package eu.openaire.urls_worker.controllers;

import eu.openaire.urls_worker.components.AssignmentsHandler;
import eu.openaire.urls_worker.util.UriBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;


@RestController
@RequestMapping("")
public class GeneralController {

    private static final Logger logger = LoggerFactory.getLogger(GeneralController.class);

    private final String controllerIp;


    public GeneralController(@Value("${info.controllerIp}") String controllerIp) {
        this.controllerIp = controllerIp;
    }


    @GetMapping("isAlive")
    public ResponseEntity<?> isWorkerAlive() {
        logger.info("Received an \"isAlive\" request.");
        return ResponseEntity.ok().build();
    }


    public static boolean shouldShutdownWorker = false;

    @GetMapping("shutdownWorker")
    public ResponseEntity<?> shutdownWorkerGracefully(HttpServletRequest request)
    {
        String initMsg = "Received a \"shutdownWorker\" request.";
        ResponseEntity<?> responseEntity = passSecurityChecks(request, initMsg);
        if ( responseEntity != null )
            return responseEntity;

        String finalMsg = "";
        if ( shouldShutdownWorker )
            finalMsg = " The worker has already received a \"shutdownWorker\" (which was not canceled afterwards).";
        else
            shouldShutdownWorker = true;

        finalMsg += " The worker will shutdown, after finishing current work.";
        logger.info(initMsg + finalMsg);
        return ResponseEntity.ok().body(finalMsg + "\n");
    }


    @GetMapping("cancelShutdownWorker")
    public ResponseEntity<?> cancelShutdownWorkerGracefully(HttpServletRequest request)
    {
        String initMsg = "Received a \"cancelShutdownWorker\" request.";
        ResponseEntity<?> responseEntity = passSecurityChecks(request, initMsg);
        if ( responseEntity != null )
            return responseEntity;

        shouldShutdownWorker = false;
        String finalMsg = " Any previous \"shutdownWorker\"-request is canceled. The \"maxAssignmentsBatchesToHandleBeforeShutdown\" will still be honored (if it's set).";
        logger.info(initMsg + finalMsg);
        return ResponseEntity.ok().body(finalMsg + "\n");
    }


    @GetMapping("getHandledAssignmentsCounts")
    public ResponseEntity<?> getHandledAssignmentsCounts()
    {
        return ResponseEntity.ok(AssignmentsHandler.assignmentsNumsHandled);
    }


    public ResponseEntity<?> passSecurityChecks(HttpServletRequest request, String initMsg)
    {
        if ( request == null ) {
            logger.error(initMsg + " The \"HttpServletRequest\" is null!");
            return ResponseEntity.internalServerError().build();
        }
        String remoteAddr = request.getHeader("X-FORWARDED-FOR");
        if ( remoteAddr == null || "".equals(remoteAddr) )
            remoteAddr = request.getRemoteAddr();

        if ( ! (remoteAddr.equals("127.0.0.1") || remoteAddr.equals(UriBuilder.ip) || remoteAddr.equals(controllerIp)) ) {
            logger.error(initMsg + " The request came from another IP: " + remoteAddr + " | while this worker has the IP: " + UriBuilder.ip);
            return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
        }

        // TODO - If the Controller's ip is actually a domain name, then we have to calculate its IP-address one time
        // Ad a regex to check that the controller's "IP" contains only numbers and dots, if not, then we have a DOMAIN.
        // So use the following code to get the number-IP address:
        /*
        String address = java.net.InetAddress.getByName(controllerIp).getHostAddress();
        // TOdo - checks for potential "null" or exceptions in the above code, in case the domain resolution failed
        * */

        return null;    // The checks are passing.
    }

}