Allow cap deletion

Caps/ContentView.swift

@@ -45,6 +45,9 @@ struct ContentView: View {
     
     @State
     var showUpdateCapNameAlert = false
+
+    @State
+    var showDeleteCapAlert = false
     
     @State
     var updatedCapName = ""
@@ -138,10 +141,13 @@ struct ContentView: View {
                                 Label("Rename", systemSymbol: .pencil)
                             }
                             .tint(.purple)
-                            Button(role: .destructive) { startDeleteCap(cap: cap)
+                            Button {
+                                selectedCapId = cap.id
+                                showDeleteCapAlert = true
                             } label: {
                                 Label("Delete", systemSymbol: .trashCircleFill)
                             }
+                            .tint(.red)
                         }
                         .swipeActions(edge: .leading) {
                             Button {
@@ -149,7 +155,7 @@ struct ContentView: View {
                             } label: {
                                 Label("Images", systemSymbol: .photoStack)
                             }
-                            .tint(.purple)
+                            .tint(.blue)
                         }
                 }
                 .refreshable {
@@ -288,6 +294,14 @@ struct ContentView: View {
                   primaryButton: .default(Text("Download"), action: downloadClassifier),
                   secondaryButton: .cancel())
         }
+        .alert(Text("Delete cap"),
+               isPresented: $showDeleteCapAlert,
+               actions: {
+            Button("Delete", role: .destructive, action: saveNewCapName)
+            Button("Cancel", role: .cancel, action: {})
+        }, message: {
+            Text("Confirm the deletion of cap \(selectedCapId ?? 0)")
+        })
         .alert("Update name", isPresented: $showUpdateCapNameAlert, actions: {
             TextField("Name", text: $updatedCapName)
             Button("Update", action: saveNewCapName)
@@ -405,8 +419,15 @@ struct ContentView: View {
         showImageOverviewForCap = true
     }
 
-    private func startDeleteCap(cap: Cap) {
-        // TODO: Implement
+    private func startDeleteCap() {
+        guard let cap = selectedCapId else {
+            return
+        }
+        Task {
+            guard await database.delete(cap: cap) else {
+                return
+            }
+        }
     }
 }
 

Caps/Data/Database.swift

@@ -35,7 +35,11 @@ final class Database: ObservableObject {
     }
 
     var nextCapId: Int {
-        (caps.values.max()?.id ?? 0) + 1
+        var next = 1
+        while caps[next] != nil {
+            next += 1
+        }
+        return next
     }
 
     @AppStorage("changed")
@@ -621,15 +625,15 @@ final class Database: ObservableObject {
 
     func delete(image: CapImage) async -> Bool {
         guard hasServerAuthentication else {
-            log("No authorization to set main image")
+            log("No authorization to delete cap image")
             return false
         }
-        guard var cap = cap(for: image.cap) else {
-            log("No cap \(image.cap) to set main image")
+        guard let cap = cap(for: image.cap) else {
+            log("No cap \(image.cap) to delete cap image")
             return false
         }
         guard image.version < cap.imageCount else {
-            log("Invalid main image \(image.version) for \(cap.id) with only \(cap.imageCount) images")
+            log("Invalid image \(image.version) to delete for \(cap.id) with only \(cap.imageCount) images")
             return false
         }
 
@@ -667,6 +671,43 @@ final class Database: ObservableObject {
         }
     }
 
+    func delete(cap: Int) async -> Bool {
+        guard hasServerAuthentication else {
+            log("No authorization to delete cap")
+            return false
+        }
+        guard caps[cap] != nil else {
+            log("No cap \(cap) to delete")
+            return false
+        }
+
+        let url = serverUrl.appendingPathComponent("delete/\(cap)")
+        var request = URLRequest(url: url)
+        request.httpMethod = "POST"
+        request.addValue(serverAuthenticationKey, forHTTPHeaderField: "key")
+        do {
+            let (_, response) = try await URLSession.shared.data(for: request)
+            guard let httpResponse = response as? HTTPURLResponse else {
+                log("Unexpected response deleting cap \(cap): \(response)")
+                return false
+            }
+            guard httpResponse.statusCode == 200 else {
+                log("Failed to delete cap \(cap): Response \(httpResponse.statusCode)")
+                return false
+            }
+
+            // Delete cached images
+            images.removeCachedImages(for: cap)
+            // Delete cap
+            caps[cap] = nil
+            log("Deleted cap \(cap)")
+            return true
+        } catch {
+            log("Failed to delete cap \(cap): \(error)")
+            return false
+        }
+    }
+
     // MARK: Classification
 
     /// The compiled recognition model on disk