KCD/JSONMapper.swift

   1 //
   2 //  JSONMapper.swift
   3 //  KCD
   4 //
   5 //  Created by Hori,Masaki on 2017/02/22.
   6 //  Copyright © 2017年 Hori,Masaki. All rights reserved.
   7 //
   8
   9 import Cocoa
  10 import SwiftyJSON
  11
  12 struct MappingConfiguration<T: NSManagedObject> {
  13     let entity: Entity<T>
  14     let dataKeys: [String]
  15     let primaryKey: String
  16     let compositPrimaryKeys: [String]?
  17     let editorStore: CoreDataAccessor
  18     let ignoreKeys: [String]
  19
  20     init(entity: Entity<T>,
  21          dataKeys: [String] = ["api_data"],
  22          primaryKey: String = "id",
  23          compositPrimaryKeys: [String]? = nil,
  24          editorStore: CoreDataAccessor,
  25          ignoreKeys: [String] = []) {
  26         self.entity = entity
  27         self.dataKeys = dataKeys
  28         self.primaryKey = primaryKey
  29         self.compositPrimaryKeys = compositPrimaryKeys
  30         self.editorStore = editorStore
  31         self.ignoreKeys = ignoreKeys
  32     }
  33 }
  34
  35 protocol JSONMapper {
  36     associatedtype ObjectType: NSManagedObject
  37
  38     init(_ apiResponse: APIResponse)
  39
  40     var apiResponse: APIResponse { get }
  41     var configuration: MappingConfiguration<ObjectType> { get }
  42
  43     func registerElement(_ element: JSON, to object: ObjectType)
  44     func commit()
  45     func beginRegister(_ object: ObjectType)
  46     func handleExtraValue(_ value: JSON, forKey key: String, to object: ObjectType) -> Bool
  47     func finishOperating()
  48 }
  49
  50 extension String {
  51     func keyByDeletingPrefix() -> String {
  52         if self.characters.count < 5 { return self }
  53         let s = self.index(self.startIndex, offsetBy: 4)
  54         return self[s..<self.endIndex]
  55     }
  56 }
  57
  58 extension JSONMapper {
  59     var data: JSON { return apiResponse.json[configuration.dataKeys] }
  60
  61     private func isEqual(_ lhs: AnyObject?, _ rhs: AnyObject?) -> Bool {
  62         if lhs == nil, rhs == nil { return true }
  63         if let lhs = lhs, let rhs = rhs { return lhs.isEqual(rhs) }
  64         return false
  65     }
  66     func setValueIfNeeded(_ value: JSON, to object: ObjectType, forKey key: String) {
  67         var validValue = value.object as AnyObject?
  68         do {
  69             try object.validateValue(&validValue, forKey: key)
  70         } catch {
  71             return
  72         }
  73
  74         let old = object.value(forKey: key)
  75         if !isEqual(old as AnyObject?, validValue) {
  76             object.willChangeValue(forKey: key)
  77             object.setValue(validValue, forKey: key)
  78             object.didChangeValue(forKey: key)
  79         }
  80     }
  81
  82     func registerElement(_ element: JSON, to object: ObjectType) {
  83         beginRegister(object)
  84         element.forEach { (key: String, value: JSON) in
  85             if configuration.ignoreKeys.contains(key) { return }
  86             if handleExtraValue(value, forKey: key, to: object) { return }
  87             switch value.type {
  88             case .array:
  89                 value.array?.enumerated().forEach {
  90                     let newKey = "\(key)_\($0.offset)"
  91                     setValueIfNeeded($0.element, to: object, forKey: newKey)
  92                 }
  93             case .dictionary:
  94                 value.forEach { (subKey: String, subValue) in
  95                     let newKey = "\(key)_D_\(subKey.keyByDeletingPrefix())"
  96                     setValueIfNeeded(subValue, to: object, forKey: newKey)
  97                 }
  98             default:
  99                 setValueIfNeeded(value, to: object, forKey: key)
 100             }
 101         }
 102     }
 103     private var sortDescriptors: [NSSortDescriptor] {
 104         let keys = configuration.compositPrimaryKeys ?? [configuration.primaryKey]
 105         return keys.map { NSSortDescriptor(key: $0, ascending: true) }
 106     }
 107     private func objectSearch(_ objects: [ObjectType], _ element: JSON) -> ObjectType? {
 108         let keys = configuration.compositPrimaryKeys ?? [configuration.primaryKey]
 109         let keyPiar = keys.map { (key: $0, apiKey: "api_\($0)") }
 110         return objects.binarySearch {
 111             for piar in keyPiar {
 112                 guard let v1 = $0.value(forKey: piar.key)
 113                     else { return .orderedAscending }
 114                 if element[piar.apiKey].type == .null { return .orderedDescending }
 115                 let v2 = element[piar.apiKey].object
 116                 return (v1 as AnyObject).compare(v2)
 117             }
 118             return .orderedDescending
 119         }
 120     }
 121     func commit() {
 122         let store = configuration.editorStore
 123         guard let objects = try? store.objects(with: configuration.entity, sortDescriptors: sortDescriptors)
 124             else { return print("Can not get entity named \(configuration.entity.name)") }
 125         let list = (data.type == .array ? data.arrayValue : [data])
 126         list.forEach {
 127             if let object = objectSearch(objects, $0) {
 128                 registerElement($0, to: object)
 129             } else if let new = store.insertNewObject(for: configuration.entity) {
 130                 registerElement($0, to: new)
 131             } else {
 132                 fatalError("Can not get entity named \(configuration.entity.name)")
 133             }
 134         }
 135         finishOperating()
 136         store.saveActionCore()
 137     }
 138
 139     func beginRegister(_ object: ObjectType) {}
 140     func handleExtraValue(_ value: JSON, forKey key: String, to object: ObjectType) -> Bool {
 141         return false
 142     }
 143     func finishOperating() {}
 144 }