using System;
using System.Linq;
using System.Collections.Generic;
using SwissAcademic.Citavi;
using SwissAcademic.Citavi.Metadata;
using SwissAcademic.Collections;
using SwissAcademic.Drawing;

namespace SwissAcademic.Citavi.Citations
{
   public class ComponentPartFilter
      :
      IComponentPartFilter
   {
      public IEnumerable<ITextUnit> GetTextUnits(ComponentPart componentPart, Template template, Citation citation, out bool handled)
      {
		handled = false;
		
		//ComponentPartFilter - SuppressURIParts V1.0.cs
		
		//EXAMPLE
		//http://www.url.de/path1/path2/path3/page.html
		
		var suppressHTTP = false;		//true: www.url.de/path1/path2/path3/page.html
		var suppressWWW = false;			//true: url.de/path1/path2/path3/page.html
		var suppressPath = true;		//true: url.de
		

		
		
		if (componentPart == null) return null;
		if (citation == null || citation.Reference == null) return null;

		var onlineAddress = citation.Reference.OnlineAddress;
		if (string.IsNullOrEmpty(onlineAddress)) return null;

		var onlineAddressFieldElement = componentPart.GetFieldElements().FirstOrDefault(fieldElement => fieldElement.PropertyId == ReferencePropertyId.OnlineAddress);
		if (onlineAddressFieldElement == null) return null;

		var onlineAddressUri = new Uri(onlineAddress);
		if (onlineAddressUri == null) return null;


		var scheme = onlineAddressUri.Scheme;										//EXAMPLE: http
		var path = onlineAddressUri.PathAndQuery;									//EXAMPLE: /path1/path2/path3/page.html
		var host = onlineAddressUri.Host;											//EXAMPLE:	www.url.de
		var hostWithoutWWW = string.Empty;

	
		
		var hostParts = onlineAddressUri.Host.Split('.');
		if (hostParts.Count() > 0 && hostParts[0].Equals("www", StringComparison.OrdinalIgnoreCase))
		{
		    hostWithoutWWW = String.Join(".", hostParts.Where((x, index) => index > 0));	//EXAMPLE: url.de
		}
		else if (hostParts.Count() > 0)
		{
		    hostWithoutWWW = String.Join(".", hostParts);		
		}
		
		if (suppressHTTP) scheme = string.Empty;
		if (!string.IsNullOrEmpty(scheme)) scheme = scheme + "://";
		
		if (suppressWWW) host = hostWithoutWWW;
		if (suppressPath) path = string.Empty;
		
		var result = scheme + host + path;
		
		
		if (string.IsNullOrEmpty(result)) return null;

		var hostNameLiteralElement = new LiteralElement(componentPart, result);
		componentPart.Elements.ReplaceItem(onlineAddressFieldElement, hostNameLiteralElement);

		
		
		
		//all literal elements should always be output:
		foreach(LiteralElement literalElement in componentPart.Elements.OfType<LiteralElement>())
		{
			literalElement.ApplyCondition = ElementApplyCondition.Always;
		}

		return null;
         
      }
   }
}