//
import UIKit
import Alamofire
import CoreData


enum LoaderError:String{
    case
    JsonFailed,
    PathFailed,
    NoEntityDescription,
    UnknownError
}

enum DbTable:String{
    case
    VehiclesEntity,
    PhotosEntity,
    ModelsEntity,
    NewsEntity,
    StylesEntity
}

class UpdateDbClass {
    
    
    static func updateDatabase(entityName:String,completionHandler: @escaping () -> Void){
      var url = URL(string: UrlRepository.VehiclesJsonUrl!)!
      
   
      var table = ""
          switch entityName {
          case DbTable.VehiclesEntity.rawValue:
              table = "Vehicles"
              url = URL(string: UrlRepository.VehiclesJsonUrl!)!
          case DbTable.PhotosEntity.rawValue:
              table = "Photos"
              url = URL(string: UrlRepository.PhotosJsonUrl!)!
               table = "Styles"
                url = Bundle.main.url(forResource: "Styles", withExtension: "json")!
                  // url = URL(string: UrlRepository.NewsJsonUrl!)!
          default:
              break
          }
          let uuid = UUID().uuidString
          let parameters: Parameters = [
              "id": uuid
          ]

     let queue = DispatchQueue(label: "com.my.test", qos: .background, attributes: .concurrent)
    

      AF.request(url, method: .get, parameters: parameters, encoding: URLEncoding(destination: .queryString), headers: nil).responseJSON(queue:queue){ response in
              switch response.result {
              case let .success(value):
                  if let items = value as? [[String: Any]] {

                      var itemsArray:[Int32] = []
                      for item in items{
                          if let id = item["id"] as? Int32{
                               itemsArray.append(id)
                          }
                      }

                      guard let entity = NSEntityDescription.entity(forEntityName: table, in:(CoreDataStack.sharedManager.mainObjectContext)) else {
                          fatalError("Could not find entity descriptions!")
                      }

              switch entityName {

                  case DbTable.StylesEntity.rawValue: //Styles
                      checkDeletedRecords(jsonItems: itemsArray,table: table)

                      for item in items{
                          guard let id = item["id"] as? Int32 else {return}
                          //Check if not exists
                          if  !CheckIfExists(id: id,table:table){
                             print("id \(id) does not exist")
                              //Insert Record
                              let object = Styles(entity: entity, insertInto: CoreDataStack.sharedManager.mainObjectContext)
                      object.setValue(item["id"], forKey: "id")
                      object.setValue(item["style"] as! String, forKey: "style")
                      object.setValue(item["image"] as! String, forKey: "image")
         
                      CoreDataStack.sharedManager.saveMainContext()
                          }
                          else{    //Update Record
                             // print("id \(item["id"]) exists")

                              do{
                                  let fetchRequest = NSFetchRequest<Styles>(entityName:"Styles")
                                  let predicate = NSPredicate(format: "id == %d",item["id"] as! Int32)
                                  fetchRequest.predicate = predicate
                                  let req =  try CoreDataStack.sharedManager.mainObjectContext.fetch(fetchRequest)
                                  let object = req[0] as NSManagedObject
                                object.setValue(item["style"] as! String, forKey: "style")
                                 object.setValue(item["image"] as! String, forKey: "image")
                                

                                   CoreDataStack.sharedManager.saveMainContext()

                              }catch{
                                  print("there was an error")
                              }
                              completionHandler()
                          }
                      }
                      break;

             
                      default:
                          break
                      }
                   }
                  break
              case let .failure(error):
                  print(error as NSError)
                  break
              }
          }
      

       }
      


  
}

protocol CoreDataWorkerProtocol {
    associatedtype EntityType
}

enum VoidResult {
    case success
    case failure(NSError)
}