package middleware

import (
	"net/http"
	"time"

	"bd-server/app/main/api/internal/config"
	"bd-server/app/main/model"
	jwtx "bd-server/common/jwt"
)

const (
	HeaderMembershipExpired = "X-Membership-Expired"
)

// MembershipExpiredInterceptor 检测代理会员是否过期，过期则写入响应头
// 由于是全局中间件（在 AuthInterceptor 之前执行），需要自己从请求头解析 JWT
type MembershipExpiredInterceptor struct {
	AgentModel model.AgentModel
	Config     config.Config
}

func NewMembershipExpiredInterceptor(agentModel model.AgentModel, c config.Config) *MembershipExpiredInterceptor {
	return &MembershipExpiredInterceptor{
		AgentModel: agentModel,
		Config:     c,
	}
}

func (m *MembershipExpiredInterceptor) Handle(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// 先检测会员过期状态（必须在 next() 之前设置响应头，否则响应已发送 header 无法生效）
		needNotifyExpired := false

		// 由于全局中间件在路由中间件之前执行，context 中可能没有 claims
		// 先尝试从 context 获取，如果没有则自己从 Authorization 头解析
		claims := getClaimsFromContext(r)
		if claims == nil {
			claims = parseClaimsFromAuthHeader(r, m.Config.JwtAuth.AccessSecret)
		}

		if claims != nil && claims.UserType == model.UserTypeNormal && r.URL.Path != "/api/v1/agent/info" {
			agent, err := m.AgentModel.FindOneByUserId(r.Context(), claims.UserId)
			if err == nil && agent != nil {
				// 到期时间已过，说明会员已过期（不管等级是否已降级为 normal）
				if agent.MembershipExpiryTime.Valid && !agent.MembershipExpiryTime.Time.After(time.Now()) {
					needNotifyExpired = true
				}
			}
		}

		// 在 next() 之前设置响应头（此时 headers 还没发送给客户端）
		if needNotifyExpired {
			w.Header().Set(HeaderMembershipExpired, "true")
		}

		// 执行业务逻辑
		next(w, r)
	}
}

func getClaimsFromContext(r *http.Request) *jwtx.JwtClaims {
	value := r.Context().Value(jwtx.ExtraKey)
	if value == nil {
		return nil
	}
	if claims, ok := value.(*jwtx.JwtClaims); ok {
		return claims
	}
	return nil
}

func parseClaimsFromAuthHeader(r *http.Request, secret string) *jwtx.JwtClaims {
	authHeader := r.Header.Get("Authorization")
	if authHeader == "" {
		return nil
	}
	claims, err := jwtx.ParseJwtToken(authHeader, secret)
	if err != nil {
		return nil
	}
	return claims
}