<?php
/**
 * API\Reports\Coupons\Stats\DataStore class file.
 *
 * @package WooCommerce Admin/Classes
 */

namespace Automattic\WooCommerce\Admin\API\Reports\Coupons\Stats;

defined( 'ABSPATH' ) || exit;
use \Automattic\WooCommerce\Admin\API\Reports\Coupons\DataStore as CouponsDataStore;
use \Automattic\WooCommerce\Admin\API\Reports\DataStoreInterface;
use \Automattic\WooCommerce\Admin\API\Reports\TimeInterval;
use \Automattic\WooCommerce\Admin\API\Reports\SqlQuery;

/**
 * API\Reports\Coupons\Stats\DataStore.
 */
class DataStore extends CouponsDataStore implements DataStoreInterface {
	/**
	 * Mapping columns to data type to return correct response types.
	 *
	 * @var array
	 */
	protected $column_types = array(
		'date_start'     => 'strval',
		'date_end'       => 'strval',
		'date_start_gmt' => 'strval',
		'date_end_gmt'   => 'strval',
		'amount'         => 'floatval',
		'coupons_count'  => 'intval',
		'orders_count'   => 'intval',
	);

	/**
	 * SQL columns to select in the db query.
	 *
	 * @var array
	 */
	protected $report_columns;

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

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

	/**
	 * Assign report columns once full table name has been assigned.
	 */
	protected function assign_report_columns() {
		$table_name           = self::get_db_table_name();
		$this->report_columns = array(
			'amount'        => 'SUM(discount_amount) as amount',
			'coupons_count' => 'COUNT(DISTINCT coupon_id) as coupons_count',
			'orders_count'  => "COUNT(DISTINCT {$table_name}.order_id) as orders_count",
		);
	}

	/**
	 * Updates the database query with parameters used for Products Stats report: categories and order status.
	 *
	 * @param array $query_args       Query arguments supplied by the user.
	 */
	protected function update_sql_query_params( $query_args ) {
		global $wpdb;

		$clauses = array(
			'where' => '',
			'join'  => '',
		);

		$order_coupon_lookup_table = self::get_db_table_name();

		$included_coupons = $this->get_included_coupons( $query_args, 'coupons' );
		if ( $included_coupons ) {
			$clauses['where'] .= " AND {$order_coupon_lookup_table}.coupon_id IN ({$included_coupons})";
		}

		$order_status_filter = $this->get_status_subquery( $query_args );
		if ( $order_status_filter ) {
			$clauses['join']  .= " JOIN {$wpdb->prefix}wc_order_stats ON {$order_coupon_lookup_table}.order_id = {$wpdb->prefix}wc_order_stats.order_id";
			$clauses['where'] .= " AND ( {$order_status_filter} )";
		}

		$this->add_time_period_sql_params( $query_args, $order_coupon_lookup_table );
		$this->add_intervals_sql_params( $query_args, $order_coupon_lookup_table );
		$clauses['where_time'] = $this->get_sql_clause( 'where_time' );

		$this->interval_query->add_sql_clause( 'limit', $this->get_sql_clause( 'limit' ) );
		$this->interval_query->add_sql_clause( 'order_by', $this->get_sql_clause( 'order_by' ) );
		$this->interval_query->add_sql_clause( 'select', $this->get_sql_clause( 'select' ) );
		$this->interval_query->add_sql_clause( 'select', 'AS time_interval' );

		foreach ( array( 'join', 'where_time', 'where' ) as $clause ) {
			$this->interval_query->add_sql_clause( $clause, $clauses[ $clause ] );
			$this->total_query->add_sql_clause( $clause, $clauses[ $clause ] );
		}
	}

	/**
	 * Returns the report data based on parameters supplied by the user.
	 *
	 * @since 3.5.0
	 * @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',
			'before'   => TimeInterval::default_before(),
			'after'    => TimeInterval::default_after(),
			'fields'   => '*',
			'interval' => 'week',
			'coupons'  => array(),
		);
		$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();

			$data = (object) array(
				'data'    => array(),
				'total'   => 0,
				'pages'   => 0,
				'page_no' => 0,
			);

			$selections      = $this->selected_columns( $query_args );
			$totals_query    = array();
			$intervals_query = array();
			$limit_params    = $this->get_limit_sql_params( $query_args );
			$this->update_sql_query_params( $query_args, $totals_query, $intervals_query );

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

			$db_interval_count       = count( $db_intervals );
			$expected_interval_count = TimeInterval::intervals_between( $query_args['after'], $query_args['before'], $query_args['interval'] );
			$total_pages             = (int) ceil( $expected_interval_count / $limit_params['per_page'] );
			if ( $query_args['page'] < 1 || $query_args['page'] > $total_pages ) {
				return $data;
			}

			$this->total_query->add_sql_clause( 'select', $selections );
			$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 $data;
			}

			// @todo remove these assignements when refactoring segmenter classes to use query objects.
			$totals_query          = array(
				'from_clause'       => $this->total_query->get_sql_clause( 'join' ),
				'where_time_clause' => $this->total_query->get_sql_clause( 'where_time' ),
				'where_clause'      => $this->total_query->get_sql_clause( 'where' ),
			);
			$intervals_query       = array(
				'select_clause'     => $this->get_sql_clause( 'select' ),
				'from_clause'       => $this->interval_query->get_sql_clause( 'join' ),
				'where_time_clause' => $this->interval_query->get_sql_clause( 'where_time' ),
				'where_clause'      => $this->interval_query->get_sql_clause( 'where' ),
				'limit'             => $this->get_sql_clause( 'limit' ),
			);
			$segmenter             = new Segmenter( $query_args, $this->report_columns );
			$totals[0]['segments'] = $segmenter->get_totals_segments( $totals_query, $table_name );
			$totals                = (object) $this->cast_numbers( $totals[0] );

			// Intervals.
			$this->update_intervals_sql_params( $query_args, $db_interval_count, $expected_interval_count, $table_name );
			$this->interval_query->add_sql_clause( 'select', ", MAX({$table_name}.date_created) 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 $data;
			}

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

			if ( TimeInterval::intervals_missing( $expected_interval_count, $db_interval_count, $limit_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'], $limit_params['per_page'], $db_interval_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 );
			}
			$segmenter->add_intervals_segments( $data, $intervals_query, $table_name );
			$this->create_interval_subtotals( $data->intervals );

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

		return $data;
	}

	/**
	 * 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' );
	}
}
