using Infrastructure.Data;
using Infrastructure.Domain;
using Infrastructure.Extensions;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Infrastructure.Web.Mvc
{
    public class TreeCrudController<TEntity, TEditModel> : CrudController<TEntity, TEditModel> where TEntity : BaseTreeEntity<TEntity>
    {
        public TreeCrudController(IRepository<TEntity> repo) : base(repo)
        {
        }

        public override void ToEntity(TEditModel model, TEntity entity)
        {
            if (entity != null && !entity.ParentId.HasValue)
            {
                var root = this.Repo.ReadOnlyTable().FirstOrDefault(o => o.ParentId == null);
                if (root == null)
                {
                    throw new Exception("根节点没有初始化");
                }
                entity.ParentId = root.Id;
            }
        }

        protected override void BeforeEdit(TEntity entity, TEditModel model)
        {
            if (entity.ParentId != null)
            {
                if (entity.ParentId == entity.Id)
                {
                    throw new Exception("上级节点不能是当前节点");
                }
                var parentNode = this.Repo.ReadOnlyTable().Where(o => o.Id == entity.ParentId).FirstOrDefault();
                var parentList = this.Repo.ReadOnlyTable()
                    .Where(o => o.Left <= parentNode.Left && o.Right >= parentNode.Right)
                    .ToList()
                    .ToTree()
                    .FirstOrDefault(o => o.Id == entity.ParentId);
                while (parentList is not null && parentList.ParentId.HasValue)
                {
                    if (parentList.ParentId == entity.Id)
                    {
                        throw new Exception("上级节点不能是当前节点的下级节点");
                    }
                    else
                    {
                        parentList = parentList.Parent;
                    }
                }
            }
        }

        protected override void AfterEdit(TEntity entity, TEditModel model)
        {
            var root = this.Repo.Table().ToList().FirstOrDefault(o => o.ParentId == null);
            root.Update();
            this.Repo.SaveChanges();
        }

        protected override void AfterDelete(List<Guid> list)
        {
            this.AfterEdit(default(TEntity), default(TEditModel));
        }
    }
}