<?php 
/* $Id$ */
namespace Mammut\DB\Model;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

use Mammut\DB\Sql\Expression\iExpression;

/**
 * View information class.
 * 
 * This class contains information about a specific view. You can use it to create a new
 * view, or you receive a instance via the getInfo() method of a View object.
 * 
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\DB\Model
 */
class ViewInfo extends \Mammut\StrictObject implements XMLModel {
	
	/**
	 * @var string
	 */
	private $name = "";
	private $base = false;
	
	/**
	 * @var array
	 */
	private $columns = array();
	private $joins = array();

	public function __construct($name) {
		$this->name = $name;
	}

	public function getName() {
		return $this->name;
	}

	public function setName($name) {
		$this->name = $name;
	}

	public function getBase() {
		return $this->base;
	}

	public function setBase($name) {
		$this->base = $name;
	}

	public function getColumnCount() {
		return count($this->columns);
	}

	public function addColumn($base, $name, $alias = false) {
		if($alias === false)
			$alias = $name;
		
		foreach($this->columns as $cname=>$values) {
			if($cname == $alias)
				throw new \InvalidArgumentException("dublicate column name: " . $alias);
		}
		$this->columns[$alias] = array('type' => 'default', 'base' => $base,'basecolumn' => $name);
	}
	
	/**
	 * Defines a calculated column based on a expression
	 * @param iExpression $expression
	 * @param string $name
	 * @throws \InvalidArgumentException
	 */
	public function addVirtualColumn(iExpression $expression, $name) {
		if(empty($name))
			throw new \InvalidArgumentException("missing column name");
		
		foreach($this->columns as $cname=>$values) {
			if($cname == $name)
				throw new \InvalidArgumentException("dublicate column name: " . $name);
		}
		$this->columns[$alias] = array('type' => 'virtual', 'expression' => $expression);
	}
	
	/**
	 * Defines a column which has a fixed value
	 * @param mixed $value the column name
	 * @param string $name the column name
	 * @throws \InvalidArgumentException
	 */
	public function addFixColumn($value, $name) {
		if(empty($name))
			throw new \InvalidArgumentException("missing column name");
		
		foreach($this->columns as $cname=>$values) {
			if($cname == $name)
				throw new \InvalidArgumentException("dublicate column name: " . $name);
		}
		$this->columns[$alias] = array('type' => 'fix', 'value' => $value);
	}
	
	/**
	 * returns the info object of a specific column
	 *
	 * @param mixed $col
	 *        	the column name or index
	 * @return ColumnInfo
	 */
	public function getColumnInfo($col) {
		// echo "seaching colinfo for $col\n";
		if(is_int($col)) {
			$keys = array_keys($this->columns);
			$col = $keys[$col];
			// echo "seaching colinfo for $col\n";
		}
		if(empty($this->columns[$col]))
			throw new \InvalidArgumentException("invalid column index");
		return $this->columns[$col];
	}

	/**
	 * searches the number of a given column name
	 * 
	 * @param $name string
	 *        	the name of the column
	 * @return int the column number or -1 if none was found with the name given
	 */
	public function getColumnNum($name) {
		$c = count($this->columns);
		for($i = 0; $i < $c; $i++) {
			if($this->columns[$i]->getName() == $name)
				return $i;
		}
		return -1;
	}

	public function delColumn($id) {
		if(is_int($id)) {
			$new = array();
			
			for($i = 0; $i < $id; $i++) {
				$new[] = $this->columns[$i];
			}
			for($i = $id + 1; $i < count($this->columns); $i++) {
				$new[] = $this->columns[$i];
			}
			unset($this->columns);
			$this->columns = $new;
		}
		else {
			$i = 0;
			while(isset($this->columns[$i]) && ($this->columns[$i]->getName() != $id))
				$i++;
			
			if(isset($this->columns[$i]))
				$this->delColumn((int) $i);
		}
	}

	public function addJoinCondition($base, $type, $conds) {
		$this->joins[$base] = array('type' => $type,'cond' => $conds);
	}

	public function getJoinObjects() {
		return array_keys($this->joins);
	}

	public function getJoinInfo($name) {
		return $this->joins[$name];
	}

	public function compareTo(ViewInfo $otherInfo) {
		$colMismatch = array();
		$toremove = array();
		$missing = array();
		for($i = 0; $i < $this->getColumnCount(); $i++) {
			$c1 = $this->getColumnInfo($i);
			$found = false;
			for($j = 0; $j < $otherInfo->getColumnCount(); $j++) {
				$c2 = $otherInfo->getColumnInfo($j);
				if($c1->getName() == $c2->getName()) {
					$mismatch = array();
					if($c1->getType() != $c2->getType()) {
						$equal = false;
						$mismatch['type'] = array(
								'this' => $c1->getType(),'other' => $c2->getType());
					}
					elseif($c1->getType() == ColumnInfo::TYPE_ENUM) {
						foreach($c1->getParam() as $e) {
							if(preg_match('#values\(([a-zA-Z0-9_,]*)\)#', $e, $match)) {
								$values1 = explode(',', $match[1]);
								break;
							}
						}
						foreach($c2->getParam() as $e) {
							if(preg_match('#values\(([a-zA-Z0-9_,]*)\)#', $e, $match)) {
								$values2 = explode(',', $match[1]);
								break;
							}
						}
						if(count(array_diff($values1, $values2)) != 0) {
							$equal = false;
							$mismatch['enum'] = array('this' => $values1,'other' => $values2);
						}
					}
					if($c1->getSize() != $c2->getSize() && ($c1->getType() == ColumnInfo::TYPE_CHAR || $c1->getType() == ColumnInfo::TYPE_VCHAR || $c1->getType() == ColumnInfo::TYPE_BINARY)) {
						$equal = false;
						$mismatch['size'] = array(
								'this' => $c1->getSize(),'other' => $c2->getSize());
					}
					$found = true;
					if(count($mismatch) > 0)
						$colMismatch[$c1->getName()] = $mismatch;
				}
			}
			if(!$found) {
				array_push($missing, $c1->getName());
				$equal = false;
			}
		}
		for($i = 0; $i < $otherInfo->getColumnCount(); $i++) {
			$c1 = $otherInfo->getColumnInfo($i);
			$found = false;
			for($j = 0; $j < $this->getColumnCount(); $j++) {
				$c2 = $this->getColumnInfo($j);
				if($c1->getName() == $c2->getName())
					$found = true;
			}
			if(!$found) {
				array_push($toremove, $c1->getName());
				$equal = false;
			}
		}
		$result = new \stdClass();
		if(count($missing) > 0)
			$result->missingColumns = $missing;
		if(count($colMismatch) > 0)
			$result->differentColumns = $colMismatch;
		if(count($toremove) > 0)
			$result->additionalColumns = $toremove;
		return $result;
	}

	public static function fromXML($data) {
		if($data instanceof \SimpleXMLElement)
			$xml = $data;
		else
			$xml = simplexml_load_string((string) $data);
		$result = new ViewInfo((string) $xml['name']);
		
		$result->setBase((string) $xml['base']);
		// add base columns		
		foreach($xml->vcolumn as $c) {
			$result->addColumn($result->getBase(), (string) $c['column'], (string) $c['alias']);
		}
		// add additional columns
		foreach($xml->join as $j) {
			$type = (string) $j['type'];
			$base = (string) $j['base'];
			foreach($j->vcolumn as $c) {
				$result->addColumn($base, (string) $c['column'], (string) $c['alias']);
			}
		}
		foreach($xml->join as $j) {
			$type = (string) $j['type'];
			$base = (string) $j['base'];
			$conds = array();
			foreach($j->condition as $c) {
				$con = (string) $c;
				if(preg_match('#^([a-zA-Z0-9_-]+(.[a-zA-Z0-9_-]+))?([<>=!]{1,3})([a-zA-Z0-9_-]+(.[a-zA-Z0-9_-]+))?$#', $con, $match)) {
					$conds[] = array(
							'left' => $match[1],'operator' => $match[3],'right' => $match[4]);
				}
				else
					throw new \Exception("unparsable condition: {$con}");
			}
			$result->addJoinCondition($base, $type, $conds);
		}
		return $result;
	}

	public function toXML() {
		$xml = '<view';
		$xml .= ' name="' . $this->name . '"';
		$xml .= ' transaction="' . ($this->transactionSave ? 'true' : 'false') . '"';
		$xml .= '>';
		$xml .= '<primary>' . implode(',', $this->primary) . '</primary>';
		
		foreach($this->indexes as $name=>$fields)
			$xml .= '<index name="' . $name . '">' . implode(',', $fields) . '</index>';
		
		foreach($this->columns as $c)
			$xml .= $c->toXML();
		
		$xml .= '</view>';
		return $xml;
	}
}