From c735bd0381671600a3d5ecb32bd6ee0100e8b18d Mon Sep 17 00:00:00 2001
From: Javier Cicchelli <javier@rock-n-code.com>
Date: Thu, 15 Dec 2022 02:13:14 +0100
Subject: [PATCH] Implemented the support for the view status in the BrowseView
 view for the Browse module.

---
 BeReal/UI/Views/ContentView.swift             |   6 +-
 .../Sources/Browse/UI/Views/BrowseView.swift  | 134 +++++++++++++-----
 2 files changed, 103 insertions(+), 37 deletions(-)

diff --git a/BeReal/UI/Views/ContentView.swift b/BeReal/UI/Views/ContentView.swift
index e0c3f70..a3b8a2c 100644
--- a/BeReal/UI/Views/ContentView.swift
+++ b/BeReal/UI/Views/ContentView.swift
@@ -38,6 +38,8 @@ struct ContentView: View {
             // TODO: upload a new file
         } showProfile: {
             showSheet = .profile
+        } login: {
+            showSheet = .login
         }
         .sheet(item: $showSheet) { sheet in
             switch sheet {
@@ -71,6 +73,7 @@ private extension ContentView {
         let createFolder: ActionClosure
         let uploadFile: ActionClosure
         let showProfile: ActionClosure
+        let login: ActionClosure
         
         // MARK: Body
         
@@ -84,7 +87,8 @@ private extension ContentView {
                         ),
                         createFolder: createFolder,
                         uploadFile: uploadFile,
-                        showProfile: showProfile
+                        showProfile: showProfile,
+                        login: login
                     )
                 }
             } else {
diff --git a/Modules/Sources/Browse/UI/Views/BrowseView.swift b/Modules/Sources/Browse/UI/Views/BrowseView.swift
index ab7dcfe..030c0ed 100644
--- a/Modules/Sources/Browse/UI/Views/BrowseView.swift
+++ b/Modules/Sources/Browse/UI/Views/BrowseView.swift
@@ -18,6 +18,7 @@ public struct BrowseView: View {
     
     // MARK: States
     
+    @State private var status: ViewStatus = .loading
     @State private var items: [any FileSystemItemIdentifiable] = []
     @State private var stack: Stack?
     
@@ -27,6 +28,7 @@ public struct BrowseView: View {
     private let createFolder: ActionClosure
     private let uploadFile: ActionClosure
     private let showProfile: ActionClosure
+    private let login: ActionClosure
     
     private let getItems: GetItemsUseCase = .init()
     
@@ -36,51 +38,83 @@ public struct BrowseView: View {
         folder: Folder,
         createFolder: @escaping ActionClosure,
         uploadFile: @escaping ActionClosure,
-        showProfile: @escaping ActionClosure
+        showProfile: @escaping ActionClosure,
+        login: @escaping ActionClosure
     ) {
         self.folder = folder
         self.createFolder = createFolder
         self.uploadFile = uploadFile
         self.showProfile = showProfile
+        self.login = login
     }
     
     // MARK: Body
     
     public var body: some View {
-        List(items, id: \.id) { item in
-            switch item {
-            case is Folder:
-                makeFolderItem(for: item)
-            case is Document:
-                DocumentItem(item: item) {
-                    // TODO: show the item id in a viewer...
-                } download: {
-                    // TODO: download the item id from the backend.
-                } delete: {
-                    // TODO: delete the item id from the backend.
-                }
-            default:
-                EmptyView()
+        content
+            .navigationTitle(folder.name)
+            .toolbar {
+                BrowseToolbar(
+                    createFolder: createFolder,
+                    uploadFile: uploadFile,
+                    showProfile: showProfile
+                )
+            }
+            .task(id: folder) {
+                await loadItems()
             }
-        }
-        .listStyle(.inset)
-        .navigationTitle(folder.name)
-        .toolbar {
-            BrowseToolbar(
-                createFolder: createFolder,
-                uploadFile: uploadFile,
-                showProfile: showProfile
-            )
-        }
-        .task(id: folder) {
-            await getItemsOrStop()
-        }
     }
 }
 
 // MARK: - UI
 
 private extension BrowseView {
+    
+    // MARK: Properties
+    
+    @ViewBuilder var content: some View {
+        switch status {
+        case .noCredentials:
+            MessageView(
+                type: .noCredentials,
+                action: login
+            )
+        case .loading:
+            LoadingView()
+        case .loaded:
+            List(items, id: \.id) { item in
+                switch item {
+                case is Folder:
+                    makeFolderItem(for: item)
+                case is Document:
+                    DocumentItem(item: item) {
+                        // TODO: show the item id in a viewer...
+                    } download: {
+                        // TODO: download the item id from the backend.
+                    } delete: {
+                        // TODO: delete the item id from the backend.
+                    }
+                default:
+                    EmptyView()
+                }
+            }
+            .listStyle(.inset)
+        case .empty:
+            MessageView(
+                type: .empty,
+                action: uploadFile
+            )
+        case .error:
+            MessageView(type: .error) {
+                Task {
+                    await loadItems()
+                }
+            }
+        }
+    }
+    
+    // MARK: Functions
+    
     @ViewBuilder func makeFolderItem(
         for item: any FileSystemItemIdentifiable
     ) -> some View {
@@ -99,32 +133,58 @@ private extension BrowseView {
                 folder: folder,
                 createFolder: createFolder,
                 uploadFile: uploadFile,
-                showProfile: showProfile
+                showProfile: showProfile,
+                login: login
             ),
             tagged: .browse(folder),
             in: $stack
         )
     }
+
 }
                 
 // MARK: - Helpers
 
 private extension BrowseView {
-    func getItemsOrStop() async {
-        guard let account else { return }
+    func loadItems() async {
+        guard let account else {
+            status = .noCredentials
+            return
+        }
 
         do {
-            items = try await getItems(
+            status = .loading
+
+            let loadedItems = try await getItems(
                 id: folder.id,
                 username: account.username,
                 password: account.password
             )
+            
+            if loadedItems.isEmpty {
+                status = .empty
+            } else {
+                items = loadedItems
+                status = .loaded
+            }
         } catch {
-            // TODO: handle the error appropriately.
+            status = .error
         }
     }
 }
 
+// MARK: - Enumerations
+
+private extension BrowseView {
+    enum ViewStatus {
+        case noCredentials
+        case loading
+        case loaded
+        case empty
+        case error
+    }
+}
+
 // MARK: - Previews
 
 struct BrowseView_Previews: PreviewProvider {
@@ -134,11 +194,13 @@ struct BrowseView_Previews: PreviewProvider {
                 id: UUID().uuidString,
                 name: "Some folder name"
             )) {
-                // ...
+                // create folder closure.
             } uploadFile: {
-                // ...
+                // upload file closure.
             } showProfile: {
-                // ...
+                // show profile closure.
+            } login: {
+                // login closure.
             }
         }
     }