squidex/backend/src/Squidex.Domain.Apps.Entities/Comments/DomainObject/Guards/GuardComments.cs

// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschraenkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using System.Collections.Generic;
using Squidex.Domain.Apps.Entities.Comments.Commands;
using Squidex.Domain.Apps.Events.Comments;
using Squidex.Infrastructure;
using Squidex.Infrastructure.EventSourcing;
using Squidex.Infrastructure.Translations;
using Squidex.Infrastructure.Validation;

namespace Squidex.Domain.Apps.Entities.Comments.DomainObject.Guards
{
    public static class GuardComments
    {
        public static void CanCreate(CreateComment command)
        {
            Guard.NotNull(command, nameof(command));

            Validate.It(e =>
            {
                if (string.IsNullOrWhiteSpace(command.Text))
                {
                    e(Not.Defined("Text"), nameof(command.Text));
                }
            });
        }

        public static void CanUpdate(UpdateComment command, string commentsId, List<Envelope<CommentsEvent>> events)
        {
            Guard.NotNull(command, nameof(command));

            var comment = FindComment(events, command.CommentId);

            if (!string.Equals(commentsId, command.Actor.Identifier) && !comment.Payload.Actor.Equals(command.Actor))
            {
                throw new DomainException(T.Get("comments.notUserComment"));
            }

            Validate.It(e =>
            {
                if (string.IsNullOrWhiteSpace(command.Text))
                {
                    e(Not.Defined("Text"), nameof(command.Text));
                }
            });
        }

        public static void CanDelete(DeleteComment command, string commentsId, List<Envelope<CommentsEvent>> events)
        {
            Guard.NotNull(command, nameof(command));

            var comment = FindComment(events, command.CommentId);

            if (!string.Equals(commentsId, command.Actor.Identifier) && !comment.Payload.Actor.Equals(command.Actor))
            {
                throw new DomainException(T.Get("comments.notUserComment"));
            }
        }

        private static Envelope<CommentCreated> FindComment(List<Envelope<CommentsEvent>> events, DomainId commentId)
        {
            Envelope<CommentCreated>? result = null;

            foreach (var @event in events)
            {
                if (@event.Payload is CommentCreated created && created.CommentId == commentId)
                {
                    result = @event.To<CommentCreated>();
                }
                else if (@event.Payload is CommentDeleted deleted && deleted.CommentId == commentId)
                {
                    result = null;
                }
            }

            if (result == null)
            {
                throw new DomainObjectNotFoundException(commentId.ToString());
            }

            return result;
        }
    }
}