/// Handler middleware utilities
///
/// Centralized JWT validation + rate limiting for all HTTP handlers.
/// Eliminates boilerplate across endpoints, improves testability.

use actix_web::{HttpRequest, HttpResponse};
use serde_json::json;
use crate::http_server::AppState;

/// Result type for middleware operations
pub type MiddlewareResult<T> = Result<T, HttpResponse>;

/// Validate JWT token + check rate limit
///
/// Handles:
/// 1. Extract Authorization header
/// 2. Validate JWT (if auth enabled)
/// 3. Check rate limit (if limiter enabled)
/// 4. Return error response on failure
///
/// # Usage
/// ```ignore
/// validate_and_rate_limit(&req, &state, "compact", 10)?;
/// // If we get here, both JWT and rate limit checks passed
/// ```
pub fn validate_and_rate_limit(
    req: &HttpRequest,
    state: &AppState,
    endpoint: &str,
    rate_limit: u32,
) -> MiddlewareResult<()> {
    // 1. JWT validation (if enabled)
    if let Some(jwt_validator) = &state.jwt_validator {
        let auth_header = req
            .headers()
            .get("Authorization")
            .and_then(|h| h.to_str().ok())
            .ok_or_else(|| {
                HttpResponse::Unauthorized().json(json!({
                    "error": "Missing Authorization header"
                }))
            })?;

        crate::jwt_validator::JwtValidator::extract_bearer_token(auth_header).map_err(|e| {
            HttpResponse::Unauthorized().json(json!({
                "error": format!("JWT validation failed: {}", e)
            }))
        })?;
    }

    // 2. Rate limiting (if enabled)
    state
        .rate_limiter
        .check("default", endpoint)
        .map_err(|e| {
            HttpResponse::TooManyRequests().json(json!({
                "error": format!("Rate limit exceeded: {}", e.reason())
            }))
        })?;

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_middleware_result_type_is_result() {
        // Verify type alias works
        let _result: MiddlewareResult<()> = Ok(());
        let _result: MiddlewareResult<()> = Err(HttpResponse::Unauthorized().finish());
    }

    #[test]
    fn test_validate_and_rate_limit_signature() {
        // Just verify the function signature is correct (compile-time test)
        // Runtime tests require full AppState with mocks
        let _ = validate_and_rate_limit;
    }
}