Created Tweet View Model to handle the logic and send to the view

OpenTweet.xcodeproj/project.pbxproj

@@ -17,6 +17,7 @@
 		009C4C9B1D9F0D4100F0BC6C /* timeline.json in Resources */ = {isa = PBXBuildFile; fileRef = 009C4C9A1D9F0D4100F0BC6C /* timeline.json */; };
 		F799789D2C516EB50059C33E /* Tweet.swift in Sources */ = {isa = PBXBuildFile; fileRef = F799789C2C516EB50059C33E /* Tweet.swift */; };
 		F79978A02C516F030059C33E /* DateExtension.swift in Sources */ = {isa = PBXBuildFile; fileRef = F799789F2C516F030059C33E /* DateExtension.swift */; };
+		F79978A62C5172010059C33E /* TimeLineViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = F79978A52C5172010059C33E /* TimeLineViewModel.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -54,6 +55,7 @@
 		009C4C9D1D9F104800F0BC6C /* README.md */ = {isa = PBXFileReference; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 		F799789C2C516EB50059C33E /* Tweet.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Tweet.swift; sourceTree = "<group>"; };
 		F799789F2C516F030059C33E /* DateExtension.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DateExtension.swift; sourceTree = "<group>"; };
+		F79978A52C5172010059C33E /* TimeLineViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TimeLineViewModel.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -106,6 +108,7 @@
 		009C4C6A1D9F0CD600F0BC6C /* OpenTweet */ = {
 			isa = PBXGroup;
 			children = (
+				F79978A42C5171EC0059C33E /* ViewModel */,
 				F799789E2C516EE60059C33E /* Extensions */,
 				F799789B2C516E950059C33E /* Model */,
 				009C4C6B1D9F0CD600F0BC6C /* AppDelegate.swift */,
@@ -160,6 +163,14 @@
 			path = Extensions;
 			sourceTree = "<group>";
 		};
+		F79978A42C5171EC0059C33E /* ViewModel */ = {
+			isa = PBXGroup;
+			children = (
+				F79978A52C5172010059C33E /* TimeLineViewModel.swift */,
+			);
+			path = ViewModel;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -300,6 +311,7 @@
 			files = (
 				F799789D2C516EB50059C33E /* Tweet.swift in Sources */,
 				F79978A02C516F030059C33E /* DateExtension.swift in Sources */,
+				F79978A62C5172010059C33E /* TimeLineViewModel.swift in Sources */,
 				009C4C6E1D9F0CD600F0BC6C /* TimelineViewController.swift in Sources */,
 				009C4C6C1D9F0CD600F0BC6C /* AppDelegate.swift in Sources */,
 			);

OpenTweet/ViewModel/TimeLineViewModel.swift

@@ -0,0 +1,61 @@
+//
+//  TimeLineViewModel.swift
+//  OpenTweet
+//
+//  Created by Danilo Silveira on 2024-07-24.
+//  Copyright © 2024 OpenTable, Inc. All rights reserved.
+//
+
+import Foundation
+
+protocol TimeLineProtocol {
+    func reloadContent()
+}
+
+class TimeLineViewModel {
+    private var timelineTweets: [Tweet] = []
+    private var timelineProtocol : TimeLineProtocol?
+
+    func setProtocol(timelineProtocol: TimeLineProtocol) {
+        self.timelineProtocol = timelineProtocol
+    }
+
+    func getTimeLineTweetCounts() -> Int {
+        timelineTweets.count
+    }
+
+    func getTweet(for Index: Int) -> Tweet {
+        timelineTweets[Index]
+    }
+
+    func fetchTimelineFromJson() {
+        do {
+            guard let path = Bundle.main.path(forResource: "timeline", ofType: "json"),
+                  let data = try String(contentsOfFile: path).data(using: .utf8) else { return }
+            let decoder = JSONDecoder()
+            let formatter = ISO8601DateFormatter()
+            formatter.formatOptions = [.withFullDate]
+
+            decoder.dateDecodingStrategy = .custom({ decoder in
+                let container = try decoder.singleValueContainer()
+                let dateString = try container.decode(String.self)
+
+                if let date = formatter.date(from: dateString) {
+                    return date
+                }
+
+                throw DecodingError.dataCorruptedError(in: container, debugDescription: "Cannot decode date string \(dateString)")
+            })
+
+            // Decoding data for the Tweet Model
+            let timeLine = try decoder.decode([String:[Tweet]].self, from: data)
+
+            // Sorting in ascending order and trigger the protocol to reload the table
+            timelineTweets = timeLine["timeline"]?.sorted(by: { $0.date < $1.date}) ?? []
+            self.timelineProtocol?.reloadContent()
+
+        } catch {
+            print(error.localizedDescription)
+        }
+    }
+}