Supports new “versions” key in source JSON

Allows sources to list multiple versions of an app.

Preserves backwards compatibility by assigning legacy version values when assigning AppVersions.

AltStoreCore/Model/AppVersion.swift

@@ -46,6 +46,43 @@ public class AppVersion: NSManagedObject, Decodable, Fetchable
     {
         super.init(entity: entity, insertInto: context)
     }
+    
+    private enum CodingKeys: String, CodingKey
+    {
+        case version
+        case date
+        case localizedDescription
+        case downloadURL
+        case size
+    }
+    
+    public required init(from decoder: Decoder) throws
+    {
+        guard let context = decoder.managedObjectContext else { preconditionFailure("Decoder must have non-nil NSManagedObjectContext.") }
+        
+        super.init(entity: AppVersion.entity(), insertInto: context)
+        
+        do
+        {
+            let container = try decoder.container(keyedBy: CodingKeys.self)
+            
+            self.version = try container.decode(String.self, forKey: .version)
+            self.date = try container.decode(Date.self, forKey: .date)
+            self.localizedDescription = try container.decodeIfPresent(String.self, forKey: .localizedDescription)
+            
+            self.downloadURL = try container.decode(URL.self, forKey: .downloadURL)
+            self.size = try container.decode(Int64.self, forKey: .size)
+        }
+        catch
+        {
+            if let context = self.managedObjectContext
+            {
+                context.delete(self)
+            }
+            
+            throw error
+        }
+    }
 }
 
 public extension AppVersion
@@ -54,4 +91,26 @@ public extension AppVersion
     {
         return NSFetchRequest<AppVersion>(entityName: "AppVersion")
     }
+    
+    class func makeAppVersion(
+        version: String,
+        date: Date,
+        localizedDescription: String? = nil,
+        downloadURL: URL,
+        size: Int64,
+        appBundleID: String,
+        sourceID: String? = nil,
+        in context: NSManagedObjectContext) -> AppVersion
+    {
+        let appVersion = AppVersion(context: context)
+        appVersion.version = version
+        appVersion.date = date
+        appVersion.localizedDescription = localizedDescription
+        appVersion.downloadURL = downloadURL
+        appVersion.size = size
+        appVersion.appBundleID = appBundleID
+        appVersion.sourceID = sourceID
+
+        return appVersion
+    }
 }