feat: implement async methods for saving and opening file

src/io.rs

@@ -3,11 +3,55 @@ use std::{
     path::PathBuf,
 };
 
+use rfd::AsyncFileDialog;
+use tokio::fs;
+
+pub async fn open_file() -> Result<(PathBuf, String), String> {
+    let handle_result = AsyncFileDialog::new()
+        .set_directory("/")
+        .pick_file()
+        .await
+        .ok_or(String::from("Dialog cancelled"));
+
+    match handle_result {
+        Ok(handle) => {
+            let path = handle.path().to_owned();
+            let content_result = fs::read_to_string(&path).await.map_err(|e| e.to_string());
+
+            match content_result {
+                Ok(content) => Ok((path, content)),
+                Err(e) => Err(e),
+            }
+        }
+        Err(e) => Err(e),
+    }
+}
+
+pub async fn save_file(path: Option<PathBuf>, text: String) -> Result<PathBuf, String> {
+    let save_path = match path {
+        Some(p) => p,
+        None => AsyncFileDialog::new()
+            .set_directory("/")
+            .save_file()
+            .await
+            .ok_or(String::from("Dialog cancelled"))?
+            .path()
+            .to_owned(),
+    };
+
+    let save_result = fs::write(&save_path, text).await.map_err(|e| e.to_string());
+
+    match save_result {
+        Ok(_) => Ok(save_path),
+        Err(err) => Err(err),
+    }
+}
+
 pub fn save_file_to_disk(path: PathBuf, text: String) {
     let save_result = write(path, text);
 
     match save_result {
-        Ok(_) => {},
+        Ok(_) => {}
         Err(err) => eprintln!("Error: {}", err),
     }
 }