<?php
/**
 * API\Reports\Downloads\Stats\DataStore class file.
 */

namespace Automattic\Kkart\Admin\API\Reports\Downloads\Stats;

defined( 'ABSPATH' ) || exit;

use \Automattic\Kkart\Admin\API\Reports\Downloads\DataStore as DownloadsDataStore;
use \Automattic\Kkart\Admin\API\Reports\DataStoreInterface;
use \Automattic\Kkart\Admin\API\Reports\TimeInterval;
use \Automattic\Kkart\Admin\API\Reports\SqlQuery;

/**
 * API\Reports\Downloads\Stats\DataStore.
 */
class DataStore extends DownloadsDataStore implements DataStoreInterface {

	/**
	 * Mapping columns to data type to return correct response types.
	 *
	 * @var array
	 */
	protected $column_types = array(
		'download_count' => 'intval',
	);

	/**
	 * Cache identifier.
	 *
	 * @var string
	 */
	protected $cache_key = 'downloads_stats';

	/**
	 * Data store context used to pass to filters.
	 *
	 * @var string
	 */
	protected $context = 'downloads_stats';

	/**
	 * Assign report columns once full table name has been assigned.
	 */
	protected function assign_report_columns() {
		$this->report_columns = array(
			'download_count' => 'COUNT(DISTINCT download_log_id) as download_count',
		);
	}

	/**
	 * Returns the report data based on parameters supplied by the user.
	 *
	 * @param array $query_args  Query parameters.
	 * @return stdClass|WP_Error Data.
	 */
	public function get_data( $query_args ) {
		global $wpdb;

		$table_name = self::get_db_table_name();

		// These defaults are only partially applied when used via REST API, as that has its own defaults.
		$defaults   = array(
			'per_page' => get_option( 'posts_per_page' ),
			'page'     => 1,
			'order'    => 'DESC',
			'orderby'  => 'date',
			'fields'   => '*',
			'interval' => 'week',
			'before'   => TimeInterval::default_before(),
			'after'    => TimeInterval::default_after(),
		);
		$query_args = wp_parse_args( $query_args, $defaults );
		$this->normalize_timezones( $query_args, $defaults );

		/*
		 * We need to get the cache key here because
		 * parent::update_intervals_sql_params() modifies $query_args.
		 */
		$cache_key = $this->get_cache_key( $query_args );
		$data      = $this->get_cached_data( $cache_key );

		if ( false === $data ) {
			$this->initialize_queries();
			$selections = $this->selected_columns( $query_args );
			$this->add_sql_query_params( $query_args );
			$this->add_time_period_sql_params( $query_args, $table_name );
			$this->add_intervals_sql_params( $query_args, $table_name );

			$this->interval_query->add_sql_clause( 'select', $this->get_sql_clause( 'select' ) . ' AS time_interval' );
			$this->interval_query->str_replace_clause( 'select', 'date_created', 'timestamp' );
			$this->interval_query->str_replace_clause( 'where_time', 'date_created', 'timestamp' );

			$db_intervals = $wpdb->get_col(
				$this->interval_query->get_query_statement()
			); // WPCS: cache ok, DB call ok, , unprepared SQL ok.

			$db_records_count = count( $db_intervals );

			$params                  = $this->get_limit_params( $query_args );
			$expected_interval_count = TimeInterval::intervals_between( $query_args['after'], $query_args['before'], $query_args['interval'] );
			$total_pages             = (int) ceil( $expected_interval_count / $params['per_page'] );
			if ( $query_args['page'] < 1 || $query_args['page'] > $total_pages ) {
				return array();
			}

			$this->update_intervals_sql_params( $query_args, $db_records_count, $expected_interval_count, $table_name );
			$this->interval_query->str_replace_clause( 'where_time', 'date_created', 'timestamp' );
			$this->total_query->add_sql_clause( 'select', $selections );
			$this->total_query->add_sql_clause( 'where', $this->interval_query->get_sql_clause( 'where' ) );
			$totals = $wpdb->get_results(
				$this->total_query->get_query_statement(),
				ARRAY_A
			); // WPCS: cache ok, DB call ok, unprepared SQL ok.

			if ( null === $totals ) {
				return new \WP_Error( 'kkart_analytics_downloads_stats_result_failed', __( 'Sorry, fetching downloads data failed.', 'kkart' ) );
			}

			$this->interval_query->add_sql_clause( 'order_by', $this->get_sql_clause( 'order_by' ) );
			$this->interval_query->add_sql_clause( 'limit', $this->get_sql_clause( 'limit' ) );
			$this->interval_query->add_sql_clause( 'select', ', MAX(timestamp) AS datetime_anchor' );
			if ( '' !== $selections ) {
				$this->interval_query->add_sql_clause( 'select', ', ' . $selections );
			}

			$intervals = $wpdb->get_results(
				$this->interval_query->get_query_statement(),
				ARRAY_A
			); // WPCS: cache ok, DB call ok, unprepared SQL ok.

			if ( null === $intervals ) {
				return new \WP_Error( 'kkart_analytics_downloads_stats_result_failed', __( 'Sorry, fetching downloads data failed.', 'kkart' ) );
			}

			$totals = (object) $this->cast_numbers( $totals[0] );
			$data   = (object) array(
				'totals'    => $totals,
				'intervals' => $intervals,
				'total'     => $expected_interval_count,
				'pages'     => $total_pages,
				'page_no'   => (int) $query_args['page'],
			);

			if ( $this->intervals_missing( $expected_interval_count, $db_records_count, $params['per_page'], $query_args['page'], $query_args['order'], $query_args['orderby'], count( $intervals ) ) ) {
				$this->fill_in_missing_intervals( $db_intervals, $query_args['adj_after'], $query_args['adj_before'], $query_args['interval'], $data );
				$this->sort_intervals( $data, $query_args['orderby'], $query_args['order'] );
				$this->remove_extra_records( $data, $query_args['page'], $params['per_page'], $db_records_count, $expected_interval_count, $query_args['orderby'], $query_args['order'] );
			} else {
				$this->update_interval_boundary_dates( $query_args['after'], $query_args['before'], $query_args['interval'], $data->intervals );
			}
			$this->create_interval_subtotals( $data->intervals );

			$this->set_cached_data( $cache_key, $data );
		}

		return $data;
	}

	/**
	 * Normalizes order_by clause to match to SQL query.
	 *
	 * @param string $order_by Order by option requeste by user.
	 * @return string
	 */
	protected function normalize_order_by( $order_by ) {
		if ( 'date' === $order_by ) {
			return 'time_interval';
		}

		return $order_by;
	}

	/**
	 * Initialize query objects.
	 */
	protected function initialize_queries() {
		$this->clear_all_clauses();
		unset( $this->subquery );
		$this->total_query = new SqlQuery( $this->context . '_total' );
		$this->total_query->add_sql_clause( 'from', self::get_db_table_name() );

		$this->interval_query = new SqlQuery( $this->context . '_interval' );
		$this->interval_query->add_sql_clause( 'from', self::get_db_table_name() );
		$this->interval_query->add_sql_clause( 'group_by', 'time_interval' );
	}
}
