favoritter/internal/middleware/context.go

// SPDX-License-Identifier: AGPL-3.0-or-later

package middleware

import (
	"context"
	"net/http"

	"kode.naiv.no/olemd/favoritter/internal/model"
)

type contextKey string

const (
	userKey      contextKey = "user"
	csrfTokenKey contextKey = "csrf_token"
	realIPKey    contextKey = "real_ip"
)

// UserFromContext returns the authenticated user from the request context, or nil.
func UserFromContext(ctx context.Context) *model.User {
	u, _ := ctx.Value(userKey).(*model.User)
	return u
}

// CSRFTokenFromContext returns the CSRF token from the request context.
func CSRFTokenFromContext(ctx context.Context) string {
	s, _ := ctx.Value(csrfTokenKey).(string)
	return s
}

// RealIPFromContext returns the real client IP from the request context.
func RealIPFromContext(ctx context.Context) string {
	s, _ := ctx.Value(realIPKey).(string)
	return s
}

// RequireLogin redirects to the login page if no user is authenticated.
func RequireLogin(basePath string) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			if UserFromContext(r.Context()) == nil {
				http.Redirect(w, r, basePath+"/login", http.StatusSeeOther)
				return
			}
			next.ServeHTTP(w, r)
		})
	}
}

// RequireAdmin returns 403 if the user is not an admin.
func RequireAdmin(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		user := UserFromContext(r.Context())
		if user == nil || !user.IsAdmin() {
			w.WriteHeader(http.StatusForbidden)
			w.Write([]byte("Forbidden"))
			return
		}
		next.ServeHTTP(w, r)
	})
}