Sign the macOS app and keep its state in SwiftData with iCloud sync

mac/Sources/Byre/Drafts.swift

@@ -1,5 +1,6 @@
 import Foundation
 import Observation
+import SwiftData
 
 private struct Saved: Codable {
     struct Composer: Codable {
@@ -39,30 +40,43 @@ final class Drafts {
     private var lostImages: [String: Int] = [:]
     private var checked: [String: [String]] = [:]
     private var texts: [String: String] = [:]
-    @ObservationIgnored private let storeKey: String
+    @ObservationIgnored private let scope: String
     @ObservationIgnored private var timer: Task<Void, Never>?
+    @ObservationIgnored private var dirty = false
 
     init(origin: URL, login: String) {
-        storeKey = "byre.drafts.\(draftOrigin(origin)).\(login)"
-        let saved = Self.read(storeKey)
-        for (key, d) in saved.composer {
-            if !d.text.isEmpty {
-                composerTexts[key] = d.text
-            }
-            if d.images > 0 {
-                lostImages[key] = d.images
+        scope = "\(draftOrigin(origin)).\(login)"
+        load(Self.read(scope))
+    }
+
+    private func load(_ saved: Saved) {
+        composerTexts = saved.composer.filter { !$0.value.text.isEmpty }.mapValues(\.text)
+        lostImages = saved.composer.reduce(into: [:]) { lost, d in
+            let n = d.value.images - (composerImages[d.key] ?? 0)
+            if n > 0 {
+                lost[d.key] = n
             }
         }
         checked = saved.checked
         texts = saved.texts
     }
 
-    private static func read(_ key: String) -> Saved {
-        guard let raw = UserDefaults.standard.string(forKey: key) else {
+    func reload() {
+        if !dirty && sending.isEmpty {
+            load(Self.read(scope))
+        }
+    }
+
+    private static func records(_ scope: String) -> [DraftRecord] {
+        fetchRecords(FetchDescriptor(predicate: #Predicate { $0.scope == scope }, sortBy: [SortDescriptor(\.saved, order: .reverse)]))
+    }
+
+    private static func read(_ scope: String) -> Saved {
+        guard let record = records(scope).first else {
             return Saved()
         }
         do {
-            return try JSONDecoder().decode(Saved.self, from: Data(raw.utf8))
+            return try JSONDecoder().decode(Saved.self, from: record.json)
         } catch {
             log.error("read drafts: \(String(describing: error), privacy: .public)")
             return Saved()
@@ -91,6 +105,7 @@ final class Drafts {
     }
 
     private func save() {
+        dirty = true
         timer?.cancel()
         timer = Task { [weak self] in
             try? await Task.sleep(for: .milliseconds(400))
@@ -103,6 +118,10 @@ final class Drafts {
     func flush() {
         timer?.cancel()
         timer = nil
+        guard dirty else {
+            return
+        }
+        dirty = false
         var out = Saved(checked: checked, texts: texts)
         let keys = Set(composerTexts.keys).union(composerImages.keys).union(sending.map(\.key)).union(lostImages.keys)
         for key in keys {
@@ -114,7 +133,18 @@ final class Drafts {
             }
         }
         do {
-            UserDefaults.standard.set(String(decoding: try JSONEncoder().encode(out), as: UTF8.self), forKey: storeKey)
+            let json = try JSONEncoder().encode(out)
+            let records = Self.records(scope)
+            if records.isEmpty {
+                persistence.insert(DraftRecord(scope: scope, json: json))
+            } else {
+                records[0].json = json
+                records[0].saved = Date()
+                for record in records.dropFirst() {
+                    persistence.delete(record)
+                }
+            }
+            saveRecords()
         } catch {
             log.error("save drafts: \(String(describing: error), privacy: .public)")
         }
@@ -153,6 +183,7 @@ final class Drafts {
         let send = DraftSend(key: key, text: text, images: images)
         sending.append(send)
         composerTexts[key] = nil
+        dirty = true
         return send
     }
 
@@ -166,6 +197,7 @@ final class Drafts {
                 composerTexts[send.key] = text
             }
         }
+        dirty = true
         flush()
     }
 
@@ -199,6 +231,7 @@ final class Drafts {
     func clearAnswer(_ id: String) {
         checked[id] = nil
         texts[id] = nil
+        dirty = true
         flush()
     }
 }