using System;
using System.ComponentModel;
using System.Linq;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;

namespace comal.timesheets
{
    public abstract class SingleDataModel<TEntity, TItem> : CoreDataModel<TEntity>, ISingleDataModel<TEntity, TItem>
        where TEntity : Entity, IRemotable, IPersistent, new() 
        where TItem : SingleDataModelItem<TEntity>, new()
    {

        private TItem _item;

        public TItem Item
        {
            get => _item;
            set => SetProperty(ref _item, value);
        }
        
        public virtual void BeforeLoad(MultiQuery query, Guid id)
        {
        }

        public virtual void AfterLoad(MultiQuery query, Guid id)
        {
        }

        private TItem CreateItem(TEntity entity)
        {
            CoreTable table = new CoreTable();
            table.LoadColumns(Columns);
            CoreRow row = table.NewRow();
            if (entity != null)
                table.LoadRow(row, entity);
            return new TItem() { Row = row, Parent = this };  
            
        }
        
        public void Load(TEntity entity, Action loaded = null)
        {
            MultiQuery query = new MultiQuery();
            
            BeforeLoad(query, entity.ID);

            Item = CreateItem(entity);
            Item.PropertyChanged += (sender, args) => DoPropertyChanged(sender, args);
            
            if (query.Count > 0)
            {
                query.Query(
                    (q) =>
                    {
                        AfterLoad(q, entity.ID);
                        loaded?.Invoke();
                    });
            }
            else
            {
                AfterLoad(query, entity.ID);
                loaded?.Invoke();
            }

        }
        
        public void Load(Guid id, Action loaded = null)
        {
            MultiQuery query = new MultiQuery();
            
            query.Add(
                new Filter<TEntity>(x=>x.ID).IsEqualTo(id),
                Columns
            );
            
            BeforeLoad(query, id);
            
            query.Query(
                (q) =>
                {
                    var row = q.Get<TEntity>().Rows.FirstOrDefault();
                    Item = (row != null)
                        ? new TItem() { Row = row, Parent = this }
                        : CreateItem(null);
                    Item.PropertyChanged += (sender, args) => DoPropertyChanged(sender, args);
                    
                    AfterLoad(q, id);
                    loaded?.Invoke();
                });
        }


        protected virtual void BeforeSave(TItem item)
        {
            
        }
        
        protected virtual void AfterSave(TItem item)
        {
            
        }
        
        public void Save(String auditmessage)
        {
            BeforeSave(Item);
            new Client<TEntity>().Save(Item.Entity,auditmessage);
            AfterSave(Item);
        }
        
    }
}