package middleware

import (
	"net/http"
	"strings"

	"nixcn-cms/internal/cryptography"

	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
	"github.com/spf13/viper"
)

func JWTAuth() gin.HandlerFunc {
	jwtSecret := []byte(viper.GetString("secrets.jwt_secret"))

	return func(c *gin.Context) {
		auth := c.GetHeader("Authorization")
		if auth == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"error": "missing Authorization header",
			})
			return
		}

		// Split header to 2
		parts := strings.SplitN(auth, " ", 2)
		if len(parts) != 2 || parts[0] != "Bearer" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"error": "invalid Authorization header format",
			})
			return
		}

		tokenStr := parts[1]

		// Verify access token
		claims := &cryptography.JwtClaims{}
		token, err := jwt.ParseWithClaims(
			tokenStr,
			claims,
			func(token *jwt.Token) (any, error) {
				return jwtSecret, nil
			},
		)

		if err != nil || !token.Valid {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"error": "invalid or expired token",
			})
			return
		}

		c.Set("user_id", claims.UserID)
		c.Next()
	}
}