<?php
/**
 * Loyalty programme performance for the store owner's dashboard.
 *
 * @package LoyaltySpin
 */

namespace LoyaltyPress\Admin;

use LoyaltyPress\Coins\Ledger;
use LoyaltyPress\Coins\Redeem;

defined( 'ABSPATH' ) || exit;

/**
 * Stats (cached for 15 minutes per period).
 */
class Stats {

	const PERIODS = array( 7, 30, 90 );

	/**
	 * Get stats for the last N days.
	 *
	 * @param int $days Period.
	 * @return array
	 */
	public static function get( $days = 30 ) {
		$days = in_array( (int) $days, self::PERIODS, true ) ? (int) $days : 30;
		$key  = 'loyaltypress_stats_' . $days;
		$hit  = get_transient( $key );
		if ( is_array( $hit ) ) {
			return $hit;
		}
		$stats = self::compute( $days );
		set_transient( $key, $stats, 15 * MINUTE_IN_SECONDS );
		return $stats;
	}

	/**
	 * Clear cached stats (after big changes).
	 */
	public static function flush() {
		foreach ( self::PERIODS as $d ) {
			delete_transient( 'loyaltypress_stats_' . $d );
		}
	}

	/**
	 * Compute.
	 *
	 * @param int $days Period.
	 * @return array
	 */
	private static function compute( $days ) {
		global $wpdb;
		$l     = Ledger::table();
		$p     = $wpdb->prefix . 'loyaltypress_';
		$since = gmdate( 'Y-m-d H:i:s', time() - DAY_IN_SECONDS * $days );

		// phpcs:disable WordPress.DB.DirectDatabaseQuery,WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		$members     = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(DISTINCT user_id) FROM %i', $l ) );
		$new_members = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM (SELECT user_id, MIN(created_at) first_at FROM %i GROUP BY user_id) x WHERE x.first_at >= %s', $l, $since ) );
		$order_ids   = array_map( 'intval', $wpdb->get_col( $wpdb->prepare( "SELECT DISTINCT order_id FROM %i WHERE type = 'earn' AND order_id > 0 AND created_at >= %s ORDER BY order_id DESC LIMIT 3000", $l, $since ) ) );
		$buyers      = array_map( 'intval', $wpdb->get_col( $wpdb->prepare( "SELECT DISTINCT user_id FROM %i WHERE type = 'earn' AND order_id > 0 AND created_at >= %s", $l, $since ) ) );
		$repeaters   = 0;
		if ( $buyers ) {
			$in        = implode( ',', array_fill( 0, count( $buyers ), '%d' ) );
			$repeaters = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM (SELECT user_id FROM %i WHERE type = 'earn' AND order_id > 0 AND user_id IN ({$in}) GROUP BY user_id HAVING COUNT(DISTINCT order_id) > 1) r", array_merge( array( $l ), $buyers ) ) ); // phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
		}
		$redeemed = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COALESCE(-SUM(amount),0) FROM %i WHERE type = 'redeem' AND created_at >= %s", $l, $since ) )
			- (int) $wpdb->get_var( $wpdb->prepare( "SELECT COALESCE(SUM(amount),0) FROM %i WHERE type = 'refund' AND created_at >= %s", $l, $since ) );
		$issued   = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COALESCE(SUM(amount),0) FROM %i WHERE amount > 0 AND type IN ('earn','prize','adjust') AND created_at >= %s", $l, $since ) );
		$spins    = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i WHERE created_at >= %s', $p . 'spin_results', $since ) );
		// phpcs:enable

		$sales = 0.0;
		$tier  = 0.0;
		foreach ( $order_ids as $id ) {
			$order = wc_get_order( $id );
			if ( ! $order ) {
				continue;
			}
			$sales += (float) $order->get_total() - (float) $order->get_total_refunded();
			foreach ( $order->get_fees() as $fee ) {
				if ( 'tier' === $fee->get_meta( '_loyaltypress_fee' ) ) {
					$tier += abs( (float) $fee->get_total() );
				}
			}
		}

		$customers = new \WP_User_Query(
			array(
				'role'        => 'customer',
				'number'      => 1,
				'fields'      => 'ID',
				'count_total' => true,
			)
		);
		$coins_val = Redeem::value_of( max( 0, $redeemed ) );
		$cost      = $coins_val + $tier;

		return array(
			'days'          => $days,
			'members'       => $members,
			'customers'     => (int) $customers->get_total(),
			'new_members'   => $new_members,
			'orders'        => count( $order_ids ),
			'sales'         => $sales,
			'buyers'        => count( $buyers ),
			'repeat_rate'   => $buyers ? round( $repeaters / count( $buyers ) * 100 ) : 0,
			'coins_issued'  => $issued,
			'coins_used'    => max( 0, $redeemed ),
			'coins_value'   => $coins_val,
			'tier_discount' => $tier,
			'cost'          => $cost,
			'cost_pct'      => $sales > 0 ? round( $cost / $sales * 100, 1 ) : 0,
			'spins'         => $spins,
			'at'            => time(),
		);
	}
}