using Microsoft.AspNetCore.Http;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace Hncore.Infrastructure.Core.Web
{
    public static class HttpContextExtension
    {
        public static string GetUserIp(this HttpContext context)
        {
            var ip = context.Request.Headers["X-Forwarded-For"].FirstOrDefault();
            if (string.IsNullOrEmpty(ip))
            {
                ip = context.Connection.RemoteIpAddress.ToString();
            }

            return ip;
        }

        public static string GetAbsoluteUri(this HttpRequest request)
        {
            return new StringBuilder()
                .Append(request.Scheme)
                .Append("://")
                .Append(request.Host)
                .Append(request.PathBase)
                .Append(request.Path)
                .Append(request.QueryString)
                .ToString();
        }

        public static async Task<string> ReadBodyAsStringAsync(this HttpRequest request)
        {
            request.EnableBuffering();
                
            var requestReader = new StreamReader(request.Body);
                
            var requestBody = await requestReader.ReadToEndAsync();

            request.Body.Position = 0;

            return requestBody;
        }
    }

    public static class IsLocalExtension
    {
        private const string NullIpAddress = "::1";

        public static bool IsLocal(this HttpRequest req)
        {
            var connection = req.HttpContext.Connection;
            if (connection.RemoteIpAddress.IsSet())
            {
                return connection.LocalIpAddress.IsSet()
                    ? connection.RemoteIpAddress.Equals(connection.LocalIpAddress)
                    : IPAddress.IsLoopback(connection.RemoteIpAddress);
            }

            return true;
        }

        private static bool IsSet(this IPAddress address)
        {
            return address != null && address.ToString() != NullIpAddress;
        }
    }
}