<?php
/**
 * Shared wpdb helpers for Bookline repositories.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Infrastructure\Persistence;

use DateTimeImmutable;
use DateTimeZone;
use RuntimeException;
use wpdb;

/**
 * Base for prepared-query repositories.
 *
 * @since 0.1.0
 */
abstract class AbstractWpdbRepository {

	/**
	 * Backing field.
	 *
	 * @var wpdb
	 */
	protected wpdb $db;

	/**
	 * Constructor.
	 *
	 * @param wpdb|null $db Database handle.
	 */
	public function __construct( ?wpdb $db = null ) {
		if ( null === $db ) {
			global $wpdb;
			$db = $wpdb;
		}
		$this->db = $db;
	}

	/**
	 * Prefixed table name.
	 *
	 * @param string $suffix Table suffix without prefix (e.g. bookings).
	 *
	 * @since 0.1.0
	 */
	protected function table( string $suffix ): string {
		return $this->db->prefix . 'bookline_' . $suffix;
	}

	/**
	 * Format a UTC instant for DATETIME storage.
	 *
	 * @param DateTimeImmutable $dt Instant.
	 *
	 * @since 0.1.0
	 */
	protected function format_datetime( DateTimeImmutable $dt ): string {
		return $dt->setTimezone( new DateTimeZone( 'UTC' ) )->format( 'Y-m-d H:i:s' );
	}

	/**
	 * Parse a DATETIME string as UTC.
	 *
	 * @param string $value MySQL DATETIME.
	 *
	 * @throws RuntimeException When the value is invalid.
	 *
	 * @since 0.1.0
	 */
	protected function parse_datetime( string $value ): DateTimeImmutable {
		$dt = DateTimeImmutable::createFromFormat( 'Y-m-d H:i:s', $value, new DateTimeZone( 'UTC' ) );
		if ( false === $dt ) {
			throw new RuntimeException( 'Invalid DATETIME value from database.' );
		}
		return $dt;
	}

	/**
	 * Encode meta array to JSON or null.
	 *
	 * @param array<string, mixed>|null $meta Meta.
	 *
	 * @throws RuntimeException When encoding fails.
	 *
	 * @since 0.1.0
	 */
	protected function encode_meta( ?array $meta ): ?string {
		if ( null === $meta ) {
			return null;
		}
		$json = wp_json_encode( $meta );
		if ( false === $json ) {
			throw new RuntimeException( 'Failed to encode meta JSON.' );
		}
		return $json;
	}

	/**
	 * Decode meta JSON.
	 *
	 * @param string|null $json JSON.
	 * @return array<string, mixed>|null
	 *
	 * @since 0.1.0
	 */
	protected function decode_meta( ?string $json ): ?array {
		if ( null === $json || '' === $json ) {
			return null;
		}
		$decoded = json_decode( $json, true );
		return is_array( $decoded ) ? $decoded : null;
	}

	/**
	 * Last insert id as int.
	 *
	 * @since 0.1.0
	 */
	protected function last_insert_id(): int {
		return (int) $this->db->insert_id;
	}

	/**
	 * Run a prepared statement when prepare() succeeded.
	 *
	 * @param string|null $sql Prepared SQL.
	 *
	 * @since 0.1.0
	 */
	protected function query_prepared( ?string $sql ): void {
		if ( ! is_string( $sql ) ) {
			return;
		}
		$this->db->query( $sql );
	}

	/**
	 * Count rows that have not been soft-deleted.
	 *
	 * @param string $suffix Table suffix (services, agents, locations).
	 */
	protected function count_not_deleted( string $suffix ): int {
		$sql = $this->db->prepare(
			'SELECT COUNT(*) FROM %i WHERE `deleted_at` IS NULL',
			$this->table( $suffix )
		);
		if ( ! is_string( $sql ) ) {
			return 0;
		}
		return (int) $this->db->get_var( $sql );
	}
}