Add sudo escalation for root protected files

src/mirro/main.py

@@ -2,7 +2,6 @@
 import argparse
 import tempfile
 import subprocess
-import shutil
 import os
 from pathlib import Path
 import time
@@ -14,10 +13,14 @@ def read_file(path: Path) -> str:
         return ""
     return path.read_text(encoding="utf-8", errors="replace")
 
+
 def write_file(path: Path, content: str):
     path.write_text(content, encoding="utf-8")
 
-def backup_original(original_path: Path, original_content: str, backup_dir: Path) -> Path:
+
+def backup_original(
+    original_path: Path, original_content: str, backup_dir: Path
+) -> Path:
     backup_dir.mkdir(parents=True, exist_ok=True)
     timestamp = time.strftime("%Y%m%dT%H%M%SZ", time.gmtime())
     uid = uuid.uuid4().hex[:8]
@@ -26,11 +29,24 @@ def backup_original(original_path: Path, original_content: str, backup_dir: Path
     backup_path.write_text(original_content, encoding="utf-8")
     return backup_path
 
+
 def main():
-    parser = argparse.ArgumentParser(description="Safely edit a file with automatic original backup if changed.")
+    parser = argparse.ArgumentParser(
+        description="Safely edit a file with automatic original backup if changed."
+    )
     parser.add_argument("file", type=str, help="Path to file to edit")
-    parser.add_argument("--backup-dir", type=str, default=str(Path.home() / ".local/share/mirro"), help="Backup directory")
-    parser.add_argument("--editor", type=str, default=os.environ.get("EDITOR", "nano"), help="Editor to use")
+    parser.add_argument(
+        "--backup-dir",
+        type=str,
+        default=str(Path.home() / ".local/share/mirro"),
+        help="Backup directory",
+    )
+    parser.add_argument(
+        "--editor",
+        type=str,
+        default=os.environ.get("EDITOR", "nano"),
+        help="Editor to use",
+    )
 
     args = parser.parse_args()
 
@@ -38,24 +54,32 @@ def main():
     backup_dir = Path(args.backup_dir).expanduser().resolve()
     editor_cmd = args.editor.split()
 
+    # Permission checks
+    parent = target.parent
+    if target.exists() and not os.access(target, os.W_OK):
+        print(f"Need elevated privileges to open {target}")
+        return 1
+    if not target.exists() and not os.access(parent, os.W_OK):
+        print(f"Need elevated privileges to create {target}")
+        return 1
+
     # Read original
     original_content = read_file(target)
 
     # Temp file for editing
-    with tempfile.NamedTemporaryFile(delete=False, prefix="mirro-", suffix=target.suffix) as tf:
+    with tempfile.NamedTemporaryFile(
+        delete=False, prefix="mirro-", suffix=target.suffix
+    ) as tf:
         temp_path = Path(tf.name)
     write_file(temp_path, original_content)
 
-
     # Launch editor
     subprocess.call(editor_cmd + [str(temp_path)])
 
-
     # Read edited
     edited_content = read_file(temp_path)
     temp_path.unlink(missing_ok=True)
 
-
     if edited_content == original_content:
         print("file hasn't changed")
         return
@@ -67,5 +91,6 @@ def main():
     # Overwrite target
     target.write_text(edited_content, encoding="utf-8")
 
+
 if __name__ == "__main__":
     main()