Refactoring

submodules/TelegramCore/Sources/TelegramEngine/Data/TelegramEngineData.swift

@@ -0,0 +1,97 @@
+import SwiftSignalKit
+import Postbox
+
+public protocol TelegramEngineDataItem {
+    associatedtype Result
+}
+
+protocol AnyPostboxViewDataItem {
+    var key: PostboxViewKey { get }
+
+    func _extract(view: PostboxView) -> Any
+}
+
+protocol PostboxViewDataItem: TelegramEngineDataItem, AnyPostboxViewDataItem {
+    func extract(view: PostboxView) -> Result
+}
+
+extension PostboxViewDataItem {
+    func _extract(view: PostboxView) -> Any {
+        return self.extract(view: view)
+    }
+}
+
+public extension TelegramEngine {
+    final class EngineData {
+        public struct Item {
+        }
+
+        private let account: Account
+
+        init(account: Account) {
+            self.account = account
+        }
+
+        private func _subscribe(items: [AnyPostboxViewDataItem]) -> Signal<[Any], NoError> {
+            return self.account.postbox.combinedView(keys: items.map(\.key))
+            |> map { views -> [Any] in
+                var results: [Any] = []
+
+                for item in items {
+                    guard let view = views.views[item.key] else {
+                        preconditionFailure()
+                    }
+                    results.append(item._extract(view: view))
+                }
+
+                return results
+            }
+        }
+
+        public func subscribe<T0: TelegramEngineDataItem>(_ t0: T0) -> Signal<T0.Result, NoError> {
+            return self._subscribe(items: [t0 as! AnyPostboxViewDataItem])
+            |> map { results -> T0.Result in
+                return results[0] as! T0.Result
+            }
+        }
+        public func get<T0: TelegramEngineDataItem>(_ t0: T0) -> Signal<T0.Result, NoError> {
+            return self.subscribe(t0)
+            |> take(1)
+        }
+
+        public func subscribe<
+            T0: TelegramEngineDataItem,
+            T1: TelegramEngineDataItem
+        >(
+            _ t0: T0,
+            _ t1: T1
+        ) -> Signal<
+            (
+                T0.Result,
+                T1.Result
+            ),
+        NoError> {
+            return self._subscribe(items: [t0 as! AnyPostboxViewDataItem])
+            |> map { results -> (T0.Result, T1.Result) in
+                return (
+                    results[0] as! T0.Result,
+                    results[1] as! T1.Result
+                )
+            }
+        }
+        public func get<
+            T0: TelegramEngineDataItem,
+            T1: TelegramEngineDataItem
+        >(
+            _ t0: T0,
+            _ t1: T1
+        ) -> Signal<
+            (
+                T0.Result,
+                T1.Result
+            ),
+        NoError> {
+            return self.subscribe(t0, t1) |> take(1)
+        }
+    }
+}