package eu.openaire.urls_controller.controllers;

import eu.openaire.urls_controller.configuration.ImpalaConnector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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 java.sql.Connection;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

@RestController
@RequestMapping("/impala")
public class ImpalaController {

    // This controller will test the connectivity with the database and return statistics!

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


    @GetMapping("get10PublicationIdsTest")
    public ResponseEntity<?> get10PublicationIdsTest() {

        Connection con = ImpalaConnector.getInstance().getConnection();
        if ( con == null )
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Problem when connecting with the Impala-database!");

        String query = "SELECT id FROM publication LIMIT 10;";

        try ( ResultSet res = con.prepareStatement(query).executeQuery()) {
            if ( !res.first() ) {
                String errorMsg = "No results retrieved from the \"getAssignmentsQuery\"!";
                logger.error(errorMsg);
                return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(errorMsg);
            }

            List<String> publications = new ArrayList<>();
            do {
                publications.add(res.getString(0));
            } while ( res.next() );

            return new ResponseEntity<String>(publications.toString(), HttpStatus.OK);

        } catch (Exception e) {
            String errorMsg = "Problem when executing \"getAssignmentsQuery\": " + query;
            logger.error(errorMsg, e);
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(errorMsg);
        } finally {
            ImpalaConnector.closeConnection(con);
        }
    }

}