<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2019 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Changelog;

use Joomla\CMS\Http\HttpFactory;
use Joomla\CMS\Language\Text;
use Joomla\CMS\Log\Log;
use Joomla\CMS\Object\CMSObject;
use Joomla\CMS\Version;
use Joomla\Registry\Registry;
use RuntimeException;

// phpcs:disable PSR1.Files.SideEffects
\defined('JPATH_PLATFORM') or die;
// phpcs:enable PSR1.Files.SideEffects

/**
 * Changelog class.
 *
 * @since  4.0.0
 */
class Changelog extends CMSObject
{
    /**
     * Update manifest `<element>` element
     *
     * @var    string
     * @since  4.0.0
     */
    protected $element;

    /**
     * Update manifest `<type>` element
     *
     * @var    string
     * @since  4.0.0
     */
    protected $type;

    /**
     * Update manifest `<version>` element
     *
     * @var    string
     * @since  4.0.0
     */
    protected $version;

    /**
     * Update manifest `<security>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $security = array();

    /**
     * Update manifest `<fix>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $fix = array();

    /**
     * Update manifest `<language>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $language = array();

    /**
     * Update manifest `<addition>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $addition = array();

    /**
     * Update manifest `<change>` elements
     *
     * @var    array
     * @since  4.0.0
     */
    protected $change = array();

    /**
     * Update manifest `<remove>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $remove = array();

    /**
     * Update manifest `<maintainer>` element
     *
     * @var    array
     * @since  4.0.0
     */
    protected $note = array();

    /**
     * List of node items
     *
     * @var    array
     * @since  4.0.0
     */
    private $items = array();

    /**
     * Resource handle for the XML Parser
     *
     * @var    resource
     * @since  4.0.0
     */
    protected $xmlParser;

    /**
     * Element call stack
     *
     * @var    array
     * @since  4.0.0
     */
    protected $stack = array('base');

    /**
     * Object containing the current update data
     *
     * @var    \stdClass
     * @since  4.0.0
     */
    protected $currentChangelog;

    /**
     * The version to match the changelog
     *
     * @var    string
     * @since  4.0.0
     */
    private $matchVersion = '';

    /**
     * Object containing the latest changelog data
     *
     * @var    \stdClass
     * @since  4.0.0
     */
    protected $latest;

    /**
     * Gets the reference to the current direct parent
     *
     * @return  string
     *
     * @since   4.0.0
     */
    protected function getStackLocation()
    {
        return implode('->', $this->stack);
    }

    /**
     * Get the last position in stack count
     *
     * @return  string
     *
     * @since   4.0.0
     */
    protected function getLastTag()
    {
        return $this->stack[\count($this->stack) - 1];
    }

    /**
     * Set the version to match.
     *
     * @param   string  $version  The version to match
     *
     * @return  void
     *
     * @since   4.0.0
     */
    public function setVersion(string $version)
    {
        $this->matchVersion = $version;
    }

    /**
     * XML Start Element callback
     *
     * @param   object  $parser  Parser object
     * @param   string  $name    Name of the tag found
     * @param   array   $attrs   Attributes of the tag
     *
     * @return  void
     *
     * @note    This is public because it is called externally
     * @since   1.7.0
     */
    public function startElement($parser, $name, $attrs = array())
    {
        $this->stack[] = $name;
        $tag           = $this->getStackLocation();

        // Reset the data
        if (isset($this->$tag)) {
            $this->$tag->data = '';
        }

        $name = strtolower($name);

        if (!isset($this->currentChangelog->$name)) {
            $this->currentChangelog->$name = new \stdClass();
        }

        $this->currentChangelog->$name->data = '';

        foreach ($attrs as $key => $data) {
            $key                                 = strtolower($key);
            $this->currentChangelog->$name->$key = $data;
        }
    }

    /**
     * Callback for closing the element
     *
     * @param   object  $parser  Parser object
     * @param   string  $name    Name of element that was closed
     *
     * @return  void
     *
     * @note    This is public because it is called externally
     * @since   1.7.0
     */
    public function endElement($parser, $name)
    {
        array_pop($this->stack);

        switch ($name) {
            case 'SECURITY':
            case 'FIX':
            case 'LANGUAGE':
            case 'ADDITION':
            case 'CHANGE':
            case 'REMOVE':
            case 'NOTE':
                $name = strtolower($name);
                $this->currentChangelog->$name->data = $this->items;
                $this->items = array();
                break;
            case 'CHANGELOG':
                if (version_compare($this->currentChangelog->version->data, $this->matchVersion, '==') === true) {
                    $this->latest = $this->currentChangelog;
                }

                // No version match, empty it
                $this->currentChangelog = new \stdClass();
                break;
            case 'CHANGELOGS':
                // If the latest item is set then we transfer it to where we want to
                if (isset($this->latest)) {
                    foreach (get_object_vars($this->latest) as $key => $val) {
                        $this->$key = $val;
                    }

                    unset($this->latest);
                    unset($this->currentChangelog);
                } elseif (isset($this->currentChangelog)) {
                    // The update might be for an older version of j!
                    unset($this->currentChangelog);
                }
                break;
        }
    }

    /**
     * Character Parser Function
     *
     * @param   object  $parser  Parser object.
     * @param   object  $data    The data.
     *
     * @return  void
     *
     * @note    This is public because its called externally.
     * @since   1.7.0
     */
    public function characterData($parser, $data)
    {
        $tag = $this->getLastTag();

        switch ($tag) {
            case 'ITEM':
                $this->items[] = $data;
                break;
            case 'SECURITY':
            case 'FIX':
            case 'LANGUAGE':
            case 'ADDITION':
            case 'CHANGE':
            case 'REMOVE':
            case 'NOTE':
                break;
            default:
                // Throw the data for this item together
                $tag = strtolower($tag);

                if (isset($this->currentChangelog->$tag)) {
                    $this->currentChangelog->$tag->data .= $data;
                }
                break;
        }
    }

    /**
     * Loads an XML file from a URL.
     *
     * @param   string  $url  The URL.
     *
     * @return  boolean  True on success
     *
     * @since   4.0.0
     */
    public function loadFromXml($url)
    {
        $version    = new Version();
        $httpOption = new Registry();
        $httpOption->set('userAgent', $version->getUserAgent('Joomla', true, false));

        try {
            $http     = HttpFactory::getHttp($httpOption);
            $response = $http->get($url);
        } catch (RuntimeException $e) {
            $response = null;
        }

        if ($response === null || $response->code !== 200) {
            // @todo: Add a 'mark bad' setting here somehow
            Log::add(Text::sprintf('JLIB_UPDATER_ERROR_EXTENSION_OPEN_URL', $url), Log::WARNING, 'jerror');

            return false;
        }

        $this->currentChangelog = new \stdClass();

        $this->xmlParser = xml_parser_create('');
        xml_set_object($this->xmlParser, $this);
        xml_set_element_handler($this->xmlParser, 'startElement', 'endElement');
        xml_set_character_data_handler($this->xmlParser, 'characterData');

        if (!xml_parse($this->xmlParser, $response->body)) {
            Log::add(
                sprintf(
                    'XML error: %s at line %d',
                    xml_error_string(xml_get_error_code($this->xmlParser)),
                    xml_get_current_line_number($this->xmlParser)
                ),
                Log::WARNING,
                'updater'
            );

            return false;
        }

        xml_parser_free($this->xmlParser);

        return true;
    }
}