package eu.openaire.urls_controller.controllers;

import com.google.common.collect.HashMultimap;
import eu.openaire.urls_controller.models.Assignment;
import eu.openaire.urls_controller.models.Datasource;
import eu.openaire.urls_controller.models.Task;
import eu.openaire.urls_controller.payloads.responces.AssignmentResponse;
import eu.openaire.urls_controller.util.FileUtils;
import eu.openaire.urls_controller.util.GenericUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.*;

@RestController
@RequestMapping("/urls")
public class UrlController {

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


    public UrlController() {

    }


    @GetMapping("")
    public ResponseEntity<?> getUrls(@RequestParam String workerId, @RequestParam int tasksLimit) {

        List<Task> tasks = new ArrayList<>();

        // TODO - Create the Assignment from the id-urls stored in the database up to the tasks-limit.
        int assignmentId = 0;

        Assignment assignment = new Assignment(assignmentId, tasks, workerId, new Date());

        // TODO - Write the Assignment details to the database and then send it to the worker.

        logger.info("Sending assignment_" + assignment.getAssignmentId() + " to worker with ID: " + workerId);

        return ResponseEntity.status(200).header("Content-Type", "application/json").body(new AssignmentResponse(assignment));
    }


    private static int assignmentId = -1;    // Just for the "getTestUrls"-endpoint.

    @GetMapping("test")
    public ResponseEntity<?> getTestUrls(@RequestParam String workerId, @RequestParam int tasksLimit) {

        try {
            new FileUtils();    // Find the input file.
        } catch (Exception e) {
            logger.error(e.getMessage());
            return ResponseEntity.status(500).body("The resource file for the requested tasks was not found.");
        }

        List<Task> tasks = new ArrayList<>();
        HashMultimap<String, String> loadedIdUrlPairs;
        boolean isFirstRun = true;
        boolean tasksLimitReached = false;

        // Start loading urls.
        while ( true ) {
            loadedIdUrlPairs = FileUtils.getNextIdUrlPairBatchFromJson(); // Take urls from jsonFile.

            if ( FileUtils.isFinishedLoading(loadedIdUrlPairs.isEmpty(), isFirstRun) )	// Throws RuntimeException which is automatically passed on.
                break;
            else
                isFirstRun = false;

            Set<Map.Entry<String, String>> pairs = loadedIdUrlPairs.entries();

            for ( Map.Entry<String,String> pair : pairs )
            {
                if ( tasks.size() >= tasksLimit ) {
                    tasksLimitReached = true;
                    break;
                }

                int randomNum = GenericUtils.getRandomNumber(1, 5);
                tasks.add(new Task(pair.getKey(), pair.getValue(), new Datasource("ID_" + randomNum, "NAME_" + randomNum)));
            }// end pairs-for-loop

            if ( tasksLimitReached ) {
                logger.debug("Done loading urls from the inputFile as the tasksLimit (" + tasksLimit + ") was reached.");
                break;
            }
        }// end loading-while-loop

        if ( FileUtils.inputScanner != null )
            FileUtils.inputScanner.close();

        Assignment assignment = new Assignment((++assignmentId), tasks, workerId, new Date());

        logger.info("Sending assignment_" + assignment.getAssignmentId() + " with " + tasks.size() + " tasks (" + FileUtils.duplicateIdUrlEntries + " more tasks were discarded as duplicates), to worker with ID: " + workerId);

        return ResponseEntity.status(200).header("Content-Type", "application/json").body(new AssignmentResponse(assignment));
    }

}