[Add] Structure

src/config.rs

@@ -0,0 +1,65 @@
+use std::{env, time::Duration};
+
+#[derive(Clone, Debug)]
+pub struct RateLimitConfig {
+    pub window: Duration,
+    pub general_requests: usize,
+    pub registration_requests: usize,
+    pub transport_connections: usize,
+    pub transport_connections_per_ip: usize,
+}
+
+pub fn cors_origin() -> String {
+    env::var("CORS_ORIGIN").unwrap_or_else(|_| "https://tensamin.net".to_string())
+}
+
+impl Default for RateLimitConfig {
+    fn default() -> Self {
+        Self {
+            window: Duration::from_secs(60),
+            general_requests: 120,
+            registration_requests: 20,
+            transport_connections: 512,
+            transport_connections_per_ip: 32,
+        }
+    }
+}
+
+impl RateLimitConfig {
+    pub fn from_env() -> Self {
+        let defaults = Self::default();
+        Self {
+            window: env_duration("RATE_LIMIT_WINDOW_SECONDS", defaults.window),
+            general_requests: env_usize("RATE_LIMIT_GENERAL_REQUESTS", defaults.general_requests),
+            registration_requests: env_usize(
+                "RATE_LIMIT_REGISTRATION_REQUESTS",
+                defaults.registration_requests,
+            ),
+            transport_connections: env_usize(
+                "RATE_LIMIT_TRANSPORT_CONNECTIONS",
+                defaults.transport_connections,
+            ),
+            transport_connections_per_ip: env_usize(
+                "RATE_LIMIT_TRANSPORT_CONNECTIONS_PER_IP",
+                defaults.transport_connections_per_ip,
+            ),
+        }
+    }
+}
+
+fn env_usize(name: &str, fallback: usize) -> usize {
+    env::var(name)
+        .ok()
+        .and_then(|value| value.parse::<usize>().ok())
+        .filter(|value| *value > 0)
+        .unwrap_or(fallback)
+}
+
+fn env_duration(name: &str, fallback: Duration) -> Duration {
+    env::var(name)
+        .ok()
+        .and_then(|value| value.parse::<u64>().ok())
+        .filter(|value| *value > 0)
+        .map(Duration::from_secs)
+        .unwrap_or(fallback)
+}