package middleware

import (
	"net/http"
)

// APIKey returns middleware that validates the X-API-Key header
// against the expected key. Returns 401 if missing or invalid.
func APIKey(expectedKey string) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			if r.Header.Get("X-API-Key") != expectedKey {
				w.Header().Set("Content-Type", "application/json")
				w.WriteHeader(http.StatusUnauthorized)
				w.Write([]byte(`{"error":"unauthorized"}`))
				return
			}
			next.ServeHTTP(w, r)
		})
	}
}
