<?php
/**
 * Backup record DTO.
 *
 * @package Shiftora\Backup
 */

declare(strict_types=1);

namespace Shiftora\Backup;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Immutable data transfer object representing a row in shiftora_backups.
 */
final class BackupRecord {

	public function __construct(
		public readonly int    $id,
		public readonly int    $migration_id,
		public readonly string $file_path,
		public readonly int    $file_size,
		public readonly string $tables_json,
		public readonly string $created_at,
		public readonly string $label = '',
		public readonly string $status = 'complete',
		public readonly ?int   $connection_id = null,
		public readonly ?string $expires_at = null
	) {}

	/** Creates a BackupRecord from a wpdb row object or array. */
	public static function from_row( object|array $row ): self {
		if ( is_array( $row ) ) {
			$row = (object) $row;
		}

		return new self(
			id:           (int) $row->id,
			migration_id: (int) ( $row->migration_id ?? 0 ),
			file_path:    (string) $row->file_path,
			file_size:    (int) $row->file_size,
			tables_json:  isset( $row->tables_json ) ? (string) $row->tables_json : (string) ( $row->tables ?? '[]' ),
			created_at:   (string) $row->created_at,
			label:        isset( $row->label ) ? (string) $row->label : '',
			status:       isset( $row->status ) ? (string) $row->status : 'complete',
			connection_id: isset( $row->connection_id ) ? (int) $row->connection_id : null,
			expires_at:   isset( $row->expires_at ) ? (string) $row->expires_at : null
		);
	}

	/**
	 * The backed-up tables.
	 *
	 * @return string[]
	 */
	public function tables(): array {
		$decoded = json_decode( $this->tables_json, true );
		return is_array( $decoded ) ? $decoded : [];
	}

	/** Human-readable file size. */
	public function formatted_size(): string {
		$bytes = $this->file_size;
		if ( $bytes < 1024 ) {
			return $bytes . ' B';
		}
		if ( $bytes < 1_048_576 ) {
			return round( $bytes / 1024, 1 ) . ' KB';
		}
		return round( $bytes / 1_048_576, 1 ) . ' MB';
	}

	/** Whether the backup file still exists on disk. */
	public function file_exists(): bool {
		return file_exists( $this->file_path );
	}

	/**
	 * Whether this dump could be restored from right now.
	 *
	 * Status only records that the dump finished writing. Retention, a manual
	 * sweep or a restored backups table can leave a "complete" row with no file,
	 * and a replaced or truncated file is refused by the restorer on the same
	 * size check, so restore controls should call this instead of reading status.
	 */
	public function is_restorable(): bool {
		if ( 'complete' !== $this->status || ! is_file( $this->file_path ) ) {
			return false;
		}

		$size = @filesize( $this->file_path );

		return false !== $size && (int) $size === $this->file_size;
	}

	/** Whether this snapshot has expired. */
	public function is_expired(): bool {
		if ( null === $this->expires_at ) {
			return false;
		}
		return strtotime( $this->expires_at ) !== false && strtotime( $this->expires_at ) < time();
	}
}