Ensure proper naming of images on system start

Sources/App/CapServer.swift

@@ -82,9 +82,9 @@ final class CapServer: ServerOwner {
     func loadData() throws {
         loadClassifierVersion(at: classifierVersionFile)
         try loadCaps()
-        try updateCounts()
         saveCapCountHTML()
         try ensureExistenceOfChangedImagesFile()
+        organizeImages()
     }
 
     private func loadClassifierVersion(at url: URL) {
@@ -171,6 +171,38 @@ final class CapServer: ServerOwner {
         try? content.data(using: .utf8)!.write(to: htmlFile)
     }
     
+    private func organizeImages() {
+        caps.keys.forEach(organizeImage)
+    }
+    
+    private func organizeImage(for cap: Int) {
+        guard let images = try? images(in: folder(of: cap)) else {
+            log("Failed to get image urls for cap \(cap)")
+            return
+        }
+        var sorted: [(id: Int, url: URL)] = images.compactMap {
+            guard let id = Int($0.deletingPathExtension().lastPathComponent) else {
+                return nil
+            }
+            return (id, $0)
+        }.sorted { $0.id < $1.id }
+        for version in 0..<images.count {
+            guard version != sorted[version].id else {
+                continue
+            }
+            let last = sorted.popLast()!.url
+            let newUrl = file(of: cap, version: version)
+            do {
+                try fm.moveItem(at: last, to: newUrl)
+            } catch {
+                log("Failed to move file \(last.path) to \(newUrl.path): \(error)")
+                return
+            }
+            sorted.insert((version, newUrl), at: version)
+        }
+        caps[cap]?.count = sorted.count
+    }
+
     // MARK: Paths
 
     func folder(of cap: Int) -> URL {
@@ -207,9 +239,9 @@ final class CapServer: ServerOwner {
         }
     }
 
-    func countImages(in folder: URL) throws -> Int {
+    private func images(in folder: URL) throws -> [URL] {
         try fm.contentsOfDirectory(at: folder, includingPropertiesForKeys: nil)
-            .filter({ $0.pathExtension == "jpg" }).count
+            .filter { $0.pathExtension == "jpg" }
     }
 
     /**
@@ -220,7 +252,7 @@ final class CapServer: ServerOwner {
         guard fm.fileExists(atPath: f.path) else {
             return 0
         }
-        return try countImages(in: f)
+        return try images(in: f).count
     }
 
     // MARK: Images