using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Tanshu.Common;
using Tanshu.Accounts.Contracts;
using System.Windows.Forms;
using System.Threading;
using Tanshu.Accounts.Repository;
using Tanshu.Accounts.Entities;

namespace Tanshu.Accounts.PointOfSale
{
    public class BillHelperFunctions
    {
        BindingSource bindingSource;
        OrderedDictionary<BillItemKey, BillInventory> bill;
        BillItemKey oldKey;
        BillItemKey newKey;
        public BillHelperFunctions(BindingSource bindingSource, OrderedDictionary<BillItemKey, BillInventory> bill, int productID)
        {
            this.bindingSource = bindingSource;
            this.bill = bill;
            this.oldKey = new BillItemKey(productID, false);
            this.newKey = new BillItemKey(productID, true);
        }
        public void SetDiscount(string name, decimal discount)
        {
            if (discount > 1 || discount < 0)
                return;
            decimal maxDiscount = SaleVoucherBI.GetProductDiscountLimit(newKey.ProductID);
            if (discount > maxDiscount)
                MessageBox.Show(string.Format("Maximum discount for {0} is {1:P}", name, maxDiscount), "Excessive Discount", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            if (bill.ContainsKey(oldKey))
                bill[oldKey].Discount = discount;
            if (bill.ContainsKey(newKey))
                bill[newKey].Discount = discount;
            return;
        }
        #region Add Product
        public BillInventory AddProduct()
        {
            BillInventory product;
            if ((!bill.ContainsKey(oldKey)) && (!bill.ContainsKey(newKey)))
            {
                //No new or old
                product = SaleVoucherBI.GetDefaultSaleBillItem(newKey.ProductID);
                product = AddProduct(product);
            }
            else if (bill.ContainsKey(newKey))
            {
                //Has new or both
                bindingSource.CurrencyManager.Position = bill.IndexOfKey(newKey);
                product = bill[newKey];
                product.Quantity += 1;
            }
            else
            {
                //Has only old
                product = SaleVoucherBI.GetDefaultSaleBillItem(oldKey.ProductID);
                product.Discount = bill[oldKey].Discount;
                product.Price = bill[oldKey].Price;
                product = AddProduct(product);
            }
            return product;
        }
        private BillInventory AddProduct(BillInventory product)
        {
            bill.Add(new BillItemKey(product.ProductID, true), product);
            bindingSource.DataSource = bill.Values;
            bindingSource.CurrencyManager.Position = bindingSource.CurrencyManager.Count + 1;
            return product;
        }
        #endregion
        #region Quantity
        public void SetQuantity(BillInventory product, decimal quantity, bool prompt)
        {
            if (prompt && !GetInput("Price", ref quantity))
                return;

            if (product.Printed == 0)
            { // new
                if (!prompt)
                    quantity += product.Quantity;
                SetQuantity(product, quantity);
            }
            else if (bill.ContainsKey(newKey))
            {
                BillInventory newProduct = bill[newKey];
                if (prompt)
                    SetQuantity(newProduct, quantity - product.Printed);
                else
                    SetQuantity(newProduct, newProduct.Quantity + quantity);
            }
            else
            {
                ////Has only old
                if (prompt)
                    quantity -= product.Printed;
                if (quantity > 0 || Session.IsAllowed(RoleConstants.EDIT_PRINTED_PRODUCT))
                {
                    var newProduct = SaleVoucherBI.GetDefaultSaleBillItem(product.ProductID);
                    newProduct.Price = product.Price;
                    newProduct.Discount = product.Discount;
                    newProduct = AddProduct(newProduct);
                    SetQuantity(newProduct, quantity);
                }
            }
        }
        private void SetQuantity(BillInventory product, decimal quantity)
        {
            if (quantity < 0 && !Session.IsAllowed(RoleConstants.EDIT_PRINTED_PRODUCT))
                return;
            if (bill.ContainsKey(oldKey))
            {
                var totalQuantity = bill[oldKey].Quantity + quantity;
                if (totalQuantity < 0)
                    quantity += 0 - totalQuantity;
            }
            product.Quantity = quantity;
        }
        #endregion
        public void SetPrice(BillInventory product)
        {
            if (!Allowed(product, RoleConstants.CHANGE_RATE))
                return;
            decimal rate = product.Price;
            if (!GetInput("Price", ref rate))
                return;
            if (rate == 0 && !Session.IsAllowed(RoleConstants.ZERO_RATE))
                return;
            if (bill.ContainsKey(new BillItemKey(product.ProductID, true)))
                bill[new BillItemKey(product.ProductID, true)].Price = rate;
            if (bill.ContainsKey(new BillItemKey(product.ProductID, false)))
                bill[new BillItemKey(product.ProductID, false)].Price = rate;
        }
        private void InputBox_Validating(object sender, InputBoxValidatingArgs e)
        {
        }
        private bool Allowed(BillInventory item, RoleConstants role)
        {
            if (item == null)
                return false;
            if (!Session.IsAllowed(role))
                return false;
            return true;
        }
        private bool GetInput(string prompt, ref decimal amount)
        {
            InputBoxResult result = InputBox.Show(prompt, amount.ToString(), InputBox_Validating);
            if (!result.OK)
                return false;
            if (!decimal.TryParse(result.Text, out amount))
                return false;
            return true;
        }
    }
}