<?php


class Less_Tree_Mixin_Call extends Less_Tree{

	public $selector;
	public $arguments;
	public $index;
	public $currentFileInfo;

	public $important;
	public $type = 'MixinCall';

	/**
	 * less.js: tree.mixin.Call
	 *
	 */
	public function __construct($elements, $args, $index, $currentFileInfo, $important = false){
		$this->selector = new Less_Tree_Selector($elements);
		$this->arguments = $args;
		$this->index = $index;
		$this->currentFileInfo = $currentFileInfo;
		$this->important = $important;
	}

	//function accept($visitor){
	//	$this->selector = $visitor->visit($this->selector);
	//	$this->arguments = $visitor->visit($this->arguments);
	//}


	public function compile($env){

		$rules = array();
		$match = false;
		$isOneFound = false;
		$candidates = array();
		$defaultUsed = false;
		$conditionResult = array();

		$args = array();
		foreach($this->arguments as $a){
			$args[] = array('name'=> $a['name'], 'value' => $a['value']->compile($env) );
		}

		foreach($env->frames as $frame){

			$mixins = $frame->find($this->selector);

			if( !$mixins ){
				continue;
			}

			$isOneFound = true;
			$defNone = 0;
			$defTrue = 1;
			$defFalse = 2;

			// To make `default()` function independent of definition order we have two "subpasses" here.
			// At first we evaluate each guard *twice* (with `default() == true` and `default() == false`),
			// and build candidate list with corresponding flags. Then, when we know all possible matches,
			// we make a final decision.

			$mixins_len = count($mixins);
			for( $m = 0; $m < $mixins_len; $m++ ){
				$mixin = $mixins[$m];

				if( $this->IsRecursive( $env, $mixin ) ){
					continue;
				}

				if( $mixin->matchArgs($args, $env) ){

					$candidate = array('mixin' => $mixin, 'group' => $defNone);

					if( $mixin instanceof Less_Tree_Ruleset ){

						for( $f = 0; $f < 2; $f++ ){
							Less_Tree_DefaultFunc::value($f);
							$conditionResult[$f] = $mixin->matchCondition( $args, $env);
						}
						if( $conditionResult[0] || $conditionResult[1] ){
							if( $conditionResult[0] != $conditionResult[1] ){
								$candidate['group'] = $conditionResult[1] ? $defTrue : $defFalse;
							}

							$candidates[] = $candidate;
						}
					}else{
						$candidates[] = $candidate;
					}

					$match = true;
				}
			}

			Less_Tree_DefaultFunc::reset();


			$count = array(0, 0, 0);
			for( $m = 0; $m < count($candidates); $m++ ){
				$count[ $candidates[$m]['group'] ]++;
			}

			if( $count[$defNone] > 0 ){
				$defaultResult = $defFalse;
			} else {
				$defaultResult = $defTrue;
				if( ($count[$defTrue] + $count[$defFalse]) > 1 ){
					throw new Exception( 'Ambiguous use of `default()` found when matching for `'. $this->format($args) + '`' );
				}
			}


			$candidates_length = count($candidates);
			$length_1 = ($candidates_length == 1);

			for( $m = 0; $m < $candidates_length; $m++){
				$candidate = $candidates[$m]['group'];
				if( ($candidate === $defNone) || ($candidate === $defaultResult) ){
					try{
						$mixin = $candidates[$m]['mixin'];
						if( !($mixin instanceof Less_Tree_Mixin_Definition) ){
							$mixin = new Less_Tree_Mixin_Definition('', array(), $mixin->rules, null, false);
							$mixin->originalRuleset = $mixins[$m]->originalRuleset;
						}
						$rules = array_merge($rules, $mixin->evalCall($env, $args, $this->important)->rules);
					} catch (Exception $e) {
						//throw new Less_Exception_Compiler($e->getMessage(), $e->index, null, $this->currentFileInfo['filename']);
						throw new Less_Exception_Compiler($e->getMessage(), null, null, $this->currentFileInfo);
					}
				}
			}

			if( $match ){
				if( !$this->currentFileInfo || !isset($this->currentFileInfo['reference']) || !$this->currentFileInfo['reference'] ){
					Less_Tree::ReferencedArray($rules);
				}

				return $rules;
			}
		}

		if( $isOneFound ){
			throw new Less_Exception_Compiler('No matching definition was found for `'.$this->Format( $args ).'`', null, $this->index, $this->currentFileInfo);

		}else{
			throw new Less_Exception_Compiler(trim($this->selector->toCSS()) . " is undefined in ".$this->currentFileInfo['filename'], null, $this->index);
		}

	}

	/**
	 * Format the args for use in exception messages
	 *
	 */
	private function Format($args){
		$message = array();
		if( $args ){
			foreach($args as $a){
				$argValue = '';
				if( $a['name'] ){
					$argValue += $a['name']+':';
				}
				if( is_object($a['value']) ){
					$argValue += $a['value']->toCSS();
				}else{
					$argValue += '???';
				}
				$message[] = $argValue;
			}
		}
		return implode(', ',$message);
	}


	/**
	 * Are we in a recursive mixin call?
	 *
	 * @return bool
	 */
	private function IsRecursive( $env, $mixin ){

		foreach($env->frames as $recur_frame){
			if( !($mixin instanceof Less_Tree_Mixin_Definition) ){

				if( $mixin === $recur_frame ){
					return true;
				}

				if( isset($recur_frame->originalRuleset) && $mixin->ruleset_id === $recur_frame->originalRuleset ){
					return true;
				}
			}
		}

		return false;
	}

}