<?php
class ImportItemError extends Exception {}

class ImportFileError extends Exception {}

function import($file) {
	static $imported = array();
	$file = realpath($file);
	if (isset($imported[$file])) {
		return $imported[$file];
	}
	try {
		$imported[$file] = new Import($file);
		return $imported[$file];
	}
	catch (ImportFileError $e) {
		return false;
	}
}

class Import {

	private
	$_variables = array(),
	$_constants = array(),
	$_functions = array(),
	$_classes = array();

	public function __construct($file) {
		if (!is_file($file)) {
			throw new ImportFileError('Unable to find "'.$file.'" for import.');
		}

		// Get the variables and execute the script
		$this->pre_vars = get_defined_vars();
		include $file;
		$this->post_vars = get_defined_vars();
		$this->_variables = array_diff($this->post_vars, $this->pre_vars);

		// Get the functions and the classes
		$contents = file_get_contents($file);
		preg_match_all('/function\s+([a-zA-Z0-9_]+)/', $contents, $functions);
		preg_match_all('/class\s+([a-zA-Z0-9_]+)/', $contents, $classes);
		$this->_functions = $functions[1];
		$this->_classes = $classes[1];

		// Clean out methods confused as functions		
		foreach ($this->_functions as $key => $function) {
			if (!function_exists($function)) {
				unset($this->_functions[$key]);
			}
		}
		sort($this->_functions);
	}

	public function allVariables() {
		return $this->_variables;
	}

	public function allConstants() {
		return $this->_constants;
	}

	public function allFunctions() {
		return $this->_functions;
	}

	public function allClasses() {
		return $this->_classes;
	}

	public function __get($item) {
		if ($key = array_search($item, $this->_classes)) {
			return $this->_classes[$key];
		}
		elseif (isset($this->_variables[$item])) {
			$this->_variables[$item];
		}
		else {
			throw new ImportItemError('Imported variable or class "'.$item.'" not found.');
		}
	}

	public function __call($item, $args = array()) {
		if ($key = array_search($item, $this->_classes)) {
			return $this->_classes[$key];
		}
		elseif (in_array($item, $this->_functions)) {
			return call_user_func_array($item, $args);
		}
		else {
			throw new ImportItemError('Imported function or class "'.$item.'" not found.');
		}
	}

}
?>