package consul

import (
	"context"
	"errors"
	"fmt"
	"net"
	"sync"

	"github.com/gogf/gf/contrib/registry/consul/v2"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/net/gsel"
	"github.com/gogf/gf/v2/net/gsvc"
	"github.com/gogf/gf/v2/util/grand"
)

var initOnce sync.Once

// Init 初始化 Consul 注册中心（延迟初始化，首次调用时执行）
func Init() {
	initOnce.Do(func() {
		consulAddr := g.Cfg().MustGet(context.Background(), "consul.address").String()
		if consulAddr == "" {
			g.Log().Warning(context.Background(), "⚠️  Consul 配置未找到，跳过初始化")
			return
		}
		registry, err := consul.New(consul.WithAddress(consulAddr))
		if err != nil {
			g.Log().Errorf(context.Background(), "Consul 初始化失败: %v", err)
			return
		}
		gsvc.SetRegistry(registry)
		gsel.SetBuilder(gsel.NewBuilderRoundRobin())
		g.Log().Infof(context.Background(), "✅ Consul 初始化成功: %s", consulAddr)
	})
}

func init() {
	// 默认自动初始化（保持向后兼容）
	Init()
}
func getLocalIP() (string, error) {
	// 获取本机所有网络接口
	addrs, err := net.InterfaceAddrs()
	if err != nil {
		return "", err
	}

	for _, addr := range addrs {
		// 检查是否是IP地址
		if ipNet, ok := addr.(*net.IPNet); ok && !ipNet.IP.IsLoopback() {
			if ipNet.IP.To4() != nil {
				// 返回第一个非回环的IPv4地址
				return ipNet.IP.String(), nil
			}
		}
	}

	return "", fmt.Errorf("无法找到本地IP地址")
}
func getInstanceAddrByIp(ctx context.Context, ip string, services []gsvc.Service) (addr string) {
	for _, s := range services {
		if s.GetEndpoints()[0].Host() == ip {
			addr = s.GetEndpoints()[0].String()
			return
		}
	}
	return
}
func GetInstanceAddr(ctx context.Context, name string) (addr string, err error) {
	watch, err := gsvc.GetRegistry().Watch(ctx, name)
	service, err := watch.Proceed()
	if err != nil || service == nil {
		err = errors.New("获取customerService服务实例失败！")
		return
	}
	//优先使用客户端IP获取实例(前后端在同一台机器调试)
	addr = getInstanceAddrByIp(ctx, g.RequestFromCtx(ctx).GetClientIp(), service)
	if !g.IsEmpty(addr) {
		return
	}
	//优先使用gateway同IP的服务实例(前后端不同机器调试)
	addr, err = getLocalIP()
	if err != nil {
		return
	}
	addr = getInstanceAddrByIp(ctx, addr, service)
	if !g.IsEmpty(addr) {
		return
	}
	//随机获取一个服务实例
	maxService := grand.N(0, len(service)-1)
	addr = service[maxService].GetEndpoints()[0].String()
	return
}