using System;
using System.Collections.Generic;
using System.Drawing;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;
using Color = DocumentFormat.OpenXml.Spreadsheet.Color;
using Font = DocumentFormat.OpenXml.Spreadsheet.Font;

namespace ImageToSpreadsheet
{
    internal static class Program
    {
        private static void Main(string[] args)
        {
            Console.WriteLine(DateTime.Now);

            var bmp = new Bitmap(args[0]);
            bmp.RotateFlip(RotateFlipType.Rotate270FlipY);

            string xlsPath = args[0] + ".xlsx";
            using (var document = SpreadsheetDocument.Create(xlsPath, SpreadsheetDocumentType.Workbook, true))
            {
                var workbookPart = document.AddWorkbookPart();
                var worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
                var book = new Workbook();
                worksheetPart.Worksheet = new Worksheet();

                // Columns
                var columns = new Columns();
                for (int i = 0; i < bmp.Width; i++)
                {
                    columns.AppendChild(new Column {Min = (uint) i + 1, Max = (uint) i + 1, Width = (1 - 12 + 5) / 7d + 1, CustomWidth = true});
                }
                worksheetPart.Worksheet.AppendChild(columns);

                // Styles
                Dictionary<System.Drawing.Color, uint> colors;
                var stylesPart = workbookPart.AddNewPart<WorkbookStylesPart>();
                stylesPart.Stylesheet = GenerateStyleSheet(bmp, out colors);

                // Bitmap
                var sheetData = worksheetPart.Worksheet.AppendChild(new SheetData());
                for (int i = 0; i < bmp.Height; i++)
                {
                    var row = sheetData.AppendChild(new Row {Height = 1.0, CustomHeight = true});
                    for (int j = 0; j < bmp.Width; j++)
                    {
                        var cell = new Cell {StyleIndex = colors[bmp.GetPixel(i, j)]};
                        row.AppendChild(cell);
                    }
                }

                var sheets = book.AppendChild(new Sheets());
                var sheet = new Sheet
                {
                    Name = "Лист1",
                    SheetId = 1,
                    Id = workbookPart.GetIdOfPart(worksheetPart)
                };
                sheets.AppendChild(sheet);

                document.WorkbookPart.Workbook = book;
                document.WorkbookPart.Workbook.Save();

                workbookPart.Workbook.Save();
            }

            Console.WriteLine(DateTime.Now);
            Console.Read();
        }

        private static Stylesheet GenerateStyleSheet(Bitmap bmp, out Dictionary<System.Drawing.Color, uint> colors)
        {
            var fills = new Fills(
                new Fill(new PatternFill {PatternType = PatternValues.None}),
                new Fill(new PatternFill {PatternType = PatternValues.Gray125}));

            var cellFormats = new CellFormats(new CellFormat {FontId = 0, FillId = 0, BorderId = 0});

            var stylesheet = new Stylesheet(
                new Fonts(
                    new Font(
                        new FontSize {Val = 11},
                        new Color {Rgb = new HexBinaryValue {Value = "000000"}},
                        new FontName {Val = "Calibri"})

                    ),
                fills,
                new Borders(
                    new Border(
                        new LeftBorder() ,
                        new RightBorder(),
                        new TopBorder(),
                        new BottomBorder(),
                        new DiagonalBorder())
                    ),
                cellFormats
                );

            colors = new Dictionary<System.Drawing.Color, uint>();
            var hash = GetColorsSet(bmp);

            uint i = 1;
            foreach (var t in hash)
            {
                fills.AppendChild(
                    new Fill(new PatternFill(new ForegroundColor {Rgb = new HexBinaryValue {Value = ToHex(t)}})
                    {
                        PatternType = PatternValues.Solid
                    }));

                cellFormats.AppendChild(new CellFormat {FontId = 0, FillId = i+1, BorderId = 0, ApplyFont = true});

                colors[t] = i++;
            }

            return stylesheet;
        }

        private static string ToHex(System.Drawing.Color c)
        {
            return c.R.ToString("X2") + c.G.ToString("X2") + c.B.ToString("X2");
        }

        private static IEnumerable<System.Drawing.Color> GetColorsSet(Bitmap bmp)
        {
            var hash = new HashSet<System.Drawing.Color>();

            for (int i = 0; i < bmp.Width; i++)
            {
                for (int j = 0; j < bmp.Height; j++)
                {
                    hash.Add(bmp.GetPixel(i, j));
                }
            }

            return hash;
        }
    }
}