/*
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at <http://www.mozilla.org/MPL/>.
 * 
 * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
 * WARRANTY OF ANY KIND, either express or implied. See the License for the specific
 * language governing rights and limitations under the License.
 * 
 * The Original Code is the Venice Web Communities System.
 * 
 * The Initial Developer of the Original Code is Eric J. Bowersox <erbo@silcom.com>,
 * for Silverwrist Design Studios.  Portions created by Eric J. Bowersox are
 * Copyright (C) 2003 Eric J. Bowersox/Silverwrist Design Studios.  All Rights Reserved.
 * 
 * Contributor(s): 
 */
package com.silverwrist.dynamo.unistore;

import java.security.acl.AclNotFoundException;
import java.util.*;
import org.apache.commons.collections.*;
import org.apache.log4j.Logger;
import com.silverwrist.dynamo.Namespaces;
import com.silverwrist.dynamo.db.NamespaceCache;
import com.silverwrist.dynamo.db.UserManagement;
import com.silverwrist.dynamo.except.*;
import com.silverwrist.dynamo.iface.*;
import com.silverwrist.dynamo.security.SecurityReferenceMonitor;
import com.silverwrist.dynamo.util.*;

class MessageImpl implements UniStoreMessage
{
  /*--------------------------------------------------------------------------------
   * Static data members
   *--------------------------------------------------------------------------------
   */

  private static Logger logger = Logger.getLogger(MessageImpl.class);

  /*--------------------------------------------------------------------------------
   * Attributes
   *--------------------------------------------------------------------------------
   */

  private MessageOps m_ops;                 // database operations object
  private NamespaceCache m_nscache;         // namespace cache
  private SecurityReferenceMonitor m_srm;   // security reference monitor
  private UserManagement m_users;           // user manager
  private long m_id;                        // the message ID
  private long m_parentid;                  // the parent message ID
  private int m_seq;                        // sequence within parent
  private int m_creator;                    // UID of creator
  private java.util.Date m_posted;          // date message was posted
  private int m_aclid = -1;                 // ACL id
  private ReferenceMap m_properties;        // properties cache
  private int m_text_count = -1;            // number of text parts
  private int m_binary_count = -1;          // number of binary parts
  private ReferenceMap m_part_to_text;      // mapping from part index to text part
  private ReferenceMap m_pk_to_text;        // mapping from property key to text part
  private ReferenceMap m_part_to_binary;    // mapping from part index to binary part
  private ReferenceMap m_pk_to_binary;      // mapping from property key to binary part

  /*--------------------------------------------------------------------------------
   * Constructor
   *--------------------------------------------------------------------------------
   */

  MessageImpl(MessageOps ops, NamespaceCache nscache, SecurityReferenceMonitor srm, UserManagement users, Map params)
  {
    m_ops = ops;
    m_nscache = nscache;
    m_srm = srm;
    m_users = users;
    m_id = ((Long)(params.get(ManagerOps.PARAM_MSGID))).longValue();
    m_parentid = ((Long)(params.get(ManagerOps.PARAM_PARENT))).longValue();
    m_seq = ((Integer)(params.get(ManagerOps.PARAM_SEQ))).intValue();
    m_creator = ((Integer)(params.get(ManagerOps.PARAM_CREATOR))).intValue();
    m_posted = (java.util.Date)(params.get(ManagerOps.PARAM_POSTED));
    Integer tmp = (Integer)(params.get(ManagerOps.PARAM_ACLID));
    if (tmp!=null)
      m_aclid = tmp.intValue();
    m_properties = new ReferenceMap(ReferenceMap.HARD,ReferenceMap.SOFT);
    m_part_to_text = new ReferenceMap(ReferenceMap.HARD,ReferenceMap.SOFT);
    m_pk_to_text = new ReferenceMap(ReferenceMap.HARD,ReferenceMap.SOFT);
    m_part_to_binary = new ReferenceMap(ReferenceMap.HARD,ReferenceMap.SOFT);
    m_pk_to_binary = new ReferenceMap(ReferenceMap.HARD,ReferenceMap.SOFT);

  } // end constructor

  /*--------------------------------------------------------------------------------
   * Implementations from interface ObjectProvider
   *--------------------------------------------------------------------------------
   */

  /**
   * Retrieves an object from this <CODE>ObjectProvider</CODE>.
   *
   * @param namespace The namespace to interpret the name relative to.
   * @param name The name of the object to be retrieved.
   * @return The object reference specified.
   */
  public Object getObject(String namespace, String name)
  {
    try
    { // convert the namespace name to an ID here
      PropertyKey key = new PropertyKey(m_nscache.namespaceNameToId(namespace),name);
      Object rc = null;
      synchronized (this)
      { // start by looking in the properties map
	rc = m_properties.get(key);
	if (rc==null)
	{ // no use - need to try the database
	  rc = m_ops.getProperty(m_id,key);
	  if (rc!=null)
	    m_properties.put(key,rc);

	} // end if

      } // end synchronized block

      if (rc==null)
	throw new NoSuchObjectException(this.toString(),namespace,name);
      return rc;

    } // end try
    catch (DatabaseException e)
    { // translate into our NoSuchObjectException but retain the DatabaseException
      throw new NoSuchObjectException(this.toString(),namespace,name,e);

    } // end catch

  } // end getObject

  /*--------------------------------------------------------------------------------
   * Implementations from interface SecureObjectStore
   *--------------------------------------------------------------------------------
   */

  /**
   * Sets an object into this message's properties.
   *
   * @param caller The user performing the operation.
   * @param namespace The namespace to interpret the name relative to.
   * @param name The name of the object to be set.
   * @param value The object to set into the message's properties.
   * @return The previous object that was set into the message's properties under this namespace and name, or
   *         <CODE>null</CODE> if there was no such object.
   * @exception com.silverwrist.dynamo.except.DatabaseException If there was an error setting the object value.
   * @exception com.silverwrist.dynamo.except.DynamoSecurityException If the specified user is not permitted to
   *            set this object value into this message's properties.
   */
  public Object setObject(DynamoUser caller, String namespace, String name, Object value)
      throws DatabaseException, DynamoSecurityException
  {
    testPermission(caller,namespace,"set.property","no.setProperty");
    Object rc = null;
    // convert the namespace name to an ID here
    PropertyKey key = new PropertyKey(m_nscache.namespaceNameToId(namespace),name);
    synchronized (this)
    { // start by setting the database value
      rc = m_ops.setProperty(m_id,key,value);
      
      // and cache it, too
      m_properties.put(key,value);

    } // end synchronized block

    // TODO: m_post.postUpdate(new GlobalPropertyUpdateEvent(this,namespace,name));
    return rc;

  } // end setObject

  /**
   * Removes an object from this message's properties.
   *
   * @param caller The user performing the operation.
   * @param namespace The namespace to interpret the name relative to.
   * @param name The name of the object to be removed.
   * @return The previous object that was set into the message's properties under this namespace and name, or
   *         <CODE>null</CODE> if there was no such object.
   * @exception com.silverwrist.dynamo.except.DatabaseException If there was an error removing the object value.
   * @exception com.silverwrist.dynamo.except.DynamoSecurityException If the specified user is not permitted to
   *            remove this object value from this message's properties.
   */
  public Object removeObject(DynamoUser caller, String namespace, String name)
      throws DatabaseException, DynamoSecurityException
  {
    testPermission(caller,namespace,"remove.property","no.removeProperty");
    Object rc = null;
    // convert the namespace name to an ID here
    PropertyKey key = new PropertyKey(m_nscache.namespaceNameToId(namespace),name);
    synchronized (this)
    { // start by killing the database value
      rc = m_ops.removeProperty(m_id,key);

      // and remove the cached value, too
      m_properties.remove(key);

    } // end synchronized block

    // TODO: m_post.postUpdate(new GlobalPropertyUpdateEvent(this,namespace,name));
    return rc;

  } // end removeObject

  /**
   * Returns a collection of all object namespaces that have been set into this message's properties.
   *
   * @return A {@link java.util.Collection Collection} containing {@link java.lang.String String} objects specifying
   *         all the object namespaces.
   * @exception com.silverwrist.dynamo.except.DatabaseException If there was an error getting the namespace list.
   */
  public Collection getNamespaces() throws DatabaseException
  {
    // call through to the database to get the list of namespace IDs
    int[] ids = m_ops.getPropertyNamespaceIDs(m_id);

    ArrayList rc = new ArrayList(ids.length);
    for (int i=0; i<ids.length; i++)
      rc.add(m_nscache.namespaceIdToName(ids[i]));
    return Collections.unmodifiableList(rc);

  } // end getNamespaces

  /**
   * Returns a collection of all object names that have been set into this message's properties under
   * a given namespace.
   *
   * @param namespace The namespace to look for names under.
   * @return A {@link java.util.Collection Collection} containing {@link java.lang.String String} objects
   *         specifying all the object names for this namespace.
   * @exception com.silverwrist.dynamo.except.DatabaseException If there was an error getting the object name list.
   */
  public Collection getNamesForNamespace(String namespace) throws DatabaseException
  {
    // call through to the database to get the data for this namespace
    int nsid = m_nscache.namespaceNameToId(namespace);
    Map data = m_ops.getAllProperties(m_id,nsid);

    // we both create the return value and cache the data values
    ArrayList rc = new ArrayList(data.size());
    synchronized (this)
    { // do the transfer...
      Iterator it = data.entrySet().iterator();
      while (it.hasNext())
      { // copy one entry at a time
	Map.Entry ntry = (Map.Entry)(it.next());
	rc.add(ntry.getKey().toString());
	m_properties.put(new PropertyKey(nsid,ntry.getKey().toString()),ntry.getValue());

      } // end while

    } // end synchronized block

    return Collections.unmodifiableList(rc);

  } // end getNamesForNamespace

  /*--------------------------------------------------------------------------------
   * Implementations from interface UniStoreMessage
   *--------------------------------------------------------------------------------
   */

  public long getMessageID()
  {
    return m_id;

  } // end getMessageID

  public long getParentMessageID()
  {
    return m_parentid;

  } // end getParentMessageID

  public void setParentMessageID(DynamoUser caller, long id) throws DatabaseException, DynamoSecurityException
  {
    testPermission(caller,Namespaces.UNISTORE_PERMISSIONS_NAMESPACE,"set.parent","no.setParent");
    synchronized (this)
    { // reset the parent message ID
      m_ops.setParentMessageID(m_id,id);
      m_parentid = id;

    } // end synchronized block

    // TODO: send out an update?

  } // end setParentMessageID

  public int getSequence()
  {
    return m_seq;

  } // end getSequence

  public void setSequence(DynamoUser caller, int seq) throws DatabaseException, DynamoSecurityException
  {
    testPermission(caller,Namespaces.UNISTORE_PERMISSIONS_NAMESPACE,"set.parent","no.setParent");
    synchronized (this)
    { // reset the sequence number
      m_ops.setSequence(m_id,seq);
      m_seq = seq;

    } // end if

    // TODO: send out an update?

  } // end setSequence

  public int getCreatorUID()
  {
    return m_creator;

  } // end getCreatorUID

  public DynamoUser getCreator() throws DatabaseException
  {
    return m_users.getUser(m_creator);

  } // end getCreator

  public java.util.Date getPostDate()
  {
    return m_posted;

  } // end getPostDate

  public DynamoAcl getAcl() throws DatabaseException, AclNotFoundException
  {
    return m_srm.getAcl(m_aclid);

  } // end getAcl

  public void setAcl(DynamoUser caller, DynamoAcl acl) throws DatabaseException, DynamoSecurityException
  {
    testPermission(caller,Namespaces.UNISTORE_PERMISSIONS_NAMESPACE,"set.ACL","no.setACL");
    int aclid = -1;
    if (acl!=null)
      aclid = acl.getAclID();
    synchronized (this)
    { // reset the ACL ID
      m_ops.setAclID(m_id,aclid);
      m_aclid = aclid;

    } // end synchronized block

    // TODO: post an update?

  } // end setAcl

  public synchronized int getNumTextParts() throws DatabaseException
  {
    if (m_text_count<0)
      m_text_count = m_ops.getNumTextParts(m_id);
    return m_text_count;

  } // end getNumTextParts

  public synchronized int getNumBinaryParts() throws DatabaseException
  {
    if (m_binary_count<0)
      m_binary_count = m_ops.getNumBinaryParts(m_id);
    return m_binary_count;

  } // end getNumBinaryParts

  public UniStoreTextPart getTextPart(int index) throws DatabaseException
  {
    Integer key = new Integer(index);
    TextPartImpl rc = null;
    synchronized (this)
    { // look in the part-to-text map first
      rc = (TextPartImpl)(m_part_to_text.get(key));
      if (rc==null)
      { // OK, look up the part in the database
	Map params = m_ops.loadTextPart(m_id,index);
	PropertyKey otherkey = (PropertyKey)(params.get(MessageOps.PARAM_IDENTITY));
	rc = (TextPartImpl)(m_pk_to_text.get(otherkey));
	if (rc==null)
	{ // need to create a new object
	  rc = new TextPartImpl(m_ops.getTextPartOps(),m_nscache,this,params);
	  m_part_to_text.put(key,rc);
	  m_pk_to_text.put(otherkey,rc);

	} // end if
	else // feed back into the parts map
	  m_part_to_text.put(key,rc);

      } // end if
      else
      { // need to reinsert into property key map
	QualifiedNameKey qnk = rc.getPartIdentity();
	PropertyKey pk = new PropertyKey(m_nscache.namespaceNameToId(qnk.getNamespace()),qnk.getName());
	m_pk_to_text.put(pk,rc);

      } // end else

    } // end synchronized block

    return rc;

  } // end getTextPart

  public UniStoreTextPart getTextPart(String namespace, String name) throws DatabaseException
  {
    PropertyKey key = new PropertyKey(m_nscache.namespaceNameToId(namespace),name);
    TextPartImpl rc = null;
    synchronized (this)
    { // look in the PK-to-text map first
      rc = (TextPartImpl)(m_pk_to_text.get(key));
      if (rc==null)
      { // OK, look up the part in the database
	Map params = m_ops.loadTextPart(m_id,key);
	Integer otherkey = (Integer)(params.get(MessageOps.PARAM_PART));
	rc = (TextPartImpl)(m_part_to_text.get(otherkey));
	if (rc==null)
	{ // OK, need to create the object
	  rc = new TextPartImpl(m_ops.getTextPartOps(),m_nscache,this,params);
	  m_part_to_text.put(otherkey,rc);
	  m_pk_to_text.put(key,rc);

	} // end if
	else // feed back into the PKs map
	  m_pk_to_text.put(key,rc);

      } // end if
      else  // reinsert into part key map
	m_part_to_text.put(new Integer(rc.getPartIndex()),rc);

    } // end synchronized block

    return rc;

  } // end getTextPart

  public UniStoreBinaryPart getBinaryPart(int index) throws DatabaseException
  {
    Integer key = new Integer(index);
    BinaryPartImpl rc = null;
    synchronized (this)
    { // look in the part-to-binary map first
      rc = (BinaryPartImpl)(m_part_to_binary.get(key));
      if (rc==null)
      { // OK, look up the part in the database
	Map params = m_ops.loadBinaryPart(m_id,index);
	PropertyKey otherkey = (PropertyKey)(params.get(MessageOps.PARAM_IDENTITY));
	rc = (BinaryPartImpl)(m_pk_to_binary.get(otherkey));
	if (rc==null)
	{ // need to create a new object
	  rc = new BinaryPartImpl(m_ops.getBinaryPartOps(),m_nscache,this,params);
	  m_part_to_binary.put(key,rc);
	  m_pk_to_binary.put(otherkey,rc);

	} // end if
	else // feed back into the parts map
	  m_part_to_binary.put(key,rc);

      } // end if
      else
      { // need to reinsert into property key map
	QualifiedNameKey qnk = rc.getPartIdentity();
	PropertyKey pk = new PropertyKey(m_nscache.namespaceNameToId(qnk.getNamespace()),qnk.getName());
	m_pk_to_binary.put(pk,rc);

      } // end else

    } // end synchronized block

    return rc;

  } // end getBinaryPart

  public UniStoreBinaryPart getBinaryPart(String namespace, String name) throws DatabaseException
  {
    PropertyKey key = new PropertyKey(m_nscache.namespaceNameToId(namespace),name);
    BinaryPartImpl rc = null;
    synchronized (this)
    { // look in the PK-to-binary map first
      rc = (BinaryPartImpl)(m_pk_to_binary.get(key));
      if (rc==null)
      { // OK, look up the part in the database
	Map params = m_ops.loadBinaryPart(m_id,key);
	Integer otherkey = (Integer)(params.get(MessageOps.PARAM_PART));
	rc = (BinaryPartImpl)(m_part_to_binary.get(otherkey));
	if (rc==null)
	{ // OK, need to create the object
	  rc = new BinaryPartImpl(m_ops.getBinaryPartOps(),m_nscache,this,params);
	  m_part_to_binary.put(otherkey,rc);
	  m_pk_to_binary.put(key,rc);

	} // end if
	else // feed back into the PKs map
	  m_pk_to_binary.put(key,rc);

      } // end if
      else  // reinsert into part key map
	m_part_to_binary.put(new Integer(rc.getPartIndex()),rc);

    } // end synchronized block

    return rc;

  } // end getBinaryPart

  public List getTextParts() throws DatabaseException
  {
    int n = this.getNumTextParts();
    ArrayList rc = new ArrayList(n);
    for (int i=1; i<=n; i++)
      rc.add(this.getTextPart(i));
    return Collections.unmodifiableList(rc);

  } // end getTextParts

  public List getBinaryParts() throws DatabaseException
  {
    int n = this.getNumBinaryParts();
    ArrayList rc = new ArrayList(n);
    for (int i=1; i<=n; i++)
      rc.add(this.getBinaryPart(i));
    return Collections.unmodifiableList(rc);

  } // end getBinaryParts

  /*--------------------------------------------------------------------------------
   * External operations
   *--------------------------------------------------------------------------------
   */

  void testPermission(DynamoUser caller, String perm_namespace, String perm_name, String fail_message)
      throws DatabaseException, DynamoSecurityException
  {
    if (caller.equals(m_srm.getAdminUser()))
      return;  // Administrator can do anything
    if (m_aclid==-1)
    { // no ACL - rely on fallback method
      if (caller.getUID()==m_creator)
	return;  // the creator can do anything, but no one else can

    } // end if
    else
    { // test against the ACL
      try
      { // look up the ACL
	if (m_srm.getAcl(m_aclid).testPermission(caller,perm_namespace,perm_name))
	  return;

      } // end try
      catch (AclNotFoundException e)
      { // ACL not found - go to fallback mechanism
	logger.warn("ACL " + m_aclid + " not found while testing message " + m_id);
	if (caller.getUID()==m_creator)
	  return;  // the creator can do anything, but no one else can

      } // end catch

    } // end else

    // Throw a DynamoSecurityException indicating what you're not permitted to do.
    DynamoSecurityException de = new DynamoSecurityException(MessageImpl.class,"UniStoreMessages",fail_message);
    de.setParameter(0,String.valueOf(m_id));
    throw de;

  } // end testPermission

} // end class MessageImpl