package cz.bcas.fp5.application.rest.filters.cors;


import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * Restovy filter ktery pridava CORS hlavicky.
 */
@WebFilter(asyncSupported = true, urlPatterns = {"/api/frontend/*"})
public class CORSFilter implements Filter {

    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;

        // Authorize (allow) all domains to consume the content
        ((HttpServletResponse) servletResponse).addHeader("Access-Control-Allow-Origin", "*");
        ((HttpServletResponse) servletResponse).addHeader("Access-Control-Allow-Methods", "GET, OPTIONS, HEAD, PUT, POST");
        ((HttpServletResponse) servletResponse).addHeader("Access-Control-Allow-Headers", "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With");


        HttpServletResponse resp = (HttpServletResponse) servletResponse;

        // For HTTP OPTIONS verb/method reply with ACCEPTED status code -- per CORS handshake
        if (request.getMethod().equals("OPTIONS")) {
            resp.setStatus(HttpServletResponse.SC_ACCEPTED);
            return;
        }

        // pass the request along the filter chain
        chain.doFilter(request, servletResponse);
    }

    @Override
    public void destroy() {
        //neni potreba
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        //neni potreba
    }

}