using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using Microsoft.CodeAnalysis.VisualBasic.Syntax;
using Org.BouncyCastle.Asn1.Mozilla;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace PRSDesktop.Panels.Products.Locations;


/// <summary>
/// Interaction logic for StockHoldingRelocationWindow.xaml
/// </summary>
public partial class StockHoldingRelocationWindow : Window, INotifyPropertyChanged
{
    public StockHolding From { get; private init; }

    public enum RelocationMode
    {
        Issue,
        Transfer,
        ReleaseAllocations
    }

    private RelocationMode _mode;
    public RelocationMode Mode
    {
        get => _mode;
        set
        {
            _mode = value;

            UpdateMode();
        }
    }

    public bool ShowHeader => ShowFrom || IsTargetEditable || IsJobEditable;

    private bool _showFrom = true;
    public bool ShowFrom
    {
        get => _showFrom;
        set
        {
            _showFrom = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(ShowHeader));
        }
    }

    private bool _isTargetEditable = true;
    public bool IsTargetEditable
    {
        get => _isTargetEditable;
        set
        {
            _isTargetEditable = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(ShowHeader));
        }
    }

    private bool _isJobEditable = false;
    public bool IsJobEditable
    {
        get => _isJobEditable;
        set
        {
            _isJobEditable = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(ShowHeader));
        }
    }

    private StockLocation? _originalTarget;
    public StockLocation? OriginalTarget
    {
        get => _originalTarget;
        set
        {
            _originalTarget = value;
            To = value;
        }
    }

    private Job? _originalJob;
    public Job? OriginalJob
    {
        get => _originalJob;
        set
        {
            _originalJob = value;
            Job = value;
        }
    }

    private Job? _job;
    public Job? Job
    {
        get => _job;
        set
        {
            _job = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(CanSave));
            OnPropertyChanged($"{nameof(Job)}.{nameof(Job.JobNumber)}");
            OnPropertyChanged($"{nameof(Job)}.{nameof(Job.Name)}");

            UpdateMode();
        }
    }

    private StockLocation? _to;
    public StockLocation? To
    {
        get => _to;
        set
        {
            _to = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(CanSave));
            OnPropertyChanged($"{nameof(To)}.{nameof(To.Code)}");
            OnPropertyChanged($"{nameof(To)}.{nameof(To.Description)}");
        }
    }

    private bool _requireChangeTarget = false;
    /// <summary>
    /// Require that the target location be changed before allowing the "Save" button to be clicked.
    /// </summary>
    public bool RequireChangeTarget
    {
        get => _requireChangeTarget;
        set
        {
            _requireChangeTarget = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(CanSave));
        }
    }

    public bool CanSave
    {
        get
        {
            if(Grid.TotalIssued <= 0)
            {
                return false;
            }
            if(IsTargetEditable && (To?.ID ?? Guid.Empty) == Guid.Empty)
            {
                return false;
            }
            if (RequireChangeTarget)
            {
                if(IsTargetEditable && IsJobEditable)
                {
                    return (To?.ID ?? Guid.Empty) != (OriginalTarget?.ID ?? Guid.Empty)
                        || (Job?.ID ?? Guid.Empty) != (OriginalJob?.ID ?? Guid.Empty);
                }
                else if (IsTargetEditable)
                {
                    return (To?.ID ?? Guid.Empty) != (OriginalTarget?.ID ?? Guid.Empty);
                }
                else if (IsJobEditable)
                {
                    return (Job?.ID ?? Guid.Empty) != (OriginalJob?.ID ?? Guid.Empty);
                }
            }
            return true;
        }
    }

    public StockHoldingRelocationWindow(StockHolding from, IEnumerable<JobRequisitionItem> items, RelocationMode mode)
    {
        Client.EnsureColumns(from, Columns.None<StockHolding>().Add(x => x.Location.Code));

        From = from;

        InitializeComponent();

        SetRequisitionItems(items);
        Mode = mode;
    }

    private void UpdateMode()
    {
        if(Mode == RelocationMode.Issue)
        {
            var jobID = Job?.ID ?? Guid.Empty;
            foreach(var item in Grid.Items)
            {
                if(item.JRI.ID != Guid.Empty && item.JRI.Job.ID != jobID)
                {
                    item.Editable = false;
                    item.Issued = 0;
                }
                else
                {
                    item.Editable = true;
                }
            }
            Title = "Issue Items";
            IsJobEditable = true;
            IsTargetEditable = false;
            ShowFrom = true;
        }
        else if(Mode == RelocationMode.Transfer)
        {
            foreach(var item in Grid.Items)
            {
                item.Editable = item.JRI.ID == Guid.Empty || Security.IsAllowed<CanEditAllocatedJobRequisitions>();
            }
            IsJobEditable = true;
            IsTargetEditable = true;
            ShowFrom = false;
            RequireChangeTarget = true;
            Title = "Transfer Stock";
        }
        else if(Mode == RelocationMode.ReleaseAllocations)
        {
            ShowFrom = false;
            IsTargetEditable = false;
            IsJobEditable = false;
            Title = "Release Stock";
        }
    }

    private void Grid_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if(e.PropertyName == nameof(Grid.TotalIssued))
        {
            OnPropertyChanged(nameof(CanSave));
        }
    }

    public void SetRequisitionItems(IEnumerable<JobRequisitionItem> items)
    {
        var rItems = items.AsIList();

        var rIDs = rItems.Select(x => x.ID).Where(x => x != Guid.Empty).ToArray();
        var quantities = Client.Query(
            StockHolding.GetFilter(From)
                .Combine(new Filter<StockMovement>(x => x.JobRequisitionItem.ID).InList(rIDs)),
            Columns.None<StockMovement>().Add(x => x.Units).Add(x => x.JobRequisitionItem.ID))
            .ToObjects<StockMovement>().GroupBy(x => x.JobRequisitionItem.ID).ToDictionary(x => x.Key, x => x.Sum(x => x.Units));

        var requidItems = new List<StockHoldingRelocationItem>();
        var newItems = new List<StockHoldingRelocationItem>();
        foreach(var item in rItems)
        {
            var qty = item.ID != Guid.Empty ? quantities.GetValueOrDefault(item.ID) : item.Qty;
            if(item.ID != Guid.Empty && qty <= 0)
            {
                // We can't do anything with this; it shouldn't be shown.
                continue;
            }

            var newItem = new StockHoldingRelocationItem
            {
                Issued = 0,
                Quantity = qty,
                MaxValue = item.ID == Guid.Empty ? double.MaxValue : qty,
                Text = item.ID == Guid.Empty
                    ? "Unrequisitioned Items"
                    : $"{item.Job.JobNumber}: #{item.Requisition.Number} ({item.Requisition.Description})",
                JRI = item
            };

            if(item.ID == Guid.Empty)
            {
                newItems.Add(newItem);
            }
            else
            {
                requidItems.Add(newItem);
            }
        }

        int i = 1;
        foreach(var item in requidItems)
        {
            item.ItemNumber = $"{i}. ";
            newItems.Add(item);
            ++i;
        }

        Grid.Items = newItems;
        Grid.Refresh(true, true);
    }

    public Dictionary<Guid, double> GetQuantities()
    {
        return Grid.Items.ToDictionary(x => x.JRI.ID, x => x.Issued);
    }
    public StockLocation GetTargetLocation()
    {
        return To ?? new StockLocation();
    }

    public event PropertyChangedEventHandler? PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string? propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    #region Target Location

    public static StockLocation? LookupLocation(string? column = null, string? value = null)
    {
        var grid = new MultiSelectDialog<StockLocation>(
            LookupFactory.DefineFilter<StockLocation>(),
            Columns.None<StockLocation>().Add(x => x.ID).Add(x => x.Code).Add(x => x.Description),
            multiselect: false);
        if (grid.ShowDialog(column, value))
        {
            return grid.Data().Rows.First().ToObject<StockLocation>();
        }
        else
        {
            return null;
        }
    }

    private bool DoLookupLocation(string? column, string? value)
    {
        if(LookupLocation(column, value) is StockLocation location)
        {
            To = location;
            return true;
        }
        else
        {
            return false;
        }
    }

    private void ToBox_LostFocus(object sender, RoutedEventArgs e)
    {
        DoSearchLocation();
    }

    private void ToButton_Click(object sender, RoutedEventArgs e)
    {
        DoLookupLocation(null, null);
    }

    private void DoSearchLocation()
    {
        if (ToBox.Text.IsNullOrWhiteSpace() || ToBox.Text == To?.Code)
        {
            To = null;
            return;
        }

        var location = Client.Query(
                new Filter<StockLocation>(x => x.Code).IsEqualTo(ToBox.Text),
                Columns.None<StockLocation>().Add(x => x.ID).Add(x => x.Code).Add(x => x.Description))
            .ToObjects<StockLocation>().FirstOrDefault();
        if(location is not null)
        {
            To = location;
        }
        else
        {
            if(!DoLookupLocation(nameof(To.Code), ToBox.Text))
            {
                To = null;
            }
        }
    }

    private void ToBox_OnKeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
            DoSearchLocation();
    }

    #endregion

    #region Job

    private bool DoLookupJob(string? column, string? value)
    {
        var grid = new MultiSelectDialog<Job>(
            LookupFactory.DefineFilter<Job>(),
            Columns.None<Job>().Add(x => x.ID).Add(x => x.JobNumber).Add(x => x.Name),
            multiselect: false);
        if (grid.ShowDialog(column, value))
        {
            Job = grid.Data().Rows.First().ToObject<Job>();
            return true;
        }
        else
        {
            return false;
        }
    }

    private void JobBox_LostFocus(object sender, RoutedEventArgs e)
    {
        DoSearchJob();
    }

    private void JobButton_Click(object sender, RoutedEventArgs e)
    {
        DoLookupJob(null, null);
    }

    private void DoSearchJob()
    {
        if (JobBox.Text.IsNullOrWhiteSpace() || JobBox.Text == To?.Code)
        {
            Job = null;
            return;
        }

        var job = Client.Query(
                new Filter<Job>(x => x.JobNumber).IsEqualTo(JobBox.Text),
                Columns.None<Job>().Add(x => x.ID).Add(x => x.JobNumber).Add(x => x.Name))
            .ToObjects<Job>().FirstOrDefault();
        if(job is not null)
        {
            Job = job;
        }
        else
        {
            if(!DoLookupJob(nameof(Job.JobNumber), JobBox.Text))
            {
                Job = null;
            }
        }
    }

    private void JobBox_OnKeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
            DoSearchJob();
    }

    #endregion

    private void OKButton_Click(object sender, RoutedEventArgs e)
    {
        DialogResult = true;
        Close();
    }

    private void CancelButton_Click(object sender, RoutedEventArgs e)
    {
        DialogResult = false;
        Close();
    }

}