using MediaBrowser.Controller.Drawing;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Logging;
using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using TagLib;
using TagLib.IFD;
using TagLib.IFD.Entries;
using TagLib.IFD.Tags;

namespace MediaBrowser.Providers.Photos
{
    public class PhotoProvider : ICustomMetadataProvider<Photo>, IHasChangeMonitor
    {
        private readonly ILogger _logger;
        private readonly IImageProcessor _imageProcessor;

        public PhotoProvider(ILogger logger, IImageProcessor imageProcessor)
        {
            _logger = logger;
            _imageProcessor = imageProcessor;
        }

        public Task<ItemUpdateType> FetchAsync(Photo item, MetadataRefreshOptions options, CancellationToken cancellationToken)
        {
            item.SetImagePath(ImageType.Primary, item.Path);
            item.SetImagePath(ImageType.Backdrop, item.Path);

            // Examples: https://github.com/mono/taglib-sharp/blob/a5f6949a53d09ce63ee7495580d6802921a21f14/tests/fixtures/TagLib.Tests.Images/NullOrientationTest.cs

            try
            {
                var file = File.Create(item.Path);

                var image = file as TagLib.Image.File;

                var tag = file.GetTag(TagTypes.TiffIFD) as IFDTag;

                if (tag != null)
                {
                    var structure = tag.Structure;

                    if (structure != null)
                    {
                        var exif = structure.GetEntry(0, (ushort)IFDEntryTag.ExifIFD) as SubIFDEntry;

                        if (exif != null)
                        {
                            var exifStructure = exif.Structure;

                            if (exifStructure != null)
                            {
                                var entry = exifStructure.GetEntry(0, (ushort)ExifEntryTag.ApertureValue) as RationalIFDEntry;

                                if (entry != null)
                                {
                                    double val = entry.Value.Numerator;
                                    val /= entry.Value.Denominator;
                                    item.Aperture = val;
                                }

                                entry = exifStructure.GetEntry(0, (ushort)ExifEntryTag.ShutterSpeedValue) as RationalIFDEntry;

                                if (entry != null)
                                {
                                    double val = entry.Value.Numerator;
                                    val /= entry.Value.Denominator;
                                    item.ShutterSpeed = val;
                                }
                            }
                        }
                    }
                }

                item.CameraManufacturer = image.ImageTag.Make;
                item.CameraModel = image.ImageTag.Model;

                var rating = image.ImageTag.Rating;
                if (rating.HasValue)
                {
                    item.CommunityRating = rating;
                }
                else
                {
                    item.CommunityRating = null;
                }

                item.Overview = image.ImageTag.Comment;

                if (!string.IsNullOrWhiteSpace(image.ImageTag.Title))
                {
                    item.Name = image.ImageTag.Title;
                }

                var dateTaken = image.ImageTag.DateTime;
                if (dateTaken.HasValue)
                {
                    item.DateCreated = dateTaken.Value;
                    item.PremiereDate = dateTaken.Value;
                    item.ProductionYear = dateTaken.Value.Year;
                }

                var size = _imageProcessor.GetImageSize(item.Path);
                item.Height = Convert.ToInt32(size.Height);
                item.Width = Convert.ToInt32(size.Width);

                item.Genres = image.ImageTag.Genres.ToList();
                item.Tags = image.ImageTag.Keywords.ToList();
                item.Software = image.ImageTag.Software;

                Model.Drawing.ImageOrientation orientation;
                if (Enum.TryParse(image.ImageTag.Orientation.ToString(), true, out orientation))
                {
                    item.Orientation = orientation;
                }

                item.ExposureTime = image.ImageTag.ExposureTime;
                item.FocalLength = image.ImageTag.FocalLength;
            }
            catch (Exception e)
            {
                _logger.ErrorException("Image Provider - Error reading image tag for {0}", e, item.Path);
            }

            const ItemUpdateType result = ItemUpdateType.ImageUpdate | ItemUpdateType.MetadataImport;
            return Task.FromResult(result);
        }

        public string Name
        {
            get { return "Embedded Information"; }
        }

        public bool HasChanged(IHasMetadata item, IDirectoryService directoryService, DateTime date)
        {
            return item.DateModified > date;
        }
    }
}