package tarau.jinni;
/*
* Copyright (C) Paul Tarau 1996-1999
*/

import java.io.*;
import java.net.*;
import java.applet.*;

public class IO {
  
   public static IOPeer peer=null;
   public static Applet applet=null;

   public static boolean showOutput=true;
   public static boolean showErrors=true;
   public final static int showTrace=0;
   public static long maxAnswers=0; // 0 means all, >0 means ask

   public static final Reader input=toReader(System.in);
   public static Writer output=toWriter(System.out);
   
   static Reader toReader(InputStream f) {
     return new BufferedReader(new InputStreamReader(f));
   }
   
   static Reader toFileReader(String fname) {
     return url_or_file(fname);
   }
                              
   static Writer toWriter(OutputStream f) {
     return new BufferedWriter(new OutputStreamWriter(f));
   }
   
   static Writer toFileWriter(String s) {
     Writer f=null;
     //mes("HERE"+s);
     try { 
       f=toWriter(new FileOutputStream(s));
     }
     catch(IOException e) {
       errmes("write error, to: "+s);
     }
     return f;
   }
     
   public static Reader getStdInput() {
     return input;
   }
   
   public static Writer getStdOutput() {
     return output;
   }
   
   synchronized static public final void print(Writer f,String s) {
      if(!showOutput) return;
      if(peer==null) {
        try {
          f.write(s);f.flush();
        }
        catch(IOException e) {
          System.err.println("*** error in printing: "+e);
        }
      }
      else
        peer.print(s);
      return;
   }

   public static final void println(Writer o,String s) {
      print(o,s+"\n");
   }

   public static final void print(String s) {
      print(getStdOutput(),s);
   }

   public static final void println(String s) {
      println(getStdOutput(),s);
   }

   // for now just stubs: usable if IO comes from elswere i.e. sockets
   static final String read_from(Reader f) {
     return readln(f);
   }

   // for now just stubs: usable if IO comes from elswere i.e. sockets
   static final void write_to(Writer f,String s) {
     println(f,s);
   }
   
   static final int MAXBUF=1<<30;
   
   static String readLine(Reader f) throws IOException {
     StringBuffer s=new StringBuffer();
     for(int i=0; i<MAXBUF; i++) {
         int c=f.read();
         if(c=='\0'||c=='\n'||c==-1||
            (c=='\r'&&'\n'==f.read())
         ) {
           if(i==0 && c==-1) return null; 
           break;
         }
         s.append(c);
       }
     return s.toString();
   }
   
   static final String readln(Reader f) {
     trace(2,"READLN TRACE: entering");
     String s=null;
     try {
       if(f instanceof BufferedReader) {
         s=((BufferedReader)f).readLine();
       }
       else
         s=readLine(f);
     }
     catch(IOException e) {
         errmes("error in readln: e.toString()");
     }
     trace(2,"READLN TRACE:"+"<"+s+">");
     return s;
   }

   public static final String readln() {
      String s;
      if(peer==null) {
        s=readln(getStdInput());
      }
      else {
        s=peer.readln();
      }
      return s;
   }

   public static final String promptln(String prompt) {
     print(prompt);
     return readln();
   }

   public static final void mes(String s) {
     println(getStdOutput(),s);
   }

   public static final void trace(int level,String s) {
      if(!showOutput || showTrace<level) return; 
      if(peer==null) {
        println(getStdOutput(),s);
      }
      else
        peer.traceln(s);
   }

   public static final void trace(String s) {
      if(showTrace>=1) println(getStdOutput(),s);
   }

   public static void printStackTrace(Throwable e) {
     if(showErrors) {
       //ByteArrayOutputStream b=new ByteArrayOutputStream();
       //PrintWriter fb=new PrintWriter(b);   
       CharArrayWriter b=new CharArrayWriter();
       PrintWriter fb=new PrintWriter(b);
       e.printStackTrace(fb);
       IO.errmes(b.toString());
       fb.close();
     }
   }

   public static final void errmes(String s) {
      if(showErrors) println(getStdOutput(),s);
   }

   synchronized public static final void errmes(String s,Throwable e) {
      errmes(s);
      printStackTrace(e);
   }


   public static final void assertion(String Mes) {
     IO.errmes("assertion failed",(new java.lang.Exception(Mes)));
   }

   public static final int system(String cmd) {
    //IO.mes("executing: <"+cmd+">");
    try {
      Runtime.getRuntime().exec(cmd);
    }
    catch(IOException e) {
      IO.errmes("error in system cmd: "+cmd,e);
      return 0;
    }
    return 1;
   }

   public static final Reader url2stream(String f) {
     return url2stream(f,false);
   }

   public static final Reader url2stream(String f,boolean quiet) {
     Reader stream=null;
     try {
        URL url=new URL(f);
        stream=toReader(url.openStream());
     }
     catch(MalformedURLException e) {
        if(quiet) return null;
        IO.errmes("bad URL: "+f,e);
     }
     catch(IOException e) {
        if(quiet) return null;
        IO.errmes("unable to read URL: "+f,e);
     }

     return stream;
   }

   public static String getBaseDir() {
     if(null == applet) return "";
     String appletURL=applet.getCodeBase().toString();
     int slash=appletURL.lastIndexOf('/');
     if(slash>=0) appletURL=appletURL.substring(0,slash+1);
     //IO.mes("APPLET can load files from: "+baseDir+"\n");
     return appletURL;
   }

   public static final Reader url_or_file(String s)  {
      Reader stream=null;
      try {
      if(applet!=null) {
        String baseDir=getBaseDir();
        //mes("$$ baseDir: "+baseDir);
        stream=url2stream(baseDir+s,true);
      }
      
      if(null==stream) 
        stream=url2stream(s,true);
    
      if(null==stream && null==IO.applet) 
        stream=toReader(new FileInputStream(s));
      }
      catch(IOException e) {
      }
      return stream;
   }

   public static final Reader string_to_stream(String s) throws IOException {
      StringReader stream=new StringReader(s);
       return stream;
   }

   public static final URL find_url(String s) {
      String valid=null;
      Reader stream;
      
      String baseDir=getBaseDir();
        valid=baseDir+s;
      stream=url2stream(valid,true);
      
      if(null==stream) {
        valid=s;
        stream=url2stream(valid,true);
      }
      try {
        stream.close();
      }
      catch(IOException e) {
        valid=null;
      }

     URL url=null;

     try {
       url=new URL(valid);
     }
     catch(MalformedURLException e) {}
     
     return url;
   }
}