using System;
using System.Collections.Generic;
using System.Linq;
using InABox.Core;

namespace comal.timesheets
{
    
    
    public abstract class ListDataModel<TEntity, TItem> : CoreDataModel<TEntity>, IListDataModel<TEntity, TItem>
        where TEntity : Entity, IRemotable, IPersistent, new() 
        where TItem : CoreDataModelItem, new()
    {
        public SortOrder<TEntity> Sort => LookupFactory.DefineSort<TEntity>();
        
        private IEnumerable<TItem> _allitems;
        
        protected IList<TItem> _items = new List<TItem>();
        public IList<TItem> Items
        {
            get => _items;
            set => SetProperty(ref _items, value);
        }
        
        public void Search(Func<TItem, bool> predicate)
        {
            Items = predicate != null
                ? new List<TItem>(_allitems.Where(predicate))
                : new List<TItem>(_allitems);
        }
        
        public virtual void BeforeLoad(MultiQuery query, Filter<TEntity> filter)
        {
            
        }        
        
        public virtual void AfterLoad(MultiQuery query, Filter<TEntity> filter)
        {
            
        }

        public void Load(Filter<TEntity> filter, Action loaded = null)
        {
            MultiQuery query = new MultiQuery();
            
            query.Add(
                filter,
                Columns,
                Sort
            );
            
            BeforeLoad(query, filter);
            
            query.Query(
                (q) =>
                {
                    _allitems = new List<TItem>(q.Get<TEntity>().Rows.Select(row => CreateItem<TItem>(row)));
                    
                    Search(null);
                    AfterLoad(q, filter);
                    loaded?.Invoke();                        
  
                });
        }

        protected T CreateItem<T>(CoreRow row) where T : CoreDataModelItem, new()
        {
            var result = new T() { Row = row, Parent = this };
            result.PropertyChanged += (sender, args) => DoPropertyChanged(result, args);
            return result;
        }
    }
    

    
}