feat(config): implement config loading

src/core/config.rs

@@ -0,0 +1,54 @@
+use std::{env, fs, path::PathBuf, sync::LazyLock};
+
+use serde::{Deserialize, Serialize};
+
+/// Application's configuration
+#[derive(Deserialize, Serialize)]
+pub struct Config {
+    /// Path to the directory where app data is stored.
+    pub soar_path: String,
+}
+
+impl Config {
+    /// Creates a new configuration by loading it from the configuration file.
+    /// If the configuration file is not found, it generates a new default configuration.
+    pub fn new() -> Self {
+        let home_config = env::var("XDG_CONFIG_HOME").unwrap_or_else(|_| {
+            env::var("HOME").map_or_else(
+                |_| panic!("Failed to retrieve HOME environment variable"),
+                |home| format!("{}/.config", home),
+            )
+        });
+        let pkg_config = PathBuf::from(home_config).join(env!("CARGO_PKG_NAME"));
+        let config_path = pkg_config.join("config.json");
+        let content = match fs::read(&config_path) {
+            Ok(content) => content,
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                fs::create_dir_all(pkg_config).unwrap();
+                Config::generate(config_path)
+            }
+            Err(e) => {
+                panic!("Error reading config file: {:?}", e);
+            }
+        };
+        serde_json::from_slice(&content)
+            .unwrap_or_else(|e| panic!("Failed to parse config file: {:?}", e))
+    }
+
+    fn generate(config_path: PathBuf) -> Vec<u8> {
+        let def_config = Self {
+            soar_path: "$HOME/.soar".to_string(),
+        };
+        let serialized = serde_json::to_vec_pretty(&def_config).unwrap();
+        fs::write(config_path, &serialized).unwrap();
+        serialized
+    }
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub static CONFIG: LazyLock<Config> = LazyLock::new(Config::default);

src/core/mod.rs

@@ -0,0 +1 @@
+pub mod config;