package middleware

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

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

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

func JWTAuth(secret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		auth := c.GetHeader("Authorization")
		if auth == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "missing authorization"})
			return
		}
		parts := strings.SplitN(auth, " ", 2)
		if len(parts) != 2 || parts[0] != "Bearer" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid authorization format"})
			return
		}
		claims := &JWTClaims{}
		token, err := jwt.ParseWithClaims(parts[1], claims, func(t *jwt.Token) (interface{}, error) {
			return []byte(secret), nil
		})
		if err != nil || !token.Valid {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
			return
		}
		c.Set("user_id", claims.UserID)
		c.Set("username", claims.Username)
		c.Set("role", claims.Role)
		c.Next()
	}
}

func GenerateToken(secret string, userID uint, username, role string, expireHours int) (string, error) {
	claims := JWTClaims{
		UserID:   userID,
		Username: username,
		Role:     role,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(expireHours) * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(secret))
}