reinhardt-auth 0.1.1

//! Authentication handlers for login, logout, and user management
//!
//! Provides ready-to-use handlers for common authentication workflows

// This module uses the deprecated User trait for backward compatibility.
// Login handler accepts Box<dyn User> to preserve existing authentication APIs.
#![allow(deprecated)]
use crate::AuthenticationBackend;
use crate::User;
use crate::session::{SESSION_KEY_USER_ID, Session, SessionId, SessionStore};
use async_trait::async_trait;
use reinhardt_core::exception::Result;
use reinhardt_http::Handler;
use reinhardt_http::{Request, Response};
use serde::{Deserialize, Serialize};
use std::sync::Arc;

/// Login credentials
///
/// # Examples
///
/// ```
/// use reinhardt_auth::handlers::LoginCredentials;
///
/// let credentials = LoginCredentials {
///     username: "user".to_string(),
///     password: "password".to_string(),
/// };
///
/// assert_eq!(credentials.username, "user");
/// ```
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LoginCredentials {
	/// The user's login name.
	pub username: String,
	/// The user's password.
	pub password: String,
}

/// Session cookie name
pub const SESSION_COOKIE_NAME: &str = "sessionid";

/// Login handler
///
/// Handles user login with username/password authentication
///
/// # Examples
///
/// ```ignore
/// use reinhardt_auth::handlers::LoginHandler;
/// use reinhardt_auth::session::InMemorySessionStore;
/// use reinhardt_auth::core::backend::AuthenticationBackend;
/// use std::sync::Arc;
///
/// let session_store = Arc::new(InMemorySessionStore::new());
/// // AuthenticationBackend is a trait - use a concrete implementation
/// let auth_backend = Arc::new(YourAuthBackendImpl::new());
/// let handler = LoginHandler::new(session_store, auth_backend);
/// ```
pub struct LoginHandler<S: SessionStore, A: AuthenticationBackend> {
	session_store: Arc<S>,
	auth_backend: Arc<A>,
}

impl<S: SessionStore, A: AuthenticationBackend> LoginHandler<S, A> {
	/// Create a new login handler
	///
	/// # Examples
	///
	/// ```ignore
	/// use reinhardt_auth::handlers::LoginHandler;
	/// use reinhardt_auth::session::InMemorySessionStore;
	/// use reinhardt_auth::backend::AuthBackend;
	/// use std::sync::Arc;
	///
	/// let session_store = Arc::new(InMemorySessionStore::new());
	/// // AuthBackend is a trait - use a concrete implementation
	/// let auth_backend = Arc::new(YourAuthBackendImpl::new());
	/// let handler = LoginHandler::new(session_store, auth_backend);
	/// ```
	pub fn new(session_store: Arc<S>, auth_backend: Arc<A>) -> Self {
		Self {
			session_store,
			auth_backend,
		}
	}

	fn extract_session_id(&self, request: &Request) -> Option<SessionId> {
		request
			.headers
			.get(hyper::header::COOKIE)
			.and_then(|v| v.to_str().ok())
			.and_then(|cookies| {
				cookies.split(';').find_map(|cookie| {
					let mut parts = cookie.trim().splitn(2, '=');
					if parts.next()? == SESSION_COOKIE_NAME {
						Some(parts.next()?.to_string())
					} else {
						None
					}
				})
			})
	}

	async fn perform_login(&self, user: Box<dyn User>) -> Result<(SessionId, String)> {
		let session_id = self.session_store.create_session_id();
		let mut session = Session::new();
		session.set(SESSION_KEY_USER_ID, serde_json::json!(user.id()));

		self.session_store.save(&session_id, &session).await;

		let cookie_str = format!(
			"{}={}; HttpOnly; Secure; Path=/; SameSite=Lax",
			SESSION_COOKIE_NAME, session_id
		);

		Ok((session_id, cookie_str))
	}
}

#[async_trait]
impl<S: SessionStore + 'static, A: AuthenticationBackend + 'static> Handler for LoginHandler<S, A> {
	async fn handle(&self, request: Request) -> Result<Response> {
		if let Some(user) = self
			.auth_backend
			.authenticate(&request)
			.await
			.ok()
			.flatten()
		{
			// Invalidate old session to prevent session fixation attacks
			if let Some(old_session_id) = self.extract_session_id(&request) {
				self.session_store.delete(&old_session_id).await;
			}

			let (_session_id, cookie_str) = self.perform_login(user).await?;

			Ok(Response::ok()
				.with_header("Set-Cookie", &cookie_str)
				.with_json(&serde_json::json!({
					"success": true,
					"message": "Login successful"
				}))?)
		} else {
			Ok(
				Response::new(Response::unauthorized().status).with_json(&serde_json::json!({
					"success": false,
					"message": "Invalid credentials"
				}))?,
			)
		}
	}
}

/// Logout handler
///
/// Handles user logout by clearing the session
///
/// # Examples
///
/// ```
/// use reinhardt_auth::handlers::LogoutHandler;
/// use reinhardt_auth::session::InMemorySessionStore;
/// use std::sync::Arc;
///
/// let session_store = Arc::new(InMemorySessionStore::new());
/// let handler = LogoutHandler::new(session_store);
/// ```
pub struct LogoutHandler<S: SessionStore> {
	session_store: Arc<S>,
}

impl<S: SessionStore> LogoutHandler<S> {
	/// Create a new logout handler
	///
	/// # Examples
	///
	/// ```
	/// use reinhardt_auth::handlers::LogoutHandler;
	/// use reinhardt_auth::session::InMemorySessionStore;
	/// use std::sync::Arc;
	///
	/// let session_store = Arc::new(InMemorySessionStore::new());
	/// let handler = LogoutHandler::new(session_store);
	/// ```
	pub fn new(session_store: Arc<S>) -> Self {
		Self { session_store }
	}

	fn extract_session_id(&self, request: &Request) -> Option<SessionId> {
		request
			.headers
			.get(hyper::header::COOKIE)
			.and_then(|v| v.to_str().ok())
			.and_then(|cookies| {
				cookies.split(';').find_map(|cookie| {
					let mut parts = cookie.trim().splitn(2, '=');
					if parts.next()? == SESSION_COOKIE_NAME {
						Some(parts.next()?.to_string())
					} else {
						None
					}
				})
			})
	}
}

#[async_trait]
impl<S: SessionStore + 'static> Handler for LogoutHandler<S> {
	async fn handle(&self, request: Request) -> Result<Response> {
		if let Some(session_id) = self.extract_session_id(&request) {
			self.session_store.delete(&session_id).await;
		}

		let cookie_str = format!("{}=; HttpOnly; Path=/; Max-Age=0", SESSION_COOKIE_NAME);

		Ok(Response::ok()
			.with_header("Set-Cookie", &cookie_str)
			.with_json(&serde_json::json!({
				"success": true,
				"message": "Logout successful"
			}))?)
	}
}

#[cfg(test)]
mod tests {
	use super::*;
	use crate::AuthenticationError;
	use crate::SimpleUser;
	use crate::session::InMemorySessionStore;
	use bytes::Bytes;
	use hyper::{HeaderMap, Method};
	use rstest::rstest;
	use uuid::Uuid;

	struct TestAuthBackend {
		test_user: Option<SimpleUser>,
	}

	#[async_trait]
	impl AuthenticationBackend for TestAuthBackend {
		async fn authenticate(
			&self,
			_request: &Request,
		) -> std::result::Result<Option<Box<dyn User>>, AuthenticationError> {
			if let Some(user) = &self.test_user {
				Ok(Some(Box::new(user.clone())))
			} else {
				Ok(None)
			}
		}

		async fn get_user(
			&self,
			_user_id: &str,
		) -> std::result::Result<Option<Box<dyn User>>, AuthenticationError> {
			if let Some(user) = &self.test_user {
				Ok(Some(Box::new(user.clone())))
			} else {
				Ok(None)
			}
		}
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_success() {
		let session_store = Arc::new(InMemorySessionStore::new());
		let test_user = SimpleUser {
			id: Uuid::now_v7(),
			username: "testuser".to_string(),
			email: "test@example.com".to_string(),
			is_active: true,
			is_admin: false,
			is_staff: false,
			is_superuser: false,
		};
		let auth_backend = Arc::new(TestAuthBackend {
			test_user: Some(test_user),
		});

		let handler = LoginHandler::new(session_store, auth_backend);
		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		let response = handler.handle(request).await.unwrap();
		assert_eq!(response.status, reinhardt_http::Response::ok().status);
		assert!(response.headers.contains_key("set-cookie"));

		// Verify Secure flag is present in session cookie
		let cookie_value = response
			.headers
			.get("set-cookie")
			.unwrap()
			.to_str()
			.unwrap();
		assert!(
			cookie_value.contains("Secure"),
			"Session cookie must include Secure flag"
		);
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_failure() {
		let session_store = Arc::new(InMemorySessionStore::new());
		let auth_backend = Arc::new(TestAuthBackend { test_user: None });

		let handler = LoginHandler::new(session_store, auth_backend);
		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		let response = handler.handle(request).await.unwrap();
		assert_eq!(
			response.status,
			reinhardt_http::Response::unauthorized().status
		);
	}

	#[rstest]
	#[tokio::test]
	async fn test_logout_handler() {
		let session_store = Arc::new(InMemorySessionStore::new());
		let session_id = session_store.create_session_id();
		let mut session = Session::new();
		session.set(SESSION_KEY_USER_ID, serde_json::json!("user123"));
		session_store.save(&session_id, &session).await;

		let handler = LogoutHandler::new(session_store.clone());

		let mut headers = HeaderMap::new();
		headers.insert(
			"cookie",
			format!("{}={}", SESSION_COOKIE_NAME, session_id)
				.parse()
				.unwrap(),
		);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/logout")
			.headers(headers)
			.body(Bytes::new())
			.build()
			.unwrap();

		let response = handler.handle(request).await.unwrap();
		assert_eq!(response.status, reinhardt_http::Response::ok().status);
		assert!(response.headers.contains_key("set-cookie"));

		assert!(session_store.load(&session_id).await.is_none());
	}

	#[rstest]
	#[tokio::test]
	async fn test_logout_handler_no_session() {
		let session_store = Arc::new(InMemorySessionStore::new());
		let handler = LogoutHandler::new(session_store);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/logout")
			.body(Bytes::new())
			.build()
			.unwrap();

		let response = handler.handle(request).await.unwrap();
		assert_eq!(response.status, reinhardt_http::Response::ok().status);
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_session_contains_user_id() {
		// Arrange
		let session_store = Arc::new(InMemorySessionStore::new());
		let user_id = Uuid::now_v7();
		let test_user = SimpleUser {
			id: user_id,
			username: "session_user".to_string(),
			email: "session@example.com".to_string(),
			is_active: true,
			is_admin: false,
			is_staff: false,
			is_superuser: false,
		};
		let auth_backend = Arc::new(TestAuthBackend {
			test_user: Some(test_user),
		});
		let handler = LoginHandler::new(session_store.clone(), auth_backend);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert - extract session ID from Set-Cookie header
		let cookie_value = response
			.headers
			.get("set-cookie")
			.unwrap()
			.to_str()
			.unwrap();
		let session_id: String = cookie_value
			.split(';')
			.next()
			.unwrap()
			.split('=')
			.nth(1)
			.unwrap()
			.to_string();

		let session = session_store.load(&session_id).await.unwrap();
		let stored_user_id = session.get(SESSION_KEY_USER_ID).unwrap();
		assert_eq!(stored_user_id, &serde_json::json!(user_id.to_string()));
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_cookie_attributes() {
		// Arrange
		let session_store = Arc::new(InMemorySessionStore::new());
		let test_user = SimpleUser {
			id: Uuid::now_v7(),
			username: "cookie_user".to_string(),
			email: "cookie@example.com".to_string(),
			is_active: true,
			is_admin: false,
			is_staff: false,
			is_superuser: false,
		};
		let auth_backend = Arc::new(TestAuthBackend {
			test_user: Some(test_user),
		});
		let handler = LoginHandler::new(session_store, auth_backend);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert
		let cookie_value = response
			.headers
			.get("set-cookie")
			.unwrap()
			.to_str()
			.unwrap();
		assert!(
			cookie_value.contains("HttpOnly"),
			"Cookie must include HttpOnly flag"
		);
		assert!(
			cookie_value.contains("Secure"),
			"Cookie must include Secure flag"
		);
		assert!(
			cookie_value.contains("SameSite=Lax"),
			"Cookie must include SameSite=Lax"
		);
	}

	#[rstest]
	#[tokio::test]
	async fn test_logout_handler_clears_session_cookie() {
		// Arrange
		let session_store = Arc::new(InMemorySessionStore::new());
		let handler = LogoutHandler::new(session_store);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/logout")
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert
		let cookie_value = response
			.headers
			.get("set-cookie")
			.unwrap()
			.to_str()
			.unwrap();
		assert!(
			cookie_value.contains("Max-Age=0"),
			"Logout cookie must set Max-Age=0 to clear the session"
		);
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_response_body_structure() {
		// Arrange
		let session_store = Arc::new(InMemorySessionStore::new());
		let test_user = SimpleUser {
			id: Uuid::now_v7(),
			username: "body_user".to_string(),
			email: "body@example.com".to_string(),
			is_active: true,
			is_admin: false,
			is_staff: false,
			is_superuser: false,
		};
		let auth_backend = Arc::new(TestAuthBackend {
			test_user: Some(test_user),
		});
		let handler = LoginHandler::new(session_store, auth_backend);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert - response body should contain success and message fields
		let body: serde_json::Value = serde_json::from_slice(&response.body).unwrap();
		assert_eq!(body["success"], true);
		assert_eq!(body["message"], "Login successful");
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_inactive_user_rejected() {
		// Arrange - auth backend returns no user (simulating inactive user rejection)
		let session_store = Arc::new(InMemorySessionStore::new());
		let auth_backend = Arc::new(TestAuthBackend { test_user: None });
		let handler = LoginHandler::new(session_store, auth_backend);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert
		assert_eq!(
			response.status,
			reinhardt_http::Response::unauthorized().status
		);
		let body: serde_json::Value = serde_json::from_slice(&response.body).unwrap();
		assert_eq!(body["success"], false);
		assert_eq!(body["message"], "Invalid credentials");
	}

	#[rstest]
	#[tokio::test]
	async fn test_login_handler_invalidates_old_session() {
		// Arrange
		let session_store = Arc::new(InMemorySessionStore::new());
		let old_session_id = session_store.create_session_id();
		let mut old_session = Session::new();
		old_session.set(SESSION_KEY_USER_ID, serde_json::json!("old_user"));
		session_store.save(&old_session_id, &old_session).await;

		let test_user = SimpleUser {
			id: Uuid::now_v7(),
			username: "new_user".to_string(),
			email: "new@example.com".to_string(),
			is_active: true,
			is_admin: false,
			is_staff: false,
			is_superuser: false,
		};
		let auth_backend = Arc::new(TestAuthBackend {
			test_user: Some(test_user),
		});
		let handler = LoginHandler::new(session_store.clone(), auth_backend);

		let mut headers = HeaderMap::new();
		headers.insert(
			"cookie",
			format!("{}={}", SESSION_COOKIE_NAME, old_session_id)
				.parse()
				.unwrap(),
		);

		let request = Request::builder()
			.method(Method::POST)
			.uri("/login")
			.headers(headers)
			.body(Bytes::new())
			.build()
			.unwrap();

		// Act
		let response = handler.handle(request).await.unwrap();

		// Assert - login succeeds
		assert_eq!(response.status, reinhardt_http::Response::ok().status);

		// Assert - old session is invalidated
		assert!(
			session_store.load(&old_session_id).await.is_none(),
			"Old session must be invalidated on login"
		);

		// Assert - new session is created with a different ID
		let cookie_value = response
			.headers
			.get("set-cookie")
			.unwrap()
			.to_str()
			.unwrap();
		let cookie_pair = cookie_value.split(';').next().unwrap();
		let mut parts = cookie_pair.splitn(2, '=');
		let cookie_name = parts.next().unwrap();
		let cookie_val = parts.next().unwrap();
		assert_eq!(
			cookie_name, SESSION_COOKIE_NAME,
			"Expected session cookie name to be {SESSION_COOKIE_NAME}"
		);
		let new_session_id: String = cookie_val.to_string();
		assert_ne!(
			new_session_id, old_session_id,
			"New session ID must differ from old session ID"
		);
		assert!(
			session_store.load(&new_session_id).await.is_some(),
			"New session must exist"
		);
	}
}