//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.IO;

namespace Spludlow.Html
{
	/// <summary>
	/// Some simple that helpers for HtmlAgilityPack
	/// that do the HTTP Get also
	/// Can be handy for automating downloads from web pages
	/// </summary>
	public class Web
	{
		public static string UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36";

		public static string[] DownloadLinks(string url)
		{
			return DownloadLinks(url, null, url);
		}

		public static string[] DownloadLinks(string url, string referer)
		{
			return DownloadLinks(url, referer, url);
		}

		public static string[] DownloadLinks(string url, string referer, string absoluteUrl)
		{
			string html = Spludlow.Net.Http.GetText(url, null, null, referer, UserAgent);

			return Spludlow.Html.Parse.ExtractLinks(html, absoluteUrl);
		}

		public static string[] DownloadImageLinks(string url)
		{
			return DownloadImageLinks(url, null, url);
		}

		public static string[] DownloadImageLinks(string url, string referer)
		{
			return DownloadImageLinks(url, referer, url);
		}

		public static string[] DownloadImageLinks(string url, string referer, string absoluteUrl)
		{
			string html = Spludlow.Net.Http.GetText(url, null, null, referer, UserAgent);
			return Spludlow.Html.Parse.ExtractImages(html, absoluteUrl);
		}

		public static string[] DownloadLinksFilter(string url, string referer, string filter)
		{
			string[] completeLinks = DownloadLinks(url, referer);

			if (filter == null)
				return completeLinks;

			string[] filters = Spludlow.Text.Split(filter, ',', true, false);

			List<string> links = new List<string>();
			foreach (string link in completeLinks)
			{
				string lowLink = link.ToLower();
				foreach (string filterWord in filters)
				{
					if (lowLink.Contains(filterWord) == true)
					{
						links.Add(link);
						break;
					}
				}
			}

			return links.ToArray();
		}

		public static string[] DownloadFiles(string url, string referer, string directory, string filter)
		{
			string[] links = DownloadLinksFilter(url, referer, filter);
			return DownloadFiles(links, url, directory);
		}

		public static string[] DownloadFiles(string[] links, string referer, string directory)
		{
			List<string> result = new List<string>();

			foreach (string link in links)
			{
				string filename = directory + @"\" + GetFilename(link);
				filename = Spludlow.Io.Files.UniqueExistingName(filename);

				if (link.StartsWith("http") == true)
				{
					try
					{
						Spludlow.Net.Http.GetDataFile(link, filename, null, null, referer, UserAgent, false);
						result.Add(link);
					}
					catch (Exception ee)
					{
						Spludlow.Log.Warning("Spludlow.Html.Web; Download File Error:\t" + link, ee);
					}
				}
			}

			return result.ToArray();
		}

		public static string GetFilename(string url)
		{
			string name = Path.GetFileName(url);
			if (name == "")
				name = Path.GetDirectoryName(url);
			return Spludlow.Io.Paths.LegalFileName(name);
		}
	}
}