sessions/internal/router/rest/mw_auth.go

package rest

import (
	"context"
	"net/http"

	"gitea.dwysokinski.me/twhelp/sessions/internal/domain"
	"gitea.dwysokinski.me/twhelp/sessions/internal/router/rest/internal/model"
)

type authCtxKey struct{}

//counterfeiter:generate -o internal/mock/api_key_verifier.gen.go . APIKeyVerifier
type APIKeyVerifier interface {
	Verify(ctx context.Context, key string) (domain.User, error)
}

func authMiddleware(verifier APIKeyVerifier) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			key := r.Header.Get("X-API-Key")
			if key == "" {
				renderJSON(w, http.StatusUnauthorized, model.ErrorResp{
					Error: model.APIError{
						Code:    "unauthorized",
						Message: "invalid API key",
					},
				})
				return
			}

			u, err := verifier.Verify(r.Context(), key)
			if err != nil {
				renderJSON(w, http.StatusUnauthorized, model.ErrorResp{
					Error: model.APIError{
						Code:    "unauthorized",
						Message: "invalid API key",
					},
				})
				return
			}

			next.ServeHTTP(w, r.WithContext(userToContext(r.Context(), u)))
		})
	}
}

func userToContext(ctx context.Context, u domain.User) context.Context {
	return context.WithValue(ctx, authCtxKey{}, u)
}

func userFromContext(ctx context.Context) (domain.User, bool) {
	u, ok := ctx.Value(authCtxKey{}).(domain.User)
	return u, ok
}