Feed cache

Model/Cache/FeedCacheModel.swift

@@ -0,0 +1,62 @@
+import Cache
+import Foundation
+import Logging
+import SwiftyJSON
+
+struct FeedCacheModel {
+    static let shared = FeedCacheModel()
+    let logger = Logger(label: "stream.yattee.cache.feed")
+
+    static let diskConfig = DiskConfig(name: "feed")
+    static let memoryConfig = MemoryConfig()
+
+    let storage = try! Storage<String, JSON>(
+        diskConfig: Self.diskConfig,
+        memoryConfig: Self.memoryConfig,
+        transformer: CacheModel.jsonTransformer
+    )
+
+    func storeFeed(account: Account, videos: [Video]) {
+        let date = dateFormatter.string(from: Date())
+        logger.info("caching feed \(account.feedCacheKey) -- \(date)")
+        let feedTimeObject: JSON = ["date": date]
+        let videosObject: JSON = ["videos": videos.map(\.json).map(\.object)]
+        try? storage.setObject(feedTimeObject, forKey: feedTimeCacheKey(account.feedCacheKey))
+        try? storage.setObject(videosObject, forKey: account.feedCacheKey)
+    }
+
+    func retrieveFeed(account: Account) -> [Video] {
+        logger.info("retrieving cache for \(account.feedCacheKey)")
+
+        if let json = try? storage.object(forKey: account.feedCacheKey),
+           let videos = json.dictionaryValue["videos"]
+        {
+            return videos.arrayValue.map { Video.from($0) }
+        }
+
+        return []
+    }
+
+    func getFeedTime(account: Account) -> Date? {
+        if let json = try? storage.object(forKey: feedTimeCacheKey(account.feedCacheKey)),
+           let string = json.dictionaryValue["date"]?.string,
+           let date = dateFormatter.date(from: string)
+        {
+            return date
+        }
+
+        return nil
+    }
+
+    func clear() {
+        try? storage.removeAll()
+    }
+
+    private var dateFormatter: ISO8601DateFormatter {
+        .init()
+    }
+
+    private func feedTimeCacheKey(_ feedCacheKey: String) -> String {
+        "\(feedCacheKey)-feedTime"
+    }
+}