MultimediaItem.cs

using System;
using System.IO;
using System.Xml;
using Waher.Content.Emoji;
 
namespace Waher.Content.Markdown.Model
{
    public class MultimediaItem : IImageSource
    {
        private readonly MarkdownDocument doc;
        private readonly string url;
        private readonly string title;
        private string extension;
        private string contentType;
        private readonly int? width;
        private readonly int? height;
 
        public MultimediaItem(MarkdownDocument Doc, string Url, string Title, int? Width, int? Height)
        {
            this.doc = Doc;
            this.url = Url;
            this.title = Title;
            this.width = Width;
            this.height = Height;
        }
 
        public MarkdownDocument Document => this.doc;
 
        public string Url => this.url;
 
        public string Title => this.title;
 
        public int? Width => this.width;
 
        public int? Height => this.height;
 
        public string Extension
        {
            get
            {
                if (this.extension is null)
                {
                    int i = this.url.IndexOfAny(questionOrHash);
                    if (i > 0)
                    {
                        this.extension = Path.GetExtension(this.url.Substring(0, i));
 
                        if (string.IsNullOrEmpty(this.extension))
                        {
                            int j = this.url.IndexOf('?', i + 1);
                            if (j > i)
                                this.extension = Path.GetExtension(this.url.Substring(0, j));
                            else
                                this.extension = Path.GetExtension(this.url);
                        }
                    }
                    else
                        this.extension = Path.GetExtension(this.url);
                }
 
                return this.extension;
            }
        }
 
        private static readonly char[] questionOrHash = new char[] { '?', '#' };
 
        public string ContentType
        {
            get
            {
                if (this.contentType is null)
                    this.contentType = InternetContent.GetContentType(this.Extension);
 
                return this.contentType;
            }
        }
 
        public void Export(XmlWriter Output)
        {
            Output.WriteStartElement("MultimediaItem");
            Output.WriteAttributeString("url", this.url);
            Output.WriteAttributeString("title", this.title);
            Output.WriteAttributeString("extension", this.extension);
            Output.WriteAttributeString("contentType", this.contentType);
 
            if (this.width.HasValue)
                Output.WriteAttributeString("width", this.width.Value.ToString());
 
            if (this.height.HasValue)
                Output.WriteAttributeString("height", this.height.Value.ToString());
 
            Output.WriteEndElement();
        }
 
        public override bool Equals(object obj)
        {
            return obj is MultimediaItem Obj &&
                this.url == Obj.url &&
                this.title == Obj.title &&
                this.extension == Obj.extension &&
                this.contentType == Obj.contentType &&
                this.width == Obj.width &&
                this.height == Obj.height;
        }
 
        public override int GetHashCode()
        {
            int h1 = this.url?.GetHashCode() ?? 0;
            int h2 = this.title?.GetHashCode() ?? 0;
 
            h1 = ((h1 << 5) + h1) ^ h2;
 
            h2 = this.extension?.GetHashCode() ?? 0;
            h1 = ((h1 << 5) + h1) ^ h2;
 
            h2 = this.contentType?.GetHashCode() ?? 0;
            h1 = ((h1 << 5) + h1) ^ h2;
 
            h2 = this.width?.GetHashCode() ?? 0;
            h1 = ((h1 << 5) + h1) ^ h2;
 
            h2 = this.height?.GetHashCode() ?? 0;
            h1 = ((h1 << 5) + h1) ^ h2;
 
            return h1;
        }
 
    }
}