package httpapi

import "net/http"

func AllowOrigin(
	origin string,
	next http.Handler,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Add("Vary", "Origin")

		if r.Header.Get("Origin") == origin {
			w.Header().Set("Access-Control-Allow-Origin", origin)
			w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
			w.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS")

			if r.Method == http.MethodOptions {
				w.WriteHeader(http.StatusNoContent)
				return
			}
		}

		next.ServeHTTP(w, r)
	})
}