Add UserDefaultsManager.swift

Sources/SwiftUtils/UserDefaultsManager.swift

@@ -0,0 +1,64 @@
+//
+//  UserDefaultsManager.swift
+//
+//
+//  Created by ensan on 2023/07/21.
+//
+
+import Foundation
+
+public protocol UserDefaultsKeys: RawRepresentable where RawValue == String {
+    associatedtype Manager: UserDefaultsManager
+    init(keyPath: PartialKeyPath<Manager>)
+}
+
+public protocol UserDefaultsManager {
+    associatedtype Keys: UserDefaultsKeys where Keys.Manager == Self
+    var userDefaults: UserDefaults { get }
+    mutating func update<T: Codable>(_ value: KeyPath<Self, T>, newValue: T)
+    mutating func update<T: Codable>(_ value: KeyPath<Self, T>, process: (inout T) -> Void)
+}
+
+public extension UserDefaultsManager {
+    mutating func update<T: Codable>(_ value: KeyPath<Self, T>, newValue: T) {
+        if let value = value as? WritableKeyPath {
+            self[keyPath: value] = newValue
+            update(value: value)
+        }
+    }
+
+    mutating func update<T: Codable>(_ value: KeyPath<Self, T>, process: (inout T) -> Void) {
+        if let value = value as? WritableKeyPath {
+            process(&self[keyPath: value])
+            update(value: value)
+        }
+    }
+}
+
+public extension UserDefaultsManager {
+    mutating func update(value: WritableKeyPath<Self, some Codable>) {
+        do {
+            let data = try JSONEncoder().encode(self[keyPath: value])
+            let key = Keys(keyPath: value)
+            userDefaults.set(data, forKey: key.rawValue)
+        } catch {
+            debug(error)
+        }
+    }
+
+    static func load<T: StaticInitialValueAvailable>(key: Keys, userDefaults: UserDefaults) -> T {
+        if let value = userDefaults.data(forKey: key.rawValue) {
+            do {
+                let value = try JSONDecoder().decode(T.self, from: value)
+                return value
+            } catch {
+                debug(error)
+            }
+        }
+        return T.initialValue
+    }
+}
+
+public protocol StaticInitialValueAvailable: Codable {
+    static var initialValue: Self {get}
+}