package response

import (
	"context"
	"lone-services/pkg/utils"
	"net/http"
	"net/url"
	"strconv"

	"google.golang.org/grpc"
	"google.golang.org/grpc/metadata"
)

type ctxKey string

const (
	CtxUserId    ctxKey = "X-User-Id"
	CtxUserName  ctxKey = "X-User-Name"
	CtxRefresh   ctxKey = "X-Refresh"
	CtxClientIP  ctxKey = "X-Client-Ip"
	CtxUserAgent ctxKey = "X-User-Agent"
)

type UserInfo struct {
	ID        int64
	Name      string
	RawUID    string
	Refresh   string
	ClientIP  string
	UserAgent string
	Valid     bool
}

func GetUserInfo(ctx context.Context) UserInfo {
	rawUID, _ := ctx.Value(CtxUserId).(string)
	name, _ := ctx.Value(CtxUserName).(string)
	refresh, _ := ctx.Value(CtxRefresh).(string)
	clientIP, _ := ctx.Value(CtxClientIP).(string)
	userAgent, _ := ctx.Value(CtxUserAgent).(string)

	info := UserInfo{
		RawUID:    rawUID,
		Name:      name,
		Refresh:   refresh,
		ClientIP:  clientIP,
		UserAgent: userAgent,
	}
	if rawUID == "" {
		return info
	}
	uid, err := strconv.ParseInt(rawUID, 10, 64)
	if err != nil {
		info.Valid = false
		return info
	}
	info.ID = uid
	info.Valid = true
	return info
}

// getRealClientIP 获取真实客户端IP，优先 X‑Forwarded‑For，其次 X‑Real‑IP，最后 RemoteAddr
func getRealClientIP(r *http.Request) string {
	xff := r.Header.Get("X-Forwarded-For")
	if xff != "" {
		return xff
	}
	xri := r.Header.Get("X-Real-Ip")
	if xri != "" {
		return xri
	}
	return r.RemoteAddr
}

func UserReadMiddleware(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		newCtx := r.Context()
		newCtx = context.WithValue(newCtx, CtxUserId, r.Header.Get("X-User-Id"))
		newCtx = context.WithValue(newCtx, CtxUserName, r.Header.Get("X-User-Name"))
		newCtx = context.WithValue(newCtx, CtxRefresh, r.Header.Get("X-Refresh"))
		newCtx = context.WithValue(newCtx, CtxClientIP, getRealClientIP(r))
		newCtx = context.WithValue(newCtx, CtxUserAgent, r.UserAgent())
		next(w, r.WithContext(newCtx))
	}
}

func UserClientInterceptor(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
	user := GetUserInfo(ctx)
	md := metadata.New(map[string]string{})

	if user.Valid {
		md.Set("x-user-id", user.RawUID)
		md.Set("x-user-name", url.QueryEscape(user.Name))
	}

	if user.Refresh != utils.StringEmpty {
		md.Set("x-refresh", user.Refresh)
	}
	if user.ClientIP != utils.StringEmpty {
		md.Set("x-client-ip", user.ClientIP)
	}
	if user.UserAgent != utils.StringEmpty {
		md.Set("x-user-agent", url.QueryEscape(user.UserAgent))
	}

	ctx = metadata.NewOutgoingContext(ctx, md)
	return invoker(ctx, method, req, reply, cc, opts...)
}