<?php
/**
 * This file provides the part of lessphp API (https://github.com/leafo/lessphp)
 * to be a drop-in replacement for following products:
 *  - Drupal 7, by the less module v3.0+ (https://drupal.org/project/less)
 *  - Symfony 2
 */

// Register autoloader for non-composer installations
if ( !class_exists( 'Less_Parser' ) ) {
	require_once __DIR__ . '/lib/Less/Autoloader.php';
	Less_Autoloader::register();
}

class lessc {

	public static $VERSION = Less_Version::less_version;

	public $importDir = '';
	protected $allParsedFiles = [];
	protected $libFunctions = [];
	protected $registeredVars = [];
	private $formatterName;
	private $options = [];

	public function __construct( $lessc = null, $sourceName = null ) {
	}

	public function setImportDir( $dirs ) {
		$this->importDir = (array)$dirs;
	}

	public function addImportDir( $dir ) {
		$this->importDir = (array)$this->importDir;
		$this->importDir[] = $dir;
	}

	public function setFormatter( $name ) {
		$this->formatterName = $name;
	}

	public function setPreserveComments( $preserve ) {
	}

	public function registerFunction( $name, $func ) {
		$this->libFunctions[$name] = $func;
	}

	public function unregisterFunction( $name ) {
		unset( $this->libFunctions[$name] );
	}

	public function setVariables( $variables ) {
		foreach ( $variables as $name => $value ) {
			$this->setVariable( $name, $value );
		}
	}

	public function setVariable( $name, $value ) {
		$this->registeredVars[$name] = $value;
	}

	public function unsetVariable( $name ) {
		unset( $this->registeredVars[$name] );
	}

	public function setOptions( $options ) {
		foreach ( $options as $name => $value ) {
			$this->setOption( $name, $value );
		}
	}

	public function setOption( $name, $value ) {
		$this->options[$name] = $value;
	}

	public function parse( $buffer, $presets = [] ) {
		$this->setVariables( $presets );

		$parser = new Less_Parser( $this->getOptions() );
		$parser->setImportDirs( $this->getImportDirs() );
		foreach ( $this->libFunctions as $name => $func ) {
			$parser->registerFunction( $name, $func );
		}
		$parser->parse( $buffer );
		if ( count( $this->registeredVars ) ) {
			$parser->ModifyVars( $this->registeredVars );
		}

		return $parser->getCss();
	}

	protected function getOptions() {
		$options = [ 'relativeUrls' => false ];
		switch ( $this->formatterName ) {
			case 'compressed':
				$options['compress'] = true;
				break;
		}
		if ( is_array( $this->options ) ) {
			$options = array_merge( $options, $this->options );
		}
		return $options;
	}

	protected function getImportDirs() {
		$dirs_ = (array)$this->importDir;
		$dirs = [];
		foreach ( $dirs_ as $dir ) {
			$dirs[$dir] = '';
		}
		return $dirs;
	}

	public function compile( $string, $name = null ) {
		$oldImport = $this->importDir;
		$this->importDir = (array)$this->importDir;

		$this->allParsedFiles = [];

		$parser = new Less_Parser( $this->getOptions() );
		$parser->SetImportDirs( $this->getImportDirs() );
		if ( count( $this->registeredVars ) ) {
			$parser->ModifyVars( $this->registeredVars );
		}
		foreach ( $this->libFunctions as $name => $func ) {
			$parser->registerFunction( $name, $func );
		}
		$parser->parse( $string );
		$out = $parser->getCss();

		$parsed = Less_Parser::AllParsedFiles();
		foreach ( $parsed as $file ) {
			$this->addParsedFile( $file );
		}

		$this->importDir = $oldImport;

		return $out;
	}

	public function compileFile( $fname, $outFname = null ) {
		if ( !is_readable( $fname ) ) {
			throw new Exception( 'load error: failed to find ' . $fname );
		}

		$pi = pathinfo( $fname );

		$oldImport = $this->importDir;

		$this->importDir = (array)$this->importDir;
		$this->importDir[] = Less_Parser::AbsPath( $pi['dirname'] ) . '/';

		$this->allParsedFiles = [];
		$this->addParsedFile( $fname );

		$parser = new Less_Parser( $this->getOptions() );
		$parser->SetImportDirs( $this->getImportDirs() );
		if ( count( $this->registeredVars ) ) {
			$parser->ModifyVars( $this->registeredVars );
		}
		foreach ( $this->libFunctions as $name => $func ) {
			$parser->registerFunction( $name, $func );
		}
		$parser->parseFile( $fname );
		$out = $parser->getCss();

		$parsed = Less_Parser::AllParsedFiles();
		foreach ( $parsed as $file ) {
			$this->addParsedFile( $file );
		}

		$this->importDir = $oldImport;

		if ( $outFname !== null ) {
			return file_put_contents( $outFname, $out );
		}

		return $out;
	}

	public function checkedCompile( $in, $out ) {
		if ( !is_file( $out ) || filemtime( $in ) > filemtime( $out ) ) {
			$this->compileFile( $in, $out );
			return true;
		}
		return false;
	}

	/**
	 * Execute lessphp on a .less file or a lessphp cache structure
	 *
	 * The lessphp cache structure contains information about a specific
	 * less file having been parsed. It can be used as a hint for future
	 * calls to determine whether or not a rebuild is required.
	 *
	 * The cache structure contains two important keys that may be used
	 * externally:
	 *
	 * compiled: The final compiled CSS
	 * updated: The time (in seconds) the CSS was last compiled
	 *
	 * The cache structure is a plain-ol' PHP associative array and can
	 * be serialized and unserialized without a hitch.
	 *
	 * @param mixed $in Input
	 * @param bool $force Force rebuild?
	 * @return array lessphp cache structure
	 */
	public function cachedCompile( $in, $force = false ) {
		// assume no root
		$root = null;

		if ( is_string( $in ) ) {
			$root = $in;
		} elseif ( is_array( $in ) and isset( $in['root'] ) ) {
			if ( $force or !isset( $in['files'] ) ) {
				// If we are forcing a recompile or if for some reason the
				// structure does not contain any file information we should
				// specify the root to trigger a rebuild.
				$root = $in['root'];
			} elseif ( isset( $in['files'] ) and is_array( $in['files'] ) ) {
				foreach ( $in['files'] as $fname => $ftime ) {
					if ( !file_exists( $fname ) or filemtime( $fname ) > $ftime ) {
						// One of the files we knew about previously has changed
						// so we should look at our incoming root again.
						$root = $in['root'];
						break;
					}
				}
			}
		} else {
			// TODO: Throw an exception? We got neither a string nor something
			// that looks like a compatible lessphp cache structure.
			return null;
		}

		if ( $root !== null ) {
			// If we have a root value which means we should rebuild.
			$out = [];
			$out['root'] = $root;
			$out['compiled'] = $this->compileFile( $root );
			$out['files'] = $this->allParsedFiles();
			$out['updated'] = time();
			return $out;
		} else {
			// No changes, pass back the structure
			// we were given initially.
			return $in;
		}
	}

	public function ccompile( $in, $out, $less = null ) {
		if ( $less === null ) {
			$less = new self;
		}
		return $less->checkedCompile( $in, $out );
	}

	public static function cexecute( $in, $force = false, $less = null ) {
		if ( $less === null ) {
			$less = new self;
		}
		return $less->cachedCompile( $in, $force );
	}

	public function allParsedFiles() {
		return $this->allParsedFiles;
	}

	protected function addParsedFile( $file ) {
		$this->allParsedFiles[Less_Parser::AbsPath( $file )] = filemtime( $file );
	}
}
