using Comal.Classes;
using InABox.Core;
using InABox.Database;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PRS.Shared;

internal class Update_8_55 : DatabaseUpdateScript
{
    public override VersionNumber Version => new(8, 55);

    public override bool Update()
    {
        Logger.Send(LogType.Information, "", $"Updating uninitialised stock movement TransferIDs");

        var transactionIDs = DbFactory.NewProvider(Logger.Main)
            .Query(
                Filter<StockMovement>.Where(x => x.Type).InList(StockMovementType.TransferOut, StockMovementType.TransferIn)
                    .And(x => x.TransferID).IsEqualTo(null),
                Columns.None<StockMovement>()
                    .Add(x => x.Transaction))
            .Rows
            .Select(x => x.Get<StockMovement, Guid>(x => x.Transaction))
            .ToHashSet();

        Logger.Send(LogType.Information, "", $"Found {transactionIDs.Count} uninitialised transactions");

        var total = transactionIDs.Count;

        while (transactionIDs.Count > 0)
        {
            Logger.Send(LogType.Information, "", $"Updating Stock Movements: {(double)(total - transactionIDs.Count) / total * 100:F2}%");

            var nIDs = Math.Min(transactionIDs.Count, 100);
            var ids = new Guid[nIDs];

            var i = 0;
            foreach(var id in transactionIDs)
            {
                if (i == nIDs) break;

                ids[i] = id;
                ++i;
            }
            foreach(var id in ids)
            {
                transactionIDs.Remove(id);
            }

            var movementsTable = DbFactory.NewProvider(Logger.Main)
                .Query(
                    Filter<StockMovement>.Where(x => x.Transaction).InList(ids)
                        .And(x => x.Type).InList(StockMovementType.TransferOut, StockMovementType.TransferIn)
                        .And(x => x.TransferID).IsEqualTo(null),
                    Columns.None<StockMovement>()
                        .Add(x => x.ID)
                        .Add(x => x.Transaction)
                        .Add(x => x.Type)
                        .Add(x => x.Date)
                        .Add(x => x.System));
            var movements = 
                movementsTable
                .ToObjects<StockMovement>()
                .GroupByDictionary(x => x.Transaction);
            
            Logger.Send(LogType.Information, "", $"Updating {movementsTable.Rows.Count} movements");

            var updates = new List<StockMovement>();
            foreach(var (transaction, transactionMovements) in movements)
            {
                transactionMovements.SortBy(x => x.Date);

                while(transactionMovements.Count > 0)
                {
                    var movement = transactionMovements[0];
                    transactionMovements.RemoveAt(0);

                    var otherType = movement.Type == StockMovementType.TransferOut ? StockMovementType.TransferIn : StockMovementType.TransferOut;

                    var transfer = Guid.NewGuid();
                    movement.TransferID = transfer;

                    var first = transactionMovements.FirstOrDefault(x => x.Type == otherType);
                    if(first is not null)
                    {
                        first.TransferID = transfer;
                        transactionMovements.Remove(first);

                        updates.Add(movement);
                        updates.Add(first);
                    }
                }
            }
            DbFactory.NewProvider(Logger.Main).Save(updates);
        }

        Logger.Send(LogType.Information, "", $"Finished updating uninitialised stock movement TransferIDs");
        return true;
    }
}