using System;
using System.Drawing;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using ApplicationServices;
using DataLayer;
using Dinah.Core;
using Dinah.Core.Windows.Forms;
using LibationWinForms.Dialogs;

namespace LibationWinForms
{
    // INSTRUCTIONS TO UPDATE DATA_GRID_VIEW
    // - delete current DataGridView
    // - view > other windows > data sources
    // - refresh
    // OR
    // - Add New Data Source
    //   Object. Next
    //   LibationWinForms
    //     AudibleDTO
    //       GridEntry
    // - go to Design view
    // - click on Data Sources > ProductItem. drowdown: DataGridView
    // - drag/drop ProductItem on design surface
    public partial class ProductsGrid : UserControl
    {
        public event EventHandler<int> VisibleCountChanged;
        public event EventHandler BackupCountsChanged;

        // alias
        private DataGridView _dataGridView => gridEntryDataGridView;

		public ProductsGrid()
		{
			InitializeComponent();

            // sorting breaks filters. must reapply filters after sorting
            _dataGridView.Sorted += (_, __) => Filter();
            _dataGridView.CellFormatting += HiddenFormatting;
            _dataGridView.CellContentClick += DataGridView_CellContentClick;

            EnableDoubleBuffering();
		}

		private void EnableDoubleBuffering()
		{
			var propertyInfo = _dataGridView.GetType().GetProperty("DoubleBuffered", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);

			//var before = (bool)propertyInfo.GetValue(dataGridView);
            propertyInfo.SetValue(_dataGridView, true, null);
			//var after = (bool)propertyInfo.GetValue(dataGridView);
		}        

        #region Button controls

        private async void DataGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            // handle grid button click: https://stackoverflow.com/a/13687844
            if (e.RowIndex < 0 || _dataGridView.Columns[e.ColumnIndex] is not DataGridViewButtonColumn)
                return;

            var liveGridEntry = getGridEntry(e.RowIndex);

            switch (_dataGridView.Columns[e.ColumnIndex].DataPropertyName)
            {
                case GridEntry.LIBERATE_COLUMN_NAME:
                    await Liberate_Click(liveGridEntry);
                    break;
                case GridEntry.EDIT_TAGS_COLUMN_NAME:
                    EditTags_Click(liveGridEntry);
                    break;
            }
        }

        private async Task Liberate_Click(GridEntry liveGridEntry)
        {
            var libraryBook = liveGridEntry.LibraryBook;

            // liberated: open explorer to file
            if (TransitionalFileLocator.Audio_Exists(libraryBook.Book))
            {
                var filePath = TransitionalFileLocator.Audio_GetPath(libraryBook.Book);
                if (!Go.To.File(filePath))
                    MessageBox.Show($"File not found:\r\n{filePath}");
                return;
            }

            // else: liberate
            await BookLiberation.ProcessorAutomationController.BackupSingleBookAsync(libraryBook, (_, __) => RefreshRow(libraryBook.Book.AudibleProductId));
        }

        private void EditTags_Click(GridEntry liveGridEntry)
        {
            var bookDetailsForm = new BookDetailsDialog(liveGridEntry.Title, liveGridEntry.Tags);
            if (bookDetailsForm.ShowDialog() != DialogResult.OK)
                return;

            var qtyChanges = LibraryCommands.UpdateTags(liveGridEntry.LibraryBook.Book, bookDetailsForm.NewTags);
            if (qtyChanges == 0)
                return;

            //Re-apply filters
            Filter();
        }

        #endregion

        #region UI display functions

		private bool hasBeenDisplayed = false;
        public void Display()
        {
            if (hasBeenDisplayed)
                return;
            hasBeenDisplayed = true;

            //
            // transform into sorted GridEntry.s BEFORE binding
            //
            using var context = DbContexts.GetContext();
            var lib = context.GetLibrary_Flat_NoTracking();

            // if no data. hide all columns. return
            if (!lib.Any())
            {
                for (var i = _dataGridView.ColumnCount - 1; i >= 0; i--)
                    _dataGridView.Columns.RemoveAt(i);
                return;
            }

            var orderedGridEntries = lib
                .Select(lb => new GridEntry(lb)).ToList()
                // default load order
                .OrderByDescending(ge => ge.PurchaseDate)
                //// more advanced example: sort by author, then series, then title
                //.OrderBy(ge => ge.Authors)
                //    .ThenBy(ge => ge.Series)
                //    .ThenBy(ge => ge.Title)
                .ToList();

            //
            // BIND
            //
            gridEntryBindingSource.DataSource = new SortableBindingList2<GridEntry>(orderedGridEntries);

            //
            // FILTER
            //
            Filter();

            BackupCountsChanged?.Invoke(this, EventArgs.Empty);
        }

        public void RefreshRow(string productId)
        {
            var rowId = getRowIndex((ge) => ge.AudibleProductId == productId);

            // update cells incl Liberate button text
            _dataGridView.InvalidateRow(rowId);

            // needed in case filtering by -IsLiberated and it gets changed to Liberated. want to immediately show the change
            Filter();

            BackupCountsChanged?.Invoke(this, EventArgs.Empty);
        }

        #region format text cells. ie: not buttons

        private void HiddenFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            var dgv = (DataGridView)sender;
            // no action needed for buttons
            if (e.RowIndex < 0 || dgv.Columns[e.ColumnIndex] is DataGridViewButtonColumn)
                return;

            var isHidden = getGridEntry(e.RowIndex).TagsEnumerated.Contains("hidden");

            getCell(e).Style
                = isHidden
                ? new DataGridViewCellStyle { ForeColor = Color.LightGray }
                : dgv.DefaultCellStyle;
        }

        #endregion

        #endregion

        #region filter

        string _filterSearchString;
        private void Filter() => Filter(_filterSearchString);
        public void Filter(string searchString)
        {
            _filterSearchString = searchString;

			if (_dataGridView.Rows.Count == 0)
				return;

            var searchResults = SearchEngineCommands.Search(searchString);
            var productIds = searchResults.Docs.Select(d => d.ProductId).ToList();

            // https://stackoverflow.com/a/18942430
            var currencyManager = (CurrencyManager)BindingContext[_dataGridView.DataSource];
            currencyManager.SuspendBinding();
            {
                for (var r = _dataGridView.RowCount - 1; r >= 0; r--)
                    _dataGridView.Rows[r].Visible = productIds.Contains(getGridEntry(r).AudibleProductId);
            }

            //Causes repainting of the DataGridView
            currencyManager.ResumeBinding();
			VisibleCountChanged?.Invoke(this, _dataGridView.AsEnumerable().Count(r => r.Visible));
        }

        #endregion

        #region DataGridView Macros

        private int getRowIndex(Func<GridEntry, bool> func) => _dataGridView.GetRowIdOfBoundItem(func);
        private GridEntry getGridEntry(int rowIndex) => _dataGridView.GetBoundItem<GridEntry>(rowIndex);
        private DataGridViewCell getCell(DataGridViewCellFormattingEventArgs e) => _dataGridView.Rows[e.RowIndex].Cells[e.ColumnIndex];

        #endregion
    }
}