<?php

/**
 * Part of the Joomla Framework Application Package
 *
 * @copyright  (C) 2013 Open Source Matters, Inc. <https://www.joomla.org>
 * @license        GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\Application;

use Joomla\Application\Event\ApplicationErrorEvent;
use Joomla\Application\Event\ApplicationEvent;
use Joomla\Event\DispatcherAwareInterface;
use Joomla\Event\DispatcherAwareTrait;
use Joomla\Event\EventInterface;
use Joomla\Registry\Registry;
use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;

/**
 * Joomla Framework Base Application Class
 *
 * @since  1.0.0
 */
abstract class AbstractApplication implements
    ConfigurationAwareApplicationInterface,
    LoggerAwareInterface,
    DispatcherAwareInterface
{
    use LoggerAwareTrait;
    use DispatcherAwareTrait;

    /**
     * The application configuration object.
     *
     * @var    Registry
     * @since  1.0.0
     */
    protected $config;

    /**
     * Class constructor.
     *
     * @param  Registry|null  $config  An optional argument to provide dependency injection for the
     *                                 application's config object.  If the argument is a Registry
     *                                 object that object will become the application's config object,
     *                                 otherwise a default config object is created.
     *
     * @since   1.0.0
     */
    public function __construct(?Registry $config = null)
    {
        $this->config = $config ?: new Registry();

        // Set the execution datetime and timestamp;
        $this->set('execution.datetime', \gmdate('Y-m-d H:i:s'));
        $this->set('execution.timestamp', \time());
        $this->set('execution.microtimestamp', \microtime(true));

        $this->initialise();
    }

    /**
     * Method to close the application.
     *
     * @param  integer  $code  The exit code (optional; default is 0).
     *
     * @return  void
     *
     * @codeCoverageIgnore
     * @since   1.0.0
     */
    public function close($code = 0)
    {
        exit($code);
    }

    /**
     * Dispatches an application event if the dispatcher has been set.
     *
     * @param  string               $eventName  The event to dispatch.
     * @param  EventInterface|null  $event      The event object.
     *
     * @return  EventInterface|null  The dispatched event or null if no dispatcher is set
     *
     * @since   2.0.0
     */
    protected function dispatchEvent(string $eventName, ?EventInterface $event = null): ?EventInterface
    {
        try {
            $dispatcher = $this->getDispatcher();
        } catch (\UnexpectedValueException $exception) {
            return null;
        }

        return $dispatcher->dispatch($eventName, $event ?: new ApplicationEvent($eventName, $this));
    }

    /**
     * Method to run the application routines.
     *
     * Most likely you will want to instantiate a controller and execute it, or perform some sort of task directly.
     *
     * @return  mixed
     *
     * @since   1.0.0
     */
    abstract protected function doExecute();

    /**
     * Execute the application.
     *
     * @return  void
     *
     * @since   1.0.0
     */
    public function execute()
    {
        try {
            $this->dispatchEvent(ApplicationEvents::BEFORE_EXECUTE);

            // Perform application routines.
            $this->doExecute();

            $this->dispatchEvent(ApplicationEvents::AFTER_EXECUTE);
        } catch (\Throwable $throwable) {
            $this->dispatchEvent(ApplicationEvents::ERROR, new ApplicationErrorEvent($throwable, $this));
        }
    }

    /**
     * Returns a property of the object or the default value if the property is not set.
     *
     * @param  string  $key      The name of the property.
     * @param  mixed   $default  The default value (optional) if none is set.
     *
     * @return  mixed   The value of the configuration.
     *
     * @since   1.0.0
     */
    public function get($key, $default = null)
    {
        return $this->config->get($key, $default);
    }

    /**
     * Get the logger.
     *
     * @return  LoggerInterface
     *
     * @since   1.0.0
     */
    public function getLogger()
    {
        // If a logger hasn't been set, use NullLogger
        if (!($this->logger instanceof LoggerInterface)) {
            $this->setLogger(new NullLogger());
        }

        return $this->logger;
    }

    /**
     * Custom initialisation method.
     *
     * Called at the end of the AbstractApplication::__construct method.
     * This is for developers to inject initialisation code for their application classes.
     *
     * @return  void
     *
     * @codeCoverageIgnore
     * @since   1.0.0
     */
    protected function initialise()
    {
    }

    /**
     * Modifies a property of the object, creating it if it does not already exist.
     *
     * @param  string  $key    The name of the property.
     * @param  mixed   $value  The value of the property to set (optional).
     *
     * @return  mixed   Previous value of the property
     *
     * @since   1.0.0
     */
    public function set($key, $value = null)
    {
        $previous = $this->config->get($key);
        $this->config->set($key, $value);

        return $previous;
    }

    /**
     * Sets the configuration for the application.
     *
     * @param  Registry  $config  A registry object holding the configuration.
     *
     * @return  $this
     *
     * @since   1.0.0
     */
    public function setConfiguration(Registry $config)
    {
        $this->config = $config;

        return $this;
    }
}
