<?php
/* $Id$ */
namespace Mammut\DB\Sql;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

use Mammut\DB\Sql\Elements\Table;

/**
 * Trait that adds the "FROM" context to queries
 *
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\DB\Sql
 */
trait Targetable {

	/**
	 * Defines the base of the query.
	 *
	 * Examples:
	 * - simple table:			from('tablename')
	 * - simple table w/alias:	from(['a' => 'tablename'])
	 * - schema table:			from('tablename','mysc');
	 * - database table:		from('tablename', NULL, 'mydb')
	 * - subselect:				from(['a' => $select])
	 *
	 * @param string|array|Table $table
	 *			The query base. Allowed values are tablenames, identifier names or
	 *			select objects. Use arg1,arg2,... to use database.schema.table namestyle (NULL = default).
	 *			Subselects and aliasing can be with an [alias=>object] array.
	 * @return $this
	 */
	public function from($table) {
		if(!(is_string($table) || is_array($table) || ($table instanceof Table) || ($table instanceof Select)))
			throw new \InvalidArgumentException('$table must be a string|array|Table|Select');

		$args = func_get_args();
		switch (count($args)) {
			case 1:
				if (is_string($table) || $table instanceof Table) {
					$this->setup[self::TABLE] = $table;
				}
				elseif(is_array($table)) {
					if (count($table) != 1)
						throw new \InvalidArgumentException('$table must be a array of size 1');
					$alias = key($table);
					$table = current($table);
					
					if (is_array($table)) {
						switch (count($table)) {
							case 1:
								$table = new Table($table[0]);
								break;
							case 2:
								$table = new Table($table[1], NULL, $table[0]);
								break;
							case 3:
								$table = new Table($table[2], $table[1], $table[0]);
								break;
							case 4:
								$table = new Table($table[3], $table[2], $v[1], $table[0]);
								break;
							default:
								throw new \OutOfBoundsException('table segment array too big');
						}
					}
					
					if (is_string($table) || $table instanceof Table  || $table instanceof Select) {
						if (is_numeric($alias))
							$this->setup[self::TABLE] = $table;
						else
							$this->setup[self::TABLE] = [$alias => $table];
					}
					else {
						var_dump($alias, $table);
						die();
					}	
				}
			break;
			case 2:
				$this->setup[self::TABLE] = new Table($args[1], NULL, $args[0]);
			break;
			case 3:
				$this->setup[self::TABLE] = new Table($args[2], $args[1], $args[0]);
			break;
			case 4:
				$this->setup[self::TABLE] = new Table($args[3], $args[2], $v[1], $args[0]);
			break;
			default:
				throw new \OutOfBoundsException('table segment array too big');
		}
		return $this;
	}

	/**
	 *
	 * @return Table
	 */
	public function getTarget() {
		return isset($this->setup[self::TABLE]) ? $this->setup[self::TABLE] : NULL;
	}
}