package net.suberic.crypto.examples;

import net.suberic.crypto.*;

import javax.mail.*;
import javax.mail.internet.*;

import java.util.Set;
import java.util.Iterator;
import java.security.Key;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * An example of using this API to read an encrypted message.
 */
public class ReadEncryptedMessage {

  /**
   * Runs the Example.
   */
  public static void main(String[] argv) {
    try {

      if (argv.length < 3) {
	System.err.println("usage:  ReadEncrytpedMessage filename keystore password");
	System.err.println("note:  the passphrase for id.p12 (S/MIME) is 'hello world'");
	System.err.println("and for bob.skr is 'TestingPassphrase'");
	System.exit(-1);
      }
      Session mailSession = Session.getDefaultInstance(System.getProperties());
      
      // create the message.
      FileInputStream fis = new FileInputStream(new File(argv[0]));
      MimeMessage msg = new MimeMessage(mailSession, fis);
      
      // get our encryption utilities.
      //EncryptionUtils cryptoUtils = EncryptionManager.getEncryptionUtils(msg);
      String cryptotype = EncryptionManager.checkEncryptionType(msg);
      EncryptionUtils cryptoUtils = EncryptionManager.getEncryptionUtils(cryptotype);

      if (cryptoUtils == null) {
	System.err.println("failed to get encryption utilities.");
	System.exit(-1);
      }
      // load the associated store(s)
      
      String keyStore = argv[1];
      char[] pw = argv[2].toCharArray();

      if (pw.length == 0)
	pw = null;

      EncryptionKeyManager keyMgr = cryptoUtils.createKeyManager();
      keyMgr.loadPrivateKeystore(new FileInputStream(new File(keyStore)), pw);

      // we're not sure which key we should use, so let's just go through 
      // each one.
      
      Set privateKeys = keyMgr.privateKeyAliases();
      Iterator iter = privateKeys.iterator();
      MimeMessage decryptedMsg = null;
      while (decryptedMsg == null && iter.hasNext()) {
	Key privateKey = keyMgr.getPrivateKey((String) iter.next(), pw);
	try {
	  decryptedMsg = cryptoUtils.decryptMessage(mailSession, msg, privateKey);
	} catch (Exception e) {
	  Object o = msg.getContent();
	  System.err.println("msg.getContent() = " + o + ", a " + o.getClass().getName());
	  System.err.println("error decrypting message with key " + privateKey + ":  " + e);
	  e.printStackTrace();
	}
      }

      if (decryptedMsg != null) {
	decryptedMsg.writeTo(System.out);
      } else {
	System.out.println("failed to decrypt message.");
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

}