/*
 * ============LICENSE_START=======================================================
 *  Copyright (C) 2023-2024 Nordix Foundation
 *  ================================================================================
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  SPDX-License-Identifier: Apache-2.0
 *  ============LICENSE_END=========================================================
 */

package org.onap.cps.ncmp.dmi.rest.stub.controller;

import static org.onap.cps.ncmp.api.NcmpResponseStatus.SUCCESS;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.cloudevents.CloudEvent;
import io.cloudevents.core.builder.CloudEventBuilder;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import org.onap.cps.ncmp.api.impl.utils.EventDateTimeFormatter;
import org.onap.cps.ncmp.dmi.rest.stub.model.data.operational.CmHandle;
import org.onap.cps.ncmp.dmi.rest.stub.model.data.operational.DataOperationRequest;
import org.onap.cps.ncmp.dmi.rest.stub.model.data.operational.DmiDataOperationRequest;
import org.onap.cps.ncmp.dmi.rest.stub.utils.ResourceFileReaderUtil;
import org.onap.cps.ncmp.events.async1_0_0.Data;
import org.onap.cps.ncmp.events.async1_0_0.DataOperationEvent;
import org.onap.cps.ncmp.events.async1_0_0.Response;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("${rest.api.dmi-stub-base-path}")
@RequiredArgsConstructor
@Slf4j
public class DmiRestStubController {

    private static final String DEFAULT_TAG = "tagD";
    private static final String dataOperationEventType = "org.onap.cps.ncmp.events.async1_0_0.DataOperationEvent";
    private static final Map<String, String> moduleSetTagPerCmHandleId = new HashMap<>();
    private final KafkaTemplate<String, CloudEvent> cloudEventKafkaTemplate;
    private final ObjectMapper objectMapper;
    private final ApplicationContext applicationContext;
    @Value("${app.ncmp.async-m2m.topic}")
    private String ncmpAsyncM2mTopic;
    @Value("${delay.module-references-delay-ms}")
    private long moduleReferencesDelayMs;
    @Value("${delay.module-resources-delay-ms}")
    private long moduleResourcesDelayMs;
    @Value("${delay.data-for-cm-handle-delay-ms}")
    private long dataForCmHandleDelayMs;

    /**
     * This code defines a REST API endpoint for adding new the module set tag mapping. The endpoint receives the
     * cmHandleId and moduleSetTag as request body and add into moduleSetTagPerCmHandleId map with the provided
     * values.
     *
     * @param requestBody map of cmHandleId and moduleSetTag
     * @return a ResponseEntity object containing the updated moduleSetTagPerCmHandleId map as the response body
     */
    @PostMapping("/v1/tagMapping")
    public ResponseEntity<Map<String, String>> addTagForMapping(@RequestBody final Map<String, String> requestBody) {
        moduleSetTagPerCmHandleId.putAll(requestBody);
        return new ResponseEntity<>(requestBody, HttpStatus.CREATED);
    }

    /**
     * This code defines a GET endpoint of  module set tag mapping.
     *
     * @return The map represents the module set tag mapping.
     */
    @GetMapping("/v1/tagMapping")
    public ResponseEntity<Map<String, String>> getTagMapping() {
        return ResponseEntity.ok(moduleSetTagPerCmHandleId);
    }

    /**
     * This code defines a GET endpoint of  module set tag by cm handle ID.
     *
     * @return The map represents the module set tag mapping filtered by cm handle ID.
     */
    @GetMapping("/v1/tagMapping/ch/{cmHandleId}")
    public ResponseEntity<String> getTagMappingByCmHandleId(@PathVariable final String cmHandleId) {
        return ResponseEntity.ok(moduleSetTagPerCmHandleId.get(cmHandleId));
    }

    /**
     * This code defines a REST API endpoint for updating the module set tag mapping. The endpoint receives the
     * cmHandleId and moduleSetTag as request body and updates the moduleSetTagPerCmHandleId map with the provided
     * values.
     *
     * @param requestBody map of cmHandleId and moduleSetTag
     * @return a ResponseEntity object containing the updated moduleSetTagPerCmHandleId map as the response body
     */

    @PutMapping("/v1/tagMapping")
    public ResponseEntity<Map<String, String>> updateTagMapping(@RequestBody final Map<String, String> requestBody) {
        moduleSetTagPerCmHandleId.putAll(requestBody);
        return ResponseEntity.noContent().build();
    }

    /**
     * It contains a method to delete an entry from the moduleSetTagPerCmHandleId map.
     * The method takes a cmHandleId as a parameter and removes the corresponding entry from the map.
     *
     * @return a ResponseEntity containing the updated map.
     */
    @DeleteMapping("/v1/tagMapping/ch/{cmHandleId}")
    public ResponseEntity<String> deleteTagMappingByCmHandleId(@PathVariable final String cmHandleId) {
        moduleSetTagPerCmHandleId.remove(cmHandleId);
        return ResponseEntity.ok(String.format("Mapping of %s is deleted successfully", cmHandleId));
    }

    /**
     * Get all modules for given cm handle.
     *
     * @param cmHandleId              The identifier for a network function, network element, subnetwork,
     *                                or any other cm object by managed Network CM Proxy
     * @param moduleReferencesRequest module references request body
     * @return ResponseEntity response entity having module response as json string.
     */
    @PostMapping("/v1/ch/{cmHandleId}/modules")
    public ResponseEntity<String> getModuleReferences(@PathVariable("cmHandleId") final String cmHandleId,
                                                      @RequestBody final Object moduleReferencesRequest) {
        delay(moduleReferencesDelayMs);
        try {
            log.info("Incoming DMI request body: {}",
                    objectMapper.writeValueAsString(moduleReferencesRequest));
        } catch (final JsonProcessingException jsonProcessingException) {
            log.info("Unable to parse dmi data operation request to json string");
        }
        final String moduleResponseContent = getModuleResourceResponse(cmHandleId,
                "ModuleResponse.json");
        log.info("cm handle: {} requested for modules", cmHandleId);
        return ResponseEntity.ok(moduleResponseContent);
    }

    /**
     * Retrieves module resources for a given cmHandleId.
     *
     * @param cmHandleId                 The identifier for a network function, network element, subnetwork,
     *                                   or any other cm object by managed Network CM Proxy
     * @param moduleResourcesReadRequest module resources read request body
     * @return ResponseEntity response entity having module resources response as json string.
     */
    @PostMapping("/v1/ch/{cmHandleId}/moduleResources")
    public ResponseEntity<String> retrieveModuleResources(
            @PathVariable("cmHandleId") final String cmHandleId,
            @RequestBody final Object moduleResourcesReadRequest) {
        delay(moduleResourcesDelayMs);
        final String moduleResourcesResponseContent = getModuleResourceResponse(cmHandleId,
                "ModuleResourcesResponse.json");
        log.info("cm handle: {} requested for modules resources", cmHandleId);
        return ResponseEntity.ok(moduleResourcesResponseContent);
    }

    /**
     * Create resource data from passthrough operational or running for a cm handle.
     *
     * @param cmHandleId              The identifier for a network function, network element, subnetwork,
     *                                or any other cm object by managed Network CM Proxy
     * @param datastoreName           datastore name
     * @param resourceIdentifier      resource identifier
     * @param options                 options
     * @param topic                   client given topic name
     * @return (@ code ResponseEntity) response entity
     */
    @PostMapping("/v1/ch/{cmHandleId}/data/ds/{datastoreName}")
    public ResponseEntity<String> getResourceDataForCmHandle(
            @PathVariable("cmHandleId") final String cmHandleId,
            @PathVariable("datastoreName") final String datastoreName,
            @RequestParam(value = "resourceIdentifier") final String resourceIdentifier,
            @RequestParam(value = "options", required = false) final String options,
            @RequestParam(value = "topic", required = false) final String topic,
            @RequestHeader(value = "Authorization", required = false) final String authorization) {
        log.info("DMI AUTH HEADER: {}", authorization);
        delay(dataForCmHandleDelayMs);
        final String sampleJson = ResourceFileReaderUtil.getResourceFileContent(applicationContext.getResource(
                ResourceLoader.CLASSPATH_URL_PREFIX + "data/operational/ietf-network-topology-sample-rfc8345.json"));
        return ResponseEntity.ok(sampleJson);
    }

    /**
     * This method is not implemented for ONAP DMI plugin.
     *
     * @param topic                   client given topic name
     * @param requestId               requestId generated by NCMP as an ack for client
     * @param dmiDataOperationRequest list of operation details
     * @return (@ code ResponseEntity) response entity
     */
    @PostMapping("/v1/data")
    public ResponseEntity<Void> getResourceDataForCmHandleDataOperation(
            @RequestParam(value = "topic") final String topic,
            @RequestParam(value = "requestId") final String requestId,
            @RequestBody final DmiDataOperationRequest dmiDataOperationRequest) {
        delay(dataForCmHandleDelayMs);
        try {
            log.info("Request received from the NCMP to DMI Plugin: {}",
                    objectMapper.writeValueAsString(dmiDataOperationRequest));
        } catch (final JsonProcessingException jsonProcessingException) {
            log.info("Unable to process dmi data operation request to json string");
        }
        dmiDataOperationRequest.getOperations().forEach(dmiDataOperation -> {
            final DataOperationEvent dataOperationEvent = getDataOperationEvent(dmiDataOperation);
            dmiDataOperation.getCmHandles().forEach(cmHandle -> {
                dataOperationEvent.getData().getResponses().get(0).setIds(List.of(cmHandle.getId()));
                final CloudEvent cloudEvent = buildAndGetCloudEvent(topic, requestId, dataOperationEvent);
                cloudEventKafkaTemplate.send(ncmpAsyncM2mTopic, UUID.randomUUID().toString(), cloudEvent);
            });
        });
        return new ResponseEntity<>(HttpStatus.ACCEPTED);
    }

    private CloudEvent buildAndGetCloudEvent(final String topic, final String requestId,
                                             final DataOperationEvent dataOperationEvent) {
        CloudEvent cloudEvent = null;
        try {
            cloudEvent = CloudEventBuilder.v1()
                    .withId(UUID.randomUUID().toString())
                    .withSource(URI.create("DMI"))
                    .withType(dataOperationEventType)
                    .withDataSchema(URI.create("urn:cps:" + dataOperationEventType + ":1.0.0"))
                    .withTime(EventDateTimeFormatter.toIsoOffsetDateTime(
                            EventDateTimeFormatter.getCurrentIsoFormattedDateTime()))
                    .withData(objectMapper.writeValueAsBytes(dataOperationEvent))
                    .withExtension("destination", topic)
                    .withExtension("correlationid", requestId)
                    .build();
        } catch (final JsonProcessingException jsonProcessingException) {
            log.error("Unable to parse event into bytes. cause : {}", jsonProcessingException.getMessage());
        }
        return cloudEvent;
    }

    private DataOperationEvent getDataOperationEvent(final DataOperationRequest dataOperationRequest) {
        final Response response = new Response();
        response.setOperationId(dataOperationRequest.getOperationId());
        response.setStatusCode(SUCCESS.getCode());
        response.setStatusMessage(SUCCESS.getMessage());
        response.setIds(dataOperationRequest.getCmHandles().stream().map(CmHandle::getId).toList());
        response.setResourceIdentifier(dataOperationRequest.getResourceIdentifier());
        response.setOptions(dataOperationRequest.getOptions());
        final String ietfNetworkTopologySample = ResourceFileReaderUtil
                .getResourceFileContent(applicationContext.getResource(
                        ResourceLoader.CLASSPATH_URL_PREFIX
                                + "data/operational/ietf-network-topology-sample-rfc8345.json"));
        final JSONParser jsonParser = new JSONParser();
        try {
            response.setResult(jsonParser.parse(ietfNetworkTopologySample));
        } catch (final ParseException parseException) {
            log.error("Unable to parse event result as json object. cause : {}", parseException.getMessage());
        }
        final List<Response> responseList = new ArrayList<>(1);
        responseList.add(response);
        final Data data = new Data();
        data.setResponses(responseList);
        final DataOperationEvent dataOperationEvent = new DataOperationEvent();
        dataOperationEvent.setData(data);
        return dataOperationEvent;
    }

    private String getModuleResourceResponse(final String cmHandleId, final String moduleResponseType) {
        if (moduleSetTagPerCmHandleId.isEmpty()) {
            log.info("Using default module responses of type ietfYang");
            return ResourceFileReaderUtil.getResourceFileContent(applicationContext.getResource(
                    ResourceLoader.CLASSPATH_URL_PREFIX
                            + String.format("module/ietfYang-%s", moduleResponseType)));
        }
        final String moduleSetTag = moduleSetTagPerCmHandleId.getOrDefault(cmHandleId, DEFAULT_TAG);
        final String moduleResponseFilePath = String.format("module/%s-%s", moduleSetTag, moduleResponseType);
        final Resource moduleResponseResource = applicationContext.getResource(
                ResourceLoader.CLASSPATH_URL_PREFIX + moduleResponseFilePath);
        log.info("Using module responses from : {}", moduleResponseFilePath);
        return ResourceFileReaderUtil.getResourceFileContent(moduleResponseResource);
    }

    private void delay(final long milliseconds) {
        try {
            Thread.sleep(milliseconds);
        } catch (final InterruptedException e) {
            log.error("Thread sleep interrupted: {}", e.getMessage());
            Thread.currentThread().interrupt();
        }
    }
}