh ) ixh = ix;
           } else {
              _outField.appendText (" Here are airport or city codes for the "
                  + "closest matches to: "+ s +"\n");
           }
           for(ix=ixl; ix<ixh; ix++){
           //  _outField.appendText(data_blk3.substring(ix*40,ix*40+40)+"\n");
           s=data_blk3.substring(ix*40,ix*40+4); // get 3 letter code
           ixm = BinarySearch(master_i, s, 11, 3, 0);
           String file2 = "air/air." +
                           master_i.substring(ixm*11+5,ixm*11+7);
           if(!file2.equals(file2_sav)) {
              data1 = ReadFileURL(file2, 80);
              data_blk = new String(data1.toString());
              file2_sav = file2;
           }
           ixm = BinarySearch(data_blk, s, 80, 3, 0);
           _outField.appendText
                 (data_blk.substring(ixm*80,ixm*80+80)+"\n");
           }
        }

        // called to read in an index or data block
        public StringBuffer ReadFileURL(String file, int nbytes) {
           StringBuffer data1 = new StringBuffer();
           boolean done = false;
           InputStream myinp = null;
           DataInputStream fin = null;
           URL myURL = null;
           int i = 0;
           String temp;

            // open URL and read from file
           try {
               myURL = new URL(this.getDocumentBase(),file);
               }
               catch (MalformedURLException e) {
                  System.out.println("MalformedURLException " );
                  System.exit(0);
               }

           try {
               myinp = myURL.openStream();
               fin = new DataInputStream (new BufferedInputStream(myinp));
           }
           catch (Exception e) {
              System.out.println("Unexpected exception: " + e);
              System.exit(0);
           }

            // initial read
           temp = " ";
           try {
              temp =  fin.readLine();
           }
           catch (Exception e) {
              System.out.println("Unexpected exception: " + e);
              done = true;
              // System.exit(0);
           }

           while(!done) {
              int sl = temp.length();
              if (sl > nbytes ) sl = nbytes;
              data1.append(temp.substring(0,sl));
              if( sl < nbytes ) {
                 for( int j=sl; j<nbytes; j++) data1.append(" ");
              }
              i += nbytes;
              try {

              // read the whole file
                 temp =  fin.readLine();
              }
              catch (Exception e) {
                 System.out.println("Unexpected exception: " + e);
                 done = true;
              }
              if( temp ==  null) {
                 done = true;
              }  else {
                 if(temp.length() <= 1) done = true;
              }
           }  // end while
        return data1;
        }

        // called to look up a string
        public int BinarySearch(String blk, String s, int ln, int lk, int off){
        //Arguments: blk - String with many lines of text, all concated together
        //           s   - String to search for (look in blk)
        //           ln  - line length in blk
        //           lk  - search length within line
        //           off - search offset within line
           int it = 0;
           int ib = (blk.length()/ln)-1;
           int il = 0;
           int ix;
           while(it <= ib) {
              il = (it+ib)/2 + 1;
              if(il > ib) il = ib;
              ix = il * ln;
              int cpr = StrComp(s, blk.substring(ix+off,ix+lk+off));
              if ( cpr == 0) {
                 return il;
              } else {
                 if( it == ib ) return il;
                 if ( cpr > 0) {
                    ib = il - 1;
                 }  else {
                    it = il;       // use it = il;  don't use: it = il + 1
                 }
              }
           }  // end while
        return il;
        }

        // called for string comparison
        public int StrComp(String r, String s){
           int ll = r.length();
           if( s.length() < ll ) ll = s.length();
           for(int i=0; i < ll; i++) {
              char r1 = r.charAt(i);
              char s1 = s.charAt(i);
              if ( s1 < r1 ) return -2;
              if ( r1 < s1 ) return 2;
           }
        // exact match up to end of one string - check for non-trailing blanks
           if ( s.length() < r.length() ) {
              for(int i=ll; i < r.length(); i++) {
                 char r1 = r.charAt(i);
                 if( r1 != ' ') return -1;
              }
           } else if ( r.length() < s.length() ) {
              for(int i=ll; i < s.length(); i++) {
                 char s1 = s.charAt(i);
                 if( s1 != ' ') return 1;
              }
           }
           return 0;
        }

     //   public boolean action(Event e_, Object arg_){
     //           lookIt();
     //           return true;
     //   }

        public boolean handleEvent(Event event) {
           if(( event.target == _button) && (event.id == Event.ACTION_EVENT)) 
           {
              _button.setBackground(ltgreen);
              cty_button.setBackground(ltgold);
              lflag = 1;
              lookIt();
              return true;
           }
           if(( event.target == cty_button)&&(event.id == Event.ACTION_EVENT)) 
           {
              _button.setBackground(ltgold);
              cty_button.setBackground(ltgreen);
              lflag = 2;
               lookName();
              return true;
           }
           if(( event.target == clr_button) && (event.id == Event.ACTION_EVENT))
           {
              _outField.setText("");
              _textField.setText("");
              return true;
           }
           if( event.target == _textField ) {
              if(event.id == Event.KEY_PRESS ) {
                 if((char)event.key == '\n' )  {
                    if(lflag == 1) {
                       lookIt();
                    } else {
                       lookName();
                    }
                    return true;
                 }
              }
           }
           return super.handleEvent(event);
        }

} // end class AirLook2