using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Linq;
using System.Collections.Generic;
using RageCoop.Core;
using Lidgren.Network;
using System.Net;
using System.Net.Sockets;

namespace RageCoop.Server
{
    static partial class Util
    {

        public static string DownloadString(string url)
        {
            try
            {
                // TLS only
                ServicePointManager.Expect100Continue = true;
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls13 | SecurityProtocolType.Tls12;
                ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
                
                WebClient client = new();
                return client.DownloadString(url);
            }
            catch
            {
                return "";
            }
        }
        public static (byte, byte[]) GetBytesFromObject(object obj)
        {
            return obj switch
            {
                byte _ => (0x01, BitConverter.GetBytes((byte)obj)),
                short _ => (0x02, BitConverter.GetBytes((short)obj)),
                ushort _ => (0x03, BitConverter.GetBytes((ushort)obj)),
                int _ => (0x04, BitConverter.GetBytes((int)obj)),
                uint _ => (0x05, BitConverter.GetBytes((uint)obj)),
                long _ => (0x06, BitConverter.GetBytes((long)obj)),
                ulong _ => (0x07, BitConverter.GetBytes((ulong)obj)),
                float _ => (0x08, BitConverter.GetBytes((float)obj)),
                bool _ => (0x09, BitConverter.GetBytes((bool)obj)),
                _ => (0x0, null),
            };
        }
        public static List<NetConnection> Exclude(this IEnumerable<NetConnection> connections,NetConnection toExclude)
        {
            return new(connections.Where(e => e != toExclude));
        }
        
        public static T Read<T>(string file) where T : new()
        {
            XmlSerializer ser = new(typeof(T));

            XmlWriterSettings settings = new()
            {
                Indent = true,
                IndentChars = ("\t"),
                OmitXmlDeclaration = true
            };

            string path = AppContext.BaseDirectory + file;
            T data;

            if (File.Exists(path))
            {
                try
                {
                    using (XmlReader stream = XmlReader.Create(path))
                    {
                        data = (T)ser.Deserialize(stream);
                    }

                    using (XmlWriter stream = XmlWriter.Create(path, settings))
                    {
                        ser.Serialize(stream, data);
                    }
                }
                catch
                {
                    using (XmlWriter stream = XmlWriter.Create(path, settings))
                    {
                        ser.Serialize(stream, data = new T());
                    }
                }
            }
            else
            {
                using (XmlWriter stream = XmlWriter.Create(path, settings))
                {
                    ser.Serialize(stream, data = new T());
                }
            }

            return data;
        }

        public static T Next<T>(this T[] values)
        {
            return values[new Random().Next(values.Length-1)];
        }

        public static string GetFinalRedirect(string url)
        {
            if (string.IsNullOrWhiteSpace(url))
                return url;

            int maxRedirCount = 8;  // prevent infinite loops
            string newUrl = url;
            do
            {
                HttpWebRequest req = null;
                HttpWebResponse resp = null;
                try
                {
                    req = (HttpWebRequest)HttpWebRequest.Create(url);
                    req.Method = "HEAD";
                    req.AllowAutoRedirect = false;
                    resp = (HttpWebResponse)req.GetResponse();
                    switch (resp.StatusCode)
                    {
                        case HttpStatusCode.OK:
                            return newUrl;
                        case HttpStatusCode.Redirect:
                        case HttpStatusCode.MovedPermanently:
                        case HttpStatusCode.RedirectKeepVerb:
                        case HttpStatusCode.RedirectMethod:
                            newUrl = resp.Headers["Location"];
                            if (newUrl == null)
                                return url;

                            if (newUrl.IndexOf("://", System.StringComparison.Ordinal) == -1)
                            {
                                // Doesn't have a URL Schema, meaning it's a relative or absolute URL
                                Uri u = new Uri(new Uri(url), newUrl);
                                newUrl = u.ToString();
                            }
                            break;
                        default:
                            return newUrl;
                    }
                    url = newUrl;
                }
                catch (WebException)
                {
                    // Return the last known good URL
                    return newUrl;
                }
                catch
                {
                    return null;
                }
                finally
                {
                    if (resp != null)
                        resp.Close();
                }
            } while (maxRedirCount-- > 0);

            return newUrl;
        }
    }
}