package middleware

import (
	"context"
	"net/http"
	"strings"

	"github.com/prabhupadasays/spsays-bff/pkg/response"
)

type contextKey string

const UserIDKey contextKey = "user_id"

// Auth is a placeholder middleware for JWT authentication.
// It extracts the Bearer token from the Authorization header,
// validates it, and sets the user ID in the request context.
func Auth(jwtSecret string) func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			authHeader := r.Header.Get("Authorization")
			if authHeader == "" {
				response.Error(w, http.StatusUnauthorized, "missing authorization header")
				return
			}

			parts := strings.SplitN(authHeader, " ", 2)
			if len(parts) != 2 || strings.ToLower(parts[0]) != "bearer" {
				response.Error(w, http.StatusUnauthorized, "invalid authorization format")
				return
			}

			token := parts[1]

			// TODO: validate JWT token and extract user ID
			_ = token
			_ = jwtSecret
			userID := "" // placeholder

			if userID == "" {
				response.Error(w, http.StatusUnauthorized, "invalid or expired token")
				return
			}

			ctx := context.WithValue(r.Context(), UserIDKey, userID)
			next.ServeHTTP(w, r.WithContext(ctx))
		})
	}
}

// GetUserID extracts the user ID from the request context.
func GetUserID(ctx context.Context) string {
	if v, ok := ctx.Value(UserIDKey).(string); ok {
		return v
	}
	return ""
}