using Biskilog_Accounting.Shared.CustomModels;
using Biskilog_Accounting.Shared.POSModels;

namespace Biskilog_Accounting.Shared.Interfaces
{
    public interface IAnalytics
    {
        /// <summary>
        /// Fetches a collection of sales transaction made from the specified start date to the end date
        /// </summary>
        /// <param name="a_start">Specified Start Date</param>
        /// <param name="a_end">Specified end Date</param>
        /// <returns></returns>
        IEnumerable<Tblcart> GetSalesTransaction(DateTime a_start, DateTime a_end);
        /// <summary>
        /// Fetches a collection of in-debt customers
        /// <returns></returns>
        IEnumerable<InDebtCustomers> GetInDebtCustomers();
        /// <summary>
        /// Fetches a collection of Product Items which are currently out of stock
        /// </summary>
        /// <returns></returns>
        IEnumerable<ProductItem> GetOutOfStockItems();
        /// <summary>
        /// Fetches a collection of the most purchased Product Items within a specified date range
        /// </summary>
        /// <param name="a_start"></param>
        /// <param name="a_end"></param>
        /// <returns></returns>
       IEnumerable<MostPurchasedItem> GetMostPurchasedItem(DateTime a_start, DateTime a_end);
        /// <summary>
        /// Fetches a collection of cancelled transaction within a specified date range
        /// </summary>
        /// <param name="a_start"></param>
        /// <param name="a_end"></param>
        /// <returns></returns>
        IEnumerable<CancelledSales> GetCancelledSales(DateTime a_start, DateTime a_end);
        /// <summary>
        /// Fetches a collection of transaction made by employees within a specified date range
        /// </summary>
        /// <param name="a_start"></param>
        /// <param name="a_end"></param>
        /// <returns>A dictionary of transactions made by employees with employee name as key</returns>
        Dictionary<string, List<SaleItem>> GetEmployeeSales(DateTime a_start, DateTime a_end);
        /// <summary>
        /// Fetches a collection of product price changes with a specified date range
        /// </summary>
        /// <param name="a_start"></param>
        /// <param name="a_end"></param>
        /// <returns></returns>
        IEnumerable<ProductPriceChange> GetPriceChanges(DateTime a_start, DateTime a_end);
        /// <summary>
        /// Fetch the trade summary which is made of the total sales made currently and previous trade
        /// </summary>
        /// <returns></returns>
        TradeSummary GetTradeSummary();
    }
}