保存文件时使用第一行内容作为文件名

Note/FormatLogViewController.swift

@@ -12,6 +12,7 @@ class FormatLogViewController: UIViewController {
     private var textView: UITextView!
     private var formatButton: UIButton!
     private var doneButton: UIBarButtonItem!
+    private var isFormatted = false
 
     override func viewDidLoad() {
         super.viewDidLoad()
@@ -61,7 +62,40 @@ class FormatLogViewController: UIViewController {
     }
 
     @objc private func didTapFormatButton() {
+        if isFormatted {
+            saveToFiles()
+        } else {
             textView.text = formatLog(textView.text)
+            isFormatted = true
+            formatButton.setTitle("保存到 iCloud", for: .normal)
+        }
+    }
+
+    private func saveToFiles() {
+        let fileName = generateFileName()
+        let fileURL = FileManager.default.temporaryDirectory.appendingPathComponent(fileName)
+
+        do {
+            try textView.text.write(to: fileURL, atomically: true, encoding: .utf8)
+            let documentPicker = UIDocumentPickerViewController(forExporting: [fileURL], asCopy: true)
+            documentPicker.delegate = self
+            present(documentPicker, animated: true)
+        } catch {
+            print("Failed to write file: \(error)")
+        }
+    }
+
+    private func generateFileName() -> String {
+        let text = textView.text ?? ""
+        let firstLine = text.components(separatedBy: .newlines).first ?? ""
+        let trimmed = firstLine.trimmingCharacters(in: .whitespaces)
+        let withoutHash = trimmed.replacingOccurrences(of: "^#\\s*", with: "", options: .regularExpression)
+        let cleanName = withoutHash.trimmingCharacters(in: .whitespaces)
+
+        if cleanName.isEmpty {
+            return "formatted_log_\(Int(Date().timeIntervalSince1970)).md"
+        }
+        return cleanName + ".md"
     }
 
     private func formatLog(_ text: String) -> String {
@@ -97,3 +131,14 @@ extension FormatLogViewController: UITextViewDelegate {
         navigationItem.rightBarButtonItem = nil
     }
 }
+
+extension FormatLogViewController: UIDocumentPickerDelegate {
+
+    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
+        // File saved to selected location
+    }
+
+    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
+        // User cancelled
+    }
+}