using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace SharpChat.Flashii {
    public static class FlashiiUrls {
        private const string BASE_URL_FILE = "msz_url.txt";
        private const string BASE_URL_FALLBACK = "https://flashii.net";

        private const string BUMP = "/_sockchat/bump";
        private const string VERIFY = "/_sockchat/verify";

        private const string BANS_CHECK = "/_sockchat/bans/check?u={0}&a={1}&x={2}&n={3}";
        private const string BANS_CREATE = "/_sockchat/bans/create";
        private const string BANS_REVOKE = "/_sockchat/bans/revoke?t={0}&s={1}&x={2}";
        private const string BANS_LIST = "/_sockchat/bans/list?x={0}";

        public static string BumpURL { get; }
        public static string VerifyURL { get; }

        public static string BansCheckURL { get; }
        public static string BansCreateURL { get; }
        public static string BansRevokeURL { get; }
        public static string BansListURL { get; }

        static FlashiiUrls() {
            BumpURL = GetURL(BUMP);
            VerifyURL = GetURL(VERIFY);
            BansCheckURL = GetURL(BANS_CHECK);
            BansCreateURL = GetURL(BANS_CREATE);
            BansRevokeURL = GetURL(BANS_REVOKE);
            BansListURL = GetURL(BANS_LIST);
        }

        public static string GetBaseURL() {
            if(!File.Exists(BASE_URL_FILE))
                return BASE_URL_FALLBACK;
            string url = File.ReadAllText(BASE_URL_FILE).Trim().Trim('/');
            if(string.IsNullOrEmpty(url))
                return BASE_URL_FALLBACK;
            return url;
        }

        public static string GetURL(string path) {
            return GetBaseURL() + path;
        }

        public static async Task BumpUsersOnlineAsync(HttpClient client, IEnumerable<(string userId, string ipAddr)> list) {
            if(client == null)
                throw new ArgumentNullException(nameof(client));
            if(list == null)
                throw new ArgumentNullException(nameof(list));
            if(!list.Any())
                return;

            string now = DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString();
            StringBuilder sb = new();
            sb.AppendFormat("bump#{0}", now);

            Dictionary<string, string> formData = new() {
                { "t", now }
            };

            foreach(var (userId, ipAddr) in list) {
                sb.AppendFormat("#{0}:{1}", userId, ipAddr);
                formData.Add(string.Format("u[{0}]", userId), ipAddr);
            }

            HttpRequestMessage req = new(HttpMethod.Post, BumpURL) {
                Headers = {
                    {  "X-SharpChat-Signature", sb.ToString().GetSignedHash() }
                },
                Content = new FormUrlEncodedContent(formData),
            };

            using HttpResponseMessage res = await client.SendAsync(req);

            try {
                res.EnsureSuccessStatusCode();
            } catch(HttpRequestException) {
                Logger.Debug(await res.Content.ReadAsStringAsync());
#if DEBUG
                throw;
#endif
            }
        }
    }
}