<?php
/**
 * FuzeWorks Async Library
 *
 * The FuzeWorks PHP FrameWork
 *
 * Copyright (C) 2013-2020 TechFuze
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * @author    TechFuze
 * @copyright Copyright (c) 2013 - 2020, TechFuze. (http://techfuze.net)
 * @license   https://opensource.org/licenses/MIT MIT License
 *
 * @link  http://techfuze.net/fuzeworks
 * @since Version 1.0.0
 *
 * @version Version 1.0.0
 */

namespace FuzeWorks\Async\Handler;
use FuzeWorks\Async\Handler;
use FuzeWorks\Async\Task;
use FuzeWorks\Async\TasksException;
use FuzeWorks\Controller;
use FuzeWorks\Controllers;
use FuzeWorks\Exception\ControllerException;
use FuzeWorks\Exception\FactoryException;
use FuzeWorks\Exception\NotFoundException;
use FuzeWorks\Factory;

class ControllerHandler implements Handler
{

    /**
     * @var string Name of the controller used to handle the task
     */
    protected $controllerName;

    /**
     * @var string The specific method to handle the task
     */
    protected $controllerMethod;

    /**
     * The namespace to use to load the controller
     *
     * @var string
     */
    protected $controllerNamespace;

    /**
     * @var string|null The method used to handle the post phase; if requested
     */
    protected $postMethod = null;

    /**
     * @var string The output to be returned to ShellWorker
     */
    protected $output;

    /**
     * @var string The postOutput to be returned to ShellWorker
     */
    protected $postOutput;

    /**
     * Input imported from the parent handler
     *
     * @var string|null
     */
    protected $parentInput;

    /**
     * ControllerHandler constructor.
     *
     * Provides all information of which controller to use. Requests get redirected to that controller.
     *
     * @param string $controllerName                The name of the controller to use
     * @param string $controllerMethod              The method to use for the task execution
     * @param string|null $postMethod               The method to use for the post execution
     * @param string $controllerNamespace           A potential custom namespace for the controller
     */
    public function __construct(string $controllerName, string $controllerMethod, string $postMethod = null, string $controllerNamespace = '\Application\Controller\\')
    {
        $this->controllerName = $controllerName;
        $this->controllerMethod = $controllerMethod;
        $this->postMethod = $postMethod;
        $this->controllerNamespace = $controllerNamespace;
    }

    /**
     * @inheritDoc
     */
    public function init(Task $task)
    {
    }

    /**
     * @inheritDoc
     * @throws TasksException
     */
    public function primaryHandler(Task $task): bool
    {
        // Set the arguments
        $args = $task->getArguments();
        array_unshift($args, $task);

        // First we fetch the controller
        $controller = $this->getController();

        // Check if method exists
        if (!method_exists($controller, $this->controllerMethod))
            throw new TasksException("Could not handle task. Method '$this->controllerMethod' not found on controller.");

        if (!method_exists($controller, 'getTaskStatus'))
            throw new TasksException("Could not handle task. Method 'getTaskStatus()' not found on controller, which is required.");

        if ($this->parentInput !== null && method_exists($controller, 'setInput'))
            $controller->setInput($this->parentInput);

        // Call method and collect output
        $this->output = call_user_func_array([$controller, $this->controllerMethod], $args);
        $success = $controller->getTaskStatus();
        if (!is_bool($success))
            throw new TasksException("Could not determine whether task has succeeded. getTaskStatus() returned non-bool.");

        return $success;
    }

    /**
     * @inheritDoc
     */
    public function getOutput(): string
    {
        return $this->output;
    }

    /**
     * @inheritDoc
     * @throws TasksException
     */
    public function postHandler(Task $task)
    {
        // Abort if no postMethod exists
        if (is_null($this->postMethod))
            throw new TasksException("Could not handle task. No post method provided.");

        // First we fetch the controller
        $controller = $this->getController();

        // Check if method exists
        if (!method_exists($controller, $this->postMethod))
            throw new TasksException("Could not handle task. Post method '$this->postMethod' not found on controller.");

        if (!method_exists($controller, 'getTaskStatus'))
            throw new TasksException("Could not handle task. Method 'getTaskStatus()' not found on controller, which is required.");

        if ($this->parentInput !== null && method_exists($controller, 'setInput'))
            $controller->setInput($this->parentInput);

        // Call method and collect output
        $this->postOutput = call_user_func_array([$controller, $this->postMethod], [$task]);
        $success = $controller->getTaskStatus();
        if (!is_bool($success))
            throw new TasksException("Could not determine whether task has succeeded. getTaskStatus() returned non-bool.");

        return $success;
    }

    /**
     * @inheritDoc
     */
    public function getPostOutput(): string
    {
        return $this->postOutput;
    }

    /**
     * @return Controller
     * @throws TasksException
     */
    private function getController(): Controller
    {
        // First load the controllers component
        try {
            /** @var Controllers $controllers */
            $controllers = Factory::getInstance('controllers');

            // Load the requested controller
            return $controllers->get($this->controllerName, [], $this->controllerNamespace);
        } catch (FactoryException $e) {
            throw new TasksException("Could not get controller. FuzeWorks\MVCR is not installed!");
        } catch (ControllerException $e) {
            throw new TasksException("Could not get controller. Controller threw exception: '" . $e->getMessage() . "'");
        } catch (NotFoundException $e) {
            throw new TasksException("Could not get controller. Controller was not found.");
        }
    }

    /**
     * @var Handler
     */
    private $parentHandler;

    /**
     * @inheritDoc
     */
    public function getParentHandler(): ?Handler
    {
        return $this->parentHandler;
    }

    /**
     * @inheritDoc
     */
    public function setParentHandler(Handler $parentHandler): void
    {
        $this->parentHandler = $parentHandler;
    }

    /**
     * @inheritDoc
     */
    public function setParentInput(string $input): void
    {
        $this->parentInput = $input;
    }
}