<?php
namespace ILJ\Core;

use ILJ\Backend\BatchInfo;
use ILJ\Core\IndexStrategy\DefaultStrategy;
use ILJ\Core\IndexStrategy\StrategyInterface;
use ILJ\Backend\Environment;
use ILJ\Database\LinkindexTemp;
use ILJ\Helper\BatchInfo as HelperBatchInfo;
use ILJ\Helper\Stopwatch;

/**
 * IndexBuilder
 *
 * This class is responsible for the creation of the links
 *
 * @package ILJ\Core
 *
 * @since 1.0.0
 */
class IndexBuilder {

	const ILJ_ACTION_AFTER_INDEX_BUILT              = 'ilj_after_index_built';
	const ILJ_FILTER_INDEX_STRATEGY                 = 'ilj_index_strategy';
	const ILJ_INITIATE_BATCH_REBUILD                = 'initiate_ilj_batch_rebuild';
	const ILJ_SET_BATCHED_INDEX_REBUILD             = 'ilj_set_batched_index_rebuild';
	const ILJ_BUILD_BATCHED_INDEX                   = 'ilj_build_batched_index';
	const ILJ_DELETE_INDEX_BY_ID                    = 'ilj_delete_index_by_id';
	const ILJ_SET_INDIVIDUAL_INDEX_REBUILD          = 'ilj_set_individual_index_rebuild';
	const ILJ_INDIVIDUAL_INDEX_REBUILD_OUTGOING     = 'ilj_individual_index_rebuild_outgoing';
	const ILJ_INDIVIDUAL_INDEX_REBUILD_INCOMING     = 'ilj_individual_index_rebuild_incoming';
	const ILJ_SET_INDIVIDUAL_INDEX_REBUILD_INCOMING = 'ilj_set_individual_index_rebuild_incoming';
	const ILJ_INDIVIDUAL_DELETE_INDEX               = 'ilj_individual_delete_index';
	const ILJ_RUN_SETTING_BATCHED_INDEX_REBUILD     = 'ilj_run_setting_batched_index_rebuild';
	const ILJ_UPDATE_STATISTICS_INFO                = 'ilj_update_statistics_info';

	/**
	 * Strategy variable
	 *
	 * @var   StrategyInterface|null
	 * @since 1.2.0
	 */
	public $strategy = null;

	public $link_options;

	public $batched_data = array();

	public $batched_data_type = '';

	public $keyword_offset = 0;

	public $keyword_type = '';

	public function __construct() {
		 $link_options = array();
		$link_options['multi_keyword_mode'] = (bool) Options::getOption(\ILJ\Core\Options\MultipleKeywords::getKey());
		$link_options['links_per_page']     = (false === $link_options['multi_keyword_mode']) ? Options::getOption(\ILJ\Core\Options\LinksPerPage::getKey()) : 0;
		$link_options['links_per_target']   = (false === $link_options['multi_keyword_mode']) ? Options::getOption(\ILJ\Core\Options\LinksPerTarget::getKey()) : 0;
		
		$this->link_options = $link_options;
		$strategy           = new DefaultStrategy();

		/**
		 * Filter and change the strategy that gets used to build the index
		 *
		 * WARNING: Changing this data may throw an exception.
		 *
		 * @since 1.2.0
		 *
		 * @param StrategyInterface $strategy
		 */
		$strategy = apply_filters(self::ILJ_FILTER_INDEX_STRATEGY, $strategy);

		if (!$strategy instanceof StrategyInterface) {
			throw new \Exception('The filtered strategy must implement StrategyInterface.');
		}

		$strategy->setLinkOptions($link_options);
		$this->setStrategy($strategy);
	}

	/**
	 * Executes all processes for building a new index
	 *
	 * @since 1.0.0
	 *
	 * @return array
	 */
	public function buildIndex() {
		if (!$this->strategy) {
			return array();
		}

		LinkindexTemp::install_temp_db();
		$stopwatch = new Stopwatch;

		$status_update = array(
			"last_update" => array(
				"batch_count" => 1,
				"batch_finished" => 0,
				"last_update" => Stopwatch::timestamp(),
				"status" => HelperBatchInfo::STATE_BUILDING,
			)
		);
		BatchInfo::update('batch_build', $status_update);

		$entries_count = $this->strategy->setIndices();
		$duration      = $stopwatch->duration();
		
		$feedback = array(
			"last_update" => array(
				"date"     => Stopwatch::timestamp(),
				"entries"  => $entries_count,
				"duration" => $duration
			)
		);

		Environment::update('linkindex', $feedback);

		LinkindexTemp::switchTableTemp();

		$status_update = array(
			"last_update" => array(
				"batch_count" => 1,
				"batch_finished" => 1,
				"last_update" => Stopwatch::timestamp(),
				"status" => HelperBatchInfo::STATE_COMPLETED,
			)
		);

		BatchInfo::update('batch_build', $status_update);

		/**
		 * Fires after the index got built.
		 *
		 * @since 1.0.0
		 */
		do_action(self::ILJ_ACTION_AFTER_INDEX_BUILT);

		return $feedback;
	}

	/**
	 * Set the individual index builds
	 *
	 * @param  int    $id
	 * @param  string $type
	 * @param  string $link_type
	 * @return void
	 */
	public function buildIndividualIndex($id, $type, $link_type) {
		if (!$this->strategy) {
			return array();
		}

		$this->strategy->setIndividualIndices($id, $type, $link_type, $this->keyword_offset, $this->keyword_type, $this->batched_data, $this->batched_data_type);

		/**
		 * Fires after the index got built.
		 *
		 * @since 1.0.0
		 */
		do_action(self::ILJ_ACTION_AFTER_INDEX_BUILT);
	}

	/**
	 * Sets the index building strategy
	 *
	 * @since 1.2.0
	 * @param StrategyInterface $strategy The strategy that gets used to build the index
	 *
	 * @return void
	 */
	public function setStrategy(StrategyInterface $strategy) {
		$this->strategy = $strategy;
	}

	/**
	 * Set the batched data value
	 *
	 * @param  mixed $batched_data
	 */
	public function setBatchedData($batched_data) {
		$this->batched_data = $batched_data;
	}

	/**
	 * Set the Type of the batched data
	 *
	 * @param  string $batched_data_type
	 */
	public function setBatchedDataType($batched_data_type) {
		$this->batched_data_type = $batched_data_type;
	}

	/**
	 * Set the keyword offset
	 *
	 * @param  int $keyword_offset
	 */
	public function setBatchedKeywordOffset($keyword_offset) {
		$this->keyword_offset = $keyword_offset;
	}

	/**
	 * Set the type of the batched keyword
	 *
	 * @param  string $keyword_type
	 */
	public function setBatchedKeywordType($keyword_type) {
		$this->keyword_type = $keyword_type;
	}

	/**
	 * Executes batched process for building a new index
	 *
	 * @since 1.3.10
	 *
	 * @return void
	 */
	public function buildBatchedIndex() {
		if (!$this->strategy) {
			return array();
		}

		$this->strategy->setBatchedIndices($this->batched_data, $this->batched_data_type, $this->keyword_offset, $this->keyword_type);

	}
}