package middleware

import (
	"net/http"
	"strings"
	"time"

	"anticaptcha/internal/config"
	"anticaptcha/internal/model"

	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
)

type Claims struct {
	UserID   uint   `json:"user_id"`
	Username string `json:"username"`
	Role     string `json:"role"`
	jwt.RegisteredClaims
}

func JWTAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "未提供认证令牌"})
			c.Abort()
			return
		}

		parts := strings.Split(authHeader, " ")
		if len(parts) != 2 || parts[0] != "Bearer" {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "认证令牌格式错误"})
			c.Abort()
			return
		}

		tokenString := parts[1]
		claims := &Claims{}

		token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
			return []byte(config.Cfg.JWT.Secret), nil
		})

		if err != nil || !token.Valid {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "无效的认证令牌"})
			c.Abort()
			return
		}

		// 将用户信息存入上下文
		c.Set("user_id", claims.UserID)
		c.Set("username", claims.Username)
		c.Set("role", claims.Role)
		c.Next()
	}
}

func AdminOnly() gin.HandlerFunc {
	return func(c *gin.Context) {
		role, exists := c.Get("role")
		if !exists || role.(string) != "admin" {
			c.JSON(http.StatusForbidden, gin.H{"error": "权限不足"})
			c.Abort()
			return
		}
		c.Next()
	}
}

func GenerateToken(userID uint, username string, role string) (string, error) {
	claims := Claims{
		UserID:   userID,
		Username: username,
		Role:     role,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(config.Cfg.JWT.ExpireTime) * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(config.Cfg.JWT.Secret))
}

func GetCurrentUserID(c *gin.Context) uint {
	if id, exists := c.Get("user_id"); exists {
		return id.(uint)
	}
	return 0
}

func GetCurrentUser(c *gin.Context) (*model.User, error) {
	// 后续从数据库查询
	return nil, nil
}