Created metrics endpoints for NFV-related information

package portal.api.metrics;

import io.swagger.v3.oas.annotations.Operation;

import io.swagger.v3.oas.annotations.responses.ApiResponse;

import io.swagger.v3.oas.annotations.responses.ApiResponses;

import io.swagger.v3.oas.annotations.tags.Tag;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.http.ResponseEntity;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import java.util.Map;

@Tag(name = "NFV_MetricsApi")

public interface MetricsApi {

    Logger log = LoggerFactory.getLogger(MetricsApi.class);

    @Operation(summary = "Get total number of registered NSDs", operationId = "getRegisteredNsds")

    @ApiResponses(value = {

            @ApiResponse(responseCode = "200", description = "Success"),

            @ApiResponse(responseCode = "400", description = "Bad Request"),

            @ApiResponse(responseCode = "500", description = "Internal Server Error")

    })

    @RequestMapping(value = "/osapi/metrics/registeredNsds", method = RequestMethod.GET, produces = "application/json;charset=utf-8")

    ResponseEntity<Map<String, Integer>> getRegisteredNsds();

    @Operation(summary = "Get total number of registered VNFs", operationId = "getRegisteredVnfs")

    @ApiResponses(value = {

            @ApiResponse(responseCode = "200", description = "Success"),

            @ApiResponse(responseCode = "400", description = "Bad Request"),

            @ApiResponse(responseCode = "500", description = "Internal Server Error")

    })

    @RequestMapping(value = "/osapi/metrics/registeredVnfs", method = RequestMethod.GET, produces = "application/json;charset=utf-8")

    ResponseEntity<Map<String, Integer>> getRegisteredVnfs();

    @Operation(summary = "Get total number of registered Mano Providers", operationId = "getRegisteredManoProviders")

    @ApiResponses(value = {

            @ApiResponse(responseCode = "200", description = "Success"),

            @ApiResponse(responseCode = "400", description = "Bad Request"),

            @ApiResponse(responseCode = "500", description = "Internal Server Error")

    })

    @RequestMapping(value = "/osapi/metrics/registeredManoProviders", method = RequestMethod.GET, produces = "application/json;charset=utf-8")

    ResponseEntity<Map<String, Integer>> getRegisteredManoProviders();

}

package portal.api.metrics;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.http.HttpStatus;

import org.springframework.http.ResponseEntity;

import org.springframework.stereotype.Controller;

import portal.api.service.ManoProviderService;

import portal.api.service.NSDService;

import portal.api.service.VxFService;

import java.util.HashMap;

import java.util.Map;

@Controller

public class MetricsApiController implements MetricsApi {

    private static final Logger log = LoggerFactory.getLogger(MetricsApiController.class);

    private final NSDService nsdService;

    private final VxFService vxfService;

    private final ManoProviderService manoProviderService;

    public MetricsApiController(NSDService nsdService, VxFService vxfService, ManoProviderService manoProviderService) {

        this.nsdService = nsdService;

        this.vxfService = vxfService;

        this.manoProviderService = manoProviderService;

    }

    @Override

    public ResponseEntity<Map<String, Integer>> getRegisteredNsds() {

        try {

            int totalNSDs = nsdService.getExperiments().size();

            Map<String, Integer> response = new HashMap<>();

            response.put("registeredNsds", totalNSDs);

            return new ResponseEntity<>(response, HttpStatus.OK);

        } catch (Exception e) {

            log.error("Couldn't retrieve total registered NSDs. ", e);

            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);

        }

    }

    @Override

    public ResponseEntity<Map<String, Integer>> getRegisteredVnfs() {

        try {

            int totalVNFs = vxfService.getVxFs().size();

            Map<String, Integer> response = new HashMap<>();

            response.put("registeredVnfs", totalVNFs);

            return new ResponseEntity<>(response, HttpStatus.OK);

        } catch (Exception e) {

            log.error("Couldn't retrieve total registered VNFs. ", e);

            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);

        }

    }

    @Override

    public ResponseEntity<Map<String, Integer>> getRegisteredManoProviders() {

        try {

            int totalManoProviders = manoProviderService.getMANOproviders().size();

            Map<String, Integer> response = new HashMap<>();

            response.put("registeredManoProviders", totalManoProviders);

            return new ResponseEntity<>(response, HttpStatus.OK);

        } catch (Exception e) {

            log.error("Couldn't retrieve total registered MANO Providers. ", e);

            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);

        }

    }

}