using System;
using System.Collections.Generic;
using System.Linq;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.Wpf;
using InABox.WPF;

namespace PRSDesktop;

public static class StockUtils
{
    public static bool RecalculateHoldingsOfLocations(Guid[] locationIDs, out List<String> report)
    {
        return RecalculateHoldings(new Filter<IStockHolding>(x => x.Location.ID).InList(locationIDs), out report);
    }
    public static bool RecalculateHoldingsOfProducts(Guid[] productIDs, out List<String> report)
    {
        return RecalculateHoldings(new Filter<IStockHolding>(x => x.Product.ID).InList(productIDs), out report);
    }

    public static bool RecalculateHoldings(Filter<IStockHolding> filter, out List<String> report)
    {
        bool result = false;
        Dictionary<String, int> messages = new();

        void AddMessage(String type)
        {
            messages.TryGetValue(type, out int count);
            messages[type] = ++count;
        }

        Progress.ShowModal("Recalculating", progress =>
        {
            progress.Report("Loading Data");
            MultiQuery query = new MultiQuery();

            query.Add(
                filter.Cast<StockHolding>(),
                Columns.Required<StockHolding>().Add(x => x.ID)
                    .Add(x => x.Location.ID)
                    .Add(x => x.Product.ID)
                    .Add(x => x.Job.ID)
                    .Add(x => x.Style.ID)
                    .AddDimensionsColumns(x => x.Dimensions, Dimensions.ColumnsType.Local)
                    .Add(x => x.Units)
                    .Add(x => x.AverageValue)
                    .Add(x => x.Available)
                    .Add(x => x.Qty)
                    .Add(x => x.Weight)
                    .Add(x => x.Value)
            );

            query.Add(
                filter.Cast<StockMovement>(),
                Columns.None<StockMovement>().Add(x => x.ID)
                    .Add(x=>x.Location.ID)
                    .Add(x => x.Product.ID)
                    .Add(x => x.Job.ID)
                    .Add(x => x.Style.ID)
                    .AddDimensionsColumns(x => x.Dimensions, Dimensions.ColumnsType.Local)
                    .Add(x => x.Units)
                    .Add(x => x.Cost)
                    .Add(x => x.JobRequisitionItem.ID)
            );
            query.Query();

            var holdings = query.Get<StockHolding>();
            var toDelete = new List<StockHolding>();
            var movements = query.Get<StockMovement>();

            double movementcount = (double)movements.Rows.Count;
            progress.Report("Processing");
            var updates = new List<StockHolding>();
            
            while (movements.Rows.Any())
            {
                double percent = ((movementcount - movements.Rows.Count) / movementcount) * 100.0;
                progress.Report($"Processing ({percent:F2}% complete)");
                var first = movements.Rows.First();
                var selected = movements.Rows.Where(x => x.IsEqualTo<StockMovement, StockMovement>(first)).ToList();

                var holdingrow = holdings.Rows.FirstOrDefault(x => x.IsEqualTo<StockHolding, StockMovement>(first));
                StockHolding holding = null;
                if (holdingrow != null)
                {
                    holdings.Rows.Remove(holdingrow);
                    holding = holdingrow.ToObject<StockHolding>();
                }

                if (holding == null)
                {
                    var firstmovement = first.ToObject<StockMovement>();
                    holding = new StockHolding();
                    holding.Location.ID = firstmovement.Location.ID;
                    holding.Product.ID = firstmovement.Product.ID;
                    holding.Style.ID = firstmovement.Style.ID;
                    holding.Job.ID = firstmovement.Job.ID;
                    holding.Dimensions.CopyFrom(firstmovement.Dimensions);
                }

                holding.Recalculate(selected.ToObjects<StockMovement>());

                if (holding.Units.IsEffectivelyEqual(0.0) && holding.Available.IsEffectivelyEqual(0.0))
                {
                    if (holding.ID != Guid.Empty)
                        toDelete.Add(holding);
                }
                else if (holding.IsChanged())
                {
                    AddMessage(holding.ID != Guid.Empty ? "updated" : "added");
                    updates.Add(holding);
                }

                foreach (var row in selected)
                    movements.Rows.Remove(row);
            }

            toDelete.AddRange(holdings.Rows.ToObjects<StockHolding>());
            foreach (var holding in toDelete)
                AddMessage("deleted");

            if (updates.Any())
            {
                result = true;
                progress.Report($"Updating {updates.Count} Holdings");
                new Client<StockHolding>().Save(updates.Where(x => x.IsChanged()), "Updated by Recalculation");
            }

            if (toDelete.Any())
            {
                result = true;
                progress.Report($"Deleting {toDelete.Count} Holdings");
                new Client<StockHolding>().Delete(toDelete, "Removed by Recalculation");
            }

        });
        report = new List<String>();
        if (messages.Any())
            report.AddRange(messages.Select(x => $"{x.Value} holdings {x.Key}"));
        else
            report.Add("Nothing to Update");

        return result;
    }

}