Add export function

TempTrack/Views/ExportSheet.swift

@@ -0,0 +1,81 @@
+import SwiftUI
+
+struct ExportSheet: View {
+
+    @Binding var isPresented: Bool
+
+    @State
+    private var isCreatingArchive = false
+
+    @State var url: URL?
+
+    @State var error: String?
+
+    @EnvironmentObject
+    private var storage: PersistentStorage
+
+    var body: some View {
+        VStack {
+            Text("Export")
+                .font(.title)
+            Text("Create a zip file of all stored data and share it.")
+            if isCreatingArchive {
+                ProgressView()
+                Text("Creating archive...")
+            }
+            if let error {
+                Text(error)
+                    .foregroundStyle(.red)
+            }
+            Spacer()
+            Button("Create archive", action: createArchive)
+                .disabled(isCreatingArchive)
+                .padding()
+            if let url {
+                ShareLink(item: url) {
+                    Label("Share archive", systemImage: "square.and.arrow.up")
+                }
+                .padding()
+                Button("Delete archive", action: deleteArchive)
+                    .padding()
+            }
+        }
+        .padding()
+    }
+
+    private func createArchive() {
+        guard !isCreatingArchive else {
+            return
+        }
+        isCreatingArchive = true
+        DispatchQueue.main.async {
+            do {
+                let url = try storage.createZip()
+                DispatchQueue.main.async {
+                    self.url = url
+                    self.error = nil
+                    self.isCreatingArchive = false
+                }
+            } catch {
+                DispatchQueue.main.async {
+                    self.error = "Failed to create archive: \(error.localizedDescription)"
+                    self.isCreatingArchive = false
+                }
+            }
+        }
+    }
+
+    private func deleteArchive() {
+        do {
+            try storage.removeZipArchive()
+            self.error = nil
+            self.url = nil
+        } catch {
+            self.error = "Failed to delete archive: \(error.localizedDescription)"
+        }
+    }
+}
+
+#Preview {
+    ExportSheet(isPresented: .constant(true))
+}

TempTrack/Views/HistoryList.swift

@@ -1,10 +1,14 @@
 import SwiftUI
+import SFSafeSymbols
 
 struct HistoryList: View {
     
     @EnvironmentObject
     var storage: PersistentStorage
-    
+
+    @State
+    private var showExportSheet = false
+
     var body: some View {
         NavigationView {
             List(storage.dailyMeasurementCounts) { day in
@@ -25,6 +29,16 @@ struct HistoryList: View {
             }
             .navigationTitle("History")
             .navigationBarTitleDisplayMode(.large)
+            .toolbar {
+                ToolbarItem {
+                    Button(action: { showExportSheet = true }) {
+                        Label("Export", systemSymbol: .arrowUpDoc)
+                    }
+                }
+            }
+            .sheet(isPresented: $showExportSheet) {
+                ExportSheet(isPresented: $showExportSheet)
+            }
         }
     }