<?php
/**
 * Base class for custom-table repositories.
 *
 * Every read is cached in the "rentbaik" object cache group and invalidated with a
 * last-changed key per table, so plugins with a persistent object cache stay fast.
 *
 * @package Rentbaik
 */

namespace Rentbaik\Database;

defined( 'ABSPATH' ) || exit;

/**
 * Shared CRUD helpers for one rentbaik_* table.
 */
abstract class Repository {

	/**
	 * Short table name, e.g. "locations".
	 *
	 * @return string
	 */
	abstract protected static function table_name(): string;

	/**
	 * Full table name.
	 *
	 * @return string
	 */
	public static function table(): string {
		return Schema::table( static::table_name() );
	}

	/**
	 * Cache group key used for last-changed invalidation.
	 *
	 * @return string
	 */
	protected static function cache_scope(): string {
		return 'rentbaik_' . static::table_name();
	}

	/**
	 * Mark the table as changed so cached reads are refreshed.
	 *
	 * @return void
	 */
	protected static function touch(): void {
		wp_cache_set_last_changed( static::cache_scope() );
		self::bump_data_version();
	}

	/**
	 * Persistent counter that changes on every write; used to key longer-lived caches (dashboard).
	 *
	 * @return void
	 */
	public static function bump_data_version(): void {
		update_option( 'rentbaik_data_version', (int) get_option( 'rentbaik_data_version', 0 ) + 1, true );
	}

	/**
	 * Current data version.
	 *
	 * @return int
	 */
	public static function data_version(): int {
		return (int) get_option( 'rentbaik_data_version', 0 );
	}

	/**
	 * Build a cache key that changes whenever the table changes.
	 *
	 * @param string $query_id Query plus its arguments.
	 * @return string
	 */
	protected static function cache_key( string $query_id ): string {
		return static::table_name() . ':' . md5( $query_id ) . ':' . wp_cache_get_last_changed( static::cache_scope() );
	}

	/**
	 * Return a cached value, or compute and cache it.
	 *
	 * Callers run their own literal $wpdb->prepare() query inside $fetch, so every SQL
	 * statement stays visible and prepared where it is written.
	 *
	 * @param string   $id    Unique id of the query and its arguments.
	 * @param callable $fetch Returns the fresh value.
	 * @return mixed
	 */
	protected static function remember( string $id, callable $fetch ) {
		$key   = static::cache_key( $id );
		$found = false;
		$value = wp_cache_get( $key, 'rentbaik', false, $found );
		if ( ! $found ) {
			$value = $fetch();
			wp_cache_set( $key, $value, 'rentbaik' );
		}
		return $value;
	}

	/**
	 * Find a row by ID.
	 *
	 * @param int $id Row ID.
	 * @return array<string, mixed>|null
	 */
	public static function find( int $id ): ?array {
		if ( $id <= 0 ) {
			return null;
		}
		$table = static::table();
		$row   = static::remember(
			'find:' . $id,
			static function () use ( $table, $id ) {
				global $wpdb;
				// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table; cached by remember().
				return $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM %i WHERE id = %d', $table, $id ), ARRAY_A );
			}
		);
		return is_array( $row ) ? $row : null;
	}

	/**
	 * Insert a row.
	 *
	 * @param array<string, mixed> $data   Column => value.
	 * @param string[]             $format Value formats (%s, %d, %f).
	 * @return int New row ID, 0 on failure.
	 */
	public static function insert( array $data, array $format ): int {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery -- Custom table write; cache invalidated below.
		$ok = $wpdb->insert( static::table(), $data, $format );
		// Read the ID before touch(): touch() writes an option, which changes $wpdb->insert_id.
		$id = $ok ? (int) $wpdb->insert_id : 0;
		static::touch();
		return $id;
	}

	/**
	 * Update a row by ID.
	 *
	 * @param int                  $id     Row ID.
	 * @param array<string, mixed> $data   Column => value.
	 * @param string[]             $format Value formats.
	 * @return bool
	 */
	public static function update( int $id, array $data, array $format ): bool {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table write; cache invalidated below.
		$ok = $wpdb->update( static::table(), $data, array( 'id' => $id ), $format, array( '%d' ) );
		static::touch();
		return false !== $ok;
	}

	/**
	 * Delete a row by ID.
	 *
	 * @param int $id Row ID.
	 * @return bool
	 */
	public static function delete( int $id ): bool {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table write; cache invalidated below.
		$ok = $wpdb->delete( static::table(), array( 'id' => $id ), array( '%d' ) );
		static::touch();
		return false !== $ok;
	}

	/**
	 * Current UTC time in MySQL format.
	 *
	 * @return string
	 */
	protected static function now(): string {
		return gmdate( 'Y-m-d H:i:s' );
	}
}