package org.vamsas.client.simpleclient;

import java.io.File;
import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.vamsas.client.ClientHandle;
import org.vamsas.client.IClient;
import org.vamsas.client.IClientFactory;
import org.vamsas.client.NoDefaultSessionException;
import org.vamsas.client.UserHandle;

/**
 * TODO document type SimpleClientFactory
 * @author jimp
 *
 */
public class SimpleClientFactory implements IClientFactory {
  private static Log log = LogFactory.getLog(SimpleClientFactory.class);

  File sessionArena;
  
  /**
   * default constructor - called by CreateClientFactory only.
   *
   */
  public SimpleClientFactory() {
    sessionArena = null;
  }
  /**
   * Create a client factory that works with sessions at the given
   * path.
   * @param path
   */
  public SimpleClientFactory(String path) throws IOException {
    // Check path is valid and read/writeable.
    File newarena = new File(path);
    if (newarena.isDirectory() && newarena.canRead() && newarena.canWrite()) {
      sessionArena = newarena;
    } else {
      sessionArena = null;
      throw(new IOException("Cannot read and write to a directory called "+path));
    }
  }
  
  /* (non-Javadoc)
   * @see org.vamsas.client.IClientFactory#getCurrentSessions()
   */
  public String[] getCurrentSessions() {
    // TODO look in the arena and enumerate session handles for return.
    return new String[] {};
  }
  /* (non-Javadoc)
   * @see org.vamsas.client.IClientFactory#getIClient(org.vamsas.client.ClientHandle)
   */
  public IClient getIClient(ClientHandle applicationHandle) throws NoDefaultSessionException {
    // create a new session
    // register new ClientHandle in session
    // create SimpleClient instance
    return null;
  }

  /* (non-Javadoc)
   * @see org.vamsas.client.IClientFactory#getIClient(org.vamsas.client.ClientHandle, java.lang.String)
   */
  public IClient getIClient(ClientHandle applicationHandle, String sessionUrn) {
    // locate session from Urn
    // check that clientHandle is unique (with default user) - if not update the clientHandle urn to make it unique.
    // wait for lock and attach to session
    // create SimpleClient instance
    return null;
  }

  /* (non-Javadoc)
   * @see org.vamsas.client.IClientFactory#getIClient(org.vamsas.client.ClientHandle, org.vamsas.client.UserHandle, java.lang.String)
   */
  public IClient getIClient(ClientHandle applicationHandle, UserHandle userId,
      String sessionUrn) {
    // locate session from Urn
    // check Uniqueness of user + ClientHandle in the session. Update clientHandle urn accordingly.
    // wait for lock, attach to session
    // create client instance
    return null;
  }

  /* (non-Javadoc)
   * @see org.vamsas.client.IClientFactory#getIClient(org.vamsas.client.ClientHandle, org.vamsas.client.UserHandle)
   */
  public IClient getIClient(ClientHandle applicationHandle, UserHandle userId) throws NoDefaultSessionException {
    // create new session
    // register SimpleClient and UserHandles in session
    // create client instance
    return null;
  }
  /**
   * make a new vamsas session from the data in the archive vamsasdocument 
   * @param applicationHandle
   * @param userId
   * @param vamsasdocument
   * @return
   */
  public IClient openSession(ClientHandle applicationHandle, UserHandle userId, ArchiveUrn vamsasdocument) throws IOException {
    // verify applicationHandle and userId
    // TODO: verify applicationHandle and userId
    // verify vamsasdocument is a valid document.
    File vamdoc = vamsasdocument.asFile();
    log.debug("Starting new session with data from "+vamsasdocument.getSessionUrn()+"(File is : "+vamdoc+")");
    VamsasArchiveReader archive = new VamsasArchiveReader(vamdoc);
    // TODO: a real validity test. The below just checks it can be read.
    if (!archive.isValid())
      throw new IOException(vamsasdocument.getSessionUrn()+" is not a valid vamsasDocument archive.");
    // create new session directory
    if (sessionArena==null)
      throw new Error("Improperly initialised SimpleClientFactory object - null sessionArena.");
    File sessdir = File.createTempFile("sess", ".simpleclient", sessionArena);
    if (!(sessdir.delete() && sessdir.mkdir()))
        throw new IOException("Could not make session directory "+sessdir);
    VamsasSession sess = new VamsasSession(sessdir);
    // copy document into session directory
    sess.setVamsasDocument(vamsasdocument.asFile());
    // create client instance and return.
    SimpleClient client=null;
    try {
      client = new SimpleClient(userId, applicationHandle, sess);
    } catch (Exception e) {
      log.error("Couldn't make a new SimpleClient instance.",e);
      throw new IOException(e.getMessage());
    }
    return client;
  }
  
  public static void main(String[] args) {
  }
}