/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 client

import (
	"fmt"
	"net/url"
	"os"
	"strconv"
	"time"
)

import (
	"github.com/dubbogo/gost/log/logger"
	gxstrings "github.com/dubbogo/gost/strings"

	constant2 "github.com/dubbogo/triple/pkg/common/constant"
)

import (
	"dubbo.apache.org/dubbo-go/v3/cluster/directory/static"
	"dubbo.apache.org/dubbo-go/v3/common"
	commonCfg "dubbo.apache.org/dubbo-go/v3/common/config"
	"dubbo.apache.org/dubbo-go/v3/common/constant"
	"dubbo.apache.org/dubbo-go/v3/common/extension"
	"dubbo.apache.org/dubbo-go/v3/config"
	"dubbo.apache.org/dubbo-go/v3/graceful_shutdown"
	"dubbo.apache.org/dubbo-go/v3/protocol"
	"dubbo.apache.org/dubbo-go/v3/protocol/protocolwrapper"
	"dubbo.apache.org/dubbo-go/v3/proxy"
)

func getEnv(key, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	return fallback
}

func updateOrCreateMeshURL(opts *ClientOptions) {
	ref := opts.Reference
	con := opts.Consumer

	if ref.URL != "" {
		logger.Infof("URL specified explicitly %v", ref.URL)
	}

	if !con.MeshEnabled {
		return
	}
	if ref.Protocol != constant2.TRIPLE {
		panic(fmt.Sprintf("Mesh mode enabled, Triple protocol expected but %v protocol found!", ref.Protocol))
	}
	if ref.ProvidedBy == "" {
		panic("Mesh mode enabled, provided-by should not be empty!")
	}

	podNamespace := getEnv(constant.PodNamespaceEnvKey, constant.DefaultNamespace)
	clusterDomain := getEnv(constant.ClusterDomainKey, constant.DefaultClusterDomain)

	var meshPort int
	if ref.MeshProviderPort > 0 {
		meshPort = ref.MeshProviderPort
	} else {
		meshPort = constant.DefaultMeshPort
	}

	ref.URL = "tri://" + ref.ProvidedBy + "." + podNamespace + constant.SVC + clusterDomain + ":" + strconv.Itoa(meshPort)
}

// ReferWithService retrieves invokers from urls.
func (opts *ClientOptions) ReferWithService(srv common.RPCService) {
	opts.refer(srv, nil)
}

func (opts *ClientOptions) ReferWithInfo(info *ClientInfo) {
	opts.refer(nil, info)
}

func (opts *ClientOptions) ReferWithServiceAndInfo(srv common.RPCService, info *ClientInfo) {
	opts.refer(srv, info)
}

func (opts *ClientOptions) refer(srv common.RPCService, info *ClientInfo) {
	ref := opts.Reference
	con := opts.Consumer

	var methods []string
	if info != nil {
		ref.InterfaceName = info.InterfaceName
		methods = info.MethodNames
		opts.id = info.InterfaceName
		opts.info = info
	} else {
		opts.id = common.GetReference(srv)
	}
	// If adaptive service is enabled,
	// the cluster and load balance should be overridden to "adaptivesvc" and "p2c" respectively.
	if con != nil && con.AdaptiveService {
		ref.Cluster = constant.ClusterKeyAdaptiveService
		ref.Loadbalance = constant.LoadBalanceKeyP2C
	}

	// cfgURL is an interface-level invoker url, in the other words, it represents an interface.
	cfgURL := common.NewURLWithOptions(
		common.WithPath(ref.InterfaceName),
		common.WithProtocol(ref.Protocol),
		common.WithMethods(methods),
		common.WithParams(opts.getURLMap()),
		common.WithParamsValue(constant.BeanNameKey, opts.id),
		common.WithParamsValue(constant.MetadataTypeKey, opts.metaDataType),
	)

	if ref.ForceTag {
		cfgURL.AddParam(constant.ForceUseTag, "true")
	}
	opts.postProcessConfig(cfgURL)

	// if mesh-enabled is set
	updateOrCreateMeshURL(opts)

	// retrieving urls from config, and appending the urls to opts.urls
	if err := opts.processURL(cfgURL); err != nil {
		panic(err)
	}

	// Get invokers according to opts.urls
	var (
		invoker protocol.Invoker
		regURL  *common.URL
	)
	invokers := make([]protocol.Invoker, len(opts.urls))
	for i, u := range opts.urls {
		if u.Protocol == constant.ServiceRegistryProtocol {
			invoker = extension.GetProtocol(constant.RegistryProtocol).Refer(u)
		} else {
			invoker = extension.GetProtocol(u.Protocol).Refer(u)
		}

		if ref.URL != "" {
			invoker = protocolwrapper.BuildInvokerChain(invoker, constant.ReferenceFilterKey)
		}

		invokers[i] = invoker
		if u.Protocol == constant.RegistryProtocol {
			regURL = u
		}
	}

	// TODO(hxmhlt): decouple from directory, config should not depend on directory module
	if len(invokers) == 1 {
		opts.invoker = invokers[0]
		if ref.URL != "" {
			hitClu := constant.ClusterKeyFailover
			if u := opts.invoker.GetURL(); u != nil {
				hitClu = u.GetParam(constant.ClusterKey, constant.ClusterKeyZoneAware)
			}
			cluster, err := extension.GetCluster(hitClu)
			if err != nil {
				panic(err)
			} else {
				opts.invoker = cluster.Join(static.NewDirectory(invokers))
			}
		}
	} else {
		var hitClu string
		if regURL != nil {
			// for multi-subscription scenario, use 'zone-aware' policy by default
			hitClu = constant.ClusterKeyZoneAware
		} else {
			// not a registry url, must be direct invoke.
			hitClu = constant.ClusterKeyFailover
			if u := invokers[0].GetURL(); u != nil {
				hitClu = u.GetParam(constant.ClusterKey, constant.ClusterKeyZoneAware)
			}
		}
		cluster, err := extension.GetCluster(hitClu)
		if err != nil {
			panic(err)
		} else {
			opts.invoker = cluster.Join(static.NewDirectory(invokers))
		}
	}

	// publish consumer's metadata
	publishServiceDefinition(cfgURL)
	// create proxy
	if info == nil {
		// todo(DMwangnima): think about a more ideal way
		if con == nil {
			panic("client must be configured with ConsumerConfig when using config.Load")
		}

		if ref.Async {
			var callback common.CallbackResponse
			if asyncSrv, ok := srv.(common.AsyncCallbackService); ok {
				callback = asyncSrv.CallBack
			}
			opts.pxy = extension.GetProxyFactory(con.ProxyFactory).GetAsyncProxy(opts.invoker, callback, cfgURL)
		} else {
			opts.pxy = extension.GetProxyFactory(con.ProxyFactory).GetProxy(opts.invoker, cfgURL)
		}
		opts.pxy.Implement(srv)
	}
	// this protocol would be destroyed in graceful_shutdown
	// please refer to (https://github.com/apache/dubbo-go/issues/2429)
	graceful_shutdown.RegisterProtocol(ref.Protocol)
}

func (opts *ClientOptions) processURL(cfgURL *common.URL) error {
	ref := opts.Reference
	if ref.URL != "" { // use user-specific urls
		/*
			 Two types of URL are allowed for opts.URL:
				1. direct url: server IP, that is, no need for a registry anymore
				2. registry url
			 They will be handled in different ways:
			 For example, we have a direct url and a registry url:
				1. "tri://localhost:10000" is a direct url
				2. "registry://localhost:2181" is a registry url.
			 Then, opts.URL looks like a string separated by semicolon: "tri://localhost:10000;registry://localhost:2181".
			 The result of urlStrings is a string array: []string{"tri://localhost:10000", "registry://localhost:2181"}.
		*/
		urlStrings := gxstrings.RegSplit(ref.URL, "\\s*[;]+\\s*")
		for _, urlStr := range urlStrings {
			serviceURL, err := common.NewURL(urlStr, common.WithProtocol(ref.Protocol))
			if err != nil {
				return fmt.Errorf(fmt.Sprintf("url configuration error,  please check your configuration, user specified URL %v refer error, error message is %v ", urlStr, err.Error()))
			}
			if serviceURL.Protocol == constant.RegistryProtocol { // serviceURL in this branch is a registry protocol
				serviceURL.SubURL = cfgURL
				opts.urls = append(opts.urls, serviceURL)
			} else { // serviceURL in this branch is the target endpoint IP address
				if serviceURL.Path == "" {
					serviceURL.Path = "/" + ref.InterfaceName
				}
				// replace params of serviceURL with params of cfgUrl
				// other stuff, e.g. IP, port, etc., are same as serviceURL
				newURL := common.MergeURL(serviceURL, cfgURL)
				newURL.AddParam("peer", "true")
				opts.urls = append(opts.urls, newURL)
			}
		}
	} else { // use registry configs
		opts.urls = config.LoadRegistries(ref.RegistryIDs, opts.registriesCompat, common.CONSUMER)
		// set url to regURLs
		for _, regURL := range opts.urls {
			regURL.SubURL = cfgURL
		}
	}
	return nil
}

func (opts *ClientOptions) CheckAvailable() bool {
	ref := opts.Reference
	if opts.invoker == nil {
		logger.Warnf("The interface %s invoker not exist, may you should check your interface config.", ref.InterfaceName)
		return false
	}
	if !opts.invoker.IsAvailable() {
		return false
	}
	return true
}

// Implement
// @v is service provider implemented RPCService
func (opts *ClientOptions) Implement(v common.RPCService) {
	if opts.pxy != nil {
		opts.pxy.Implement(v)
	} else if opts.info != nil {
		opts.info.ClientInjectFunc(v, &Client{
			invoker: opts.invoker,
			info:    opts.info,
		})
	}
}

// GetRPCService gets RPCService from proxy
func (opts *ClientOptions) GetRPCService() common.RPCService {
	return opts.pxy.Get()
}

// GetProxy gets proxy
func (opts *ClientOptions) GetProxy() *proxy.Proxy {
	return opts.pxy
}

func (opts *ClientOptions) getURLMap() url.Values {
	ref := opts.Reference
	app := opts.applicationCompat

	urlMap := url.Values{}
	// first set user params
	for k, v := range ref.Params {
		urlMap.Set(k, v)
	}
	urlMap.Set(constant.InterfaceKey, ref.InterfaceName)
	urlMap.Set(constant.TimestampKey, strconv.FormatInt(time.Now().Unix(), 10))
	urlMap.Set(constant.ClusterKey, ref.Cluster)
	urlMap.Set(constant.LoadbalanceKey, ref.Loadbalance)
	urlMap.Set(constant.RetriesKey, ref.Retries)
	urlMap.Set(constant.GroupKey, ref.Group)
	urlMap.Set(constant.VersionKey, ref.Version)
	urlMap.Set(constant.GenericKey, ref.Generic)
	urlMap.Set(constant.RegistryRoleKey, strconv.Itoa(common.CONSUMER))
	urlMap.Set(constant.ProvidedBy, ref.ProvidedBy)
	urlMap.Set(constant.SerializationKey, ref.Serialization)
	urlMap.Set(constant.TracingConfigKey, ref.TracingKey)

	urlMap.Set(constant.ReleaseKey, "dubbo-golang-"+constant.Version)
	urlMap.Set(constant.SideKey, (common.RoleType(common.CONSUMER)).Role())

	if len(ref.RequestTimeout) != 0 {
		urlMap.Set(constant.TimeoutKey, ref.RequestTimeout)
	}
	// getty invoke async or sync
	urlMap.Set(constant.AsyncKey, strconv.FormatBool(ref.Async))
	urlMap.Set(constant.StickyKey, strconv.FormatBool(ref.Sticky))

	// applicationConfig info
	if app != nil {
		urlMap.Set(constant.ApplicationKey, app.Name)
		urlMap.Set(constant.OrganizationKey, app.Organization)
		urlMap.Set(constant.NameKey, app.Name)
		urlMap.Set(constant.ModuleKey, app.Module)
		urlMap.Set(constant.AppVersionKey, app.Version)
		urlMap.Set(constant.OwnerKey, app.Owner)
		urlMap.Set(constant.EnvironmentKey, app.Environment)
	}

	// filter
	defaultReferenceFilter := constant.DefaultReferenceFilters
	if ref.Generic != "" {
		defaultReferenceFilter = constant.GenericFilterKey + "," + defaultReferenceFilter
	}
	urlMap.Set(constant.ReferenceFilterKey, commonCfg.MergeValue(ref.Filter, "", defaultReferenceFilter))

	for _, v := range ref.Methods {
		urlMap.Set("methods."+v.Name+"."+constant.LoadbalanceKey, v.LoadBalance)
		urlMap.Set("methods."+v.Name+"."+constant.RetriesKey, v.Retries)
		urlMap.Set("methods."+v.Name+"."+constant.StickyKey, strconv.FormatBool(v.Sticky))
		if len(v.RequestTimeout) != 0 {
			urlMap.Set("methods."+v.Name+"."+constant.TimeoutKey, v.RequestTimeout)
		}
	}

	return urlMap
}

// todo: figure this out
//// GenericLoad ...
//func (opts *ClientOptions) GenericLoad(id string) {
//	genericService := generic.NewGenericService(opts.id)
//	config.SetConsumerService(genericService)
//	opts.id = id
//	opts.Refer(genericService)
//	opts.Implement(genericService)
//}

// GetInvoker get invoker from ReferenceConfigs
func (opts *ClientOptions) GetInvoker() protocol.Invoker {
	return opts.invoker
}

// postProcessConfig asks registered ConfigPostProcessor to post-process the current ReferenceConfigs.
func (opts *ClientOptions) postProcessConfig(url *common.URL) {
	for _, p := range extension.GetConfigPostProcessors() {
		p.PostProcessReferenceConfig(url)
	}
}

func publishServiceDefinition(url *common.URL) {
	localService, err := extension.GetLocalMetadataService(constant.DefaultKey)
	if err != nil {
		logger.Warnf("get local metadata service failed, please check if you have imported _ \"dubbo.apache.org/dubbo-go/v3/metadata/service/local\"")
		return
	}
	localService.PublishServiceDefinition(url)
	if url.GetParam(constant.MetadataTypeKey, "") != constant.RemoteMetadataStorageType {
		return
	}
	if remoteMetadataService, err := extension.GetRemoteMetadataService(); err == nil && remoteMetadataService != nil {
		remoteMetadataService.PublishServiceDefinition(url)
	}
}