using System;
using System.ComponentModel;
using Vintasoft.Imaging;
using Vintasoft.Imaging.Codecs.ImageFiles.Tiff;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                // create new image
                using (VintasoftImage image = new VintasoftImage(100, 100))
                {
                    // save image as a TIFF file
                    image.Save("test.tif");
                }
            }
            catch (TypeInitializationException ex)
            {
                if (ex.InnerException is LicenseException)
                {
                    Console.WriteLine(ex.InnerException.Message);
                    return;
                }
                throw ex;
            }

            // add GPS tags to the TIFF file
            WriteGpsTags("test.tif", 0);

            Console.WriteLine("Press any key...");
            Console.ReadKey();
        }

        /// <summary>
        /// Writes the GPS tags into existing TIFF file.
        /// </summary>
        /// <param name="filePath">The file path.</param>
        /// <param name="pageIndex">Index of the page.</param>
        private static void WriteGpsTags(string filePath, int pageIndex)
        {
            using (TiffFile tiffFile = new TiffFile(filePath))
            {
                // get the page
                TiffPage page = tiffFile.Pages[pageIndex];
                // find existing GPS image file directory tag
                TiffTag gpsIfdTag = page.IFD.Tags.Find(TiffTagId.GpsIFD);
                // GPS image file directory
                TiffImageFileDirectory gpsIfd;
                // if file doesn't have GPS metadata
                if (gpsIfdTag == null)
                {
                    // create GPS image file directory
                    gpsIfd = new TiffImageFileDirectory();

                    // add necessary tags

                    TiffTagCollection gpsTags = gpsIfd.Tags;
                    gpsTags.Add((ushort)ExifGpsTagId.GPSVersionID, new byte[] { 3, 2, 0, 0 });
                    gpsTags.Add((ushort)ExifGpsTagId.GPSLatitudeRef, "N");
                    gpsTags.Add((ushort)ExifGpsTagId.GPSLatitude, GetLatitudeOrLongitude(34.385090));
                    gpsTags.Add((ushort)ExifGpsTagId.GPSLongitudeRef, "W");
                    gpsTags.Add((ushort)ExifGpsTagId.GPSLongitude, GetLatitudeOrLongitude(118.940933));
                    gpsTags.Add((ushort)ExifGpsTagId.GPSAltitudeRef, (byte)0);
                    gpsTags.Add((ushort)ExifGpsTagId.GPSAltitude, new TiffRational(14838, 100));
                    gpsTags.Add((ushort)ExifGpsTagId.GPSMapDatum, "WGS-84");

                    // add GPS image file directory
                    page.IFD.Tags.Add(TiffTagId.GpsIFD, gpsIfd);
                }
                else
                {
                    gpsIfd = (TiffImageFileDirectory)gpsIfdTag.Data;

                    // set data of existing tags and add missing tags the same way as above
                }
                tiffFile.SaveChanges();
            }
        }

        /// <summary>
        /// Gets the specified latitude or longitude value in degrees
        /// as corresponding TIFF tag data.
        /// </summary>
        /// <param name="degrees">The value of latitude or longitude value degrees.</param>
        /// <returns>
        /// An array of TIFF RATIONAL containing encoded value,
        /// rounded off to whole seconds.
        /// </returns>
        private static TiffRational[] GetLatitudeOrLongitude(double degrees)
        {
            TiffRational[] result = new TiffRational[3];

            double wholeDegrees = Math.Floor(degrees);
            result[0] = new TiffRational((uint)wholeDegrees, 1);

            double remainingMinutes = (degrees - wholeDegrees) * 60;
            double wholeMinutes = Math.Floor(remainingMinutes);
            result[1] = new TiffRational((uint)wholeMinutes, 1);

            double remainingSeconds = (remainingMinutes - wholeMinutes) * 60;
            double wholeSeconds = Math.Floor(remainingSeconds);
            result[2] = new TiffRational((uint)wholeSeconds, 1);

            return result;
        }

    }
}