Allow cap deletion

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