<?php
/**
 * Issued codes, uses, savings and revenue per campaign, counted in SQL.
 *
 * @package CNWS\Coupons
 */

namespace CNWS\Coupons;

defined( 'ABSPATH' ) || exit;

// phpcs:disable WordPress.DB.DirectDatabaseQuery -- Aggregates over the plugin's own tables, named through %i.

final class CampaignStats {

	/**
	 * Stats for every campaign, keyed by campaign ID. Campaigns without codes or uses are missing;
	 * use empty() for a zero row.
	 *
	 * @return array<int, array{issued: int, redemptions: int, saved: float, revenue: float}>
	 */
	public function all(): array {
		global $wpdb;

		$stats = array();

		$issued = (array) $wpdb->get_results(
			$wpdb->prepare( "SELECT campaign_id, SUM( email <> '' ) AS issued FROM %i GROUP BY campaign_id", Tables::codes() )
		);

		foreach ( $issued as $row ) {
			$stats[ (int) $row->campaign_id ]           = self::empty();
			$stats[ (int) $row->campaign_id ]['issued'] = (int) $row->issued;
		}

		$used = (array) $wpdb->get_results(
			$wpdb->prepare(
				'SELECT campaign_id, COUNT(*) AS redemptions, SUM( discount_amount ) AS saved, SUM( order_total ) AS revenue FROM %i WHERE released_at IS NULL GROUP BY campaign_id',
				Tables::redemptions()
			)
		);

		foreach ( $used as $row ) {
			$id = (int) $row->campaign_id;

			$stats[ $id ] = array_merge(
				$stats[ $id ] ?? self::empty(),
				array(
					'redemptions' => (int) $row->redemptions,
					'saved'       => round( (float) $row->saved, 2 ),
					'revenue'     => round( (float) $row->revenue, 2 ),
				)
			);
		}

		return $stats;
	}

	/**
	 * @param int $campaign_id Campaign ID.
	 */
	public function for_campaign( int $campaign_id ): array {
		return $this->all()[ $campaign_id ] ?? self::empty();
	}

	public static function empty(): array {
		return array(
			'issued'      => 0,
			'redemptions' => 0,
			'saved'       => 0.0,
			'revenue'     => 0.0,
		);
	}
}