package consul

import (
	"fmt"
	"git.makemake.in/kzkzzzz/mycommon/myconf"
	"git.makemake.in/kzkzzzz/mycommon/mygrpc"
	"git.makemake.in/kzkzzzz/mycommon/mylog"
	"git.makemake.in/kzkzzzz/mycommon/myregistry"
	"github.com/hashicorp/consul/api"
	"github.com/rs/xid"
	"go.uber.org/zap"
	"net"
	"net/url"
	"os"
	"sync"
	"time"
)

var (
	_ myregistry.IRegister = (*Consul)(nil)

	defaultLog = mylog.NewLogger(&mylog.Config{
		Level:         mylog.DebugLevel,
		NeedLogFile:   false,
		ConsoleWriter: os.Stdout,
		ZapOpt: []zap.Option{
			zap.AddCaller(), zap.AddCallerSkip(1),
		},
	})
)

type Consul struct {
	client      *api.Client
	serviceIds  map[string][]string
	serviceTags []string
	services    []*api.AgentServiceRegistration
}

type Opt func(*Consul)

func WithServiceTags(tags ...string) Opt {
	return func(c *Consul) {
		c.serviceTags = tags
	}
}

func (c *Consul) Name() string {
	return "consul"
}

func (c *Consul) Register(service *myregistry.ServiceInfo) error {
	// 健康检查
	serviceId := xid.New().String()
	hostname, err := os.Hostname()
	if err != nil {
		defaultLog.Errorf("get hostname err: %s", err)
	} else {
		serviceId = fmt.Sprintf("%s-%s", hostname, serviceId)
	}

	c.serviceIds[service.ServiceName] = append(c.serviceIds[service.ServiceName], serviceId)

	check := &api.AgentServiceCheck{
		CheckID:  serviceId,
		TCP:      fmt.Sprintf("%s:%d", service.Ip, service.Port),
		Timeout:  "5s",  // 超时时间
		Interval: "30s", // 运行检查的频率
		// 指定时间后自动注销不健康的服务节点
		// 最小超时时间为1分钟，收获不健康服务的进程每30秒运行一次，因此触发注销的时间可能略长于配置的超时时间。
		DeregisterCriticalServiceAfter: "6m",
		Status:                         api.HealthPassing,
	}

	regTags := make([]string, len(c.serviceTags))
	copy(regTags, c.serviceTags)

	if v := service.Extend["tag"]; v != "" {
		regTags = append(regTags, v)
	}

	svc := &api.AgentServiceRegistration{
		ID:      serviceId,           // 服务唯一ID
		Name:    service.ServiceName, // 服务名称
		Tags:    regTags,             // 为服务打标签
		Address: service.Ip,
		Port:    service.Port,
		Check:   check,
	}

	c.services = append(c.services, svc)

	err = c.client.Agent().ServiceRegister(svc)
	if err != nil {
		defaultLog.Errorf("retry register service err: %s: %s", svc.Name, err)
		return err
	}

	defaultLog.Infof("retry register service ok: %s", svc.Name)

	return nil
}

func (c *Consul) Deregister(service *myregistry.ServiceInfo) error {
	for _, svcId := range c.serviceIds[service.ServiceName] {
		err := c.client.Agent().ServiceDeregister(svcId)
		if err != nil {
			defaultLog.Errorf("Failed to deregister service %s: %s\n", service, err)
		}
	}
	return nil
}

func MustNew(conf *myconf.Config, opts ...Opt) *Consul {
	consul, err := New(conf, opts...)
	if err != nil {
		panic(err)
	}
	return consul
}

func New(conf *myconf.Config, opts ...Opt) (*Consul, error) {
	client, err := NewClient(&ClientConfig{
		Address:  conf.GetString("addr"),
		Token:    conf.GetString("token"),
		Username: conf.GetString("username"),
		Password: conf.GetString("password"),
	})
	if err != nil {
		return nil, err
	}

	cl := &Consul{
		client:      client,
		serviceIds:  make(map[string][]string),
		serviceTags: conf.GetStringSlice("serviceTags"),
		services:    make([]*api.AgentServiceRegistration, 0),
	}

	for _, opt := range opts {
		opt(cl)
	}

	go cl.healthCheck()

	return cl, nil
}

type ClientConfig struct {
	Address        string
	Token          string
	Username       string
	Password       string
	AutoGrpcPrefix bool
}

var (
	clientLock = &sync.Mutex{}
	clientMap  = make(map[string]*api.Client)
)

func NewClient(clientCfg *ClientConfig) (*api.Client, error) {
	clientLock.Lock()
	defer clientLock.Unlock()

	if clientCfg.Address == "" {
		return nil, fmt.Errorf("consul address is empty")
	}

	if client, ok := clientMap[clientCfg.Address]; ok {
		return client, nil
	}

	cfg := api.DefaultConfig()
	cfg.Address = clientCfg.Address

	if cfg.Address == "" {
		return nil, fmt.Errorf("consul address is empty")
	}

	cfg.Transport.DialContext = (&net.Dialer{
		Timeout:   3 * time.Second,
		KeepAlive: 20 * time.Second,
	}).DialContext
	cfg.Token = clientCfg.Token

	username := clientCfg.Username
	password := clientCfg.Password

	if username != "" && password != "" {
		cfg.HttpAuth = &api.HttpBasicAuth{
			Username: username,
			Password: password,
		}
	}

	client, err := api.NewClient(cfg)
	if err != nil {
		return nil, err
	}

	clientMap[clientCfg.Address] = client
	return client, nil
}

func (c *Consul) healthCheck() {
	var (
		lastIndex uint64
		isFirst   = true
		err       error
		meta      *api.QueryMeta
	)

	for {
		if isFirst == false {
			time.Sleep(time.Second * 2)

			// 错误的情况重新注册一次
			if err != nil {
				var isRegisterErr bool
				for _, svc := range c.services {
					err := c.client.Agent().ServiceRegister(svc)
					if err != nil {
						defaultLog.Errorf("retry register service err: %s: %s", svc.Name, err)
						isRegisterErr = true
						break
					} else {
						defaultLog.Infof("retry register service ok: %s", svc.Name)
					}
				}

				if isRegisterErr {
					continue
				}
			}

		}

		isFirst = false

		_, meta, err = c.client.Catalog().Nodes(&api.QueryOptions{
			WaitIndex: lastIndex,
			//WaitTime:  time.Second * 5,
		})
		if err != nil {
			defaultLog.Errorf("health check err: %s", err)
			continue
		}
		lastIndex = meta.LastIndex
	}
}

func (c *Consul) Client() *api.Client {
	return c.client
}

func GrpcUrl(serviceName string, conf *myconf.Config) string {
	return GrpcUrlWithTag("", serviceName, conf)
}

func GrpcUrlWithTag(tag string, serviceName string, conf *myconf.Config) string {
	return GrpcUrlWithTagByConfig(tag, serviceName, &ClientConfig{
		Address:        conf.GetString("addr"),
		Token:          conf.GetString("token"),
		Username:       conf.GetString("username"),
		Password:       conf.GetString("password"),
		AutoGrpcPrefix: true,
	})
}

func GrpcUrlWithTagByConfig(tag string, serviceName string, conf *ClientConfig) string {
	if conf.AutoGrpcPrefix {
		serviceName = mygrpc.ServicePrefix + serviceName
	}

	u := &url.URL{
		Scheme: schemeName,
		Host:   conf.Address,
		Path:   serviceName,
	}

	if u.Host == "" {
		panic("consul address is empty")
	}

	query := u.Query()
	query.Set("healthy", "true")

	if conf.Token != "" {
		query.Set("token", conf.Token)
	}

	if tag != "" {
		query.Set("tag", tag)
	}

	if conf.Username != "" && conf.Password != "" {
		u.User = url.UserPassword(conf.Username, conf.Password)
	}

	u.RawQuery = query.Encode()

	return u.String()
}