using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.WPF;
using Syncfusion.Pdf;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace PRSDesktop
{
    public class ScanGrid : DynamicDataGrid<Scan>
    {
        private List<ScanTag>? _tags;
        private Button? ExplodeBtn;

        public delegate void SelectAppliesTo(string appliesTo);
        public event SelectAppliesTo? OnSelectAppliesTo;

        public ScanGrid()
        {
            Options.BeginUpdate()
                .Clear()
                .Add(DynamicGridOption.MultiSelect)
                .Add(DynamicGridOption.DragSource)
                .Add(DynamicGridOption.SelectColumns)
                .EndUpdate();

            if (Security.CanEdit<Scan>() || Security.IsAllowed<CanSetupScanTags>())
            {
                ActionColumns.Add(new DynamicMenuColumn(MenuBuild, null));
            }
            
            // if (Security.CanEdit<Scan>())
            // {
            //     ExplodeBtn = AddButton("Explode", null, Explode_Click);
            // }
            

            HiddenColumns.Add(x => x.Tag.ID);
            HiddenColumns.Add(x => x.Tag.AppliesTo);
            HiddenColumns.Add(x => x.Document.ID);
        }

        protected override void SelectItems(CoreRow[]? rows)
        {
            base.SelectItems(rows);

            if(ExplodeBtn is not null)
            {
                ExplodeBtn.Visibility = rows is not null && rows.Any() ? Visibility.Visible : Visibility.Collapsed;
            }
        }

        public void DoExplode()
        {
            if (DoExplode(SelectedRows))
                Refresh(false,true);
        }

        private bool Explode_Click(Button button, CoreRow[] rows)
        {
            return DoExplode(rows);
        }

        private bool DoExplode(CoreRow[] rows)
        {
            Guid tagID = Guid.Empty;
            foreach (var row in rows)
            {
                var rowTag = row.Get<Scan, Guid>(x => x.Tag.ID);
                if (tagID == Guid.Empty)
                {
                    tagID = rowTag;
                }
                else if (rowTag != tagID)
                {
                    tagID = Guid.Empty;
                    break;
                }
            }

            var docIDs = rows.Select(x => x.Get<Scan, Guid>(x => x.Document.ID)).ToArray();
            var docs = new Client<Document>()
                .Query(
                    new Filter<Document>(x => x.ID).InList(docIDs),
                    new Columns<Document>(x => x.ID).Add(x => x.Data).Add(x => x.FileName))
                .ToObjects<Document>().ToDictionary(x => x.ID, x => x);

            var pages = new List<DocumentManipulationWindow.Page>();
            string filename = "";
            foreach (var docID in docIDs)
            {
                if (docs.TryGetValue(docID, out var doc))
                {
                    filename = doc.FileName;
                    var ms = new MemoryStream(doc.Data);
                    var pdfDoc = DocumentManipulationWindow.RenderToPDF(doc.FileName, ms);
                    foreach (var page in DocumentManipulationWindow.SplitIntoPages(doc.FileName, pdfDoc))
                    {
                        pages.Add(page);
                    }
                }
            }

            if (ShowDocumentWindow(pages, filename, tagID))
            {
                // ShowDocumentWindow already saves new scans, so we just need to get rid of the old ones.
                DeleteItems(rows);
                return true;
            }

            return false;
        }

        private bool SetupTags_Click(System.Windows.Controls.Button button, CoreRow[] rows)
        {
            var list = new MasterList(typeof(ScanTag));
            if (list.ShowDialog() == true)
                return true;
            return false;
        }

        public static List<ScanTag> GetVisibleScanTagList()
        {
            var tags = new Client<ScanTag>().Query().ToObjects<ScanTag>().ToList();

            var tagsList = new List<ScanTag>();
            foreach (var tag in tags)
            {
                var entity = CoreUtils.GetEntityOrNull(tag.AppliesTo);
                if (entity is null || Security.CanView(entity))
                {
                    var tagHasEmployee = new Client<ScanTagDistributionEmployee>()
                        .Query(
                            new Filter<ScanTagDistributionEmployee>(x => x.Tag.ID).IsEqualTo(tag.ID)
                                .And(x => x.Employee.ID).IsEqualTo(App.EmployeeID),
                            new Columns<ScanTagDistributionEmployee>(x => x.ID))
                        .Rows.Any();
                    if (tagHasEmployee)
                    {
                        tagsList.Add(tag);
                    }
                }
            }
            return tagsList;
        }

        private List<ScanTag> GetVisibleTags()
        {
            _tags ??= GetVisibleScanTagList();
            return _tags;
        }

        private void MenuBuild(DynamicMenuColumn column, CoreRow? row)
        {
            if (row is null) return;

            if (Security.CanEdit<Scan>() || Security.IsAllowed<CanSetupScanTags>())
            {
                var changeTag = column.AddItem("Change Tag", null, null);
                changeTag.AddItem("(No Tag)", null, new Tuple<CoreRow, ScanTag?>(row, null), SetTag_Click);
                foreach (var tag in GetVisibleTags())
                {
                    changeTag.AddItem(tag.Name, null, new Tuple<CoreRow, ScanTag?>(row, tag), SetTag_Click);
                }
            }
            if (Security.CanEdit<Scan>())
            {
                var processed = row.Get<Scan, bool>(x => x.Processed);
                column.AddItem(processed ? "Mark as not processed" : "Mark as processed", null, Process_Click);
            }
            if(OnSelectAppliesTo is not null)
            {
                column.AddItem("Go to Document", null, Document_Click);
            }
        }

        private void Document_Click(CoreRow? row)
        {
            if (row is null) return;

            OnSelectAppliesTo?.Invoke(row.Get<Scan, string>(x => x.Tag.AppliesTo));
        }

        private void SetTag_Click(Tuple<CoreRow, ScanTag?> obj)
        {
            var scan = obj.Item1.ToObject<Scan>();
            scan.Tag.ID = obj.Item2?.ID ?? Guid.Empty;
            SaveItem(scan);
            Refresh(false, true);
        }

        private void Process_Click(CoreRow? row)
        {
            if (row is null) return;

            var scan = row.ToObject<Scan>();

            if (!scan.Processed && MessageBox.Show("Doing this will remove this scan from the list. Do you wish to continue?", "Confirm", MessageBoxButton.YesNo) != MessageBoxResult.Yes)
            {
                return;
            }

            scan.Processed = !scan.Processed;
            SaveItem(scan);
            Refresh(false, true);
        }

        protected override void OnRowsDragStart(CoreRow[] rows)
        {
            var table = new CoreTable();

            table.Columns.Add(new CoreColumn { ColumnName = "ID", DataType = typeof(Guid) });
            foreach(var row in rows)
            {
                var newRow = table.NewRow();
                newRow.Set<Document, Guid>(x => x.ID, row.Get<Scan, Guid>(x => x.Document.ID));
                table.Rows.Add(newRow);
            }

            DragTable(typeof(Document), table);
        }

        public void UploadDocument(string filename, byte[] data, Guid tagID)
        {
            var document = new Document
            {
                FileName = filename,
                CRC = CoreUtils.CalculateCRC(data),
                TimeStamp = DateTime.Now,
                Data = data
            };

            new Client<Document>().Save(document, "");

            var scan = new Scan();
            scan.Document.ID = document.ID;
            scan.Tag.ID = tagID;
            scan.Employee.ID = App.EmployeeID;
            scan.Thumbnail = ImageUtils.GetPDFThumbnail(data, 256, 256);
            new Client<Scan>().Save(scan, "");

            Dispatcher.Invoke(() =>
            {
                Refresh(false, true);
            });
        }

        private static PdfDocumentBase CombinePages(IEnumerable<DocumentManipulationWindow.Page> pages)
        {
            var document = new PdfDocument();
            foreach (var page in pages)
            {
                document.ImportPage(page.Pdf, page.PageIndex);
            }
            return document;
        }

        public bool ShowDocumentWindow(List<DocumentManipulationWindow.Page> pages, string filename, Guid tagID)
        {
            var window = new DocumentManipulationWindow(pages, filename, tagID);
            if (window.ShowDialog() == true)
            {
                Progress.ShowModal("Uploading Files", (progress) =>
                {
                    foreach (var group in window.Groups)
                    {
                        progress.Report($"Uploading '{group.FileName}'");
                        var doc = CombinePages(group.Pages);

                        byte[] data;
                        using (var ms = new MemoryStream())
                        {
                            doc.Save(ms);
                            data = ms.ToArray();
                        }

                        UploadDocument(group.FileName, data, group.TagID);
                    }
                });
                return true;
            }
            return false;
        }

        protected override void DoAdd(bool OpenEditorOnDirectEdit = false)
        {
            ShowDocumentWindow(new(), "", Guid.Empty);
        }

        protected override void GenerateColumns(DynamicGridColumns columns)
        {
            columns.Add<Scan, string>(x => x.Document.FileName, 0, "Filename", "", InABox.Core.Alignment.MiddleLeft);
            columns.Add<Scan, string>(x => x.Tag.Name, 100, "Tag", "", InABox.Core.Alignment.MiddleLeft);
        }

        protected override void Reload(Filters<Scan> criteria, Columns<Scan> columns, ref SortOrder<Scan>? sort, Action<CoreTable?, Exception?> action)
        {
            criteria.Add(new Filter<Scan>(x => x.Processed).IsEqualTo(false));

            var tagFilter = new Filter<Scan>(x => x.Tag.ID).InList(GetVisibleTags().Select(x => x.ID).ToArray());
            if (Security.IsAllowed<CanSetupScanTags>())
            {
                tagFilter.Or(x => x.Tag.ID).IsEqualTo(Guid.Empty);
            }

            criteria.Add(tagFilter);
            base.Reload(criteria, columns, ref sort, action);
        }
    }
}