package at.gv.egiz.eaaf.modules.auth.sl20.utils;

import java.io.IOException;
import java.io.StringWriter;
import java.net.URISyntaxException;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.jose4j.base64url.Base64Url;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.JsonNode;

public class SL20HttpBindingUtils {
	private static final Logger log = LoggerFactory.getLogger(SL20HttpBindingUtils.class);
	
	/**
	 * Write SL2.0 response into http-response object 
	 * 
	 * @param httpReq Current http request
	 * @param httpResp Current http response
	 * @param sl20Forward SL2.0 command that should be written to response
	 * @param redirectURL SL2.0 redirect URL in case of SL2.0 redirect command and no native client (see SL2.0 specification)
	 * @param httpCodeRedirect http redirect-code in case of SL2.0 redirect command and no native client (see SL2.0 specification)
	 * @throws IOException
	 * @throws URISyntaxException
	 */
	public static void writeIntoResponse(@Nonnull HttpServletRequest httpReq, @Nonnull HttpServletResponse httpResp, 
			@Nonnull JsonNode sl20Forward, @Nullable String redirectURL,
			@Nonnull int httpCodeRedirect) throws IOException, URISyntaxException {
		//forward SL2.0 command
		httpResp.addIntHeader(SL20Constants.HTTP_HEADER_SL20_RESP, SL20Constants.CURRENT_SL20_VERSION);
		
		if (httpReq.getHeader(SL20Constants.HTTP_HEADER_SL20_CLIENT_TYPE) != null && 
				httpReq.getHeader(SL20Constants.HTTP_HEADER_SL20_CLIENT_TYPE).equals(SL20Constants.HTTP_HEADER_VALUE_NATIVE)) {
			log.debug("Client request containts 'native client' header ... ");												
			final StringWriter writer = new StringWriter();
			writer.write(sl20Forward.toString());						
			final byte[] content = writer.toString().getBytes("UTF-8");
			httpResp.setStatus(HttpServletResponse.SC_OK);
			httpResp.setContentLength(content.length);
			httpResp.setContentType(ContentType.APPLICATION_JSON.toString());						
			httpResp.getOutputStream().write(content);
											
		} else {
			log.debug("Client request containts is no native client ... ");
			final URIBuilder clientRedirectURI = new URIBuilder(redirectURL);
			clientRedirectURI.addParameter(
					SL20Constants.PARAM_SL20_REQ_COMMAND_PARAM, 
					Base64Url.encode(sl20Forward.toString().getBytes()));
			httpResp.setStatus(httpCodeRedirect);
			httpResp.setHeader("Location", clientRedirectURI.build().toString());
			
		}
		
	}
}