namespace Supercell.Laser.Logic.Home
{
    using Newtonsoft.Json;

    public static class GameTimerConfig
    {
        private const string SourceTimerPath = "D:/shiny-v27/src/Supercell.Laser.Server/Json/timers.json";

        private static readonly object SyncRoot = new object();
        private static TimerConfig CachedConfig;
        private static DateTime CachedLastWriteTimeUtc = DateTime.MinValue;

        public static TimerSnapshot GetSnapshot(DateTime utcNow)
        {
            TimerConfig config = LoadConfig();

            return new TimerSnapshot
            {
                SeasonTimeRemaining = GetSeasonTimeRemaining(config.SeasonEnd, utcNow),
                PowerPlayTimeRemaining = GetRemainingSeconds(config.PowerPlay, utcNow),
                BrawlPassTimeRemaining = GetRemainingSeconds(config.BrawlPass, utcNow)
            };
        }

        private static TimerConfig LoadConfig()
        {
            lock (SyncRoot)
            {
                string path = ResolveConfigPath();
                if (!File.Exists(path))
                {
                    return CreateDefaultConfig();
                }

                DateTime lastWriteTimeUtc = File.GetLastWriteTimeUtc(path);
                if (CachedConfig != null && lastWriteTimeUtc == CachedLastWriteTimeUtc)
                {
                    return CachedConfig;
                }

                TimerConfig loadedConfig = JsonConvert.DeserializeObject<TimerConfig>(File.ReadAllText(path))
                    ?? CreateDefaultConfig();

                CachedConfig = loadedConfig.WithDefaults(CreateDefaultConfig());
                CachedLastWriteTimeUtc = lastWriteTimeUtc;
                return CachedConfig;
            }
        }

        private static string ResolveConfigPath()
        {
            string runtimePath = Path.Combine(AppContext.BaseDirectory, "Json", "timers.json");
            if (File.Exists(runtimePath))
            {
                return runtimePath;
            }

            return SourceTimerPath;
        }

        private static int GetRemainingSeconds(DateTime targetUtc, DateTime utcNow)
        {
            return Math.Max(0, (int)(targetUtc - utcNow).TotalSeconds);
        }

        private static int GetSeasonTimeRemaining(DateTime fallbackSeasonEndUtc, DateTime utcNow)
        {
            DateTime? nextResetUtc = TryGetNextSeasonResetUtc();
            if (nextResetUtc.HasValue)
            {
                return GetRemainingSeconds(nextResetUtc.Value, utcNow);
            }

            return GetRemainingSeconds(fallbackSeasonEndUtc, utcNow);
        }

        private static DateTime? TryGetNextSeasonResetUtc()
        {
            string path = ResolveConfigPath();
            if (!File.Exists(path))
            {
                return null;
            }

            try
            {
                TimerConfig config = JsonConvert.DeserializeObject<TimerConfig>(File.ReadAllText(path));
                if (config?.NextReset == null || config.NextReset == default)
                {
                    return null;
                }

                return DateTime.SpecifyKind(config.NextReset.Value, DateTimeKind.Utc);
            }
            catch
            {
                return null;
            }
        }

        private static TimerConfig CreateDefaultConfig()
        {
            return new TimerConfig
            {
                SeasonEnd = new DateTime(2026, 12, 31, 12, 0, 0, DateTimeKind.Utc),
                BrawlPass = new DateTime(2026, 12, 31, 12, 0, 0, DateTimeKind.Utc),
                PowerPlay = new DateTime(2026, 5, 31, 12, 0, 0, DateTimeKind.Utc)
            };
        }

        private sealed class TimerConfig
        {
            [JsonProperty("seasonEnd")] public DateTime SeasonEnd { get; set; }
            [JsonProperty("brawlPass")] public DateTime BrawlPass { get; set; }
            [JsonProperty("powerPlay")] public DateTime PowerPlay { get; set; }
            [JsonProperty("lastReset")] public DateTime? LastReset { get; set; }
            [JsonProperty("nextReset")] public DateTime? NextReset { get; set; }
            [JsonProperty("seasonInterval")] public string SeasonInterval { get; set; }

            public TimerConfig WithDefaults(TimerConfig defaults)
            {
                if (SeasonEnd == default)
                {
                    SeasonEnd = defaults.SeasonEnd;
                }

                if (BrawlPass == default)
                {
                    BrawlPass = defaults.BrawlPass;
                }

                if (PowerPlay == default)
                {
                    PowerPlay = defaults.PowerPlay;
                }

                return this;
            }
        }
    }

    public sealed class TimerSnapshot
    {
        public int SeasonTimeRemaining { get; init; }
        public int PowerPlayTimeRemaining { get; init; }
        public int BrawlPassTimeRemaining { get; init; }
    }
}