/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;

public class ScpFrom{
  public static void main(String[] arg){
    if(arg.length!=2){
      System.err.println("usage: java ScpFrom user@remotehost:file1 file2");
      System.exit(-1);
    }      

    FileOutputStream fos=null;
    try{

      String user=arg[0].substring(0, arg[0].indexOf('@'));
      arg[0]=arg[0].substring(arg[0].indexOf('@')+1);
      String host=arg[0].substring(0, arg[0].indexOf(':'));
      String rfile=arg[0].substring(arg[0].indexOf(':')+1);
      String lfile=arg[1];

      String prefix=null;
      if(new File(lfile).isDirectory()){
        prefix=lfile+File.separator;
      }

      JSch jsch=new JSch();
      Session session=jsch.getSession(user, host, 22);

      // username and password will be given via UserInfo interface.
      UserInfo ui=new MyUserInfo();
      session.setUserInfo(ui);
      session.connect();

      // exec 'scp -p -f rfile' remotely
        String command="scp -p -f "+rfile;
    	Channel channel=session.openChannel("exec");
    	((ChannelExec)channel).setCommand(command);

    	// get I/O streams for remote scp
    	OutputStream out=channel.getOutputStream();
    	InputStream in=channel.getInputStream();

    	channel.connect();

    	byte[] buf=new byte[1024];

    	// send '\0'
    	buf[0]=0; out.write(buf, 0, 1); out.flush();

    	while(true) {

    		int c=checkAck(in);
    		if(c != 'T'){
    			break;
    		}

    		long modtime = 0L;
    		while(true){
    			if(in.read(buf, 0, 1)<0){
    				// error
    				break; 
    			}
    			if(buf[0]==' ')break;
    			modtime=modtime*10L+(long)(buf[0]-'0');
    		}
    		in.read(buf, 0, 2);
    		long acctime = 0L;
    		while(true){
    			if(in.read(buf, 0, 1)<0){
    				// error
    				break; 
    			}
    			if(buf[0]==' ')break;
    			acctime=acctime*10L+(long)(buf[0]-'0');
    		}

    		// send '\0'
    		buf[0]=0; out.write(buf, 0, 1); out.flush();

    		while(true){
    			c=checkAck(in);
    			if(c == 'C'){
    				break;
    			}
    		}
    		in.read(buf, 0, 5);
    		long filesize=0L;
    		while(true){
    			if(in.read(buf, 0, 1)<0){
    				// error
    				break; 
    			}
    			if(buf[0]==' ')break;
    			filesize=filesize*10L+(long)(buf[0]-'0');
    		}

    		String file=null;
    		for(int i=0;;i++){
    			in.read(buf, i, 1);
    			if(buf[i]==(byte)0x0a){
    				file=new String(buf, 0, i);
    				break;
    			}
    		}

    		System.out.println("filesize="+filesize+", file="+file);

    		// send '\0'
    		buf[0]=0; out.write(buf, 0, 1); out.flush();

    		// read a content of lfile
    		fos=new FileOutputStream(prefix==null ? lfile : prefix+file);
    		int foo;
    		while(true){
    			if(buf.length<filesize)
    				foo=buf.length;
    			else
    				foo=(int)filesize;
    			foo=in.read(buf, 0, foo);
    			if(foo<0){
    				// error 
    				break;
    			}
    			fos.write(buf, 0, foo);
    			filesize-=foo;
    			if(filesize==0L)
    				break;
    		}
    		fos.close();
    		fos=null;
    		File tempfile = new File(prefix+file);
    		tempfile.setLastModified(modtime*1000);

    		if(checkAck(in)!=0){
    			System.exit(0);
    		}

    		// send '\0'
    		buf[0]=0; out.write(buf, 0, 1); out.flush();
    	}

      session.disconnect();

      System.exit(0);
    }
    catch(Exception e){
      System.out.println(e);
      try{if(fos!=null)fos.close();}catch(Exception ee){}
    }
  }

  static int checkAck(InputStream in) throws IOException{
    int b=in.read();
    // b may be 0 for success,
    //          1 for error,
    //          2 for fatal error,
    //          -1
    if(b==0) return b;
    if(b==-1) return b;

    if(b==1 || b==2){
      StringBuffer sb=new StringBuffer();
      int c;
      do {
	c=in.read();
	sb.append((char)c);
      }
      while(c!='\n');
      if(b==1){ // error
	System.out.print(sb.toString());
      }
      if(b==2){ // fatal error
	System.out.print(sb.toString());
      }
    }
    return b;
  }

  public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
    public String getPassword(){ return passwd; }
    public boolean promptYesNo(String str){
      Object[] options={ "yes", "no" };
      int foo=JOptionPane.showOptionDialog(null, 
             str,
             "Warning", 
             JOptionPane.DEFAULT_OPTION, 
             JOptionPane.WARNING_MESSAGE,
             null, options, options[0]);
       return foo==0;
    }
  
    String passwd;
    JTextField passwordField=(JTextField)new JPasswordField(20);

    public String getPassphrase(){ return null; }
    public boolean promptPassphrase(String message){ return true; }
    public boolean promptPassword(String message){
      Object[] ob={passwordField}; 
      int result=
	  JOptionPane.showConfirmDialog(null, ob, message,
					JOptionPane.OK_CANCEL_OPTION);
      if(result==JOptionPane.OK_OPTION){
	passwd=passwordField.getText();
	return true;
      }
      else{ return false; }
    }
    public void showMessage(String message){
      JOptionPane.showMessageDialog(null, message);
    }
    final GridBagConstraints gbc = 
      new GridBagConstraints(0,0,1,1,1,1,
                             GridBagConstraints.NORTHWEST,
                             GridBagConstraints.NONE,
                             new Insets(0,0,0,0),0,0);
    private Container panel;
    public String[] promptKeyboardInteractive(String destination,
                                              String name,
                                              String instruction,
                                              String[] prompt,
                                              boolean[] echo){
      panel = new JPanel();
      panel.setLayout(new GridBagLayout());

      gbc.weightx = 1.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.gridx = 0;
      panel.add(new JLabel(instruction), gbc);
      gbc.gridy++;

      gbc.gridwidth = GridBagConstraints.RELATIVE;

      JTextField[] texts=new JTextField[prompt.length];
      for(int i=0; i<prompt.length; i++){
        gbc.fill = GridBagConstraints.NONE;
        gbc.gridx = 0;
        gbc.weightx = 1;
        panel.add(new JLabel(prompt[i]),gbc);

        gbc.gridx = 1;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weighty = 1;
        if(echo[i]){
          texts[i]=new JTextField(20);
        }
        else{
          texts[i]=new JPasswordField(20);
        }
        panel.add(texts[i], gbc);
        gbc.gridy++;
      }

      if(JOptionPane.showConfirmDialog(null, panel, 
                                       destination+": "+name,
                                       JOptionPane.OK_CANCEL_OPTION,
                                       JOptionPane.QUESTION_MESSAGE)
         ==JOptionPane.OK_OPTION){
        String[] response=new String[prompt.length];
        for(int i=0; i<prompt.length; i++){
          response[i]=texts[i].getText();
        }
	return response;
      }
      else{
        return null;  // cancel
      }
    }
  }
}