blind-select/backend/internal/middleware/auth.go

package middleware

import (
	"net/http"
	"strings"

	"github.com/blind-select/backend/internal/utils"
	"github.com/gin-gonic/gin"
)

// JWTAuth requires valid JWT
func JWTAuth(secret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			JSONError(c, http.StatusUnauthorized, "missing authorization header")
			c.Abort()
			return
		}

		tokenStr := strings.TrimPrefix(authHeader, "Bearer ")
		if tokenStr == authHeader {
			JSONError(c, http.StatusUnauthorized, "invalid authorization format")
			c.Abort()
			return
		}

		claims, err := utils.ParseToken(tokenStr, secret)
		if err != nil {
			JSONError(c, http.StatusUnauthorized, "invalid or expired token")
			c.Abort()
			return
		}

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

// AdminOnly restricts access to admin role only
func AdminOnly(secret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		role, exists := c.Get("role")
		if !exists || role != "admin" {
			JSONError(c, http.StatusForbidden, "admin access required")
			c.Abort()
			return
		}
		c.Next()
	}
}

// BlindDailyLimit limits blind selections per day
func BlindDailyLimit(secret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		userID, _ := c.Get("user_id")
		uid := userID.(uint)

		limit := getDailyLimit(uid)
		used := getTodayBlindCount(uid)

		if used >= limit {
			JSONError(c, http.StatusTooManyRequests, "daily blind selection limit reached. Upgrade to VIP for more!")
			c.Abort()
			return
		}

		c.Next()
	}
}

func getDailyLimit(userID uint) int {
	return 3 // TODO: check membership
}

func getTodayBlindCount(userID uint) int {
	return 0 // TODO: check Redis
}