<?php

namespace FL\Assistant\System\Container;

class Executable {

	private $callableReflection;
	private $invocationObject;
	private $isInstanceMethod;

	public function __construct( \ReflectionFunctionAbstract $reflFunc, $invocationObject = null ) {
		if ( $reflFunc instanceof \ReflectionMethod ) {
			$this->isInstanceMethod = true;
			$this->setMethodCallable( $reflFunc, $invocationObject );
		} else {
			$this->isInstanceMethod = false;
			$this->callableReflection = $reflFunc;
		}
	}

	private function setMethodCallable( \ReflectionMethod $reflection, $invocationObject ) {
		if ( is_object( $invocationObject ) ) {
			$this->callableReflection = $reflection;
			$this->invocationObject = $invocationObject;
		} elseif ( $reflection->isStatic() ) {
			$this->callableReflection = $reflection;
		} else {
			throw new \InvalidArgumentException(
				'ReflectionMethod callables must specify an invocation object'
			);
		}
	}

	public function __invoke() {
		$args = func_get_args();
		$reflection = $this->callableReflection;

		if ( $this->isInstanceMethod ) {
			return $reflection->invokeArgs( $this->invocationObject, $args );
		}

		return $this->callableReflection->isClosure()
			? $this->invokeClosureCompat( $reflection, $args )
			: $reflection->invokeArgs( $args );
	}

	/**
	 * @TODO Remove this extra indirection when 5.3 support is dropped
	 */
	private function invokeClosureCompat( $reflection, $args ) {
		if ( version_compare( PHP_VERSION, '5.4.0' ) >= 0 ) {
			$scope = $reflection->getClosureScopeClass();
			$closure = \Closure::bind(
				$reflection->getClosure(),
				$reflection->getClosureThis(),
				$scope ? $scope->name : null
			);
			return call_user_func_array( $closure, $args );
		} else {
			return $reflection->invokeArgs( $args );
		}
	}

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

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

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