using Comal.Classes;
using InABox.Core;
using InABox.WPF;
using Microsoft.Office.Interop.Outlook;
using Motorola.Snapi.Attributes;
using PRSDesktop.Panels.DataEntry;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Parsing;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
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 DocumentPage = PRSDesktop.Panels.DataEntry.DocumentPage;
using Exception = System.Exception;
using Image = System.Windows.Controls.Image;

namespace PRSDesktop
{
    namespace Panels.DataEntry
    {
        public class DocumentGroup
        {
            public string FileName { get; set; }

            public List<DocumentManipulationWindow.Page> Pages { get; set; }

            public Guid TagID { get; set; }

            public DocumentGroup(string fileName, List<DocumentManipulationWindow.Page> pages, Guid tagID)
            {
                FileName = fileName;
                Pages = pages;
                TagID = tagID;
            }
        }
    }


    /// <summary>
    /// Interaction logic for DocumentManipulationWindow.xaml
    /// </summary>
    public partial class DocumentManipulationWindow : Window
    {
        public List<Page> Pages { get; set; }
        public ObservableCollection<DocumentGroup> Groups { get; set; }

        private ScanTag? SelectedTag => TagBox.SelectedItem as ScanTag;

        public class Page
        {
            public string FileName { get; set; }

            public PdfLoadedDocument Pdf { get; set; }

            public int PageIndex { get; set; }

            public BitmapImage? Thumbnail { get; set; }

            public Page(string fileName, PdfLoadedDocument pdf, int pageIndex)
            {
                FileName = fileName;
                Pdf = pdf;
                PageIndex = pageIndex;
            }
        }

        public DocumentManipulationWindow(List<Page> pages, string filename, Guid tagID)
        {
            InitializeComponent();

            Groups = new();
            GroupName.Text = Path.ChangeExtension(filename, ".pdf");
            Pages = pages;
            ReloadPages();

            var tags = ScanGrid.GetVisibleScanTagList();
            TagBox.ItemsSource = tags;
            if (tagID != Guid.Empty)
            {
                TagBox.SelectedItem = tags.FirstOrDefault(x => x.ID == tagID);
            }
            TagBox.DisplayMemberPath = "Name";
        }

        private void ReloadPages()
        {
            Documents.Children.Clear();
            foreach (var page in Pages)
            {
                page.Thumbnail ??= page.Pdf.AsLoadedDocument().ExportAsImage(page.PageIndex).AsBitmapImage(false);

                var width = page.Thumbnail.Width;
                var height = page.Thumbnail.Height;

                var aspectRatio = width / height;

                if(height > 300)
                {
                    height = 300;
                    width = aspectRatio * height;
                }
                if(width > 300)
                {
                    width = 300;
                    height = width / aspectRatio;
                }

                var docPage = new DocumentPage(page) { Height = height, Margin = new Thickness(5) };
                docPage.OnSelected += DocPage_OnSelected;

                Documents.Children.Add(docPage);
            }
        }

        private void DocPage_OnSelected(DocumentPage page, bool selected)
        {
            Group.IsEnabled = Documents.Children.Cast<DocumentPage>().Any(x => x.Selected);
        }

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

        private void OK_Click(object sender, RoutedEventArgs e)
        {
            if (Pages.Any())
            {
                if (string.IsNullOrWhiteSpace(GroupName.Text))
                {
                    MessageBox.Show("You still have ungrouped pages. Please group them into a document and try again.");
                    return;
                }
                else
                {
                    var filename = Path.ChangeExtension(GroupName.Text, ".pdf");
                    if(MessageBox.Show($"You still have ungrouped pages. Do you wish to combine them into a document called \"{filename}\"?", "Combine remaining?", MessageBoxButton.YesNo) == MessageBoxResult.Yes)
                    {
                        var group = new DocumentGroup(filename, Pages.ToList(), SelectedTag?.ID ?? Guid.Empty);
                        Pages.Clear();
                        Groups.Add(group);
                    }
                    else
                    {
                        MessageBox.Show("Please group the remaining pages into a document and try again.");
                        return;
                    }
                }
            }

            DialogResult = true;
        }

        #region Grouping

        private void Group_Click(object sender, RoutedEventArgs e)
        {
            var filename = Path.ChangeExtension(GroupName.Text, ".pdf");
            if (string.IsNullOrWhiteSpace(filename))
            {
                MessageBox.Show("Please specify a document name!");
                GroupName.Focus();
                return;
            }

            var selected = Documents.Children.Cast<DocumentPage>().Where(x => x.Selected).ToList();
            foreach(var page in selected)
            {
                Documents.Children.Remove(page);
                Pages.Remove(page.Page);
            }
            var group = new DocumentGroup(filename, selected.Select(x => x.Page).ToList(), SelectedTag?.ID ?? Guid.Empty);
            Groups.Add(group);
            GroupList.ItemsSource = Groups;
            GroupName.Text = "";
            Group.IsEnabled = false;
        }

        private void Ungroup_Click(object sender, RoutedEventArgs e)
        {
            if ((sender as MenuItem)?.Tag is not DocumentGroup group) return;

            foreach(var page in group.Pages)
            {
                Pages.Add(page);
            }
            Groups.Remove(group);
            GroupList.ItemsSource = Groups;
            ReloadPages();
        }

        #endregion

        #region Drag & Drop

        private static bool TryRenderPDF(Stream stream, [NotNullWhen(true)] out PdfDocumentBase? doc)
        {
            try
            {
                doc = new PdfLoadedDocument(stream);
                return true;
            }
            catch (Exception)
            {
            }
            doc = null;
            return false;
        }
        private static bool TryRenderImage(Stream stream, [NotNullWhen(true)] out PdfDocumentBase? doc)
        {
            try
            {
                var image = new PdfBitmap(stream);

                var pdfDoc = new PdfDocument();

                var section = pdfDoc.Sections.Add();
                section.PageSettings.Margins.All = 0;
                section.PageSettings.Width = image.Width;
                section.PageSettings.Height = image.Height;

                var page = section.Pages.Add();
                page.Graphics.DrawImage(image, 0, 0, page.Size.Width, page.Size.Height);

                doc = pdfDoc;
                return true;
            }
            catch(Exception)
            {
            }
            doc = null;
            return false;
        }
        private static bool TryRenderText(Stream stream, [NotNullWhen(true)] out PdfDocumentBase? doc)
        {
            try
            {
                var bytes = new byte[stream.Length];
                stream.Read(bytes, 0, bytes.Length);
                var text = Encoding.UTF8.GetString(bytes);

                var pdfDoc = new PdfDocument();
                var page = pdfDoc.Pages.Add();

                var font = new PdfStandardFont(PdfFontFamily.Courier, 14);
                var textElement = new PdfTextElement(text, font);
                var layoutFormat = new PdfLayoutFormat
                {
                    Layout = PdfLayoutType.Paginate,
                    Break = PdfLayoutBreakType.FitPage
                };

                textElement.Draw(page, new RectangleF(0, 0, page.GetClientSize().Width, page.GetClientSize().Height), layoutFormat);

                doc = pdfDoc;
                return true;
            }
            catch (Exception)
            {
            }
            doc = null;
            return false;
        }

        public static PdfDocumentBase RenderToPDF(string filename, Stream stream)
        {
            var extension = Path.GetExtension(filename).ToLower();
            if (extension == ".pdf")
            {
                if(TryRenderPDF(stream, out var pdf)
                    || TryRenderImage(stream, out pdf)
                    || TryRenderText(stream, out pdf))
                {
                    return pdf;
                }
            }
            else if (extension == ".jpg" || extension == ".jpeg" || extension == ".png" || extension == ".bmp")
            {
                if (TryRenderImage(stream, out var pdf)
                    || TryRenderPDF(stream, out pdf)
                    || TryRenderText(stream, out pdf))
                {
                    return pdf;
                }
            }
            else
            {
                if (TryRenderText(stream, out var pdf)
                    || TryRenderImage(stream, out pdf)
                    || TryRenderPDF(stream, out pdf))
                {
                    return pdf;
                }
            }
            throw new Exception("Could not render file to PDF");
        }

        private static PdfDocumentBase RenderToPDF(string filename)
        {
            using var stream = new FileStream(filename, FileMode.Open);
            return RenderToPDF(filename, stream);
        }

        public static List<Tuple<string, PdfDocumentBase>>? HandleFileDrop(DragEventArgs e)
        {
            var dataObject = new OutlookDataObject(e.Data);

            string? desc = null;
            if (dataObject.GetDataPresent("FileGroupDescriptor")) desc = "FileGroupDescriptor";
            else if (dataObject.GetDataPresent("FileGroupDescriptorW")) desc = "FileGroupDescriptorW";

            if (desc is not null)
            {
                var docs = new List<Tuple<string, PdfDocumentBase>>();
                var filenames = (string[])dataObject.GetData(desc);
                var filestreams = (MemoryStream[])dataObject.GetData("FileContents");
                for (var i = 0; i < filenames.Length; i++)
                {
                    var filename = filenames[i];
                    var filestream = filestreams[i];
                    var doc = RenderToPDF(filename, filestream);
                    docs.Add(new(filename, doc));
                }
                return docs;
            }
            else if (dataObject.GetDataPresent(DataFormats.FileDrop))
            {
                var docs = new List<Tuple<string, PdfDocumentBase>>();
                foreach (var filename in (string[])dataObject.GetData(DataFormats.FileDrop))
                {
                    if (File.Exists(filename))
                    {
                        var doc = RenderToPDF(filename);
                        docs.Add(new(filename, doc));
                    }
                }
                return docs;
            }
            return null;
        }

        public static List<Page> SplitIntoPages(string filename, PdfDocumentBase doc)
        {
            var pages = new List<Page>();
            var loaded = doc.AsLoadedDocument();

            for(int i = 0; i < loaded.PageCount(); ++i)
            {
                pages.Add(new(filename, loaded, i));
            }
            return pages;
        }

        private void Documents_Drop(object sender, DragEventArgs e)
        {
            Task.Run(() =>
            {
                var docs = HandleFileDrop(e);
                if (docs is not null)
                {
                    Dispatcher.Invoke(() =>
                    {
                        var groupName = "";

                        foreach (var (filename, doc) in docs)
                        {
                            groupName = filename;
                            foreach(var page in SplitIntoPages(filename, doc))
                            {
                                Pages.Add(page);
                            }
                        }
                        ReloadPages();
                        if (string.IsNullOrWhiteSpace(GroupName.Text) && !string.IsNullOrWhiteSpace(groupName))
                        {
                            GroupName.Text = Path.ChangeExtension(groupName, ".pdf");
                        }
                    });
                }
            });
        }

        private void Documents_DragOver(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.FileDrop) || e.Data.GetDataPresent("FileGroupDescriptor"))
            {
                e.Effects = DragDropEffects.Copy;
            }
            else
            {
                e.Effects = DragDropEffects.None;
            }
            e.Handled = true;
        }

        #endregion

    }
}