amazfitbiptools/WatchFace.Parser/Utils/ImagesLoader.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using NLog;
using WatchFace.Parser.Attributes;

namespace WatchFace.Parser.Utils
{
    public class ImagesLoader
    {
        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
        private readonly string _imagesDirectory;

        private readonly Dictionary<long, long> _mapping;

        public ImagesLoader(string imagesDirectory)
        {
            Images = new List<Bitmap>();
            _mapping = new Dictionary<long, long>();
            _imagesDirectory = imagesDirectory;
        }

        public List<Bitmap> Images { get; }

        public void Process<T>(T serializable, string path = "")
        {
            if (!string.IsNullOrEmpty(path)) Logger.Trace("Loading images for {0} '{1}'", path, typeof(T).Name);

            long? lastImageIndexValue = null;

            foreach (var kv in ElementsHelper.SortedProperties<T>())
            {
                var id = kv.Key;
                var currentPath = string.IsNullOrEmpty(path)
                    ? id.ToString()
                    : string.Concat(path, '.', id.ToString());

                var propertyInfo = kv.Value;
                var propertyType = propertyInfo.PropertyType;
                dynamic propertyValue = propertyInfo.GetValue(serializable, null);

                var imageIndexAttribute =
                    ElementsHelper.GetCustomAttributeFor<ParameterImageIndexAttribute>(propertyInfo);
                var imagesCountAttribute =
                    ElementsHelper.GetCustomAttributeFor<ParameterImagesCountAttribute>(propertyInfo);

                if (imagesCountAttribute != null && imageIndexAttribute != null)
                    throw new ArgumentException(
                        $"Property {propertyInfo.Name} can't have both ParameterImageIndexAttribute and ParameterImagesCountAttribute"
                    );

                if (propertyType == typeof(long) || propertyType.IsGenericType &&
                    (propertyType.GetGenericTypeDefinition() == typeof(List<>) ||
                     propertyType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                {
                    if (imageIndexAttribute != null)
                    {
                        if (propertyValue == null) continue;
                        long imageIndex = propertyValue;

                        lastImageIndexValue = imageIndex;
                        var mappedIndex = LoadImage(imageIndex);
                        propertyInfo.SetValue(serializable, mappedIndex, null);
                    }
                    else if (imagesCountAttribute != null)
                    {
                        if (lastImageIndexValue == null)
                            throw new ArgumentException(
                                $"Property {propertyInfo.Name} can't be processed becuase ImageIndex isn't present or it is zero"
                            );

                        var imagesCount = propertyType.IsGenericType
                            ? (propertyType.GetGenericTypeDefinition() == typeof(Nullable<>)
                                ? propertyValue.Value
                                : propertyValue.Count)
                            : propertyValue;

                        for (var i = lastImageIndexValue + 1; i < lastImageIndexValue + imagesCount; i++)
                            LoadImage(i.Value);
                    }
                }
                else
                {
                    if (imagesCountAttribute == null && imageIndexAttribute == null)
                    {
                        if (propertyValue != null)
                            Process(propertyValue, currentPath);
                    }
                    else
                    {
                        throw new ArgumentException(
                            $"Property {propertyInfo.Name} with type {propertyType.Name} can't have ParameterImageIndexAttribute or ParameterImagesCountAttribute"
                        );
                    }
                }
            }
        }

        private long LoadImage(long index)
        {
            if (_mapping.ContainsKey(index))
                return _mapping[index];

            var fileName = Path.Combine(_imagesDirectory, $"{index}.png");
            var newImageIndex = Images.Count;
            Images.Add((Bitmap) Image.FromFile(fileName));
            _mapping[index] = newImageIndex;
            return newImageIndex;
        }
    }
}