feat: add CLI user-agent detection and error types

src/cli_detect.rs

@@ -0,0 +1,67 @@
+const CLI_PREFIXES: &[&str] = &[
+    "curl/",
+    "Wget/",
+    "HTTPie/",
+    "xh/",
+    "fetch",
+    "PowerShell/",
+    "WindowsPowerShell/",
+];
+
+pub fn is_cli_user_agent(user_agent: &str) -> bool {
+    CLI_PREFIXES
+        .iter()
+        .any(|prefix| user_agent.starts_with(prefix))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn detects_curl() {
+        assert!(is_cli_user_agent("curl/8.7.1"));
+    }
+
+    #[test]
+    fn detects_wget() {
+        assert!(is_cli_user_agent("Wget/1.21.4"));
+    }
+
+    #[test]
+    fn detects_httpie() {
+        assert!(is_cli_user_agent("HTTPie/3.2.2"));
+    }
+
+    #[test]
+    fn detects_xh() {
+        assert!(is_cli_user_agent("xh/0.22.0"));
+    }
+
+    #[test]
+    fn detects_fetch() {
+        assert!(is_cli_user_agent("fetch libfetch/2.0"));
+    }
+
+    #[test]
+    fn detects_powershell() {
+        assert!(is_cli_user_agent("PowerShell/7.4.1"));
+    }
+
+    #[test]
+    fn detects_windows_powershell() {
+        assert!(is_cli_user_agent("WindowsPowerShell/5.1"));
+    }
+
+    #[test]
+    fn rejects_browser() {
+        assert!(!is_cli_user_agent(
+            "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
+        ));
+    }
+
+    #[test]
+    fn rejects_empty() {
+        assert!(!is_cli_user_agent(""));
+    }
+}

src/error.rs

@@ -0,0 +1,19 @@
+use axum::http::StatusCode;
+use axum::response::{IntoResponse, Response};
+
+pub enum AppError {
+    IpNotFound,
+    InvalidIp,
+    DbLookupFailed,
+}
+
+impl IntoResponse for AppError {
+    fn into_response(self) -> Response {
+        let (status, message) = match self {
+            Self::IpNotFound => (StatusCode::NOT_FOUND, "IP not found in database"),
+            Self::InvalidIp => (StatusCode::BAD_REQUEST, "Invalid IP address"),
+            Self::DbLookupFailed => (StatusCode::INTERNAL_SERVER_ERROR, "Database lookup failed"),
+        };
+        (status, message).into_response()
+    }
+}

src/main.rs

@@ -1,5 +1,7 @@
+mod cli_detect;
 mod config;
 mod db;
+mod error;
 mod models;
 mod updater;