import Foundation
import RealmSwift

protocol StorageServiceProtocol {
    
    func store(vehicle: Vehicle) throws
}

public class StorageService: StorageServiceProtocol {
    
    public enum StorageError: String, LocalizedError {
        
        case openDatabaseError = "Ошибка открытия БД"
        
        public var errorDescription: String? {
            rawValue
        }
    }
    
    private static var instance: StorageService?
    
    private let realm: Realm
    
    public static var shared: StorageService {
        get throws {
            if let instance = StorageService.instance {
                return instance
            } else {
                if let service = StorageService(inMemory: Testing.isUITesting) {
                    StorageService.instance = service
                    return service
                } else {
                    throw StorageError.openDatabaseError
                }
            }
        }
    }
    
    init?(inMemory: Bool = false) {
        let config = Realm.Configuration(inMemoryIdentifier: inMemory ? "memory" : nil)
        
        guard let realm = try? Realm(configuration: config) else {
            return nil
        }
        
        self.realm = realm
    }
    
    // MARK: - StorageServiceProtocol
    
    public func store(vehicle: Vehicle) throws {
        
        try realm.write {
            realm.add(vehicle, update: .all)
        }
    }
}