<?php
/**
 * CSS `@import` node
 *
 * The general strategy here is that we don't want to wait
 * for the parsing to be completed, before we start importing
 * the file. That's because in the context of a browser,
 * most of the time will be spent waiting for the server to respond.
 *
 * On creation, we push the import path to our import queue, though
 * `import,push`, we also pass it a callback, which it'll call once
 * the file has been fetched, and parsed.
 *
 * @private
 */
class Less_Tree_Import extends Less_Tree {

	public $options;
	public $index;
	public $path;
	public $features;
	public $currentFileInfo;
	public $css;
	public $skip;
	public $root;
	public $type = 'Import';

	public function __construct( $path, $features, $options, $index, $currentFileInfo = null ) {
		$this->options = $options;
		$this->index = $index;
		$this->path = $path;
		$this->features = $features;
		$this->currentFileInfo = $currentFileInfo;

		if ( is_array( $options ) ) {
			$this->options += [ 'inline' => false ];

			if ( isset( $this->options['less'] ) || $this->options['inline'] ) {
				$this->css = !isset( $this->options['less'] ) || !$this->options['less'] || $this->options['inline'];
			} else {
				$pathValue = $this->getPath();
				// Leave any ".css" file imports as literals for the browser.
				// Also leave any remote HTTP resources as literals regardless of whether
				// they contain ".css" in their filename.
				if ( $pathValue && preg_match( '/^(https?:)?\/\/|\.css$/i', $pathValue ) ) {
					$this->css = true;
				}
			}
		}
	}

//
// The actual import node doesn't return anything, when converted to CSS.
// The reason is that it's used at the evaluation stage, so that the rules
// it imports can be treated like any other rules.
//
// In `eval`, we make sure all Import nodes get evaluated, recursively, so
// we end up with a flat structure, which can easily be imported in the parent
// ruleset.
//

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

		if ( !$this->options['inline'] && $this->root ) {
			$this->root = $visitor->visit( $this->root );
		}
	}

	/**
	 * @see Less_Tree::genCSS
	 */
	public function genCSS( $output ) {
		if ( $this->css ) {

			$output->add( '@import ', $this->currentFileInfo, $this->index );

			$this->path->genCSS( $output );
			if ( $this->features ) {
				$output->add( ' ' );
				$this->features->genCSS( $output );
			}
			$output->add( ';' );
		}
	}

	public function toCSS() {
		$features = $this->features ? ' ' . $this->features->toCSS() : '';

		if ( $this->css ) {
			return "@import " . $this->path->toCSS() . $features . ";\n";
		} else {
			return "";
		}
	}

	/**
	 * @return string|null
	 */
	public function getPath() {
		if ( $this->path instanceof Less_Tree_Quoted ) {
			$path = $this->path->value;
			$path = ( isset( $this->css ) || preg_match( '/(\.[a-z]*$)|([\?;].*)$/', $path ) ) ? $path : $path . '.less';

		// During the first pass, Less_Tree_Url may contain a Less_Tree_Variable (not yet expanded),
		// and thus has no value property defined yet. Return null until we reach the next phase.
		// https://github.com/wikimedia/less.php/issues/29
		} elseif ( $this->path instanceof Less_Tree_Url && !( $this->path->value instanceof Less_Tree_Variable ) ) {
			$path = $this->path->value->value;
		} else {
			return null;
		}

		// remove query string and fragment
		return preg_replace( '/[\?#][^\?]*$/', '', $path );
	}

	public function compileForImport( $env ) {
		return new Less_Tree_Import( $this->path->compile( $env ), $this->features, $this->options, $this->index, $this->currentFileInfo );
	}

	public function compilePath( $env ) {
		$path = $this->path->compile( $env );
		$rootpath = '';
		if ( $this->currentFileInfo && $this->currentFileInfo['rootpath'] ) {
			$rootpath = $this->currentFileInfo['rootpath'];
		}

		if ( !( $path instanceof Less_Tree_Url ) ) {
			if ( $rootpath ) {
				$pathValue = $path->value;
				// Add the base path if the import is relative
				if ( $pathValue && Less_Environment::isPathRelative( $pathValue ) ) {
					$path->value = $this->currentFileInfo['uri_root'] . $pathValue;
				}
			}
			$path->value = Less_Environment::normalizePath( $path->value );
		}

		return $path;
	}

	public function compile( $env ) {
		$evald = $this->compileForImport( $env );

		// get path & uri
		$path_and_uri = null;
		if ( is_callable( Less_Parser::$options['import_callback'] ) ) {
			$path_and_uri = call_user_func( Less_Parser::$options['import_callback'], $evald );
		}

		if ( !$path_and_uri ) {
			$path_and_uri = $evald->PathAndUri();
		}

		if ( $path_and_uri ) {
			list( $full_path, $uri ) = $path_and_uri;
		} else {
			$full_path = $uri = $evald->getPath();
		}

		// import once
		if ( $evald->skip( $full_path, $env ) ) {
			return [];
		}
		'@phan-var string $full_path';

		if ( $this->options['inline'] ) {
			// todo needs to reference css file not import
			//$contents = new Less_Tree_Anonymous($this->root, 0, array('filename'=>$this->importedFilename), true );

			Less_Parser::AddParsedFile( $full_path );
			$contents = new Less_Tree_Anonymous( file_get_contents( $full_path ), 0, [], true );

			if ( $this->features ) {
				return new Less_Tree_Media( [ $contents ], $this->features->value );
			}

			return [ $contents ];
		}

		// optional (need to be before "CSS" to support optional CSS imports. CSS should be checked only if empty($this->currentFileInfo))
		if ( isset( $this->options['optional'] ) && $this->options['optional'] && !file_exists( $full_path ) && ( !$evald->css || !empty( $this->currentFileInfo ) ) ) {
			return [];
		}

		// css ?
		if ( $evald->css ) {
			$features = ( $evald->features ? $evald->features->compile( $env ) : null );
			return new Less_Tree_Import( $this->compilePath( $env ), $features, $this->options, $this->index );
		}

		return $this->ParseImport( $full_path, $uri, $env );
	}

	/**
	 * Using the import directories, get the full absolute path and uri of the import
	 */
	public function PathAndUri() {
		$evald_path = $this->getPath();

		if ( $evald_path ) {

			$import_dirs = [];

			if ( Less_Environment::isPathRelative( $evald_path ) ) {
				// if the path is relative, the file should be in the current directory
				if ( $this->currentFileInfo ) {
					$import_dirs[ $this->currentFileInfo['currentDirectory'] ] = $this->currentFileInfo['uri_root'];
				}

			} else {
				// otherwise, the file should be relative to the server root
				if ( $this->currentFileInfo ) {
					$import_dirs[ $this->currentFileInfo['entryPath'] ] = $this->currentFileInfo['entryUri'];
				}
				// if the user supplied entryPath isn't the actual root
				$import_dirs[ $_SERVER['DOCUMENT_ROOT'] ] = '';

			}

			// always look in user supplied import directories
			$import_dirs = array_merge( $import_dirs, Less_Parser::$options['import_dirs'] );

			foreach ( $import_dirs as $rootpath => $rooturi ) {
				if ( is_callable( $rooturi ) ) {
					list( $path, $uri ) = call_user_func( $rooturi, $evald_path );
					if ( is_string( $path ) ) {
						$full_path = $path;
						return [ $full_path, $uri ];
					}
				} elseif ( !empty( $rootpath ) ) {

					$path = rtrim( $rootpath, '/\\' ) . '/' . ltrim( $evald_path, '/\\' );

					if ( file_exists( $path ) ) {
						$full_path = Less_Environment::normalizePath( $path );
						$uri = Less_Environment::normalizePath( dirname( $rooturi . $evald_path ) );
						return [ $full_path, $uri ];
					} elseif ( file_exists( $path . '.less' ) ) {
						$full_path = Less_Environment::normalizePath( $path . '.less' );
						$uri = Less_Environment::normalizePath( dirname( $rooturi . $evald_path . '.less' ) );
						return [ $full_path, $uri ];
					}
				}
			}
		}
	}

	/**
	 * Parse the import url and return the rules
	 *
	 * @param string $full_path
	 * @param string|null $uri
	 * @param mixed $env
	 * @return Less_Tree_Media|array
	 */
	public function ParseImport( $full_path, $uri, $env ) {
		$import_env = clone $env;
		if ( ( isset( $this->options['reference'] ) && $this->options['reference'] ) || isset( $this->currentFileInfo['reference'] ) ) {
			$import_env->currentFileInfo['reference'] = true;
		}

		if ( ( isset( $this->options['multiple'] ) && $this->options['multiple'] ) ) {
			$import_env->importMultiple = true;
		}

		$parser = new Less_Parser( $import_env );
		$root = $parser->parseFile( $full_path, $uri, true );

		$ruleset = new Less_Tree_Ruleset( null, $root->rules );
		$ruleset->evalImports( $import_env );

		return $this->features ? new Less_Tree_Media( $ruleset->rules, $this->features->value ) : $ruleset->rules;
	}

	/**
	 * Should the import be skipped?
	 *
	 * @param string|null $path
	 * @param Less_Environment $env
	 * @return bool|null
	 */
	private function skip( $path, $env ) {
		$path = Less_Parser::AbsPath( $path, true );

		if ( $path && Less_Parser::FileParsed( $path ) ) {

			if ( isset( $this->currentFileInfo['reference'] ) ) {
				return true;
			}

			return !isset( $this->options['multiple'] ) && !$env->importMultiple;
		}
	}
}
