using System;
using Umbraco.Cms.Core.Web;

namespace Umbraco.Cms.Core.PublishedCache
{
    // TODO: This is a mess. This is a circular reference:
    // IPublishedSnapshotAccessor -> PublishedSnapshotService -> UmbracoContext -> PublishedSnapshotService -> IPublishedSnapshotAccessor
    // Injecting IPublishedSnapshotAccessor into PublishedSnapshotService seems pretty strange
    // The underlying reason for this mess is because IPublishedContent is both a service and a model.
    // Until that is fixed, IPublishedContent will need to have a IPublishedSnapshotAccessor
    public class UmbracoContextPublishedSnapshotAccessor : IPublishedSnapshotAccessor
    {
        private readonly IUmbracoContextAccessor _umbracoContextAccessor;

        public UmbracoContextPublishedSnapshotAccessor(IUmbracoContextAccessor umbracoContextAccessor)
        {
            _umbracoContextAccessor = umbracoContextAccessor;
        }

        public IPublishedSnapshot? PublishedSnapshot
        {
            get
            {
                if (!_umbracoContextAccessor.TryGetUmbracoContext(out var umbracoContext))
                {
                    return null;
                }
                return umbracoContext?.PublishedSnapshot;
            }

            set => throw new NotSupportedException(); // not ok to set
        }

        public bool TryGetPublishedSnapshot(out IPublishedSnapshot? publishedSnapshot)
        {
            if (!_umbracoContextAccessor.TryGetUmbracoContext(out var umbracoContext))
            {
                publishedSnapshot = null;
                return false;
            }
            publishedSnapshot = umbracoContext?.PublishedSnapshot;

            return publishedSnapshot is not null;
        }
    }
}