/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * 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.
 */
package com.alibaba.csp.sentinel.dashboard.controller;

import com.alibaba.csp.sentinel.dashboard.auth.AuthAction;
import com.alibaba.csp.sentinel.dashboard.auth.AuthService.PrivilegeType;
import com.alibaba.csp.sentinel.dashboard.client.SentinelApiClient;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.discovery.MachineInfo;
import com.alibaba.csp.sentinel.dashboard.domain.Result;
import com.alibaba.csp.sentinel.dashboard.repository.rule.InMemoryRuleRepositoryAdapter;
import com.alibaba.csp.sentinel.util.StringUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Date;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

/**
 * Flow rule controller.
 *
 * @author leyou
 * @author Eric Zhao
 */
@RestController
@RequestMapping(value = "/v1/flow")
public class FlowControllerV1 {

	private final Logger logger = LoggerFactory.getLogger(FlowControllerV1.class);

	@Autowired
	private InMemoryRuleRepositoryAdapter<FlowRuleEntity> repository;

	@Autowired
	private SentinelApiClient sentinelApiClient;

	@GetMapping("/rules")
	@AuthAction(PrivilegeType.READ_RULE)
	public Result<List<FlowRuleEntity>> apiQueryMachineRules(@RequestParam String app, @RequestParam String ip,
			@RequestParam Integer port) {

		if (StringUtil.isEmpty(app)) {
			return Result.ofFail(-1, "app can't be null or empty");
		}
		if (StringUtil.isEmpty(ip)) {
			return Result.ofFail(-1, "ip can't be null or empty");
		}
		if (port == null) {
			return Result.ofFail(-1, "port can't be null");
		}
		try {
			List<FlowRuleEntity> rules = sentinelApiClient.fetchFlowRuleOfMachine(app, ip, port);
			rules = repository.saveAll(rules);
			return Result.ofSuccess(rules);
		}
		catch (Throwable throwable) {
			logger.error("Error when querying flow rules", throwable);
			return Result.ofThrowable(-1, throwable);
		}
	}

	private <R> Result<R> checkEntityInternal(FlowRuleEntity entity) {
		if (StringUtil.isBlank(entity.getApp())) {
			return Result.ofFail(-1, "app can't be null or empty");
		}
		if (StringUtil.isBlank(entity.getIp())) {
			return Result.ofFail(-1, "ip can't be null or empty");
		}
		if (entity.getPort() == null) {
			return Result.ofFail(-1, "port can't be null");
		}
		if (StringUtil.isBlank(entity.getLimitApp())) {
			return Result.ofFail(-1, "limitApp can't be null or empty");
		}
		if (StringUtil.isBlank(entity.getResource())) {
			return Result.ofFail(-1, "resource can't be null or empty");
		}
		if (entity.getGrade() == null) {
			return Result.ofFail(-1, "grade can't be null");
		}
		if (entity.getGrade() != 0 && entity.getGrade() != 1) {
			return Result.ofFail(-1, "grade must be 0 or 1, but " + entity.getGrade() + " got");
		}
		if (entity.getCount() == null || entity.getCount() < 0) {
			return Result.ofFail(-1, "count should be at lease zero");
		}
		if (entity.getStrategy() == null) {
			return Result.ofFail(-1, "strategy can't be null");
		}
		if (entity.getStrategy() != 0 && StringUtil.isBlank(entity.getRefResource())) {
			return Result.ofFail(-1, "refResource can't be null or empty when strategy!=0");
		}
		if (entity.getControlBehavior() == null) {
			return Result.ofFail(-1, "controlBehavior can't be null");
		}
		int controlBehavior = entity.getControlBehavior();
		if (controlBehavior == 1 && entity.getWarmUpPeriodSec() == null) {
			return Result.ofFail(-1, "warmUpPeriodSec can't be null when controlBehavior==1");
		}
		if (controlBehavior == 2 && entity.getMaxQueueingTimeMs() == null) {
			return Result.ofFail(-1, "maxQueueingTimeMs can't be null when controlBehavior==2");
		}
		if (entity.isClusterMode() && entity.getClusterConfig() == null) {
			return Result.ofFail(-1, "cluster config should be valid");
		}
		return null;
	}

	@PostMapping("/rule")
	@AuthAction(PrivilegeType.WRITE_RULE)
	public Result<FlowRuleEntity> apiAddFlowRule(@RequestBody FlowRuleEntity entity) {
		Result<FlowRuleEntity> checkResult = checkEntityInternal(entity);
		if (checkResult != null) {
			return checkResult;
		}
		entity.setId(null);
		Date date = new Date();
		entity.setGmtCreate(date);
		entity.setGmtModified(date);
		entity.setLimitApp(entity.getLimitApp().trim());
		entity.setResource(entity.getResource().trim());
		try {
			entity = repository.save(entity);

			publishRules(entity.getApp(), entity.getIp(), entity.getPort()).get(5000, TimeUnit.MILLISECONDS);
			return Result.ofSuccess(entity);
		}
		catch (Throwable t) {
			Throwable e = t instanceof ExecutionException ? t.getCause() : t;
			logger.error("Failed to add new flow rule, app={}, ip={}", entity.getApp(), entity.getIp(), e);
			return Result.ofFail(-1, e.getMessage());
		}
	}

	@PutMapping("/save.json")
	@AuthAction(PrivilegeType.WRITE_RULE)
	public Result<FlowRuleEntity> apiUpdateFlowRule(Long id, String app, String limitApp, String resource,
			Integer grade, Double count, Integer strategy, String refResource, Integer controlBehavior,
			Integer warmUpPeriodSec, Integer maxQueueingTimeMs) {
		if (id == null) {
			return Result.ofFail(-1, "id can't be null");
		}
		FlowRuleEntity entity = repository.findById(id);
		if (entity == null) {
			return Result.ofFail(-1, "id " + id + " dose not exist");
		}
		if (StringUtil.isNotBlank(app)) {
			entity.setApp(app.trim());
		}
		if (StringUtil.isNotBlank(limitApp)) {
			entity.setLimitApp(limitApp.trim());
		}
		if (StringUtil.isNotBlank(resource)) {
			entity.setResource(resource.trim());
		}
		if (grade != null) {
			if (grade != 0 && grade != 1) {
				return Result.ofFail(-1, "grade must be 0 or 1, but " + grade + " got");
			}
			entity.setGrade(grade);
		}
		if (count != null) {
			entity.setCount(count);
		}
		if (strategy != null) {
			if (strategy != 0 && strategy != 1 && strategy != 2) {
				return Result.ofFail(-1, "strategy must be in [0, 1, 2], but " + strategy + " got");
			}
			entity.setStrategy(strategy);
			if (strategy != 0) {
				if (StringUtil.isBlank(refResource)) {
					return Result.ofFail(-1, "refResource can't be null or empty when strategy!=0");
				}
				entity.setRefResource(refResource.trim());
			}
		}
		if (controlBehavior != null) {
			if (controlBehavior != 0 && controlBehavior != 1 && controlBehavior != 2) {
				return Result.ofFail(-1, "controlBehavior must be in [0, 1, 2], but " + controlBehavior + " got");
			}
			if (controlBehavior == 1 && warmUpPeriodSec == null) {
				return Result.ofFail(-1, "warmUpPeriodSec can't be null when controlBehavior==1");
			}
			if (controlBehavior == 2 && maxQueueingTimeMs == null) {
				return Result.ofFail(-1, "maxQueueingTimeMs can't be null when controlBehavior==2");
			}
			entity.setControlBehavior(controlBehavior);
			if (warmUpPeriodSec != null) {
				entity.setWarmUpPeriodSec(warmUpPeriodSec);
			}
			if (maxQueueingTimeMs != null) {
				entity.setMaxQueueingTimeMs(maxQueueingTimeMs);
			}
		}
		Date date = new Date();
		entity.setGmtModified(date);
		try {
			entity = repository.save(entity);
			if (entity == null) {
				return Result.ofFail(-1, "save entity fail: null");
			}

			publishRules(entity.getApp(), entity.getIp(), entity.getPort()).get(5000, TimeUnit.MILLISECONDS);
			return Result.ofSuccess(entity);
		}
		catch (Throwable t) {
			Throwable e = t instanceof ExecutionException ? t.getCause() : t;
			logger.error("Error when updating flow rules, app={}, ip={}, ruleId={}", entity.getApp(), entity.getIp(),
					id, e);
			return Result.ofFail(-1, e.getMessage());
		}
	}

	@DeleteMapping("/delete.json")
	@AuthAction(PrivilegeType.WRITE_RULE)
	public Result<Long> apiDeleteFlowRule(Long id) {

		if (id == null) {
			return Result.ofFail(-1, "id can't be null");
		}
		FlowRuleEntity oldEntity = repository.findById(id);
		if (oldEntity == null) {
			return Result.ofSuccess(null);
		}

		try {
			repository.delete(id);
		}
		catch (Exception e) {
			return Result.ofFail(-1, e.getMessage());
		}
		try {
			publishRules(oldEntity.getApp(), oldEntity.getIp(), oldEntity.getPort()).get(5000, TimeUnit.MILLISECONDS);
			return Result.ofSuccess(id);
		}
		catch (Throwable t) {
			Throwable e = t instanceof ExecutionException ? t.getCause() : t;
			logger.error("Error when deleting flow rules, app={}, ip={}, id={}", oldEntity.getApp(), oldEntity.getIp(),
					id, e);
			return Result.ofFail(-1, e.getMessage());
		}
	}

	private CompletableFuture<Void> publishRules(String app, String ip, Integer port) {
		List<FlowRuleEntity> rules = repository.findAllByMachine(MachineInfo.of(app, ip, port));
		return sentinelApiClient.setFlowRuleOfMachineAsync(app, ip, port, rules);
	}

}
