ccs: migratable config

charge-controller-supervisor/src/config.rs

@@ -15,7 +15,7 @@ pub(super) struct ConfigWatcher {
 
 pub fn init_config(path: impl AsRef<std::path::Path>) -> Option<ConfigWatcher> {
     log::trace!("loading config...");
-    let config = Config::load(&path);
+    let config = Config::load(&path).unwrap();
     log::trace!("watching config for changes...");
     let config_watcher = ConfigWatcher::new(&path);
     let _ = CONFIG_PATH.get_or_init(|| path.as_ref().to_path_buf());
@@ -48,7 +48,7 @@ impl ConfigWatcher {
             loop {
                 match rx.recv().await {
                     Some(Ok(_event)) => {
-                        let config = Config::load(&config_path);
+                        let config = Config::load(&config_path).unwrap();
 
                         if let Err(e) = overwrite_config(config).await {
                             log::error!("{e:?}");
@@ -114,17 +114,26 @@ pub async fn write_to_config<'a>() -> ConfigHandle<'a> {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
-#[serde(default)]
-pub struct Config {
-    pub primary_charge_controller: String,
-    pub enable_secondary_control: bool,
-    pub charge_controllers: Vec<ChargeControllerConfig>,
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
+#[serde(tag = "version")]
+pub enum ConfigStorage {
+    #[serde(rename = "1")]
+    V1(Config),
 }
 
-impl Config {
-    fn load(path: impl AsRef<std::path::Path>) -> Self {
-        serde_json::from_str(&std::fs::read_to_string(path).unwrap()).unwrap()
+impl Default for ConfigStorage {
+    fn default() -> Self {
+        Self::from_latest(Default::default())
+    }
+}
+
+impl ConfigStorage {
+    const fn from_latest(config: Config) -> Self {
+        Self::V1(config)
+    }
+
+    fn load(path: impl AsRef<std::path::Path>) -> eyre::Result<Self> {
+        Ok(serde_json::from_str(&std::fs::read_to_string(path)?)?)
     }
 
     fn save_to(&self, path: impl AsRef<std::path::Path>) -> eyre::Result<()> {
@@ -137,6 +146,33 @@ impl Config {
     fn save(&self) -> eyre::Result<()> {
         self.save_to(CONFIG_PATH.get().unwrap())
     }
+
+    fn into_latest(self) -> Config {
+        match self {
+            ConfigStorage::V1(config) => config,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
+#[serde(default)]
+pub struct Config {
+    pub primary_charge_controller: String,
+    pub enable_secondary_control: bool,
+    pub charge_controllers: Vec<ChargeControllerConfig>,
+}
+
+impl Config {
+    fn load(path: impl AsRef<std::path::Path>) -> eyre::Result<Self> {
+        let storage = ConfigStorage::load(path)?;
+        Ok(storage.into_latest())
+    }
+
+    fn save(&self) -> eyre::Result<()> {
+        let as_storage = ConfigStorage::from_latest(self.clone());
+        as_storage.save()?;
+        Ok(())
+    }
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]

charge-controller-supervisor/src/main.rs

@@ -59,7 +59,7 @@ async fn run() -> eyre::Result<()> {
     match args.command {
         Commands::Watch => watch(args).await,
         Commands::GenerateConfig => {
-            let config = config::Config::default();
+            let config = config::ConfigStorage::default();
             let json = serde_json::to_string_pretty(&config)?;
             println!("{json}");
             Ok(())