// Package middleware Gin 中间件集合。
package middleware

import (
	"net/http"
	"strings"

	"fashionapi/internal/pkg/jwt"
	"fashionapi/internal/pkg/response"

	"github.com/gin-gonic/gin"
)

// gin.Context 中存放身份信息的键。
const (
	ContextUserID   = "userID"
	ContextUsername = "username"
)

// bearerPrefix Authorization 头的令牌前缀。
const bearerPrefix = "Bearer "

// Auth JWT 鉴权中间件：解析 Authorization: Bearer <token>，把身份写入 Context。
//
// 令牌签发器由外部注入，避免像原实现那样在每个请求里重新加载一次配置。
func Auth(manager *jwt.Manager) gin.HandlerFunc {
	return func(c *gin.Context) {
		header := c.GetHeader("Authorization")
		if !strings.HasPrefix(header, bearerPrefix) {
			response.AbortError(c, http.StatusUnauthorized, "missing token")
			return
		}

		claims, err := manager.Parse(strings.TrimPrefix(header, bearerPrefix))
		if err != nil {
			response.AbortError(c, http.StatusUnauthorized, "invalid token")
			return
		}

		c.Set(ContextUserID, claims.UserID)
		c.Set(ContextUsername, claims.Username)
		c.Next()
	}
}

// UserIDFrom 从 Context 取出当前用户 id。
func UserIDFrom(c *gin.Context) (uint32, bool) {
	v, exists := c.Get(ContextUserID)
	if !exists {
		return 0, false
	}
	id, ok := v.(uint32)
	if !ok || id == 0 {
		return 0, false
	}
	return id, true
}