feat: implement osu! installation validation

src-tauri/src/utils.rs

@@ -0,0 +1,24 @@
+use std::path::Path;
+
+/// Checks the presence of required files in a folder and returns the percentage found.
+///
+/// # Arguments
+/// * `folder_path` - The path to the folder to check.
+/// * `required_files` - A slice of file names that should be present in the folder.
+///
+/// # Returns
+/// * `f32` - The percentage (0.0 to 100.0) of required files found in the folder.
+pub fn check_folder_completeness<P: AsRef<Path>>(folder_path: P, required_files: &[&str]) -> f32 {
+    let mut found = 0;
+    for file in required_files {
+        let file_path = folder_path.as_ref().join(file);
+        if file_path.exists() {
+            found += 1;
+        }
+    }
+    if required_files.is_empty() {
+        100.0
+    } else {
+        (found as f32 / required_files.len() as f32) * 100.0
+    }
+}