using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using com.sun.tools.javac.util;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.Wpf;
using javax.swing;

namespace PRSDesktop;

/// <summary>
/// Interaction logic for JobRequisitionStockSelectionPage.xaml
/// </summary>
public partial class StockSelectionPage : ThemableWindow, INotifyPropertyChanged
{
    public ObservableCollection<StockSelectionViewModel> ViewModels { get; } = new ObservableCollection<StockSelectionViewModel>();

    private readonly JobRequisitionItem Item;

    public Guid IssuingJobID { get; set; }

    public bool Allocated = false;

    public double TotalChosen => ViewModels.Sum(x => x.ChosenUnits);

    public StockSelectionPage(IEnumerable<StockHolding> holdings, JobRequisitionItem item, Job issuingJob, bool requisitioned = false)
    {
        Item = item;
        foreach (var holding in holdings)
        {
            ViewModels.Add(new StockSelectionViewModel(holding));
        }

        InitializeComponent();

        IssuingJobID = issuingJob.ID;
        jobLbl.Text = $"Taking stock from Job: {issuingJob.Name} ({issuingJob.JobNumber})";

        if (requisitioned)
        {
            availableUnitsLbl.Text = "Allocated";
            listView.IsEnabled = false;
            okButton.IsEnabled = false;
        }
    }

    private void SaveButton_Click(object sender, RoutedEventArgs e)
    {
        if(TotalChosen <= 0)
        {
            MessageWindow.ShowMessage("Please select at least from at least one holding to reserve.", "Error", image: MessageWindow.WarningImage);
            return;
        }

        var models = ViewModels.Where(x => x.ChosenUnits > 0);

        foreach (var model in models)
        {
            CreateStockMovements(model);
        }

        DialogResult = true;
    }

    private void CreateStockMovements(StockSelectionViewModel model)
    {
        var batch = new StockMovementBatch
        {
            TimeStamp = DateTime.Now,
            Type = StockMovementBatchType.Transfer,
            Notes = $"Allocated to Job {Item.Job.JobNumber}"
        };
        Client.Save(batch, "Created for requisitioning stock");

        var issuing = CreateBaseMovement(model, batch.ID);
        issuing.Job.ID = IssuingJobID;
        issuing.Issued = model.ChosenUnits;
        issuing.Type = StockMovementType.TransferOut;

        var receiving = CreateBaseMovement(model, batch.ID);
        receiving.Job.ID = Item.Job.ID;
        receiving.Received = model.ChosenUnits;
        receiving.JobRequisitionItem.ID = Item.ID;
        receiving.Type = StockMovementType.TransferIn;
        receiving.Transaction = issuing.Transaction;

        Client.Save(new StockMovement[] { issuing, receiving }, "Created from Reservation Management Screen");
    }

    private StockMovement CreateBaseMovement(StockSelectionViewModel model, Guid batchid)
    {
        var mvt = new StockMovement();

        mvt.Style.ID = model.Holding.Style.ID;
        mvt.Location.ID = model.Holding.Location.ID;
        mvt.Dimensions.CopyFrom(model.Holding.Dimensions);
        mvt.Batch.ID = batchid;
        mvt.Employee.ID = App.EmployeeID;
        mvt.Date = DateTime.Now;
        mvt.Product.ID = Item.Product.ID;
        mvt.Notes = $"Reservation Management Screen - allocating to Job {Item.Job.JobNumber} for Requisition Line";

        return mvt;
    }

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

    private void TextBox_TextChanged(object sender, System.Windows.Controls.TextChangedEventArgs e)
    {
        if (sender is not TextBox box || box.Tag is not StockSelectionViewModel model) return;

        if (box.Text.IsNullOrWhiteSpace()) return;

        if (double.TryParse(box.Text, out double value))
        {
            model.ChosenUnits = value;
            OnPropertyChanged(nameof(TotalChosen));
        }
        else
        {
            // This'll call the event handler again.
            box.Text = "0";
        }
    }

    private void All_Clicked(object sender, RoutedEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not StockSelectionViewModel model) return;

        model.ChosenUnits = model.Holding.Units;
        OnPropertyChanged(nameof(TotalChosen));
    }

    private void Minus_Click(object sender, RoutedEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not StockSelectionViewModel model) return;
        
        model.ChosenUnits--;
        OnPropertyChanged(nameof(TotalChosen));
    }

    private void Plus_Click(object sender, RoutedEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not StockSelectionViewModel model) return;

        model.ChosenUnits++;
        OnPropertyChanged(nameof(TotalChosen));
    }

    public event PropertyChangedEventHandler? PropertyChanged;

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

        if(propertyName == nameof(TotalChosen))
        {
            okButton.IsEnabled = TotalChosen > 0;
        }
    }
}

public class StockSelectionViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler? PropertyChanged;
    public string Location => Holding.Location.Description;
    public string Area => Holding.Location.Area.Description;
    public string Style => Holding.Style.Description;
    public double Units => Holding.Units;

    private double _chosenUnits;
    public double ChosenUnits
    {
        get => _chosenUnits;
        set
        {
            _chosenUnits = Math.Clamp(value, 0, Holding.Units);
            OnPropertyChanged();
        }
    }

    public StockHolding Holding { get; set; }

    public StockSelectionViewModel(StockHolding holding)
    {
        Holding = holding;
        ChosenUnits = 0;
    }

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