/*
 *	 Copyright 1999, Dmitry Kovalev (zmit@mail.ru), All rights reserved.
 *
 *	 Redistribution and use in source and binary forms are permitted only
 *	 as authorized by the OpenLDAP Public License.	A copy of this
 *	 license is available at http://www.OpenLDAP.org/license.html or
 *	 in file LICENSE in the top-level directory of the distribution.
 */

#include "portable.h"

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "slap.h"
#include "back-sql.h"
#include "sql-types.h"
#include "sql-wrap.h"
#include "schema-map.h"

#define MAX_ATTR_LEN 16384

typedef struct backsql_conn
{
 int ldap_cid;
 SQLHDBC dbh;
}backsql_db_conn;

int backsql_dummy(void *,void *);

void backsql_PrintErrors(SQLHENV henv, SQLHDBC hdbc, SQLHSTMT sth,int rc)
{
 SQLCHAR           msg[SQL_MAX_MESSAGE_LENGTH];    /* msg. buffer    */
 SQLCHAR           state[SQL_SQLSTATE_SIZE];       /* statement buf. */
 SDWORD        iSqlCode;                              /* return code    */
 SWORD       len=SQL_MAX_MESSAGE_LENGTH-1;                               /* return length  */

 
 Debug(LDAP_DEBUG_TRACE,"Return code: %d\n", rc,0,0);
  
 while((rc=SQLError(henv,hdbc,sth,state,&iSqlCode,msg,
             SQL_MAX_MESSAGE_LENGTH - 1, &len)) == SQL_SUCCESS
	|| rc == SQL_SUCCESS_WITH_INFO
       )
 {
  Debug(LDAP_DEBUG_TRACE,"SQL engine state: %s\n", state,0,0);
  Debug(LDAP_DEBUG_TRACE,"Native error code: %d\n",(int) iSqlCode,0,0);
  Debug(LDAP_DEBUG_TRACE,"Message: %s\n",msg,0,0);
 }
}

RETCODE backsql_Prepare(SQLHDBC dbh,SQLHSTMT *sth,char* query,int timeout)
{
 RETCODE rc;
 char drv_name[30];
 SWORD len;
 int i;
 
 rc=SQLAllocStmt(dbh,sth);
 if (rc != SQL_SUCCESS)
  return rc;
 
 //Debug(LDAP_DEBUG_TRACE,"==>_SQLPrepare()\n", 0,0,0);
 SQLGetInfo(dbh,SQL_DRIVER_NAME,drv_name,30,&len);
 //Debug(LDAP_DEBUG_TRACE,"_SQLPrepare(): driver name='%s'\n", drv_name,0,0);
 for (i=0;i<30 && drv_name[i];i++)
  drv_name[i]=toupper(drv_name[i]);
 if (!strncmp(drv_name,"SQLSRV32.DLL",30))
  {
   //stupid default result set in MS SQL Server does not support multiple active statements
   //on the same connection -- so we are trying to make it not to use default result set...
   Debug(LDAP_DEBUG_TRACE,"_SQLprepare(): enabling MS SQL Server default result set workaround\n", 0,0,0);
   rc=SQLSetStmtOption(*sth,SQL_CONCURRENCY,SQL_CONCUR_ROWVER);
   if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO)
   {
    Debug(LDAP_DEBUG_TRACE,"_SQLPrepare(): SQLSetStmtOption(SQL_CONCURRENCY,SQL_CONCUR_ROWVER) failed:\n", 0,0,0);
    backsql_PrintErrors(SQL_NULL_HENV,dbh,sth,rc);
   }
  }
 if (timeout>0)
  {
   Debug(LDAP_DEBUG_TRACE,"_SQLprepare(): setting query timeout to %d sec.\n", timeout,0,0);
   if ((rc=SQLSetStmtOption(*sth,SQL_QUERY_TIMEOUT,timeout)) != SQL_SUCCESS)
    {
     backsql_PrintErrors(SQL_NULL_HENV,dbh,sth,rc);
    }
  }
 
 //Debug(LDAP_DEBUG_TRACE,"<==_SQLPrepare() calling SQLPrepare()\n", 0,0,0);
 return SQLPrepare(*sth,query,SQL_NTS);
}

RETCODE backsql_BindParamStr(SQLHSTMT sth,int par_ind,char *str,int maxlen)
{
 RETCODE rc;
 SQLINTEGER len=SQL_NTS;
 
 rc=SQLBindParameter(sth,(SQLUSMALLINT)par_ind,SQL_PARAM_INPUT,SQL_C_CHAR,SQL_VARCHAR,
         (SQLUINTEGER)maxlen,0,(SQLPOINTER)str,(SQLUINTEGER)maxlen,NULL);
 return rc;
}

RETCODE backsql_BindParamID(SQLHSTMT sth,int par_ind,unsigned long *id)
{
 
 return SQLBindParameter(sth,(SQLUSMALLINT)par_ind,SQL_PARAM_INPUT,SQL_C_ULONG,SQL_INTEGER,
         0,0,(SQLPOINTER)id,0,(SQLINTEGER*)NULL);
}

RETCODE backsql_BindRowAsStrings(SQLHSTMT sth,BACKSQL_ROW_NTS *row)
{
 RETCODE rc;
 SQLCHAR colname[64];
 SQLSMALLINT name_len,col_type,col_scale,col_null;
 UDWORD col_prec;
 int i;
 
 if (row == NULL)
  return SQL_ERROR;
 
 //Debug(LDAP_DEBUG_TRACE,"==> backsql_BindRowAsStrings()\n",0,0,0);
 rc=SQLNumResultCols(sth,&row->ncols);
 if (rc != SQL_SUCCESS)
 {
  //Debug(LDAP_DEBUG_TRACE,"_SQLBindRowAsStrings(): SQLNumResultCols() failed:\n",0,0,0);
  backsql_PrintErrors(SQL_NULL_HENV,SQL_NULL_HDBC,sth,rc);
 }
 else
 {
  //Debug(LDAP_DEBUG_TRACE,"backsql_BindRowAsStrings: ncols=%d\n",(int)row->ncols,0,0);
  row->col_names=(char**)ch_calloc(row->ncols,sizeof(char*));
  row->cols=(char**)ch_calloc(row->ncols,sizeof(char*));
  row->col_prec=(UDWORD*)ch_calloc(row->ncols,sizeof(UDWORD));
  row->is_null=(SQLINTEGER*)ch_calloc(row->ncols,sizeof(SQLINTEGER));
  for (i=1;i<=row->ncols;i++)
  {
   rc=SQLDescribeCol(sth,(SQLSMALLINT)i,&colname[0],(SQLUINTEGER)sizeof(colname)-1,&name_len,&col_type,
          (UDWORD*) &col_prec,&col_scale,&col_null);
   row->col_names[i-1]=strdup(colname);
   //Debug(LDAP_DEBUG_TRACE,"backsql_BindRowAsStrings: col_name=%s, col_prec[%d]=%d\n",colname,(int)i,(int)col_prec);
   if (col_type == SQL_LONGVARCHAR || col_type== SQL_LONGVARBINARY)
   {
	//row->cols[i-1]=NULL;
    //row->col_prec[i-1]=-1;
	//such fields must be handled in some other way since they return 2G 
	//as their precision (at least it does so with MS SQL Server w/native driver)
	//for now, we just set fixed precision for such fields - dirty hack, but...
	//no time to deal with SQLGetData()
	col_prec=MAX_ATTR_LEN;
	row->cols[i-1]=(char*)ch_calloc((col_prec+1),sizeof(char));
    row->col_prec[i-1]=col_prec;
	rc=SQLBindCol(sth,(SQLUSMALLINT)i,SQL_C_CHAR,(SQLPOINTER)row->cols[i-1],col_prec+1,
			                               &row->is_null[i-1]);
   }
   else
   {
    row->cols[i-1]=(char*)ch_calloc((col_prec+1),sizeof(char));
    row->col_prec[i-1]=col_prec;
	rc=SQLBindCol(sth,(SQLUSMALLINT)i,SQL_C_CHAR,(SQLPOINTER)row->cols[i-1],col_prec+1,
			                               &row->is_null[i-1]);
   }
  }
 }
 //Debug(LDAP_DEBUG_TRACE,"<== backsql_BindRowAsStrings()\n",0,0,0);
 return rc;
}

RETCODE backsql_FreeRow(BACKSQL_ROW_NTS *row)
{
 int i;
 
 if (row->cols == NULL)
  return SQL_ERROR;
 for(i=0;i<row->ncols;i++)
  {
   free(row->cols[i]);
  }
 free(row->col_names);
 free(row->col_prec);
 free(row->cols);
 free(row->is_null);
 return SQL_SUCCESS;
}

int backsql_cmp_connid(backsql_db_conn *c1,backsql_db_conn *c2)
{
 if (c1->ldap_cid > c2->ldap_cid)
  return 1; 
 if (c1->ldap_cid < c2->ldap_cid)
  return -1; 
 return 0;
}


int backsql_close_db_conn(backsql_db_conn *conn)
{
 Debug(LDAP_DEBUG_TRACE,"==>backsql_close_db_conn()\n",0,0,0);
 SQLDisconnect(conn->dbh);
 SQLFreeConnect(conn->dbh);
 Debug(LDAP_DEBUG_TRACE,"<==backsql_close_db_conn()\n",0,0,0);
 return 1;
}

int backsql_init_db_env(backsql_info *si)
{
 RETCODE rc;
 Debug(LDAP_DEBUG_TRACE,"==>backsql_init_db_env()\n",0,0,0);
 if ((rc=SQLAllocEnv(&si->db_env)) != SQL_SUCCESS)
  {
   Debug(LDAP_DEBUG_TRACE,"init_db_env: SQLAllocEnv failed:\n",0,0,0);
   backsql_PrintErrors(SQL_NULL_HENV,SQL_NULL_HDBC,SQL_NULL_HENV,rc);
  }
 Debug(LDAP_DEBUG_TRACE,"<==backsql_init_db_env()\n",0,0,0);
 return SQL_SUCCESS;
}

int backsql_free_db_env(backsql_info *si)
{
 Debug(LDAP_DEBUG_TRACE,"==>backsql_free_db_env()\n",0,0,0);
 //Debug(LDAP_DEBUG_TRACE,"free_db_env(): delete AVL tree here!!!\n",0,0,0);
 
 //stop, if frontend waits for all threads to shutdown before calling this --
 //then what we are going to delete?? everything is deleted already...
 Debug(LDAP_DEBUG_TRACE,"<==backsql_free_db_env()\n",0,0,0);
 return SQL_SUCCESS;
}

backsql_db_conn* backsql_open_db_conn(backsql_info *si,int ldap_cid)
{
 backsql_db_conn *dbc=(backsql_db_conn*)ch_calloc(1,sizeof(backsql_db_conn));
 int rc;
 
 Debug(LDAP_DEBUG_TRACE,"==>backsql_open_db_conn()\n",0,0,0);
 dbc->ldap_cid=ldap_cid;
 if ((rc=SQLAllocConnect(si->db_env,&dbc->dbh)) != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO)
  {
   Debug(LDAP_DEBUG_TRACE,"backsql_open_db_conn: SQLAllocConnect() failed:\n",0,0,0);
   backsql_PrintErrors(si->db_env,SQL_NULL_HDBC,SQL_NULL_HENV,rc);
   return NULL;
  }
 if ((rc=SQLConnect(dbc->dbh,si->dbname,SQL_NTS,si->dbuser,SQL_NTS,
                      si->dbpasswd,SQL_NTS) != SQL_SUCCESS))
  {
   if (rc != SQL_SUCCESS_WITH_INFO)
    Debug(LDAP_DEBUG_TRACE,"backsql_open_db_conn: SQLConnect() failed:\n",0,0,0);
   else
	Debug(LDAP_DEBUG_TRACE,"backsql_open_db_conn: SQLConnect() succeeded with info:\n",0,0,0);
   backsql_PrintErrors(si->db_env,dbc->dbh,SQL_NULL_HENV,rc);
   if (rc != SQL_SUCCESS_WITH_INFO)
    return NULL;
  }
					     
 Debug(LDAP_DEBUG_TRACE,"backsql_open_db_conn(): connected, adding to tree\n",0,0,0);
 ldap_pvt_thread_mutex_lock(&si->dbconn_mutex);
 avl_insert(&si->db_conns,dbc,(AVL_CMP)backsql_cmp_connid,backsql_dummy);
 ldap_pvt_thread_mutex_unlock(&si->dbconn_mutex);
 Debug(LDAP_DEBUG_TRACE,"<==backsql_open_db_conn()\n",0,0,0);
 return dbc;
}

int backsql_free_db_conn(Backend *be,Connection *ldapc)
{
 backsql_info *si=(backsql_info*)be->be_private;
 backsql_db_conn tmp,*conn;
 
 Debug(LDAP_DEBUG_TRACE,"==>backsql_free_db_conn()\n",0,0,0);
 tmp.ldap_cid=ldapc->c_connid;
 ldap_pvt_thread_mutex_lock(&si->dbconn_mutex);
 conn=(backsql_db_conn*)avl_delete(&si->db_conns,&tmp,(AVL_CMP)backsql_cmp_connid);
 ldap_pvt_thread_mutex_unlock(&si->dbconn_mutex);
 //we have one thread per connection, as I understand -- so we can
 //get this out of critical section
 if (conn!=NULL)
  { 
   Debug(LDAP_DEBUG_TRACE,"backsql_free_db_conn(): closing db connection\n",0,0,0);
   backsql_close_db_conn(conn);
  }
 Debug(LDAP_DEBUG_TRACE,"<==backsql_free_db_conn()\n",0,0,0);
 return SQL_SUCCESS;
}

SQLHDBC backsql_get_db_conn(Backend *be,Connection *ldapc)
{
 backsql_info *si=(backsql_info*)be->be_private;
 backsql_db_conn *dbc;
 backsql_db_conn tmp;
 
 Debug(LDAP_DEBUG_TRACE,"==>backsql_get_db_conn()\n",0,0,0);
 
 tmp.ldap_cid=ldapc->c_connid;
 //we have one thread per connection, as I understand -- so we do not need
 // locking here
 dbc=(backsql_db_conn*)avl_find(si->db_conns,&tmp,(AVL_CMP)backsql_cmp_connid);
 if (!dbc)
  dbc=backsql_open_db_conn(si,ldapc->c_connid);
  
 if (!dbc)
 {
   Debug(LDAP_DEBUG_TRACE,"backsql_get_db_conn(): could not get connection handle -- returning NULL\n",0,0,0);
   return NULL;
 }
 ldap_pvt_thread_mutex_lock(&si->schema_mutex);
 if (!si->schema_loaded)
  {
   Debug(LDAP_DEBUG_TRACE,"backsql_get_db_conn(): first call -- reading schema map\n",0,0,0);
   backsql_load_schema_map(si,dbc->dbh);
  }
 ldap_pvt_thread_mutex_unlock(&si->schema_mutex);
 
 Debug(LDAP_DEBUG_TRACE,"<==backsql_get_db_conn()\n",0,0,0);
 return dbc->dbh;
}