<?php

/**
 * @package     Joomla.Administrator
 * @subpackage  com_finder
 *
 * @copyright   (C) 2011 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\Component\Finder\Administrator\Indexer;

use Exception;
use Joomla\CMS\Factory;
use Joomla\CMS\Plugin\CMSPlugin;
use Joomla\CMS\Table\Table;
use Joomla\Database\DatabaseInterface;
use Joomla\Database\QueryInterface;
use Joomla\Utilities\ArrayHelper;

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

/**
 * Prototype adapter class for the Finder indexer package.
 *
 * @since  2.5
 */
abstract class Adapter extends CMSPlugin
{
    /**
     * The context is somewhat arbitrary but it must be unique or there will be
     * conflicts when managing plugin/indexer state. A good best practice is to
     * use the plugin name suffix as the context. For example, if the plugin is
     * named 'plgFinderContent', the context could be 'Content'.
     *
     * @var    string
     * @since  2.5
     */
    protected $context;

    /**
     * The extension name.
     *
     * @var    string
     * @since  2.5
     */
    protected $extension;

    /**
     * The sublayout to use when rendering the results.
     *
     * @var    string
     * @since  2.5
     */
    protected $layout;

    /**
     * The mime type of the content the adapter indexes.
     *
     * @var    string
     * @since  2.5
     */
    protected $mime;

    /**
     * The access level of an item before save.
     *
     * @var    integer
     * @since  2.5
     */
    protected $old_access;

    /**
     * The access level of a category before save.
     *
     * @var    integer
     * @since  2.5
     */
    protected $old_cataccess;

    /**
     * The type of content the adapter indexes.
     *
     * @var    string
     * @since  2.5
     */
    protected $type_title;

    /**
     * The type id of the content.
     *
     * @var    integer
     * @since  2.5
     */
    protected $type_id;

    /**
     * The database object.
     *
     * @var    DatabaseInterface
     * @since  2.5
     */
    protected $db;

    /**
     * The table name.
     *
     * @var    string
     * @since  2.5
     */
    protected $table;

    /**
     * The indexer object.
     *
     * @var    Indexer
     * @since  3.0
     */
    protected $indexer;

    /**
     * The field the published state is stored in.
     *
     * @var    string
     * @since  2.5
     */
    protected $state_field = 'state';

    /**
     * Method to instantiate the indexer adapter.
     *
     * @param   object  $subject  The object to observe.
     * @param   array   $config   An array that holds the plugin configuration.
     *
     * @since   2.5
     */
    public function __construct(&$subject, $config)
    {
        // Call the parent constructor.
        parent::__construct($subject, $config);

        // Get the type id.
        $this->type_id = $this->getTypeId();

        // Add the content type if it doesn't exist and is set.
        if (empty($this->type_id) && !empty($this->type_title)) {
            $this->type_id = Helper::addContentType($this->type_title, $this->mime);
        }

        // Check for a layout override.
        if ($this->params->get('layout')) {
            $this->layout = $this->params->get('layout');
        }

        // Get the indexer object
        $this->indexer = new Indexer($this->db);
    }

    /**
     * Method to get the adapter state and push it into the indexer.
     *
     * @return  void
     *
     * @since   2.5
     * @throws  Exception on error.
     */
    public function onStartIndex()
    {
        // Get the indexer state.
        $iState = Indexer::getState();

        // Get the number of content items.
        $total = (int) $this->getContentCount();

        // Add the content count to the total number of items.
        $iState->totalItems += $total;

        // Populate the indexer state information for the adapter.
        $iState->pluginState[$this->context]['total'] = $total;
        $iState->pluginState[$this->context]['offset'] = 0;

        // Set the indexer state.
        Indexer::setState($iState);
    }

    /**
     * Method to prepare for the indexer to be run. This method will often
     * be used to include dependencies and things of that nature.
     *
     * @return  boolean  True on success.
     *
     * @since   2.5
     * @throws  Exception on error.
     */
    public function onBeforeIndex()
    {
        // Get the indexer and adapter state.
        $iState = Indexer::getState();
        $aState = $iState->pluginState[$this->context];

        // Check the progress of the indexer and the adapter.
        if ($iState->batchOffset == $iState->batchSize || $aState['offset'] == $aState['total']) {
            return true;
        }

        // Run the setup method.
        return $this->setup();
    }

    /**
     * Method to index a batch of content items. This method can be called by
     * the indexer many times throughout the indexing process depending on how
     * much content is available for indexing. It is important to track the
     * progress correctly so we can display it to the user.
     *
     * @return  boolean  True on success.
     *
     * @since   2.5
     * @throws  Exception on error.
     */
    public function onBuildIndex()
    {
        // Get the indexer and adapter state.
        $iState = Indexer::getState();
        $aState = $iState->pluginState[$this->context];

        // Check the progress of the indexer and the adapter.
        if ($iState->batchOffset == $iState->batchSize || $aState['offset'] == $aState['total']) {
            return true;
        }

        // Get the batch offset and size.
        $offset = (int) $aState['offset'];
        $limit = (int) ($iState->batchSize - $iState->batchOffset);

        // Get the content items to index.
        $items = $this->getItems($offset, $limit);

        // Iterate through the items and index them.
        for ($i = 0, $n = count($items); $i < $n; $i++) {
            // Index the item.
            $this->index($items[$i]);

            // Adjust the offsets.
            $offset++;
            $iState->batchOffset++;
            $iState->totalItems--;
        }

        // Update the indexer state.
        $aState['offset'] = $offset;
        $iState->pluginState[$this->context] = $aState;
        Indexer::setState($iState);

        return true;
    }

    /**
     * Method to remove outdated index entries
     *
     * @return  integer
     *
     * @since   4.2.0
     */
    public function onFinderGarbageCollection()
    {
        $db = $this->db;
        $type_id = $this->getTypeId();

        $query = $db->getQuery(true);
        $subquery = $db->getQuery(true);
        $subquery->select('CONCAT(' . $db->quote($this->getUrl('', $this->extension, $this->layout)) . ', id)')
            ->from($db->quoteName($this->table));
        $query->select($db->quoteName('l.link_id'))
            ->from($db->quoteName('#__finder_links', 'l'))
            ->where($db->quoteName('l.type_id') . ' = ' . $type_id)
            ->where($db->quoteName('l.url') . ' LIKE ' . $db->quote($this->getUrl('%', $this->extension, $this->layout)))
            ->where($db->quoteName('l.url') . ' NOT IN (' . $subquery . ')');
        $db->setQuery($query);
        $items = $db->loadColumn();

        foreach ($items as $item) {
            $this->indexer->remove($item);
        }

        return count($items);
    }

    /**
     * Method to change the value of a content item's property in the links
     * table. This is used to synchronize published and access states that
     * are changed when not editing an item directly.
     *
     * @param   string   $id        The ID of the item to change.
     * @param   string   $property  The property that is being changed.
     * @param   integer  $value     The new value of that property.
     *
     * @return  boolean  True on success.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function change($id, $property, $value)
    {
        // Check for a property we know how to handle.
        if ($property !== 'state' && $property !== 'access') {
            return true;
        }

        // Get the URL for the content id.
        $item = $this->db->quote($this->getUrl($id, $this->extension, $this->layout));

        // Update the content items.
        $query = $this->db->getQuery(true)
            ->update($this->db->quoteName('#__finder_links'))
            ->set($this->db->quoteName($property) . ' = ' . (int) $value)
            ->where($this->db->quoteName('url') . ' = ' . $item);
        $this->db->setQuery($query);
        $this->db->execute();

        return true;
    }

    /**
     * Method to index an item.
     *
     * @param   Result  $item  The item to index as a Result object.
     *
     * @return  boolean  True on success.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    abstract protected function index(Result $item);

    /**
     * Method to reindex an item.
     *
     * @param   integer  $id  The ID of the item to reindex.
     *
     * @return  void
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function reindex($id)
    {
        // Run the setup method.
        $this->setup();

        // Remove the old item.
        $this->remove($id, false);

        // Get the item.
        $item = $this->getItem($id);

        // Index the item.
        $this->index($item);

        Taxonomy::removeOrphanNodes();
    }

    /**
     * Method to remove an item from the index.
     *
     * @param   string  $id                The ID of the item to remove.
     * @param   bool    $removeTaxonomies  Remove empty taxonomies
     *
     * @return  boolean  True on success.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function remove($id, $removeTaxonomies = true)
    {
        // Get the item's URL
        $url = $this->db->quote($this->getUrl($id, $this->extension, $this->layout));

        // Get the link ids for the content items.
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('link_id'))
            ->from($this->db->quoteName('#__finder_links'))
            ->where($this->db->quoteName('url') . ' = ' . $url);
        $this->db->setQuery($query);
        $items = $this->db->loadColumn();

        // Check the items.
        if (empty($items)) {
            Factory::getApplication()->triggerEvent('onFinderIndexAfterDelete', array($id));

            return true;
        }

        // Remove the items.
        foreach ($items as $item) {
            $this->indexer->remove($item, $removeTaxonomies);
        }

        return true;
    }

    /**
     * Method to setup the adapter before indexing.
     *
     * @return  boolean  True on success, false on failure.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    abstract protected function setup();

    /**
     * Method to update index data on category access level changes
     *
     * @param   Table  $row  A Table object
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function categoryAccessChange($row)
    {
        $query = clone $this->getStateQuery();
        $query->where('c.id = ' . (int) $row->id);

        // Get the access level.
        $this->db->setQuery($query);
        $items = $this->db->loadObjectList();

        // Adjust the access level for each item within the category.
        foreach ($items as $item) {
            // Set the access level.
            $temp = max($item->access, $row->access);

            // Update the item.
            $this->change((int) $item->id, 'access', $temp);
        }
    }

    /**
     * Method to update index data on category access level changes
     *
     * @param   array    $pks    A list of primary key ids of the content that has changed state.
     * @param   integer  $value  The value of the state that the content has been changed to.
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function categoryStateChange($pks, $value)
    {
        /*
         * The item's published state is tied to the category
         * published state so we need to look up all published states
         * before we change anything.
         */
        foreach ($pks as $pk) {
            $query = clone $this->getStateQuery();
            $query->where('c.id = ' . (int) $pk);

            // Get the published states.
            $this->db->setQuery($query);
            $items = $this->db->loadObjectList();

            // Adjust the state for each item within the category.
            foreach ($items as $item) {
                // Translate the state.
                $temp = $this->translateState($item->state, $value);

                // Update the item.
                $this->change($item->id, 'state', $temp);
            }
        }
    }

    /**
     * Method to check the existing access level for categories
     *
     * @param   Table  $row  A Table object
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function checkCategoryAccess($row)
    {
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('access'))
            ->from($this->db->quoteName('#__categories'))
            ->where($this->db->quoteName('id') . ' = ' . (int) $row->id);
        $this->db->setQuery($query);

        // Store the access level to determine if it changes
        $this->old_cataccess = $this->db->loadResult();
    }

    /**
     * Method to check the existing access level for items
     *
     * @param   Table  $row  A Table object
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function checkItemAccess($row)
    {
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('access'))
            ->from($this->db->quoteName($this->table))
            ->where($this->db->quoteName('id') . ' = ' . (int) $row->id);
        $this->db->setQuery($query);

        // Store the access level to determine if it changes
        $this->old_access = $this->db->loadResult();
    }

    /**
     * Method to get the number of content items available to index.
     *
     * @return  integer  The number of content items available to index.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function getContentCount()
    {
        $return = 0;

        // Get the list query.
        $query = $this->getListQuery();

        // Check if the query is valid.
        if (empty($query)) {
            return $return;
        }

        // Tweak the SQL query to make the total lookup faster.
        if ($query instanceof QueryInterface) {
            $query = clone $query;
            $query->clear('select')
                ->select('COUNT(*)')
                ->clear('order');
        }

        // Get the total number of content items to index.
        $this->db->setQuery($query);

        return (int) $this->db->loadResult();
    }

    /**
     * Method to get a content item to index.
     *
     * @param   integer  $id  The id of the content item.
     *
     * @return  Result  A Result object.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function getItem($id)
    {
        // Get the list query and add the extra WHERE clause.
        $query = $this->getListQuery();
        $query->where('a.id = ' . (int) $id);

        // Get the item to index.
        $this->db->setQuery($query);
        $item = $this->db->loadAssoc();

        // Convert the item to a result object.
        $item = ArrayHelper::toObject((array) $item, Result::class);

        // Set the item type.
        $item->type_id = $this->type_id;

        // Set the item layout.
        $item->layout = $this->layout;

        return $item;
    }

    /**
     * Method to get a list of content items to index.
     *
     * @param   integer         $offset  The list offset.
     * @param   integer         $limit   The list limit.
     * @param   QueryInterface  $query   A QueryInterface object. [optional]
     *
     * @return  Result[]  An array of Result objects.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function getItems($offset, $limit, $query = null)
    {
        // Get the content items to index.
        $this->db->setQuery($this->getListQuery($query)->setLimit($limit, $offset));
        $items = $this->db->loadAssocList();

        foreach ($items as &$item) {
            $item = ArrayHelper::toObject($item, Result::class);

            // Set the item type.
            $item->type_id = $this->type_id;

            // Set the mime type.
            $item->mime = $this->mime;

            // Set the item layout.
            $item->layout = $this->layout;
        }

        return $items;
    }

    /**
     * Method to get the SQL query used to retrieve the list of content items.
     *
     * @param   mixed  $query  A QueryInterface object. [optional]
     *
     * @return  QueryInterface  A database object.
     *
     * @since   2.5
     */
    protected function getListQuery($query = null)
    {
        // Check if we can use the supplied SQL query.
        return $query instanceof QueryInterface ? $query : $this->db->getQuery(true);
    }

    /**
     * Method to get the plugin type
     *
     * @param   integer  $id  The plugin ID
     *
     * @return  string  The plugin type
     *
     * @since   2.5
     */
    protected function getPluginType($id)
    {
        // Prepare the query
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('element'))
            ->from($this->db->quoteName('#__extensions'))
            ->where($this->db->quoteName('extension_id') . ' = ' . (int) $id);
        $this->db->setQuery($query);

        return $this->db->loadResult();
    }

    /**
     * Method to get a SQL query to load the published and access states for
     * an article and category.
     *
     * @return  QueryInterface  A database object.
     *
     * @since   2.5
     */
    protected function getStateQuery()
    {
        $query = $this->db->getQuery(true);

        // Item ID
        $query->select('a.id');

        // Item and category published state
        $query->select('a.' . $this->state_field . ' AS state, c.published AS cat_state');

        // Item and category access levels
        $query->select('a.access, c.access AS cat_access')
            ->from($this->table . ' AS a')
            ->join('LEFT', '#__categories AS c ON c.id = a.catid');

        return $query;
    }

    /**
     * Method to get the query clause for getting items to update by time.
     *
     * @param   string  $time  The modified timestamp.
     *
     * @return  QueryInterface  A database object.
     *
     * @since   2.5
     */
    protected function getUpdateQueryByTime($time)
    {
        // Build an SQL query based on the modified time.
        $query = $this->db->getQuery(true)
            ->where('a.modified >= ' . $this->db->quote($time));

        return $query;
    }

    /**
     * Method to get the query clause for getting items to update by id.
     *
     * @param   array  $ids  The ids to load.
     *
     * @return  QueryInterface  A database object.
     *
     * @since   2.5
     */
    protected function getUpdateQueryByIds($ids)
    {
        // Build an SQL query based on the item ids.
        $query = $this->db->getQuery(true)
            ->where('a.id IN(' . implode(',', $ids) . ')');

        return $query;
    }

    /**
     * Method to get the type id for the adapter content.
     *
     * @return  integer  The numeric type id for the content.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function getTypeId()
    {
        // Get the type id from the database.
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('id'))
            ->from($this->db->quoteName('#__finder_types'))
            ->where($this->db->quoteName('title') . ' = ' . $this->db->quote($this->type_title));
        $this->db->setQuery($query);

        return (int) $this->db->loadResult();
    }

    /**
     * Method to get the URL for the item. The URL is how we look up the link
     * in the Finder index.
     *
     * @param   integer  $id         The id of the item.
     * @param   string   $extension  The extension the category is in.
     * @param   string   $view       The view for the URL.
     *
     * @return  string  The URL of the item.
     *
     * @since   2.5
     */
    protected function getUrl($id, $extension, $view)
    {
        return 'index.php?option=' . $extension . '&view=' . $view . '&id=' . $id;
    }

    /**
     * Method to get the page title of any menu item that is linked to the
     * content item, if it exists and is set.
     *
     * @param   string  $url  The URL of the item.
     *
     * @return  mixed  The title on success, null if not found.
     *
     * @since   2.5
     * @throws  Exception on database error.
     */
    protected function getItemMenuTitle($url)
    {
        $return = null;

        // Set variables
        $user = Factory::getUser();
        $groups = implode(',', $user->getAuthorisedViewLevels());

        // Build a query to get the menu params.
        $query = $this->db->getQuery(true)
            ->select($this->db->quoteName('params'))
            ->from($this->db->quoteName('#__menu'))
            ->where($this->db->quoteName('link') . ' = ' . $this->db->quote($url))
            ->where($this->db->quoteName('published') . ' = 1')
            ->where($this->db->quoteName('access') . ' IN (' . $groups . ')');

        // Get the menu params from the database.
        $this->db->setQuery($query);
        $params = $this->db->loadResult();

        // Check the results.
        if (empty($params)) {
            return $return;
        }

        // Instantiate the params.
        $params = json_decode($params);

        // Get the page title if it is set.
        if (isset($params->page_title) && $params->page_title) {
            $return = $params->page_title;
        }

        return $return;
    }

    /**
     * Method to update index data on access level changes
     *
     * @param   Table  $row  A Table object
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function itemAccessChange($row)
    {
        $query = clone $this->getStateQuery();
        $query->where('a.id = ' . (int) $row->id);

        // Get the access level.
        $this->db->setQuery($query);
        $item = $this->db->loadObject();

        // Set the access level.
        $temp = max($row->access, $item->cat_access);

        // Update the item.
        $this->change((int) $row->id, 'access', $temp);
    }

    /**
     * Method to update index data on published state changes
     *
     * @param   array    $pks    A list of primary key ids of the content that has changed state.
     * @param   integer  $value  The value of the state that the content has been changed to.
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function itemStateChange($pks, $value)
    {
        /*
         * The item's published state is tied to the category
         * published state so we need to look up all published states
         * before we change anything.
         */
        foreach ($pks as $pk) {
            $query = clone $this->getStateQuery();
            $query->where('a.id = ' . (int) $pk);

            // Get the published states.
            $this->db->setQuery($query);
            $item = $this->db->loadObject();

            // Translate the state.
            $temp = $this->translateState($value, $item->cat_state);

            // Update the item.
            $this->change($pk, 'state', $temp);
        }
    }

    /**
     * Method to update index data when a plugin is disabled
     *
     * @param   array  $pks  A list of primary key ids of the content that has changed state.
     *
     * @return  void
     *
     * @since   2.5
     */
    protected function pluginDisable($pks)
    {
        // Since multiple plugins may be disabled at a time, we need to check first
        // that we're handling the appropriate one for the context
        foreach ($pks as $pk) {
            if ($this->getPluginType($pk) == strtolower($this->context)) {
                // Get all of the items to unindex them
                $query = clone $this->getStateQuery();
                $this->db->setQuery($query);
                $items = $this->db->loadColumn();

                // Remove each item
                foreach ($items as $item) {
                    $this->remove($item);
                }
            }
        }
    }

    /**
     * Method to translate the native content states into states that the
     * indexer can use.
     *
     * @param   integer  $item      The item state.
     * @param   integer  $category  The category state. [optional]
     *
     * @return  integer  The translated indexer state.
     *
     * @since   2.5
     */
    protected function translateState($item, $category = null)
    {
        // If category is present, factor in its states as well
        if ($category !== null && $category == 0) {
            $item = 0;
        }

        // Translate the state
        switch ($item) {
            // Published and archived items only should return a published state
            case 1:
            case 2:
                return 1;

            // All other states should return an unpublished state
            default:
                return 0;
        }
    }
}