/** BEGIN COPYRIGHT BLOCK
 * This Program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; version 2 of the License.
 * 
 * This Program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this Program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA.
 * 
 * In addition, as a special exception, Red Hat, Inc. gives You the additional
 * right to link the code of this Program with code not covered under the GNU
 * General Public License ("Non-GPL Code") and to distribute linked combinations
 * including the two, subject to the limitations in this paragraph. Non-GPL Code
 * permitted under this exception must only link to the code of this Program
 * through those well defined interfaces identified in the file named EXCEPTION
 * found in the source code files (the "Approved Interfaces"). The files of
 * Non-GPL Code may instantiate templates or use macros or inline functions from
 * the Approved Interfaces without causing the resulting work to be covered by
 * the GNU General Public License. Only Red Hat, Inc. may make changes or
 * additions to the list of Approved Interfaces. You must obey the GNU General
 * Public License in all respects for all of the Program code and other code used
 * in conjunction with the Program except the Non-GPL Code covered by this
 * exception. If you modify this file, you may extend this exception to your
 * version of the file, but you are not obligated to do so. If you do not wish to
 * provide this exception without modification, you must delete this exception
 * statement from your version and license this file solely under the GPL without
 * exception. 
 * 
 * 
 * Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
 * Copyright (C) 2005 Red Hat, Inc.
 * All rights reserved.
 * END COPYRIGHT BLOCK **/

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif


#include "retrocl.h"

static int
entry2reple( Slapi_Entry *e, Slapi_Entry *oe );

static int
mods2reple( Slapi_Entry *e, LDAPMod **ldm );

static int
modrdn2reple( Slapi_Entry *e, const char *newrdn, int deloldrdn, 
	      LDAPMod **ldm, const char *newsup );

/******************************/

const char *attr_changenumber = "changenumber";
const char *attr_targetdn = "targetdn";
const char *attr_changetype = "changetype";
const char *attr_newrdn = "newrdn";
const char *attr_deleteoldrdn = "deleteoldrdn";
const char *attr_changes = "changes";
const char *attr_newsuperior = "newsuperior";
const char *attr_changetime = "changetime";
const char *attr_objectclass = "objectclass";
const char *attr_isreplicated = "isreplicated";

/*
 * Function: make_changes_string
 *
 * Returns:
 * 
 * Arguments:
 *
 * Description:
 * loop through the LDAPMod struct and construct the changes attribute/
 *
 */

static lenstr *make_changes_string(LDAPMod **ldm, const char **includeattrs)
{
    lenstr		*l;
    int			i, j, len;
    int			skip;

    l = lenstr_new();

    for ( i = 0; ldm[ i ] != NULL; i++ ) {
	/* If a list of explicit attributes was given, only add those */
	if ( NULL != includeattrs ) {
	    skip = 1;
	    for ( j = 0; includeattrs[ j ] != NULL; j++ ) {
		if ( strcasecmp( includeattrs[ j ], ldm[ i ]->mod_type ) == 0 ) {
		    skip = 0;
		    break;
		}
	    }
	    if ( skip ) {
		continue;
	    }
	}
	switch ( ldm[ i ]->mod_op  & ~LDAP_MOD_BVALUES ) {
	case LDAP_MOD_ADD:
	    addlenstr( l, "add: " );
	    addlenstr( l, ldm[ i ]->mod_type );
	    addlenstr( l, "\n" );
	    break;
	case LDAP_MOD_DELETE:
	    addlenstr( l, "delete: " );
	    addlenstr( l, ldm[ i ]->mod_type );
	    addlenstr( l, "\n" );
	    break;
	case LDAP_MOD_REPLACE:
	    addlenstr( l, "replace: " );
	    addlenstr( l, ldm[ i ]->mod_type );
	    addlenstr( l, "\n" );
	    break;
	}
	for ( j = 0; ldm[ i ]->mod_bvalues != NULL &&
		ldm[ i ]->mod_bvalues[ j ] != NULL; j++ ) {
	    char *buf = NULL;
	    char *bufp = NULL;

	    len = strlen( ldm[ i ]->mod_type );
	    len = LDIF_SIZE_NEEDED( len,
		    ldm[ i ]->mod_bvalues[ j ]->bv_len ) + 1;
	    buf = slapi_ch_malloc( len );
	    bufp = buf;
	    slapi_ldif_put_type_and_value_with_options( &bufp, ldm[ i ]->mod_type,
		    ldm[ i ]->mod_bvalues[ j ]->bv_val,
		    ldm[ i ]->mod_bvalues[ j ]->bv_len, 0 );
	    *bufp = '\0';

	    addlenstr( l, buf );

	    slapi_ch_free_string( &buf );
	}
	addlenstr( l, "-\n" );
    }
    return l;
}

/*
 * Function: write_replog_db
 * Arguments: be     - backend to which this change is being applied
 *            optype - type of LDAP operation being logged
 *            dn     - distinguished name of entry being changed
 *            log_m - pointer to the actual change operation on a modify
 *            flag   - only used by modrdn operations - value of deleteoldrdn 
 *            curtime - the current time
 * Returns: nothing
 * Description: Given a change, construct an entry which is to be added to the
 *              changelog database.
 */
static void
write_replog_db(
    Slapi_PBlock *pb,
    int			optype,
    char		*dn,
    LDAPMod		**log_m,
    int			flag,
    time_t		curtime,
    Slapi_Entry         *log_e,
    const char          *newrdn,
    LDAPMod		**modrdn_mods,
    const char          *newsuperior
)
{
    char		*edn;
    struct berval	*vals[ 2 ];
    struct berval	val;
    Slapi_Entry		*e;
    char		chnobuf[ 20 ];
    int			err;
    Slapi_PBlock	*newPb = NULL;
    changeNumber changenum;
    int			i;

    PR_Lock(retrocl_internal_lock);
    changenum = retrocl_assign_changenumber();
   
    PR_ASSERT( changenum > 0UL );
    slapi_log_error( SLAPI_LOG_PLUGIN, RETROCL_PLUGIN_NAME,
	    "write_replog_db: write change record %lu for dn: \"%s\"\n", 
	    changenum, ( dn == NULL ) ? "NULL" : dn );

    /* Construct the dn of this change record */
    edn = slapi_ch_smprintf( "%s=%lu,%s", attr_changenumber, changenum, RETROCL_CHANGELOG_DN);

    /*
     * Create the entry struct, and fill in fields common to all types
     * of change records.
     */
    vals[ 0 ] = &val;
    vals[ 1 ] = NULL;

    e = slapi_entry_alloc();
    slapi_entry_set_dn( e, slapi_ch_strdup( edn ));

    /* Set the objectclass attribute */
    val.bv_val = "top";
    val.bv_len = 3;
    slapi_entry_add_values( e, "objectclass", vals );

    val.bv_val = "changelogentry";
    val.bv_len = 14;
    slapi_entry_add_values( e, "objectclass", vals );

    val.bv_val = "extensibleObject";
    val.bv_len = 16;
    slapi_entry_add_values( e, "objectclass", vals );

    for ( i=0; i<retrocl_nattributes; i++ ) {
        char* attributeName = retrocl_attributes[i];

        if ( strcasecmp( attributeName, attr_isreplicated ) == 0 ) {
            int isReplicated = 0;
            char *attributeValue = NULL;

            slapi_pblock_get( pb, SLAPI_IS_REPLICATED_OPERATION, &isReplicated );
            attributeValue = isReplicated ? "TRUE" : "FALSE";

            val.bv_val = attributeValue;
            val.bv_len = strlen( attributeValue );

            slapi_entry_add_values( e, attributeName, vals );

        } else {
            Slapi_Entry *entry = NULL;
            Slapi_ValueSet *valueSet = NULL;
            int type_name_disposition = 0;
            char *actual_type_name = NULL;
            int flags = 0;
            int buffer_flags = 0;

            slapi_pblock_get( pb, SLAPI_ENTRY_POST_OP, &entry );
            if ( entry != NULL ) {
                slapi_vattr_values_get( entry, attributeName, &valueSet,
                        &type_name_disposition, &actual_type_name, flags, &buffer_flags );
            }

            if ( valueSet == NULL ) {
                slapi_pblock_get( pb, SLAPI_ENTRY_PRE_OP, &entry );
                if ( entry != NULL ) {
                    slapi_vattr_values_get( entry, attributeName, &valueSet,
                            &type_name_disposition, &actual_type_name, flags, &buffer_flags );
                }
            }

            if ( valueSet == NULL ) continue;

            slapi_entry_add_valueset( e, attributeName, valueSet );
            slapi_vattr_values_free( &valueSet, &actual_type_name, buffer_flags );
        }
    }

    /* Set the changeNumber attribute */
    sprintf( chnobuf, "%lu", changenum );
    val.bv_val = chnobuf;
    val.bv_len = strlen( chnobuf );
    slapi_entry_add_values( e, attr_changenumber, vals );

    /* Set the targetentrydn attribute */
    val.bv_val = dn;
    val.bv_len = strlen( dn );
    slapi_entry_add_values( e, attr_targetdn, vals );

    /* Set the changeTime attribute */
    val.bv_val = format_genTime (curtime);
    val.bv_len = strlen( val.bv_val );
    slapi_entry_add_values( e, attr_changetime, vals );
    slapi_ch_free( (void **)&val.bv_val );

    /*
     * Finish constructing the entry.  How to do it depends on the type
     * of modification being logged.
     */
    err = 0;
    switch ( optype ) {
    case OP_ADD:
	if ( entry2reple( e, log_e ) != 0 ) {
	    err = 1;
	}
	break;

    case OP_MODIFY:
	if ( mods2reple( e, log_m ) != 0 ) {
	    err = 1;
	}
	break;

    case OP_MODRDN:
	if ( modrdn2reple( e, newrdn, flag, modrdn_mods, newsuperior ) != 0 ) {
	    err = 1;
	}
	break;

    case OP_DELETE:
	/* Set the changetype attribute */
	val.bv_val = "delete";
	val.bv_len = 6;
	slapi_entry_add_values( e, attr_changetype, vals );
	break;
    default:
	slapi_log_error( SLAPI_LOG_FATAL, RETROCL_PLUGIN_NAME, "replog: Unknown LDAP operation type "
		"%d.\n", optype );
	err = 1;
    }

    /* Call the repl backend to add this entry */
    if ( 0 == err ) {
	int rc;

	newPb = slapi_pblock_new ();
	slapi_add_entry_internal_set_pb( newPb, e, NULL /* controls */, 
					 g_plg_identity[PLUGIN_RETROCL], 
					 0 /* actions */ );
	slapi_add_internal_pb (newPb);
	slapi_pblock_get( newPb, SLAPI_PLUGIN_INTOP_RESULT, &rc );
	slapi_pblock_destroy(newPb);
	if ( 0 != rc ) {
	    slapi_log_error( SLAPI_LOG_FATAL, RETROCL_PLUGIN_NAME,
			     "replog: an error occured while adding change "
			     "number %lu, dn = %s: %s. \n",
			     changenum, edn, ldap_err2string( rc ));
	    retrocl_release_changenumber();
	} else {
	/* Tell the change numbering system this one's committed to disk  */
	    retrocl_commit_changenumber( );
	}
    } else {
	slapi_log_error( SLAPI_LOG_FATAL, RETROCL_PLUGIN_NAME, 
			 "An error occurred while constructing "
			 "change record number %ld.\n",	changenum );
	retrocl_release_changenumber();
    }
    PR_Unlock(retrocl_internal_lock);
    if ( NULL != edn ) {
	slapi_ch_free((void **) &edn);
    }

}


/*
 * Function: entry2reple
 * Arguments: e  - a partially-constructed Slapi_Entry structure
 *            oe - the original entry (an entry being added by a client).
 * Returns: 0 on success.
 * Description: Given an Slapi_Entry struct, construct a changelog entry which will be
 *              added to the replication database.  It is assumed that e points
 *              to an entry obtained from slapi_entry_alloc().
 */
static int
entry2reple( Slapi_Entry *e, Slapi_Entry *oe )
{
    char		*p, *estr;
    struct berval	*vals[ 2 ];
    struct berval	val;
    int			len;

    vals[ 0 ] = &val;
    vals[ 1 ] = NULL;

    /* Set the changetype attribute */
    val.bv_val = "add";
    val.bv_len = 3;
    slapi_entry_add_values( e, attr_changetype, vals );

    estr = slapi_entry2str( oe, &len );
    p = estr;
    /* Skip over the dn: line */
    while (( p = strchr( p, '\n' )) != NULL ) {
	p++;
	if ( !ldap_utf8isspace( p )) {
	    break;
	}
    }
    val.bv_val = p;
    val.bv_len = len - ( p - estr ); /* length + terminating \0 */
    slapi_entry_add_values( e, attr_changes, vals );
    slapi_ch_free_string( &estr );
    return 0;
}

/*
 * Function: mods2reple
 * Arguments: e  - a partially-constructed Slapi_Entry structure
 *            ldm - an array of pointers to LDAPMod structures describing the
 *                  change applied.
 * Returns: 0 on success.
 * Description: Given a pointer to an LDAPMod struct and a dn, construct
 *              a new entry which will be added to the replication database.
 *              It is assumed that e points to an entry obtained from 
 *              slapi_entry_alloc().
 */
static int
mods2reple( Slapi_Entry *e, LDAPMod **ldm )
{
    struct berval	val;
    struct berval	*vals[ 2 ];
    lenstr		*l;
    
    vals[ 0 ] = &val;
    vals[ 1 ] = NULL;

    /* Set the changetype attribute */
    val.bv_val = "modify";
    val.bv_len = 6;
    slapi_entry_add_values( e, "changetype", vals );

    if (NULL != ldm) {
	l = make_changes_string( ldm, NULL );
	if ( NULL != l ) {
	    val.bv_val = l->ls_buf;
	    val.bv_len = l->ls_len + 1; /* string + terminating \0 */
	    slapi_entry_add_values( e, attr_changes, vals );
	    lenstr_free( &l );
	}
    }
    return 0;
}


/*
 * Function: modrdn2reple
 * Arguments: e  - a partially-constructed Slapi_Entry structure
 *            newrdn - the new relative distinguished name for the entry
 *            deloldrdn - the "deleteoldrdn" flag provided by the client
 *            ldm - any modifications applied as a side-effect of the modrdn
 * Returns: 0 on success
 * Description: Given a dn, a new rdn,  and a deleteoldrdn flag, construct
 * a new entry which will be added to the replication database reflecting a
 * completed modrdn operation.  The entry has the same form as above.
 * It is assumed that e points to an entry obtained from slapi_entry_alloc().
 */
static int
modrdn2reple( 
    Slapi_Entry *e, 
    const char *newrdn, 
    int deloldrdn,
    LDAPMod **ldm,
    const char *newsuperior
)
{
    struct berval	val;
    struct berval	*vals[ 2 ];
    lenstr		*l;
    static const char	*lastmodattrs[] = {"modifiersname", "modifytimestamp",
					  "creatorsname", "createtimestamp",
					  NULL };
    
    vals[ 0 ] = &val;
    vals[ 1 ] = NULL;

    val.bv_val = "modrdn";
    val.bv_len = 6;
    slapi_entry_add_values( e, attr_changetype, vals );

    if (newrdn) {
        val.bv_val = (char *)newrdn;  /* cast away const */
	val.bv_len = strlen( newrdn );
	slapi_entry_add_values( e, attr_newrdn, vals );
    }

    if ( deloldrdn == 0 ) {
	val.bv_val = "FALSE";
	val.bv_len = 5;
    } else {
	val.bv_val = "TRUE";
	val.bv_len = 4;
    }
    slapi_entry_add_values( e, attr_deleteoldrdn, vals );

    if (newsuperior) {
        val.bv_val = (char *)newsuperior;  /* cast away const */
	val.bv_len = strlen(newsuperior);
	slapi_entry_add_values(e, attr_newsuperior,vals);
    }

    if (NULL != ldm) {
	l = make_changes_string( ldm, lastmodattrs );
	if ( NULL != l ) {
	    val.bv_val = l->ls_buf;
	    val.bv_len = l->ls_len + 1; /* string + terminating \0 */
	    slapi_entry_add_values( e, attr_changes, vals );
	    lenstr_free( &l );
	}
    }

    return 0;
}

/*
 * Function: retrocl_postob
 *
 * Returns: 0 on success
 * 
 * Arguments: pblock, optype (add, del, modify etc) 
 *
 * Description: called from retrocl.c op-specific plugins.
 *
 * Please be aware that operation threads may be scheduled out between their
 * being performed inside of the LDBM database and the changelog plugin
 * running.  For example, suppose MA and MB are two modify operations on the
 * same entry.  MA may be performed on the LDBM database, and then block 
 * before the changelog runs.  MB then runs against the LDBM database and then
 * is written to the changelog.  MA starts running.  In the changelog, MB will
 * appear to have been performed before MA, but in the LDBM database the 
 * opposite will have occured.
 *  
 *
 */

int retrocl_postob (Slapi_PBlock *pb,int optype)
{
    char		*dn;
    LDAPMod		**log_m = NULL;
    int			flag = 0;
    Slapi_Entry		*te = NULL;
    Slapi_Operation     *op = NULL;
    LDAPMod		**modrdn_mods = NULL;
    char *newrdn = NULL;
    char *newsuperior = NULL;
    Slapi_Backend *be = NULL;
    time_t curtime;
    int rc;

    /*
     * Check to see if the change was made to the replication backend db.
     * If so, don't try to log it to the db (otherwise, we'd get in a loop).
     */
   
    (void)slapi_pblock_get( pb, SLAPI_BACKEND, &be );
    
    if (slapi_be_logchanges(be) == 0) {
        LDAPDebug0Args(LDAP_DEBUG_TRACE,"not applying change if not logging\n");
	return 0;
    }
    
    if (retrocl_be_changelog == NULL || be == retrocl_be_changelog) {
        LDAPDebug0Args(LDAP_DEBUG_TRACE,"not applying change if no/cl be\n");
	return 0;
    }

    slapi_pblock_get(pb, SLAPI_RESULT_CODE, &rc);

    if (rc != LDAP_SUCCESS) {
        LDAPDebug1Arg(LDAP_DEBUG_TRACE,"not applying change if op failed %d\n",rc);
	return 0;
    }

    if (slapi_op_abandoned(pb)) {
        LDAPDebug0Args(LDAP_DEBUG_PLUGIN,"not applying change if op abandoned\n");
	return 0;
    }

    curtime = current_time();
    
    (void)slapi_pblock_get( pb, SLAPI_ORIGINAL_TARGET_DN, &dn );

    /* change number could be retrieved from Operation extension stored in 
     * the pblock, or else it needs to be made dynamically. */

    /* get the operation extension and retrieve the change number */
    slapi_pblock_get( pb, SLAPI_OPERATION, &op );

    if (op == NULL) {
        LDAPDebug0Args(LDAP_DEBUG_TRACE,"not applying change if no op\n");
        return 0;
    }

	if (operation_is_flag_set(op, OP_FLAG_TOMBSTONE_ENTRY)){
        LDAPDebug0Args(LDAP_DEBUG_TRACE,"not applying change for nsTombstone entries\n");
        return 0;
	}
	
    switch ( optype ) {
    case OP_MODIFY:
    	(void)slapi_pblock_get( pb, SLAPI_MODIFY_MODS, &log_m );
    	break;
    case OP_ADD:
    	/*
    	 * For adds, we want the unnormalized dn, so we can preserve
    	 * spacing, case, when replicating it.
    	 */
    	(void)slapi_pblock_get( pb, SLAPI_ADD_ENTRY, &te );
    	if ( NULL != te ) {
    	    dn = slapi_entry_get_dn( te );
    	}
    	break;
    case OP_DELETE:
    	break;
    case OP_MODRDN:
    	(void)slapi_pblock_get( pb, SLAPI_MODRDN_NEWRDN, &newrdn );
    	(void)slapi_pblock_get( pb, SLAPI_MODRDN_DELOLDRDN, &flag );
    	(void)slapi_pblock_get( pb, SLAPI_MODIFY_MODS, &modrdn_mods );
	(void)slapi_pblock_get( pb, SLAPI_MODRDN_NEWSUPERIOR, &newsuperior); 
    	break;
    }


    /* check if we should log change to retro changelog, and
     * if so, do it here */
    write_replog_db( pb, optype, dn, log_m, flag, curtime, te,
		     newrdn, modrdn_mods, newsuperior );

    return 0;
}