using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text.RegularExpressions;

namespace AniNIX.Shared {

    public static class WebPageAPI {

        // Thanks to MSDN for this regex.
        // https://msdn.microsoft.com/en-us/library/ms998267.aspx
        public static Regex URLRegEx = new Regex(@"(ht|f)tp(s?)\:\/\/[0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*(:(0-9)*)*(\/?)([a-zA-Z0-9\-\.\?\,\'\/\\\+&%\$#_]*)?"); 

        /// <summary>
        /// Get a webpage source -- we use this instead of WebClient because Mono doesn't handle SSL well on Linux.
        /// /usr/bin/curl -s SOMEURL
        /// </summary>
        /// <param name="pageURL"> the webpage whose title we should get</param>
        /// <returns> the webpage source </returns>
        public static string GetPage(String pageURL) {
            return ExecuteCommand.Run(String.Format("/usr/bin/curl -s --max-time 5 {0}",pageURL));
        }

        /// <summary>
        /// Get a webpage title
        /// Should be equivalent to: 
        /// /bin/bash -c '/usr/bin/curl -s SOMEURL | perl -l -0777 -ne "print \$1 if /<title.*?>\s*(.*?)\s*<\/title/si"'
        /// </summary>
        /// <param name="pageURL"> the webpage whose title we should get</param>
        /// <returns> the webpage title </returns>
        public static string GetPageTitle(String pageURL) {
            string source = GetPage(pageURL);
            return Regex.Match(source, @"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups["Title"].Value;
        }

    }
}