Supports both iPhone + iPad screenshots

Prefers showing screenshots for current device, but falls back to all screenshots if there are no relevant ones.

AltStoreCore/Model/AppScreenshot.swift

@@ -8,6 +8,8 @@
 
 import CoreData
 
+import AltSign
+
 public extension AppScreenshot
 {
     static let defaultAspectRatio = CGSize(width: 9, height: 19.5)
@@ -40,6 +42,13 @@ public class AppScreenshot: NSManagedObject, Fetchable, Decodable
     @NSManaged private var width: NSNumber?
     @NSManaged private var height: NSNumber?
     
+    // Defaults to .iphone
+    @nonobjc public var deviceType: ALTDeviceType {
+        get { ALTDeviceType(rawValue: Int(_deviceType)) }
+        set { _deviceType = Int16(newValue.rawValue) }
+    }
+    @NSManaged @objc(deviceType) private var _deviceType: Int16
+    
     @NSManaged public internal(set) var appBundleID: String
     @NSManaged public internal(set) var sourceID: String
     
@@ -58,12 +67,13 @@ public class AppScreenshot: NSManagedObject, Fetchable, Decodable
         super.init(entity: entity, insertInto: context)
     }
     
-    internal init(imageURL: URL, size: CGSize?, context: NSManagedObjectContext)
+    internal init(imageURL: URL, size: CGSize?, deviceType: ALTDeviceType, context: NSManagedObjectContext)
     {
         super.init(entity: AppScreenshot.entity(), insertInto: context)
         
         self.imageURL = imageURL
         self.size = size
+        self.deviceType = deviceType
     }
     
     public required init(from decoder: Decoder) throws
@@ -79,6 +89,21 @@ public class AppScreenshot: NSManagedObject, Fetchable, Decodable
         self.width = try container.decodeIfPresent(Int16.self, forKey: .width).map { NSNumber(value: $0) }
         self.height = try container.decodeIfPresent(Int16.self, forKey: .height).map { NSNumber(value: $0) }
     }
+    
+    public override func awakeFromInsert()
+    {
+        super.awakeFromInsert()
+        
+        self.deviceType = .iphone
+    }
+}
+
+extension AppScreenshot
+{
+    var screenshotID: String {
+        let screenshotID = "\(self.imageURL.absoluteString)|\(self.deviceType)"
+        return screenshotID
+    }
 }
 
 public extension AppScreenshot
@@ -88,3 +113,89 @@ public extension AppScreenshot
         return NSFetchRequest<AppScreenshot>(entityName: "AppScreenshot")
     }
 }
+
+internal struct AppScreenshots: Decodable
+{
+    var screenshots: [AppScreenshot] = []
+    
+    enum CodingKeys: String, CodingKey
+    {
+        case iphone
+        case ipad
+    }
+    
+    init(from decoder: Decoder) throws
+    {
+        let container: KeyedDecodingContainer<CodingKeys>
+                
+        do
+        {
+            container = try decoder.container(keyedBy: CodingKeys.self)
+        }
+        catch DecodingError.typeMismatch
+        {
+            // ONLY catch the container's DecodingError.typeMismatch, not the below decodeIfPresent()'s
+            
+            // Fallback to single array.
+            
+            var collection = try Collection(from: decoder)
+            collection.deviceType = .iphone
+            
+            self.screenshots = collection.screenshots
+            
+            return
+        }
+        
+        if var collection = try container.decodeIfPresent(Collection.self, forKey: .iphone)
+        {
+            collection.deviceType = .iphone
+            self.screenshots += collection.screenshots
+        }
+        
+        if var collection = try container.decodeIfPresent(Collection.self, forKey: .ipad)
+        {
+            collection.deviceType = .ipad
+            self.screenshots += collection.screenshots
+        }
+    }
+}
+
+extension AppScreenshots
+{
+    struct Collection: Decodable
+    {
+        var screenshots: [AppScreenshot] = []
+        
+        var deviceType: ALTDeviceType = .iphone {
+            didSet {
+                self.screenshots.forEach { $0.deviceType = self.deviceType }
+            }
+        }
+        
+        init(from decoder: Decoder) throws
+        {
+            guard let context = decoder.managedObjectContext else { preconditionFailure("Decoder must have non-nil NSManagedObjectContext.") }
+            
+            var container = try decoder.unkeyedContainer()
+            
+            while !container.isAtEnd
+            {
+                do
+                {
+                    // Attempt parsing as URL first.
+                    let imageURL = try container.decode(URL.self)
+                    
+                    let screenshot = AppScreenshot(imageURL: imageURL, size: nil, deviceType: self.deviceType, context: context)
+                    self.screenshots.append(screenshot)
+                }
+                catch DecodingError.typeMismatch
+                {
+                    // Fall back to parsing full AppScreenshot (preferred).
+                    
+                    let screenshot = try container.decode(AppScreenshot.self)
+                    self.screenshots.append(screenshot)
+                }
+            }
+        }
+    }
+}