feat: add saving and reading server setting from config file

src/settings/general_settings.rs

@@ -0,0 +1,48 @@
+use core::error;
+use std::path::PathBuf;
+
+use log::warn;
+use serde::{Serialize, de::DeserializeOwned};
+
+// maybe consider some better name for this
+pub trait SettingsLike: Serialize + DeserializeOwned + Default {
+    fn get_config_dir() -> Result<PathBuf, Box<dyn error::Error>> {
+        Ok(dirs::config_local_dir()
+            .ok_or("Couldn't get config dir!")?
+            .join("checkers"))
+    }
+
+    fn get_file_path() -> Result<PathBuf, Box<dyn error::Error>>;
+
+    fn save_to_file(&self) -> Result<(), Box<dyn error::Error>> {
+        let path: PathBuf = Self::get_file_path()?;
+
+        if let Some(parent_dir) = path.parent() {
+            std::fs::create_dir_all(parent_dir)?;
+        }
+
+        let toml = toml::to_string(&self)?;
+        std::fs::write(path, toml)?;
+
+        Ok(())
+    }
+
+    fn read_from_file() -> Result<Self, Box<dyn error::Error>> {
+        Ok(toml::from_slice(&std::fs::read(Self::get_file_path()?)?)?) // i love rust
+    }
+
+    fn new() -> Self {
+        match Self::read_from_file() {
+            Ok(settings) => return settings,
+            Err(e) => warn!("Could not load settings from file, because: {}", e),
+        }
+
+        let settings = Self::default();
+
+        if let Err(e) = settings.save_to_file() {
+            warn!("Could not save server settings to the file, because: {}", e);
+        }
+
+        settings
+    }
+}

src/settings/mod.rs

@@ -0,0 +1,2 @@
+pub mod general_settings;
+pub mod server_settings;

src/settings/server_settings.rs

@@ -0,0 +1,33 @@
+use std::{
+    net::{IpAddr, Ipv4Addr, SocketAddr},
+    path::PathBuf,
+};
+
+use serde::{Deserialize, Serialize};
+
+use crate::settings::general_settings::SettingsLike;
+
+// TODO! More settings!
+#[derive(Serialize, Deserialize)]
+pub struct ServerSettings {
+    pub addr: SocketAddr,
+    pub max_connections: usize,
+    pub allow_spectators: bool,
+}
+
+impl SettingsLike for ServerSettings {
+    fn get_file_path() -> Result<PathBuf, Box<dyn std::error::Error>> {
+        Ok(Self::get_config_dir()?.join("server.toml"))
+    }
+}
+
+impl Default for ServerSettings {
+    fn default() -> Self {
+        Self {
+            addr: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 6767),
+            max_connections: 2, // Maybe this should be a const somewhere in the server code? It
+            // makes no sense to have different value than this
+            allow_spectators: false,
+        }
+    }
+}