Choose save data location

src/filesystem.rs

@@ -0,0 +1,52 @@
+use std::{fs, path::PathBuf};
+
+use anyhow::{Result, bail};
+use directories::ProjectDirs;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone)]
+pub struct Persistence {
+    config_dir: Option<PathBuf>,
+}
+
+impl Persistence {
+    pub fn new() -> Self {
+        Self {
+            config_dir: init_config_dir(),
+        }
+    }
+
+    pub fn save_config<T: Serialize>(&self, file: &str, data: &T) -> Result<()> {
+        if let Some(config_dir) = self.config_dir.as_ref() {
+            let bytes = serde_json::to_vec_pretty(data)?;
+            let filename = config_dir.join(file).with_extension("json");
+            fs::write(&filename, bytes)?;
+        }
+        Ok(())
+    }
+
+    pub fn load_config<T: for<'a> Deserialize<'a>>(&self, file: &str) -> Result<T> {
+        let Some(config_dir) = self.config_dir.as_ref() else {
+            bail!("config directory not found");
+        };
+        let filename = config_dir.join(file).with_extension("json");
+        let bytes = fs::read(filename)?;
+        Ok(serde_json::from_slice(&bytes)?)
+    }
+}
+
+fn init_config_dir() -> Option<PathBuf> {
+    let config_dir = project_dirs()?.config_dir().to_path_buf();
+    fs::create_dir_all(&config_dir).ok()?;
+    Some(config_dir)
+}
+
+pub fn init_data_dir() -> Option<PathBuf> {
+    let data_dir = project_dirs()?.data_dir().to_path_buf();
+    fs::create_dir_all(&data_dir).ok()?;
+    Some(data_dir)
+}
+
+fn project_dirs() -> Option<ProjectDirs> {
+    ProjectDirs::from("com", "virtual-boy", "Lemur")
+}