<?php
/**
 * CDbCriteria class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2010 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CDbCriteria represents a query criteria, such as conditions, ordering by, limit/offset.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CDbCriteria.php 2413 2010-09-02 02:19:56Z qiang.xue $
 * @package system.db.schema
 * @since 1.0
 */
class CDbCriteria extends CComponent
{
	const PARAM_PREFIX=':ycp';
	/**
	 * @var integer the global counter for anonymous binding parameters.
	 * This counter is used for generating the name for the anonymous parameters.
	 */
	public static $paramCount=0;
	/**
	 * @var mixed the columns being selected. This refers to the SELECT clause in an SQL
	 * statement. The property can be either a string (column names separated by commas)
	 * or an array of column names. Defaults to '*', meaning all columns.
	 */
	public $select='*';
	/**
	 * @var boolean whether to select distinct rows of data only. If this is set true,
	 * the SELECT clause would be changed to SELECT DISTINCT.
	 * @since 1.0.9
	 */
	public $distinct=false;
	/**
	 * @var string query condition. This refers to the WHERE clause in an SQL statement.
	 * For example, <code>age>31 AND team=1</code>.
	 */
	public $condition='';
	/**
	 * @var array list of query parameter values indexed by parameter placeholders.
	 * For example, <code>array(':name'=>'Dan', ':age'=>31)</code>.
	 */
	public $params=array();
	/**
	 * @var integer maximum number of records to be returned. If less than 0, it means no limit.
	 */
	public $limit=-1;
	/**
	 * @var integer zero-based offset from where the records are to be returned. If less than 0, it means starting from the beginning.
	 */
	public $offset=-1;
	/**
	 * @var string how to sort the query results. This refers to the ORDER BY clause in an SQL statement.
	 */
	public $order='';
	/**
	 * @var string how to group the query results. This refers to the GROUP BY clause in an SQL statement.
	 * For example, <code>'projectID, teamID'</code>.
	 */
	public $group='';
	/**
	 * @var string how to join with other tables. This refers to the JOIN clause in an SQL statement.
	 * For example, <code>'LEFT JOIN users ON users.id=authorID'</code>.
	 */
	public $join='';
	/**
	 * @var string the condition to be applied with GROUP-BY clause.
	 * For example, <code>'SUM(revenue)<50000'</code>.
	 * @since 1.0.1
	 */
	public $having='';
	/**
	 * @var array the relational query criteria. This is used for fetching related objects in eager loading fashion.
	 * This property is effective only when the criteria is passed as a parameter to the following methods of CActiveRecord:
	 * <ul>
	 * <li>{@link CActiveRecord::find()}</li>
	 * <li>{@link CActiveRecord::findAll()}</li>
	 * <li>{@link CActiveRecord::findByPk()}</li>
	 * <li>{@link CActiveRecord::findAllByPk()}</li>
	 * <li>{@link CActiveRecord::findByAttributes()}</li>
	 * <li>{@link CActiveRecord::findAllByAttributes()}</li>
	 * <li>{@link CActiveRecord::count()}</li>
	 * </ul>
	 * The property value will be used as the parameter to the {@link CActiveRecord::with()} method
	 * to perform the eager loading. Please refer to {@link CActiveRecord::with()} on how to specify this parameter.
	 * @since 1.1.0
	 */
	public $with;
	/**
	 * @var string the alias name of the table. If not set, it means the alias is 't'.
	 */
	public $alias;
	/**
	 * @var boolean whether the foreign tables should be joined with the primary table in a single SQL.
	 * This property is only used in relational AR queries.
	 *
	 * When this property is set true, only a single SQL will be executed for a relational AR query,
	 * even if the primary table is limited and the relationship between a foreign table and the primary
	 * table is many-to-one.
	 *
	 * When this property is set false, a SQL statement will be executed for each HAS_MANY relation.
	 *
	 * When this property is not set, if the primary table is limited, a SQL statement will be executed for each HAS_MANY relation.
	 * Otherwise, a single SQL statement will be executed for all.
	 *
	 * @since 1.1.4
	 */
	public $together;

	/**
	 * Constructor.
	 * @param array criteria initial property values (indexed by property name)
	 */
	public function __construct($data=array())
	{
		foreach($data as $name=>$value)
			$this->$name=$value;
	}

	/**
	 * Appends a condition to the existing {@link condition}.
	 * The new condition and the existing condition will be concatenated via the specified operator
	 * which defaults to 'AND'.
	 * The new condition can also be an array. In this case, all elements in the array
	 * will be concatenated together via the operator.
	 * This method handles the case when the existing condition is empty.
	 * After calling this method, the {@link condition} property will be modified.
	 * @param mixed the new condition. It can be either a string or an array of strings.
	 * @param string the operator to join different conditions. Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.0.9
	 */
	public function addCondition($condition,$operator='AND')
	{
		if(is_array($condition))
		{
			if($condition===array())
				return $this;
			$condition='('.implode(') '.$operator.' (',$condition).')';
		}
		if($this->condition==='')
			$this->condition=$condition;
		else
			$this->condition='('.$this->condition.') '.$operator.' ('.$condition.')';
		return $this;
	}

	/**
	 * Appends a search condition to the existing {@link condition}.
	 * The search condition and the existing condition will be concatenated via the specified operator
	 * which defaults to 'AND'.
	 * The search condition is generated using the SQL LIKE operator with the given column name and
	 * search keyword.
	 * @param string the column name (or a valid SQL expression)
	 * @param string the search keyword. This interpretation of the keyword is affected by the next parameter.
	 * @param boolean whether the keyword should be escaped if it contains characters % or _.
	 * When this parameter is true (default), the special characters % (matches 0 or more characters)
	 * and _ (matches a single character) will be escaped, and the keyword will be surrounded with a %
	 * character on both ends. When this parameter is false, the keyword will be directly used for
	 * matching without any change.
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @param string the LIKE operator. Defaults to 'LIKE'. You may also set this to be 'NOT LIKE'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.0.10
	 */
	public function addSearchCondition($column,$keyword,$escape=true,$operator='AND',$like='LIKE')
	{
		if($escape)
			$keyword='%'.strtr($keyword,array('%'=>'\%', '_'=>'\_', '\\'=>'\\\\')).'%';
		$condition=$column." $like ".self::PARAM_PREFIX.self::$paramCount;
		$this->params[self::PARAM_PREFIX.self::$paramCount++]=$keyword;
		return $this->addCondition($condition, $operator);
	}

	/**
	 * Appends an IN condition to the existing {@link condition}.
	 * The IN condition and the existing condition will be concatenated via the specified operator
	 * which defaults to 'AND'.
	 * The IN condition is generated by using the SQL IN operator which requires the specified
	 * column value to be among the given list of values.
	 * @param string the column name (or a valid SQL expression)
	 * @param array list of values that the column value should be in
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.0.10
	 */
	public function addInCondition($column,$values,$operator='AND')
	{
		if(($n=count($values))<1)
			return $this->addCondition('0=1',$operator); // 0=1 is used because in MSSQL value alone can't be used in WHERE
		if($n===1)
		{
			$value=reset($values);
			if($value===null)
				return $this->addCondition($column.' IS NULL');
			$condition=$column.'='.self::PARAM_PREFIX.self::$paramCount;
			$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;
		}
		else
		{
			$params=array();
			foreach($values as $value)
			{
				$params[]=self::PARAM_PREFIX.self::$paramCount;
				$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;
			}
			$condition=$column.' IN ('.implode(', ',$params).')';
		}
		return $this->addCondition($condition,$operator);
	}

	/**
	 * Appends an NOT IN condition to the existing {@link condition}.
	 * The NOT IN condition and the existing condition will be concatenated via the specified operator
	 * which defaults to 'AND'.
	 * The NOT IN condition is generated by using the SQL NOT IN operator which requires the specified
	 * column value to be among the given list of values.
	 * @param string the column name (or a valid SQL expression)
	 * @param array list of values that the column value should be in
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.1.1
	 */
	public function addNotInCondition($column,$values,$operator='AND')
	{
		if(($n=count($values))<1)
			return $this;
		if($n===1)
		{
			$value=reset($values);
			if($value===null)
				return $this->addCondition($column.' IS NOT NULL');
			$condition=$column.'!='.self::PARAM_PREFIX.self::$paramCount;
			$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;
		}
		else
		{
			$params=array();
			foreach($values as $value)
			{
				$params[]=self::PARAM_PREFIX.self::$paramCount;
				$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;
			}
			$condition=$column.' NOT IN ('.implode(', ',$params).')';
		}
		return $this->addCondition($condition,$operator);
	}

	/**
	 * Appends a condition for matching the given list of column values.
	 * The generated condition will be concatenated to the existing {@link condition}
	 * via the specified operator which defaults to 'AND'.
	 * The condition is generated by matching each column and the corresponding value.
	 * @param array list of column names and values to be matched (name=>value)
	 * @param string the operator to concatenate multiple column matching condition. Defaults to 'AND'.
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.0.10
	 */
	public function addColumnCondition($columns,$columnOperator='AND',$operator='AND')
	{
		$params=array();
		foreach($columns as $name=>$value)
		{
			if($value===null)
				$params[]=$name.' IS NULL';
			else
			{
				$params[]=$name.'='.self::PARAM_PREFIX.self::$paramCount;
				$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;
			}
		}
		return $this->addCondition(implode(" $columnOperator ",$params), $operator);
	}

	/**
	 * Adds a comparison expression to the {@link condition} property.
	 *
	 * This method is a helper that appends to the {@link condition} property
	 * with a new comparison expression. The comparison is done by comparing a column
	 * with the given value using some comparison operator.
	 *
	 * The comparison operator is intelligently determined based on the first few
	 * characters in the given value. In particular, it recognizes the following operators
	 * if they appear as the leading characters in the given value:
	 * <ul>
	 * <li><code>&lt;</code>: the column must be less than the given value.</li>
	 * <li><code>&gt;</code>: the column must be greater than the given value.</li>
	 * <li><code>&lt;=</code>: the column must be less than or equal to the given value.</li>
	 * <li><code>&gt;=</code>: the column must be greater than or equal to the given value.</li>
	 * <li><code>&lt;&gt;</code>: the column must not be the same as the given value.
	 * Note that when $partialMatch is true, this would mean the value must not be a substring
	 * of the column.</li>
	 * <li><code>=</code>: the column must be equal to the given value.</li>
	 * <li>none of the above: the column must be equal to the given value. Note that when $partialMatch
	 * is true, this would mean the value must be the same as the given value or be a substring of it.</li>
	 * </ul>
	 *
	 * Note that any surrounding white spaces will be removed from the value before comparison.
	 * When the value is empty, no comparison expression will be added to the search condition.
	 *
	 * @param string the name of the column to be searched
	 * @param mixed the column value to be compared with. If the value is a string, the aforementioned
	 * intelligent comparison will be conducted. If the value is an array, the comparison is done
	 * by exact match of any of the value in the array. If the string or the array is empty,
	 * the existing search condition will not be modified.
	 * @param boolean whether the value should consider partial text match (using LIKE and NOT LIKE operators).
	 * Defaults to false, meaning exact comparison.
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.1.1
	 */
	public function compare($column, $value, $partialMatch=false, $operator='AND')
	{
		if(is_array($value))
		{
			if($value===array())
				return $this;
			return $this->addInCondition($column,$value,$operator);
		}
		else
			$value="$value";

		if(preg_match('/^(?:\s*(<>|<=|>=|<|>|=))?(.*)$/',$value,$matches))
		{
			$value=$matches[2];
			$op=$matches[1];
		}
		else
			$op='';

		if($value==='')
			return $this;

		if($partialMatch)
		{
			if($op==='')
				return $this->addSearchCondition($column,$value,true,$operator);
			if($op==='<>')
				return $this->addSearchCondition($column,$value,true,$operator,'NOT LIKE');
		}
		else if($op==='')
			$op='=';

		$this->addCondition($column.$op.self::PARAM_PREFIX.self::$paramCount,$operator);
		$this->params[self::PARAM_PREFIX.self::$paramCount++]=$value;

		return $this;
	}

	/**
	 * Adds a between condition to the {@link condition} property.
	 *
	 * The new between condition and the existing condition will be concatenated via
	 * the specified operator which defaults to 'AND'.
	 * If one or both values are empty then the condition is not added to the existing condition.
	 * This method handles the case when the existing condition is empty.
	 * After calling this method, the {@link condition} property will be modified.
	 * @param string the name of the column to search between.
	 * @param string the beginning value to start the between search.
	 * @param string the ending value to end the between search.
	 * @param string the operator used to concatenate the new condition with the existing one.
	 * Defaults to 'AND'.
	 * @return CDbCriteria the criteria object itself
	 * @since 1.1.2
	 */
	public function addBetweenCondition($column,$valueStart,$valueEnd,$operator='AND')
	{
		if($valueStart==='' || $valueEnd==='')
			return $this;

		$paramStart=self::PARAM_PREFIX.self::$paramCount++;
		$paramEnd=self::PARAM_PREFIX.self::$paramCount++;
		$this->params[$paramStart]=$valueStart;
		$this->params[$paramEnd]=$valueEnd;
		$condition="$column BETWEEN $paramStart AND $paramEnd";

		if($this->condition==='')
			$this->condition=$condition;
		else
			$this->condition='('.$this->condition.') '.$operator.' ('.$condition.')';
		return $this;
	}

	/**
	 * Merges with another criteria.
	 * In general, the merging makes the resulting criteria more restrictive.
	 * For example, if both criterias have conditions, they will be 'AND' together.
	 * Also, the criteria passed as the parameter takes precedence in case
	 * two options cannot be merged (e.g. LIMIT, OFFSET).
	 * @param CDbCriteria the criteria to be merged with.
	 * @param boolean whether to use 'AND' to merge condition and having options.
	 * If false, 'OR' will be used instead. Defaults to 'AND'. This parameter has been
	 * available since version 1.0.6.
	 * @since 1.0.5
	 */
	public function mergeWith($criteria,$useAnd=true)
	{
		$and=$useAnd ? 'AND' : 'OR';
		if(is_array($criteria))
			$criteria=new self($criteria);
		if($this->select!==$criteria->select)
		{
			if($this->select==='*')
				$this->select=$criteria->select;
			else if($criteria->select!=='*')
			{
				$select1=is_string($this->select)?preg_split('/\s*,\s*/',trim($this->select),-1,PREG_SPLIT_NO_EMPTY):$this->select;
				$select2=is_string($criteria->select)?preg_split('/\s*,\s*/',trim($criteria->select),-1,PREG_SPLIT_NO_EMPTY):$criteria->select;
				$this->select=array_merge($select1,array_diff($select2,$select1));
			}
		}

		if($this->condition!==$criteria->condition)
		{
			if($this->condition==='')
				$this->condition=$criteria->condition;
			else if($criteria->condition!=='')
				$this->condition="({$this->condition}) $and ({$criteria->condition})";
		}

		if($this->params!==$criteria->params)
			$this->params=array_merge($this->params,$criteria->params);

		if($criteria->limit>0)
			$this->limit=$criteria->limit;

		if($criteria->offset>=0)
			$this->offset=$criteria->offset;

		if($criteria->alias!==null)
			$this->alias=$criteria->alias;

		if($this->order!==$criteria->order)
		{
			if($this->order==='')
				$this->order=$criteria->order;
			else if($criteria->order!=='')
				$this->order=$criteria->order.', '.$this->order;
		}

		if($this->group!==$criteria->group)
		{
			if($this->group==='')
				$this->group=$criteria->group;
			else if($criteria->group!=='')
				$this->group.=', '.$criteria->group;
		}

		if($this->join!==$criteria->join)
		{
			if($this->join==='')
				$this->join=$criteria->join;
			else if($criteria->join!=='')
				$this->join.=' '.$criteria->join;
		}

		if($this->having!==$criteria->having)
		{
			if($this->having==='')
				$this->having=$criteria->having;
			else if($criteria->having!=='')
				$this->having="({$this->having}) $and ({$criteria->having})";
		}

		if($criteria->distinct>0)
			$this->distinct=$criteria->distinct;

		if($criteria->together!==null)
			$this->together=$criteria->together;

		if(empty($this->with))
			$this->with=$criteria->with;
		else if(!empty($criteria->with))
			$this->with=CMap::mergeArray($this->with, $criteria->with);
	}

	/**
	 * @return array the array representation of the criteria
	 * @since 1.0.6
	 */
	public function toArray()
	{
		$result=array();
		foreach(array('select', 'condition', 'params', 'limit', 'offset', 'order', 'group', 'join', 'having', 'distinct', 'with', 'alias', 'together') as $name)
			$result[$name]=$this->$name;
		return $result;
	}
}
