using System.Linq.Expressions;

namespace YLErp.Abstract
{
    /// <summary>
    /// 数据源接口
    /// </summary>
    public interface IDataSource
    {
        /// <summary>
        /// 数据个数
        /// </summary>
        int Count { get; }

        /// <summary>
        /// 重置数据源
        /// </summary>
        void ResetDataSource();
    }

    /// <summary>
    /// 数据源接口
    /// </summary>
    public interface IDataSource<TData> : IDataSource
    {
        TData GetData(int keyId);

        /// <summary>
        /// 获取数据
        /// </summary>
        IQueryable<TData> AsQueryable(Expression<Func<TData, bool>> predicate = null);
    }

    /// <summary>
    /// 数据源接口
    /// </summary>
    public interface IDataSourceV2<TData> : IDataSource<TData>
    {
        bool TryGetData(int keyId, out TData data);
    }

    /// <summary>
    /// 数据源接口
    /// </summary>
    public interface IDataSourceKey2<TData> : IDataSource<TData>
    {
        TData GetData(string keyStr);
    }

    /// <summary>
    /// 数据源事件接口
    /// </summary>
    public interface IDataSourceEvent
    {
        /// <summary>
        /// 数据源被更新后的事件
        /// </summary>
        event EventHandler DataSourceUpdated;
    }
}