using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Xamarin.Essentials;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using XF.Material.Forms.UI.Dialogs;

namespace PRS.Mobile
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class StoreRequiScannerPage 
    {
        #region Fields / Constructor

        private StockHoldingModel _holdings = new StockHoldingModel(
            App.Data,
            () => new Filter<StockHolding>(x => x.Units).IsNotEqualTo(0.0F)
        );

        private Task _holdingsTask = null;
        
        
        List<StoreRequiItemShell> shells = new List<StoreRequiItemShell>();
        List<StoreRequiItemShell> oldShells = new List<StoreRequiItemShell>();
        Requisition requisition = new Requisition();

        Dictionary<StoreRequiItemShell, string> itemRowScannerRawResultPairs = new Dictionary<StoreRequiItemShell, string>();
        Dictionary<StoreRequiItemShell, string> itemRowScannerProcessedResultPairs = new Dictionary<StoreRequiItemShell, string>();
        private bool loading = true;
        bool containsNotes = false;

        public StoreRequiScannerPage(Guid requiID)
        {
            _holdingsTask = Task.Run(() => _holdings.Refresh(false));
            InitializeComponent();
            ConfigAll(requiID);
        }
        #endregion

        #region Config

        void ConfigAll(Guid requiID)
        {
            _scanView.Options = new ZXing.Mobile.MobileBarcodeScanningOptions()
            {
                PossibleFormats = new List<ZXing.BarcodeFormat>() { ZXing.BarcodeFormat.QR_CODE },
                AutoRotate = false,
                TryInverted = true,
                TryHarder = true,
            };

            ConfigDisplay();
            if (requiID != Guid.Empty)
            {
                requisition.ID = requiID;
                LoadExistingRequi();
            }
        }

        protected override void OnAppearing()
        {
            base.OnAppearing();
            _scanView.IsAnalyzing = true;
            _scanView.IsScanning = true;
            _scanView.AutoFocus();        }

        protected override void OnDisappearing()
        {
            _scanView.IsScanning = false;
            _scanView.IsAnalyzing = false;
            base.OnDisappearing();
        }

        async void LoadExistingRequi()
        {
            await Task.Run(() =>
            {
                CoreTable table = QueryRequi();
                while(table == null)
                    table = QueryRequi();
                requisition = table.Rows.FirstOrDefault().ToObject<Requisition>();

                string notes = CheckNotes(requisition.Notes);

                if (!string.IsNullOrWhiteSpace(requisition.Request) || !string.IsNullOrWhiteSpace(notes))
                {
                    StoreRequiItemShell shell1 = new StoreRequiItemShell()
                    {
                        IsNotes = true,
                        IsNotNotes = false,
                        BorderColor = Color.FromHex("#9f4576")
                    };
                    shell1.Summary = !string.IsNullOrWhiteSpace(requisition.Request) ? "REQUEST: " + requisition.Request + System.Environment.NewLine : "";
                    shell1.Summary = shell1.Summary + notes;
                    shells.Insert(0, shell1);
                    containsNotes = true;
                }
            });

            await Task.Run(() =>
            {
                CoreTable table = QueryRequiItems();
                while(table == null)
                    table = QueryRequiItems();
                if (table.Rows.Any())
                {
                    Device.BeginInvokeOnMainThread(() => { saveBtn.IsVisible = true; });
                    foreach (CoreRow row in table.Rows)
                    {
                        StoreRequiItemShell shell = new StoreRequiItemShell()
                        {
                            ID = row.Get<RequisitionItem, Guid>(x => x.ID),
                            ProductID = row.Get<RequisitionItem, Guid>(x => x.Product.ID),
                            ProductName = row.Get<RequisitionItem, string>(x => x.Product.Name),
                            ProductCode = row.Get<RequisitionItem, string>(x => x.Product.Code),
                            Quantity = row.Get<RequisitionItem, double>(x => x.Quantity),
                            LocationID = row.Get<RequisitionItem, Guid>(x => x.Location.ID),
                            LocationName = row.Get<RequisitionItem, string>(x => x.Location.Description),
                            Picked = row.Get<RequisitionItem, DateTime>(x => x.Picked),
                        };
                        shells.Add(shell);
                        oldShells.Add(shell);
                    }
                }
                Device.BeginInvokeOnMainThread(() =>
                {
                    requiItemListView.ItemsSource = shells;
                    if (containsNotes)
                    {
                        countLbl.Text = "Number of items: " + (shells.Count - 1);
                    }
                    else
                    {
                        countLbl.Text = "Number of items: " + shells.Count;
                    }
                });
            });
        }

        private CoreTable QueryRequi()
        {
            try
            {
                return new Client<Requisition>().Query(
                       new Filter<Requisition>(x => x.ID).IsEqualTo(requisition.ID)
                       );
            }
            catch (Exception ex)
            {
                InABox.Mobile.MobileLogging.Log(ex);
                return null;
            }
        }

        private CoreTable QueryRequiItems()
        {
            try 
            {
            return new Client<RequisitionItem>().Query
                   (
                   new Filter<RequisitionItem>(x => x.RequisitionLink.ID).IsEqualTo(requisition.ID),
                   new Columns<RequisitionItem>(ColumnTypeFlags.None).Add(
                       x => x.ID,
                       x => x.Product.ID,
                       x => x.Product.Name,
                       x => x.Product.Code,
                       x => x.Quantity,
                       x => x.Location.ID,
                       x => x.Location.Description,
                       x => x.Picked
                       )
                   );
            }
            catch (Exception ex)
            {
                InABox.Mobile.MobileLogging.Log(ex);
                return null;
            }
        }

        private string CheckNotes(string[] notes)
        {
            string combinednotes = "----------" + System.Environment.NewLine + "NOTES: " + System.Environment.NewLine;
            if (notes.Count() > 0)
            {
                foreach (var note in notes)
                {
                    combinednotes = combinednotes + note + System.Environment.NewLine;
                }
            }
            return combinednotes;
        }

        void ConfigDisplay()
        {
            scannerGrid.RaiseChild(topleft);
            scannerGrid.RaiseChild(topright);
            scannerGrid.RaiseChild(bottomright);
            scannerGrid.RaiseChild(bottomleft);
        }
        #endregion

        #region Scanning

        private async void ScanView_OnScanResult(ZXing.Result result)
        {
            if (!loading)
            {
                loading = true;
                Vibration.Vibrate();
                try
                {
                    _holdingsTask.Wait();
                    if (!itemRowScannerRawResultPairs.Values.Contains(result.Text))
                    {
                        if (!itemRowScannerProcessedResultPairs.Values.Contains(result.Text))
                        {
                            using (await MaterialDialog.Instance.LoadingDialogAsync(message: "Adding"))
                            {
                                string rawResult = result.Text;
                                Tuple<string, double> tuple = ProcessResult(result.Text);
                                var status = await LoadProduct(tuple, rawResult);
                                if (status == LoadProductStatus.InvalidCode)
                                    await DisplayAlert("Error", "Invalid Product Code", "OK");
                                else if (status == LoadProductStatus.NoHoldings)
                                    await DisplayAlert("Error", "No Holdings Found for Product", "OK");
                            }
                        }
                    }

                }
                catch (Exception e)
                {
                    MobileLogging.Log(e, "StoreRequiScanner");
                }

                loading = false;

                
            }
        }

        private Tuple<string, double> ProcessResult(string result)
        {
            double qty = 1;
            if (result.Contains("*"))
            {
                try
                {
                    int i = result.IndexOf("*");
                    string remainder = result.Substring(i);
                    result = result.Remove(i);
                    string s1 = remainder.Substring(1);
                    qty = Convert.ToDouble(s1);
                }
                catch
                {
                    loading = false;
                }
            }
            Tuple<string, double> tuple = new Tuple<string, double>(result, qty);
            return tuple;
        }


        private enum LoadProductStatus
        {
            Success,
            InvalidCode,
            NoHoldings
        }
        private async Task<LoadProductStatus> LoadProduct(Tuple<string, double> processedResultQtyTuple, string rawResult)
        {
            ProductShell? product = App.Data.Products.FirstOrDefault(x => x.Code.Equals(processedResultQtyTuple.Item1));
            if (product == null)
                return LoadProductStatus.InvalidCode;

            var holdings = _holdings.Where(x => x.ProductID == product.ID).ToArray();
            if (holdings.Length == 0)
                return LoadProductStatus.NoHoldings;
            else if (holdings.Length == 1)
                AddStoreRequiItemShell(holdings.First(), product, rawResult, processedResultQtyTuple);
            else
                UserSelectFromList(holdings, product, rawResult, processedResultQtyTuple);
            return LoadProductStatus.Success;
        }

        private void UserSelectFromList(StockHoldingShell[] list, ProductShell product, string rawResult, Tuple<string, double> processedResultQtyTuple)
        {

            StockHoldingSelectionPage page = new StockHoldingSelectionPage(_holdings, (shell) =>
            {
                AddStoreRequiItemShell(shell, product, rawResult, processedResultQtyTuple);
            });
            Navigation.PushAsync(page);
        }

        
        private void AddStoreRequiItemShell(StockHoldingShell holding, ProductShell product, string rawResult, Tuple<string, double> processedResultQtyTuple)
        {
            StoreRequiItemShell shell = new StoreRequiItemShell
            {
                ProductID = product.ID,
                ProductName = product.Name,
                ProductCode = product.Code,
                Quantity = 1,
                LocationID = holding.LocationID,
                LocationName = holding.LocationDescription,
                StyleID = holding.StyleID,
                JobID = holding.StyleID
            };
            shell.Dimensions.Unit.ID = holding.DimensionsUnitID;
            shell.Dimensions.Unit.HasQuantity = holding.DimensionsHasQuantity;
            shell.Dimensions.Unit.HasLength = holding.DimensionsHasLength;
            shell.Dimensions.Unit.HasHeight = holding.DimensionsHasHeight;
            shell.Dimensions.Unit.HasWeight = holding.DimensionsHasWeight;
            shell.Dimensions.Unit.HasWidth = holding.DimensionsHasWidth;

            shell.Dimensions.Quantity = holding.DimensionsQuantity;
            shell.Dimensions.Length = holding.DimensionsLength;
            shell.Dimensions.Height = holding.DimensionsHeight;
            shell.Dimensions.Weight = holding.DimensionsWeight;
            shell.Dimensions.Width = holding.DimensionsWidth;

            shell.Dimensions.Unit.Format = holding.DimensionsUnitFormat;
            shell.Dimensions.Unit.Formula = holding.DimensionsUnitFormula;

            shell.Dimensions.UnitSize = holding.DimensionsUnitSize;

            shells.Add(shell);

            itemRowScannerRawResultPairs.Add(shell, rawResult);
            itemRowScannerProcessedResultPairs.Add(shell, processedResultQtyTuple.Item1);

            requiItemListView.ItemsSource = null;
            requiItemListView.ItemsSource = shells;

            countLbl.IsVisible = true;

            if (containsNotes)
            {
                countLbl.Text = "Number of items: " + (shells.Count - 1);
            }
            else
            {
                countLbl.Text = "Number of items: " + shells.Count;
            }

            saveBtn.IsVisible = true;
            loading = false;
        }
        #endregion

        #region Button Presses
        private async void ExitBtn_Clicked(object sender, EventArgs e)
        {
            if (shells.Count > 0)
            {
                if (containsNotes && shells.Count > 1)
                {
                    string chosenOption = await DisplayActionSheet("Leave without saving?", "Cancel", null, "Yes", "No");
                    switch (chosenOption)
                    {
                        case "Cancel":
                            return;
                        case "Yes":
                            Navigation.PopAsync();
                            break;
                        case "No":
                            return;
                        default:
                            return;
                    }
                }
                else if (containsNotes && shells.Count == 1)
                {
                    Navigation.PopAsync();
                }
                else
                {
                    string chosenOption = await DisplayActionSheet("Leave without saving?", "Cancel", null, "Yes", "No");
                    switch (chosenOption)
                    {
                        case "Cancel":
                            return;
                        case "Yes":
                            Navigation.PopAsync();
                            break;
                        case "No":
                            return;
                        default:
                            return;
                    }
                }
            }
            else
                Navigation.PopAsync();

        }

        void SaveBtn_Clicked(object sender, EventArgs e)
        {
            StoreRequiConfirmationPage page = new StoreRequiConfirmationPage(requisition, shells, oldShells);
            page.OnSaveSelected += () => { Navigation.PopAsync(); };
            Navigation.PushAsync(page);
        }

        private async void RequiItem_Tapped(object sender, EventArgs e)
        {
            var shell = requiItemListView.SelectedItem as StoreRequiItemShell;
            if (shell == null) return;

            await RequiItemTappedAsync(shell);
        }

        private async Task RequiItemTappedAsync(StoreRequiItemShell shell)
        {
            string pickstatus = shell.Picked == DateTime.MinValue ? "not picked" : "picked (" + shell.Picked.ToString("dd MMM yy") + ")";
            string options = shell.Picked == DateTime.MinValue ? ". Mark as Picked?" : ". Remove Picked status?";

            string chosenOption = await DisplayActionSheet("Line is " + pickstatus + options, "Cancel", null, "Yes", "No");

            if (chosenOption != "Yes")
                return;

            shell.Picked = shell.Picked == DateTime.MinValue ? DateTime.Today : DateTime.MinValue;
            shell.Colour = shell.Picked == DateTime.MinValue ? Color.Default : Color.FromHex("#8fbc8f");

            requiItemListView.ItemsSource = null;
            requiItemListView.ItemsSource = shells;
        }


        void ReduceQtyBtn_Clicked(object sender, EventArgs e)
        {
            var shell = ((TappedEventArgs)e).Parameter as StoreRequiItemShell;
            if (shell == null) return;

            if (shell.Quantity <= 1)
            {
                shells.Remove(shell);
                itemRowScannerRawResultPairs.Remove(shell);
                itemRowScannerProcessedResultPairs.Remove(shell);
                if (containsNotes)
                {
                    countLbl.Text = "Number of items: " + (shells.Count - 1);
                    if (shells.Count == 1)
                    {
                        saveBtn.IsVisible = false;
                    }
                }
                else
                {
                    countLbl.Text = "Number of items: " + shells.Count;
                    if (shells.Count == 0)
                    {
                        saveBtn.IsVisible = false;
                    }
                }
            }
            else
            {
                shell.Quantity--;
            }
            requiItemListView.ItemsSource = null;
            requiItemListView.ItemsSource = shells;
        }

        void IncreaseQtyBtn_Clicked(object sender, EventArgs e)
        {
            var shell = ((TappedEventArgs)e).Parameter as StoreRequiItemShell;
            if (shell == null)
                return;

            shell.Quantity++;
            requiItemListView.ItemsSource = null;
            requiItemListView.ItemsSource = shells;
        }

        void AddItem_Clicked(object sender, EventArgs e)
        {
            if (App.Data.Products.Loaded)
            {
                if (loading)
                    return;
                loading = true;
                var products = new ProductSelectionPage(
                    (product) =>
                    {
                        Tuple<string, double> tuple = new Tuple<string, double>(product.Code, 1);
                        LoadProduct(new Tuple<string, double>(product.Code, 1), product.Code);
                    }
                );
                Navigation.PushAsync(products);
            }
        }

        void Qty_Changed(object sender, EventArgs e)
        {

        }
        #endregion
    }

   
}