/*-
 * ========================LICENSE_START=================================
 * O-RAN-SC
 * %%
 * Copyright (C) 2019 AT&T Intellectual Property and Nokia
 * %%
 * 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.
 * ========================LICENSE_END===================================
 */
package org.oransc.ric.portal.dashboard.controller;

import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.oransc.ric.e2mgr.client.api.HealthCheckApi;
import org.oransc.ric.e2mgr.client.api.NodebApi;
import org.oransc.ric.e2mgr.client.model.GetNodebResponse;
import org.oransc.ric.e2mgr.client.model.NodebIdentity;
import org.oransc.ric.e2mgr.client.model.NodebIdentityGlobalNbId;
import org.oransc.ric.e2mgr.client.model.SetupRequest;
import org.oransc.ric.portal.dashboard.DashboardApplication;
import org.oransc.ric.portal.dashboard.DashboardConstants;
import org.oransc.ric.portal.dashboard.model.ErrorTransport;
import org.oransc.ric.portal.dashboard.model.RanDetailsTransport;
import org.oransc.ric.portal.dashboard.model.SuccessTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.HttpStatusCodeException;

import io.swagger.annotations.ApiOperation;

/**
 * Proxies calls from the front end to the E2 Manager API. All methods answer
 * 502 on failure and wrap the remote details: <blockquote>HTTP server received
 * an invalid response from a server it consulted when acting as a proxy or
 * gateway.</blockquote>
 * 
 * In R1 the E2 interface does not yet implement the get-ID-list method, so this
 * class mocks up some functionality.
 */
@Configuration
@RestController
@RequestMapping(value = DashboardConstants.ENDPOINT_PREFIX + "/e2mgr", produces = MediaType.APPLICATION_JSON_VALUE)
public class E2ManagerController {

	private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

	private final List<NodebIdentity> mockNodebIdList;

	// Path parameters
	private static final String PP_RANNAME = "ranName";

	// Populated by the autowired constructor
	private final HealthCheckApi e2HealthCheckApi;
	private final NodebApi e2NodebApi;

	@Autowired
	public E2ManagerController(final HealthCheckApi e2HealthCheckApi, final NodebApi e2NodebApi,
			@Value("${e2mgr.mock.rannames:#{null}}") final String mockRanNames) {
		Assert.notNull(e2HealthCheckApi, "API must not be null");
		Assert.notNull(e2NodebApi, "API must not be null");
		this.e2HealthCheckApi = e2HealthCheckApi;
		this.e2NodebApi = e2NodebApi;
		mockNodebIdList = new ArrayList<>();
		if (mockRanNames != null) {
			logger.debug("ctor: Mocking RAN names: {}", mockRanNames);
			for (String id : mockRanNames.split(",")) {
				NodebIdentityGlobalNbId globalNbId = new NodebIdentityGlobalNbId().nbId("mockNbId").plmnId("mockPlmId");
				mockNodebIdList.add(new NodebIdentity().globalNbId(globalNbId).inventoryName(id.trim()));
			}
		}
	}

	@ApiOperation(value = "Gets the E2 manager client library MANIFEST.MF property Implementation-Version.", response = SuccessTransport.class)
	@RequestMapping(value = DashboardConstants.VERSION_PATH, method = RequestMethod.GET)
	public SuccessTransport getE2ManagerClientVersion() {
		return new SuccessTransport(200, DashboardApplication.getImplementationVersion(HealthCheckApi.class));
	}

	@ApiOperation(value = "Gets the health from the E2 manager, expressed as the response code.")
	@RequestMapping(value = "/health", method = RequestMethod.GET)
	public Object healthGet(HttpServletResponse response) {
		logger.debug("healthGet");
		try {
			e2HealthCheckApi.healthGet();
			response.setStatus(e2HealthCheckApi.getApiClient().getStatusCode().value());
			return null;
		} catch (HttpStatusCodeException ex) {
			logger.warn("healthGet failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

	// This calls other methods to simplify the task of the front-end.
	@ApiOperation(value = "Gets all RAN identities and statuses from the E2 manager.", response = RanDetailsTransport.class, responseContainer = "List")
	@RequestMapping(value = "/ran", method = RequestMethod.GET)
	public Object getRanDetails() {
		logger.debug("getRanDetails");
		List<NodebIdentity> nodebIdList = null;
		try {
			// TODO: remove mock when e2mgr delivers the getNodebIdList() method
			nodebIdList = mockNodebIdList.isEmpty() ? e2NodebApi.getNodebIdList() : mockNodebIdList;
		} catch (HttpStatusCodeException ex) {
			logger.warn("getRanDetails: getNodebIdList failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
		List<RanDetailsTransport> details = new ArrayList<>();
		for (NodebIdentity nbid : nodebIdList) {
			GetNodebResponse nbResp = null;
			try {
				// Keep looping despite failures
				nbResp = e2NodebApi.getNb(nbid.getInventoryName());
			} catch (HttpStatusCodeException ex) {
				logger.warn("getRanDetails failed for name {}: {}", nbid.getInventoryName(), ex.toString());
				nbResp = new GetNodebResponse().connectionStatus("UNKNOWN").ip("UNKNOWN").port(-1)
						.ranName(nbid.getInventoryName());
			}
			details.add(new RanDetailsTransport(nbid, nbResp));
		}
		return details;
	}

	@ApiOperation(value = "Get RAN identities list.", response = NodebIdentity.class, responseContainer = "List")
	@RequestMapping(value = "/nodeb-ids", method = RequestMethod.GET)
	public Object getNodebIdList() {
		logger.debug("getNodebIdList");
		try {
			return e2NodebApi.getNodebIdList();
		} catch (HttpStatusCodeException ex) {
			logger.warn("getNodebIdList failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

	@ApiOperation(value = "Get RAN by name.", response = GetNodebResponse.class)
	@RequestMapping(value = "/nodeb/{" + PP_RANNAME + "}", method = RequestMethod.GET)
	public Object getNb(@PathVariable(PP_RANNAME) String ranName) {
		logger.debug("getNb {}", ranName);
		try {
			return e2NodebApi.getNb(ranName);
		} catch (HttpStatusCodeException ex) {
			logger.warn("getNb failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

	@ApiOperation(value = "Close all connections to the RANs and delete the data from the nodeb-rnib DB.")
	@RequestMapping(value = "/nodeb", method = RequestMethod.DELETE)
	public Object nodebDelete(HttpServletResponse response) {
		logger.debug("nodebDelete");
		try {
			e2NodebApi.nodebDelete();
			response.setStatus(e2NodebApi.getApiClient().getStatusCode().value());
			return null;
		} catch (HttpStatusCodeException ex) {
			logger.warn("nodebDelete failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

	@ApiOperation(value = "Sets up an EN-DC RAN connection via the E2 manager.")
	@RequestMapping(value = "/endcSetup", method = RequestMethod.POST)
	public Object endcSetup(@RequestBody SetupRequest setupRequest, HttpServletResponse response) {
		logger.debug("endcSetup {}", setupRequest);
		try {
			e2NodebApi.endcSetup(setupRequest);
			response.setStatus(e2NodebApi.getApiClient().getStatusCode().value());
			return null;
		} catch (HttpStatusCodeException ex) {
			logger.warn("endcSetup failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

	@ApiOperation(value = "Sets up an X2 RAN connection via the E2 manager.")
	@RequestMapping(value = "/x2Setup", method = RequestMethod.POST)
	public Object x2Setup(@RequestBody SetupRequest setupRequest, HttpServletResponse response) {
		logger.debug("x2Setup {}", setupRequest);
		try {
			e2NodebApi.x2Setup(setupRequest);
			response.setStatus(e2NodebApi.getApiClient().getStatusCode().value());
			return null;
		} catch (HttpStatusCodeException ex) {
			logger.warn("x2Setup failed: {}", ex.toString());
			return new ResponseEntity<ErrorTransport>(new ErrorTransport(ex.getRawStatusCode(), ex.toString()),
					HttpStatus.BAD_GATEWAY);
		}
	}

}