package org.gcube.data.analysis.rconnector;

import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URLEncoder;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import javax.inject.Inject;
import javax.servlet.ServletContext;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.NewCookie;
import javax.ws.rs.core.Response;
import javax.xml.bind.DatatypeConverter;

import org.gcube.common.authorization.library.provider.AuthorizationProvider;
import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.data.access.storagehub.fs.StorageHubFS;

import lombok.extern.slf4j.Slf4j;

@Path("connect/")
@Slf4j
public class Resource {

	@Inject
	ConfigFileWriter writer;

	@Inject
	InfoRetriever infoRetriever;

	@Context ServletContext context;


	@Path("/{trId}")
	@GET
	public Response connect(@PathParam("trId") Long tabularResourceId) {
		log.info("connect called with user {} and trID {} in scope {}",AuthorizationProvider.instance.get().getClient().getId(), tabularResourceId, ScopeProvider.instance.get());

		String login = AuthorizationProvider.instance.get().getClient().getId();
		String usersHome = context.getInitParameter("usersHome");
		String filename = context.getInitParameter("filename");
		String scriptToExecute = context.getInitParameter("addUserScript");
		if (ScopeProvider.instance.get()==null || login == null || tabularResourceId ==null ) return Response.serverError().build();
		Info info;
		try{
			info = infoRetriever.retrieve(login, tabularResourceId);
			log.debug("retrieved info: "+info);
		}catch(Exception e){
			log.error("error connecting to r",e);
			return Response.serverError().build();
		}
		if (!writer.write(info, login, usersHome, filename, scriptToExecute)) return Response.serverError().build();

		return createResponse(login);	
	}


	@GET
	public Response connect() {
		log.info("connect called with user {} in scope {}",AuthorizationProvider.instance.get().getClient().getId(), ScopeProvider.instance.get());
		String login = AuthorizationProvider.instance.get().getClient().getId();
		String usersHome = context.getInitParameter("usersHome");
		String filename = context.getInitParameter("filename");
		String scriptToExecute = context.getInitParameter("addUserScript");
		if (login == null ) return Response.serverError().build();
		Info info = new Info();
		info.setUsername(login);
		info.setToken(SecurityTokenProvider.instance.get());
		if (!writer.write(info, login, usersHome, filename, scriptToExecute)) return Response.serverError().build();

		return createResponse(AuthorizationProvider.instance.get().getClient().getId());	
	}

	private Response createResponse(String userName){
		try{
			String keyFilePath = context.getInitParameter("storedKeyPath");
			String rStudioServerAddress = context.getInitParameter("rStudioAddress");

			log.debug("key file path: "+keyFilePath);
			log.debug("rstudio server address: "+rStudioServerAddress);

			Calendar now = Calendar.getInstance();
			now.add(Calendar.YEAR, 10);
			now.add(Calendar.DAY_OF_YEAR, -1);
			SimpleDateFormat sdf = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z", Locale.ENGLISH);
			String format = sdf.format(now.getTime());

			File keyFile = new File(keyFilePath);
			if (!keyFile.exists())
				return Response.serverError().build();

			byte[] keyByte = Files.readAllBytes(keyFile.toPath());

			SecretKeySpec keySpec = new SecretKeySpec(keyByte,
					"HmacSHA256");
			Mac mac = Mac.getInstance("HmacSHA256");
			mac.init(keySpec);
			byte[] result = mac.doFinal((userName+format).getBytes());

			String encoded = URLEncoder.encode(DatatypeConverter.printBase64Binary(result));

			String cookieValue = userName+"|"+URLEncoder.encode(format).replaceAll("\\+", "%20")+"|"+encoded;
			NewCookie cookie = new NewCookie("user-id", 
					cookieValue,
					"/", rStudioServerAddress, "", -1, false, true );


			return Response.seeOther(new URI("http://"+rStudioServerAddress))
					.cookie(cookie).build();
		}catch(Exception e){
			log.error("error creating response", e);
			return Response.serverError().build();}
	}

}