1 files changed, 41 insertions, 0 deletions
diff --git a/src/storage.rs b/src/storage.rs
new file mode 100644
index 0000000..90abf05
--- /dev/null
+++ b/src/storage.rs
@@ -0,0 +1,41 @@
+use etcetera::{AppStrategy, AppStrategyArgs, app_strategy::Xdg};
+use smol::unblock;
+
+pub struct StorageManager {
+	xdg: Xdg,
+	data: Option<Box<[u8]>>,
+}
+
+impl StorageManager {
+	pub fn load(app: AppStrategyArgs) -> std::io::Result<Self> {
+		let xdg = etcetera::choose_app_strategy(app).map_err(std::io::Error::other)?;
+		let data = std::fs::read(xdg.in_data_dir("save"))
+			.or_else(|_| std::fs::read(xdg.in_data_dir("save.tmp")))
+			.map(|data| data.into_boxed_slice())
+			.ok();
+
+		Ok(Self { data, xdg })
+	}
+
+	pub fn get(&self) -> Option<&[u8]> {
+		self.data.as_deref()
+	}
+
+	pub fn background_save(&mut self, data: Box<[u8]>) {
+		let tmp_file = self.xdg.in_data_dir("save.tmp");
+		let save_file = self.xdg.in_data_dir("save");
+
+		self.data = Some(data.clone());
+		unblock(move || {
+			std::fs::write(&tmp_file, &data)?;
+
+			let saved_data = std::fs::read(&tmp_file)?;
+			if *saved_data != *data {
+				return Err(std::io::Error::other("Failed to verify file integrity"));
+			}
+
+			std::fs::rename(tmp_file, save_file)?;
+			Ok(())
+		});
+	}
+}