<?php
/* $Id$ */
namespace Mammut\DB\DB2;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

use Mammut\Exception\ImplementationException;
use Mammut\DB\Model\TableInfo;

/**
 * IBM DB2 table implementation
 *
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\DB\Adapter\DB2
 */
class Table extends \Mammut\DB\Table {
	private $info = NULL; // cache

	public function __construct(DB2 &$db, $name) {
		parent::__construct($db, $name);
	}

	public function getInfo() {
		if(is_object($this->info))
			return $this->info;
		$name = $this->getName();
		$info = new TableInfo($name);
		$param = array();
		$charset = NULL;
		$collate = NULL;
		
		$sql = "SELECT ci.table_catalog db_name, 
					ci.table_schema schema_name,
					ci.table_name table_name,
					ci.column_name column_name,
					CASE WHEN pt.typtype='e' THEN 'enum' ELSE ci.data_type END AS  data_type,
					ci.character_maximum_length size,
					ci.column_default default_value,
					ci.is_nullable nullable,
					pd.description description,
					pt.typname type_name,
					pt.oid type_oid
				FROM information_schema.columns ci
				LEFT JOIN pg_class pc
				  ON pc.relname = ci.table_name
				LEFT JOIN pg_attribute pa
				  ON pa.attname = ci.column_name AND pa.attrelid = pc.oid 
				LEFT JOIN pg_description  pd
				  ON pd.objoid = pc.oid AND pd.objsubid = pa.attnum
				LEFT JOIN pg_type pt
				  ON data_type='USER-DEFINED' AND pt.typname=ci.udt_name
				WHERE ci.table_catalog=current_database() AND  ci.table_schema='" . $this->db->getSchema() . "' AND ci.table_name='{$name}'";
		
		$result = $this->db->query($sql);
		
		while($row = $result->fetchArray()) {
			$name = $row['column_name'];
			$type = $row['data_type'];
			$size = -1;
			switch(strtolower($type)) {
				case 'boolean':
					$type = ColumnInfo::TYPE_BOOLEAN;
				break;
				case 'character':
					$type = ColumnInfo::TYPE_CHAR;
					$size = $row['size'];
				break;
				case 'character varying':
					$type = ColumnInfo::TYPE_VCHAR;
					$size = $row['size'];
				break;
				case 'smallint':
					if($row['description'] == 'tiny')
						$type = ColumnInfo::TYPE_TINY;
					else
						$type = ColumnInfo::TYPE_SHORT;
				break;
				case 'integer':
					$type = ColumnInfo::TYPE_INT;
				break;
				case 'bigint':
					$type = ColumnInfo::TYPE_LONG;
				break;
				case 'date':
					$type = ColumnInfo::TYPE_DATE;
				break;
				case 'timestamp without time zone':
					$type = ColumnInfo::TYPE_DATETIME;
				break;
				case 'bytea':
					$type = ColumnInfo::TYPE_BLOB;
				break;
				case 'enum':
					$type = ColumnInfo::TYPE_ENUM;
					$evalues = $this->db->getArrayList("SELECT enumlabel FROM pg_catalog.pg_enum WHERE enumtypid=" . $row['type_oid']);
					$values = array();
					foreach($evalues as $e)
						array_push($values, $e['enumlabel']);
					$param[] = 'values(' . implode(',', $values) . ')';
					unset($evalues, $e, $values);
				break;
			}
			$cinfo = new ColumnInfo($name, $type, $size, $param, $charset, $collate);
			$info->addColumn($cinfo);
		}
		$this->info = $info;
		return $info;
	}

	public function addColumn(ColumnInfo $info, $after = NULL) {
		$colSQL = DB2Util::fieldDefSQL($this->db, $info);
		$sql = "ALTER TABLE " . $this->db->escapeTableName($this->getName()) . " ADD COLUMN " . $colSQL;
		if(is_int($after)) {
			if($after < 0)
				$sql .= ' FIRST';
			else {
				$tinfo = $this->getInfo();
				$colName = $tinfo->getColumn($after)->getName();
				$sql .= ' AFTER ' . $this->db->escapeColumnName($colName);
				unset($colName, $tinfo);
			}
		}
		$this->info = NULL;
		$this->db->query($sql);
	}

	public function alterColumn($column, ColumnInfo $newInfo) {
	}
	
	public function isIndexDefined($name) {
		throw new ImplementationException('not implemented');
	}
}