Refactor ProxyWarden routing and settings flow

src-tauri/src/safe_fs.rs

@@ -0,0 +1,53 @@
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+
+pub fn backup_path(path: &Path) -> PathBuf {
+    sibling_with_suffix(path, "bak")
+}
+
+pub fn corrupt_path(path: &Path) -> PathBuf {
+    sibling_with_suffix(
+        path,
+        &format!("corrupt.{}", uuid::Uuid::new_v4().hyphenated()),
+    )
+}
+
+pub fn temp_path(path: &Path) -> PathBuf {
+    sibling_with_suffix(path, &format!("tmp.{}", uuid::Uuid::new_v4().hyphenated()))
+}
+
+pub fn write_with_backup(path: &Path, contents: &[u8]) -> io::Result<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+
+    let temp_path = temp_path(path);
+    fs::write(&temp_path, contents)?;
+
+    let backup_path = backup_path(path);
+    if path.exists() {
+        fs::copy(path, &backup_path)?;
+        fs::remove_file(path)?;
+    }
+
+    match fs::rename(&temp_path, path) {
+        Ok(()) => Ok(()),
+        Err(error) => {
+            let _ = fs::remove_file(&temp_path);
+            if !path.exists() && backup_path.exists() {
+                let _ = fs::copy(&backup_path, path);
+            }
+            Err(error)
+        }
+    }
+}
+
+fn sibling_with_suffix(path: &Path, suffix: &str) -> PathBuf {
+    let file_name = path
+        .file_name()
+        .and_then(|value| value.to_str())
+        .unwrap_or("proxywarden-file");
+
+    path.with_file_name(format!("{file_name}.{suffix}"))
+}