using System.Collections.Generic;
using Markdig.Renderers;
using Markdig.Renderers.Html;
using Markdig.Renderers.Html.Inlines;
using Markdig.Syntax.Inlines;

namespace Website.Markdig.Extensions {
	public class BlogLinkAndImageRenderer : HtmlObjectRenderer<LinkInline> {
		private readonly LinkInlineRenderer _baseRenderer;

		public BlogLinkAndImageRenderer(LinkInlineRenderer baseRenderer) {
			_baseRenderer = baseRenderer;
		}

		private static void RenderChildren(HtmlRenderer renderer, LinkInline link) {
			var wasEnableHtmlForInline = renderer.EnableHtmlForInline;
			renderer.EnableHtmlForInline = false;
			renderer.WriteChildren(link);
			renderer.EnableHtmlForInline = wasEnableHtmlForInline;
		}

		private static void RenderImage(HtmlRenderer renderer, LinkInline link) {
			renderer.Write(@"<div class=""blog-post__image-container--container"">");
			renderer.Write(@"<div class=""blog-post__image-container"">");
			renderer.Write($@"<img src=""{link.Url}"" alt=""");
			RenderChildren(renderer, link);
			renderer.Write(@""" class=""blog-post__image-container--image"">");
			renderer.Write(@"<span class=""blog-post__image-container--tagline"">");
			RenderChildren(renderer, link);
			renderer.Write(@"</span>");
			renderer.Write(@"</div>");
			renderer.Write(@"</div>");
		}

		private void RenderLink(HtmlRenderer renderer, LinkInline link) {
			if (link.Url.StartsWith("http") || link.Url.StartsWith("//")) {
				var htmlAttributes = link.GetAttributes();
				if (htmlAttributes.Properties == null)
					htmlAttributes.Properties = new List<KeyValuePair<string, string>>();
				htmlAttributes.Properties.Add(new KeyValuePair<string, string>("target", "_blank"));
			}
			_baseRenderer.Write(renderer, link);
		}

		protected override void Write(HtmlRenderer renderer, LinkInline link) {
			link.Url = link.GetDynamicUrl != null ? link.GetDynamicUrl() ?? link.Url : link.Url;

			if (link.IsImage)
				RenderImage(renderer, link);
			else
				RenderLink(renderer, link);
		}
	}
}