<?php

/**
* Media
*
* @package Less
* @subpackage tree
*/
class Less_Tree_Media extends Less_Tree{

public $features;
public $rules;
public $index;
public $currentFileInfo;
public $isReferenced;
public $type = 'Media';

public function __construct($value = array(), $features = array(), $index = null, $currentFileInfo = null ){

$this->index = $index;
$this->currentFileInfo = $currentFileInfo;

$selectors = $this->emptySelectors();

$this->features = new Less_Tree_Value($features);

$this->rules = array(new Less_Tree_Ruleset($selectors, $value));
$this->rules[0]->allowImports = true;
}

public function accept( $visitor ){
$this->features = $visitor->visitObj($this->features);
$this->rules = $visitor->visitArray($this->rules);
}

/**
* @see Less_Tree::genCSS
*/
public function genCSS( $output ){

$output->add( '@media ', $this->currentFileInfo, $this->index );
$this->features->genCSS( $output );
Less_Tree::outputRuleset( $output, $this->rules);

}

public function compile($env) {

$media = new Less_Tree_Media(array(), array(), $this->index, $this->currentFileInfo );

$strictMathBypass = false;
if( Less_Parser::$options['strictMath'] === false) {
$strictMathBypass = true;
Less_Parser::$options['strictMath'] = true;
}

$media->features = $this->features->compile($env);

if( $strictMathBypass ){
Less_Parser::$options['strictMath'] = false;
}

$env->mediaPath[] = $media;
$env->mediaBlocks[] = $media;

array_unshift($env->frames, $this->rules[0]);
$media->rules = array($this->rules[0]->compile($env));
array_shift($env->frames);

array_pop($env->mediaPath);

return !$env->mediaPath ? $media->compileTop($env) : $media->compileNested($env);
}

public function variable($name) {
return $this->rules[0]->variable($name);
}

public function find($selector) {
return $this->rules[0]->find($selector, $this);
}

public function emptySelectors(){
$el = new Less_Tree_Element('','&', $this->index, $this->currentFileInfo );
$sels = array( new Less_Tree_Selector(array($el), array(), null, $this->index, $this->currentFileInfo) );
$sels[0]->mediaEmpty = true;
return $sels;
}

public function markReferenced(){
$this->rules[0]->markReferenced();
$this->isReferenced = true;
Less_Tree::ReferencedArray($this->rules[0]->rules);
}

// evaltop
public function compileTop($env) {
$result = $this;

if (count($env->mediaBlocks) > 1) {
$selectors = $this->emptySelectors();
$result = new Less_Tree_Ruleset($selectors, $env->mediaBlocks);
$result->multiMedia = true;
}

$env->mediaBlocks = array();
$env->mediaPath = array();

return $result;
}

public function compileNested($env) {
$path = array_merge($env->mediaPath, array($this));

// Extract the media-query conditions separated with `,` (OR).
foreach ($path as $key => $p) {
$value = $p->features instanceof Less_Tree_Value ? $p->features->value : $p->features;
$path[$key] = is_array($value) ? $value : array($value);
}

// Trace all permutations to generate the resulting media-query.
//
// (a, b and c) with nested (d, e) ->
// a and d
// a and e
// b and c and d
// b and c and e

$permuted = $this->permute($path);
$expressions = array();
foreach($permuted as $path){

for( $i=0, $len=count($path); $i < $len; $i++){
$path[$i] = Less_Parser::is_method($path[$i], 'toCSS') ? $path[$i] : new Less_Tree_Anonymous($path[$i]);
}

for( $i = count($path) - 1; $i > 0; $i-- ){
array_splice($path, $i, 0, array(new Less_Tree_Anonymous('and')));
}

$expressions[] = new Less_Tree_Expression($path);
}
$this->features = new Less_Tree_Value($expressions);



// Fake a tree-node that doesn't output anything.
return new Less_Tree_Ruleset(array(), array());
}

public function permute($arr) {
if (!$arr)
return array();

if (count($arr) == 1)
return $arr[0];

$result = array();
$rest = $this->permute(array_slice($arr, 1));
foreach ($rest as $r) {
foreach ($arr[0] as $a) {
$result[] = array_merge(
is_array($a) ? $a : array($a),
is_array($r) ? $r : array($r)
);
}
}

return $result;
}

public function bubbleSelectors($selectors) {

if( !$selectors) return;

$this->rules = array(new Less_Tree_Ruleset( $selectors, array($this->rules[0])));
}

}