package middleware

import (
	"net/http"
	"strings"

	"giteapm/config"
	"giteapm/internal/models"

	"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 AuthMiddleware(cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		tokenString := c.GetHeader("Authorization")
		if tokenString == "" {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "缺少授权令牌"})
			c.Abort()
			return
		}

		if strings.HasPrefix(tokenString, "Bearer ") {
			tokenString = tokenString[7:]
		}

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

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

		claims, ok := token.Claims.(*Claims)
		if !ok {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "无效的令牌格式"})
			c.Abort()
			return
		}

		user, err := models.GetUserByID(claims.UserID)
		if err != nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "用户不存在"})
			c.Abort()
			return
		}

		c.Set("user", user)
		c.Set("user_id", claims.UserID)
		c.Set("username", claims.Username)
		c.Set("role", claims.Role)
		c.Next()
	}
}

func RequireRole(roles ...string) gin.HandlerFunc {
	return func(c *gin.Context) {
		userRole, exists := c.Get("role")
		if !exists {
			c.JSON(http.StatusForbidden, gin.H{"error": "无法获取用户角色"})
			c.Abort()
			return
		}

		for _, role := range roles {
			if userRole == role {
				c.Next()
				return
			}
		}

		c.JSON(http.StatusForbidden, gin.H{"error": "权限不足"})
		c.Abort()
	}
}

func GetCurrentUser(c *gin.Context) (*models.User, error) {
	user, exists := c.Get("user")
	if !exists {
		return nil, jwt.ErrTokenMalformed
	}
	return user.(*models.User), nil
}