Add persistent storage

RippleChat/DataStore.swift

@@ -8,16 +8,93 @@
 import SwiftUI
 import Foundation
 
+@MainActor
 class DataStore: ObservableObject {
     @Published var personalID: String
-    @Published var friends: [String]
-    @Published var feeds: [Feed]
+    @Published var friends: [String:Int]
+    @Published var feedStores: [FeedStore]
     
-    init(personalID: String = "", friends: [String] = [], feeds: [Feed] = []) {
+    init(personalID: String = "", friends: [String:Int] = [:], feedStores: [FeedStore] = []) {
         self.personalID = personalID
         self.friends = friends
-        self.feeds = feeds
+        self.feedStores = feedStores
+    }
+    
+    private func fileURL(for filename: String) throws -> URL {
+        try FileManager.default.url(for: .documentDirectory,
+                                    in: .userDomainMask,
+                                    appropriateFor: nil,
+                                    create: false)
+        .appendingPathComponent("\(filename).json")
+    }
+    
+    func savePersonalID() async throws {
+        let task = Task {
+            let data = try JSONEncoder().encode(personalID)
+            let outfile = try fileURL(for: "personalID")
+            try data.write(to: outfile)
+        }
+        _ = try await task.value
+    }
+    
+    func saveFriends() async throws {
+        let task = Task {
+            let data = try JSONEncoder().encode(friends)
+            let outfile = try fileURL(for: "friends")
+            try data.write(to: outfile)
+        }
+        _ = try await task.value
+    }
+    
+    func loadPersonalID() async throws {
+        let task = Task<String, Error> {
+            let fileURL = try self.fileURL(for: "personalID")
+            let data = try Data(contentsOf: fileURL)
+            let personalID = try JSONDecoder().decode(String.self, from: data)
+            return personalID
+        }
+        let personalID = try await task.value
+        self.personalID = personalID
+    }
+    
+    func loadFriends() async throws {
+        let task = Task<[String:Int], Error> {
+            let fileURL = try self.fileURL(for: "friends")
+            let data = try Data(contentsOf: fileURL)
+            let friends = try JSONDecoder().decode([String:Int].self, from: data)
+            return friends
+        }
+        let friends = try await task.value
+        self.friends = friends
+    }
+    
+    func loadFeedStores() async throws {
+        let task = Task<[FeedStore], Error> {
+            var feedStores: [FeedStore] = []
+            for feedStore in self.feedStores {
+                try await feedStore.load()
+                feedStores.append(feedStore)
+            }
+            return feedStores
+        }
+        let feedStores = try await task.value
+        self.feedStores = feedStores
+    }
+
+    func saveFeedStores() async throws {
+        let task = Task {
+            for feedStore in self.feedStores {
+                try await feedStore.save(feed: feedStore.feed)
+            }
+        }
+        _ = try await task.value
     }
     
     
+    
+}
+
+
+extension DataStore {
+    static let sampleDataStore = DataStore(personalID: "BOB", friends: SettingsView_Previews.friends, feedStores: [FeedStore(feed: Feed.sampleFeed), FeedStore(feed: Feed.sampleFeed2)])
 }