<?php
/**
 * Customer credit repository.
 *
 * @package HostKhata
 */

namespace HostKhata\Database\Repositories;

defined( 'ABSPATH' ) || exit;

use HostKhata\Database\Tables;
use HostKhata\Support\Date;

/**
 * Reads and writes the credit ledger and keeps the customer's balance in step.
 *
 * @since 0.1.0
 */
final class CreditRepository extends AbstractRepository {

	/**
	 * Current balance of a customer.
	 *
	 * @since 0.1.0
	 *
	 * @param int $customer_id Customer id.
	 * @return int Minor units.
	 */
	public function balance( int $customer_id ): int {
		$table = Tables::name( 'customers' );

		return (int) $this->value( "SELECT credit_balance FROM {$table} WHERE id = %d", array( $customer_id ) );
	}

	/**
	 * Changes a customer's balance by a signed amount and writes a ledger line.
	 *
	 * The balance changes in one statement that refuses to go below zero, so two
	 * requests at once cannot spend the same credit twice.
	 *
	 * @since 0.1.0
	 *
	 * @param int    $customer_id  Customer id.
	 * @param int    $amount       Signed amount in minor units.
	 * @param string $reason       Why.
	 * @param string $related_type Related object type, such as `invoice`.
	 * @param int    $related_id   Related object id.
	 * @param int    $created_by   User id.
	 * @return int|null New balance, or null when the balance would go below zero.
	 */
	public function adjust( int $customer_id, int $amount, string $reason, string $related_type = '', int $related_id = 0, int $created_by = 0 ): ?int {
		$customers = Tables::name( 'customers' );

		$changed = $this->wpdb->query( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.PreparedSQL.NotPrepared,PluginCheck.Security.DirectDB.UnescapedDBParameter -- Table name from Tables; values prepared.
			$this->wpdb->prepare( "UPDATE {$customers} SET credit_balance = credit_balance + %d WHERE id = %d AND credit_balance + %d >= 0", $amount, $customer_id, $amount ) // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQL.NotPrepared
		);

		if ( 1 !== $changed ) {
			return null;
		}

		$balance = $this->balance( $customer_id );

		$row = array(
			'customer_id'    => $customer_id,
			'amount'         => $amount,
			'balance_after'  => $balance,
			'reason'         => $reason,
			'related_type'   => $related_type,
			'related_id'     => $related_id,
			'created_by'     => $created_by,
			'created_at_gmt' => Date::now_gmt(),
		);

		$this->wpdb->insert( Tables::name( 'credits' ), $row, array( '%d', '%d', '%d', '%s', '%s', '%d', '%d', '%s' ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching

		return $balance;
	}

	/**
	 * Ledger lines of a customer, newest first.
	 *
	 * @since 0.1.0
	 *
	 * @param int $customer_id Customer id.
	 * @param int $limit       Maximum number of lines.
	 * @return array<int, array<string, mixed>>
	 */
	public function for_customer( int $customer_id, int $limit = 100 ): array {
		$table = Tables::name( 'credits' );
		$rows  = $this->rows(
			"SELECT c.*, u.display_name AS actor_name FROM {$table} c LEFT JOIN {$this->wpdb->users} u ON u.ID = c.created_by WHERE c.customer_id = %d ORDER BY c.id DESC LIMIT %d",
			array( $customer_id, max( 1, min( 500, $limit ) ) )
		);

		return array_map(
			static function ( array $row ) {
				foreach ( array( 'id', 'customer_id', 'amount', 'balance_after', 'related_id', 'created_by' ) as $column ) {
					$row[ $column ] = (int) $row[ $column ];
				}

				$row['actor_name'] = (string) $row['actor_name'];

				return $row;
			},
			$rows
		);
	}
}