<?php
(defined('_JEXEC') && defined('ARI_FRAMEWORK_LOADED')) or die;
/**
  V4.65 22 July 2005  (c) 2000-2005 John Lim (jlim@natsoft.com.my). All rights reserved.
  Released under both BSD license and Lesser GPL library license. 
  Whenever there is any discrepancy between the two licenses, 
  the BSD license will take precedence.
	
  Set tabs to 4 for best viewing.
  
  Modified 28 August, 2005 for use with ADOdb Lite by Mark Dickenson
  
*/

// security - hide paths
if (!defined('ADODB_DIR')) die();

class ADODB2_postgres extends ADODB_DataDict {

	var $dbtype = 'postgres';
	var $seqField = false;
	var $seqPrefix = 'SEQ_';
	var $addCol = ' ADD COLUMN';
	var $quote = '"';
	var $renameTable = 'ALTER TABLE %s RENAME TO %s'; // at least since 7.1

 	function ActualType($meta)
	{
		switch($meta) {
		case 'C': return 'VARCHAR';
		case 'XL':
		case 'X': return 'TEXT';
		
		case 'C2': return 'VARCHAR';
		case 'X2': return 'TEXT';
		
		case 'B': return 'BYTEA';
			
		case 'D': return 'DATE';
		case 'T': return 'TIMESTAMP';
		
		case 'L': return 'BOOLEAN';
		case 'I': return 'INTEGER';
		case 'I1': return 'SMALLINT';
		case 'I2': return 'INT2';
		case 'I4': return 'INT4';
		case 'I8': return 'INT8';
		
		case 'F': return 'FLOAT8';
		case 'N': return 'NUMERIC';
		default:
			return $meta;
		}
	}

	function AddColumnSQL($tabname, $flds)
	{
		$tabname = $this->TableName ($tabname);
		$sql = array();
		list($lines,$pkey) = $this->_GenFields($flds);
		$alter = 'ALTER TABLE ' . $tabname . $this->addCol . ' ';
		foreach($lines as $v) {
			if (($not_null = preg_match('/NOT NULL/i',$v))) {
				$v = preg_replace('/NOT NULL/i','',$v);
			}
			if (preg_match('/^([^ ]+) .*(DEFAULT [^ ]+)/',$v,$matches)) {
				list(,$colname,$default) = $matches;
				$sql[] = $alter . str_replace($default,'',$v);
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET ' . $default;
			} else {				
				$sql[] = $alter . $v;
			}
			if ($not_null) {
				list($colname) = explode(' ',$v);
				$sql[] = 'ALTER TABLE '.$tabname.' ALTER COLUMN '.$colname.' SET NOT NULL';
			}
		}
		return $sql;
	}

	function AlterColumnSQL($tabname, $flds, $tableflds='',$tableoptions='')
	{
		if (!$tableflds) {
			if ($this->debug) $this->outp("AlterColumnSQL needs a complete table-definiton for PostgreSQL");
			return array();
		}
		return $this->_recreate_copy_table($tabname,False,$tableflds,$tableoptions);
	}

	function DropColumnSQL($tabname, $flds, $tableflds='',$tableoptions='')
	{
		$has_drop_column = 7.3 <= (float) @$this->serverInfo['version'];
		if (!$has_drop_column && !$tableflds) {
			if ($this->debug) $this->outp("DropColumnSQL needs complete table-definiton for PostgreSQL < 7.3");
		return array();
	}
		if ($has_drop_column) {
			return ADODB_DataDict::DropColumnSQL($tabname, $flds);
		}
		return $this->_recreate_copy_table($tabname,$flds,$tableflds,$tableoptions);
	}

	function DropTableSQL($tabname)
	{
		$sql = ADODB_DataDict::DropTableSQL($tabname);
		$drop_seq = $this->_DropAutoIncrement($tabname);
		if ($drop_seq) $sql[] = $drop_seq;
		return $sql;
	}

	function _CreateSuffix($fname, &$ftype, $fnotnull,$fdefault,$fautoinc,$fconstraint)
	{
		if ($fautoinc) {
			$ftype = 'SERIAL';
			return '';
		}
		$suffix = '';
		if (strlen($fdefault)) $suffix .= " DEFAULT $fdefault";
		if ($fnotnull) $suffix .= ' NOT NULL';
		if ($fconstraint) $suffix .= ' '.$fconstraint;
		return $suffix;
	}

	function _DropAutoIncrement($tabname)
	{
		$tabname = $this->connection->qstr('%'.$tabname.'%');

		$seq = $this->connection->GetOne("SELECT relname FROM pg_class WHERE NOT relname ~ 'pg_.*' AND relname LIKE $tabname AND relkind='S'");

		// check if a tables depends on the sequenz and it therefor cant and dont need to be droped separatly
		if (!$seq || $this->connection->GetOne("SELECT relname FROM pg_class JOIN pg_depend ON pg_class.relfilenode=pg_depend.objid WHERE relname='$seq' AND relkind='S' AND deptype='i'")) {
			return False;
		}
		return "DROP SEQUENCE ".$seq;
	}

	function _IndexSQL($idxname, $tabname, $flds, $idxoptions)
	{
		$sql = array();
		if ( isset($idxoptions['REPLACE']) || isset($idxoptions['DROP']) ) {
			$sql[] = sprintf ($this->dropIndex, $idxname, $tabname);
			if ( isset($idxoptions['DROP']) )
				return $sql;
		}
		if ( empty ($flds) ) {
			return $sql;
		}

		$unique = isset($idxoptions['UNIQUE']) ? ' UNIQUE' : '';
		$s = 'CREATE' . $unique . ' INDEX ' . $idxname . ' ON ' . $tabname . ' ';
		if (isset($idxoptions['HASH']))
			$s .= 'USING HASH ';

		if ( isset($idxoptions[$this->upperName]) )
			$s .= $idxoptions[$this->upperName];

		if ( is_array($flds) )
			$flds = implode(', ',$flds);
		$s .= '(' . $flds . ')';
		$sql[] = $s;
		return $sql;
	}


	function _recreate_copy_table($tabname,$dropflds,$tableflds,$tableoptions='')
	{
		if ($dropflds && !is_array($dropflds)) $dropflds = explode(',',$dropflds);
		$copyflds = array();
		foreach($this->MetaColumns($tabname) as $fld) {
			if (!$dropflds || !in_array($fld->name,$dropflds)) {
				// we need to explicit convert varchar to a number to be able to do an AlterColumn of a char column to a nummeric one
				if (preg_match('/'.$fld->name.' (I|I2|I4|I8|N|F)/i',$tableflds,$matches) && 
					in_array($fld->type,array('varchar','char','text','bytea'))) {
					$copyflds[] = "to_number($fld->name,'S99D99')";
				} else {
					$copyflds[] = $fld->name;
				}
				// identify the sequence name and the fld its on
				if ($fld->primary_key && $fld->has_default && 
					preg_match("/nextval\('([^']+)'::text\)/",$fld->default_value,$matches)) {
					$seq_name = $matches[1];
					$seq_fld = $fld->name;
				}
			}
		}
		$copyflds = implode(', ',$copyflds);
		
		$tempname = $tabname.'_tmp';
		$aSql[] = 'BEGIN';		// we use a transaction, to make sure not to loose the content of the table
		$aSql[] = "SELECT * INTO TEMPORARY TABLE $tempname FROM $tabname";
		$aSql = array_merge($aSql,$this->DropTableSQL($tabname));
		$aSql = array_merge($aSql,$this->CreateTableSQL($tabname,$tableflds,$tableoptions));
		$aSql[] = "INSERT INTO $tabname SELECT $copyflds FROM $tempname";
		if ($seq_name && $seq_fld) {	// if we have a sequence we need to set it again
			$seq_name = $tabname.'_'.$seq_fld.'_seq';	// has to be the name of the new implicit sequence
			$aSql[] = "SELECT setval('$seq_name',MAX($seq_fld)) FROM $tabname";
		}
		$aSql[] = "DROP TABLE $tempname";
		// recreate the indexes, if they not contain one of the droped columns
		foreach($this->MetaIndexes($tabname) as $idx_name => $idx_data)
		{
			if (substr($idx_name,-5) != '_pkey' && (!$dropflds || !count(array_intersect($dropflds,$idx_data['columns'])))) {
				$aSql = array_merge($aSql,$this->CreateIndexSQL($idx_name,$tabname,$idx_data['columns'],
					$idx_data['unique'] ? array('UNIQUE') : False));
			}
		}
		$aSql[] = 'COMMIT';
		return $aSql;
	}
}

?>