using Discord.Commands;
using Newtonsoft.Json.Linq;

namespace Discord_Bot
{
    public class ReminderModule : ModuleBase<SocketCommandContext>
    {
        private const long DAY_PERIOD = 24 * 60 * 60 * 1000; // 10 * 1000; //
        private Timer reminderTimer;

        [Command("reloadTimer")]
        private async Task SetReloadTimer()
        {
            ReloadTimers();
            await ReplyAsync($"Заебись");
        }

        [Command("remindertime")]
        private async Task SetReminderTime([Remainder]string message = "")
        {
            SaveToConfig("reminderTime", Utility.ParseMessage(message));
            ReloadTimers();
            await ReplyAsync($"Заебись");
        }
        
        [Command("sequence")]
        private async Task SetSequence([Remainder]string message = "")
        {
            SaveToConfig("sequence", message);
            SaveToConfig("sequenceIndex", "0");
            await ReplyAsync($"Заебись");
        }
        
        [Command("users")]
        private async Task Users([Remainder]string message = "")
        {
            SaveToConfig("users", message);
            await ReplyAsync($"Заебись");
        }
        
        private void ReloadTimers()
        {
            var reminder = GetReminderTime();
            var now = DateTime.Now;
            
            var span = (reminder - now).TotalMilliseconds;
            if (span < 0)
            {
                // skip to next period
                var d = (now - reminder).TotalMilliseconds + DAY_PERIOD;
                reminder = reminder.AddMilliseconds(d);
                span = (reminder - now).TotalMilliseconds;
            }
            reminderTimer = new Timer(SendReminder, "sd", (long)span, DAY_PERIOD);
            
            RecalcSequenceIndex();
        }

        private DateTime GetReminderTime()
        {
            var time = Functions.GetConfigItem("reminderTime");
            if (time.Type == JTokenType.Boolean)
                return DateTime.Now;

            return Utility.ParseTime(time.ToString());
        }

        private async void SendReminder(object? state)
        {
            if (!CheckSequenceAndIncrementIndex())
                return;

            var users = Functions.GetConfigItem("users").ToString();
            var message = $"{users}\nБудет чо? {DateTime.Now}";
            await ReplyAsync(message);
        }

        private void RecalcSequenceIndex()
        {
            var reminder = GetReminderTime();
            var now = DateTime.Now;
            var sequence = GetSequence();

            var span = (now - reminder).TotalMilliseconds;
            var spanMinusFullSequences = (int)MathF.Floor((float)span % (DAY_PERIOD * sequence.Length));
            var index = spanMinusFullSequences / DAY_PERIOD;
            SaveToConfig("sequenceIndex", index.ToString());
        }

        private bool CheckSequenceAndIncrementIndex()
        {
            var sequenceIndex = GetSequenceIndex();
            var sequence = GetSequence();
            if (string.IsNullOrEmpty(sequence))
                return true;

            var result = sequence[sequenceIndex] == '!';
            sequenceIndex = (sequenceIndex + 1) % sequence.Length;
            SaveToConfig("sequenceIndex", sequenceIndex.ToString());
            
            return result;
        }

        private int GetSequenceIndex()
        {
            var sequenceIndexToken = Functions.GetConfigItem("sequenceIndex");
            if (sequenceIndexToken.Type == JTokenType.Boolean)
            {
                SaveToConfig("sequenceIndex", "0");
                return 0;
            }
            return (int)sequenceIndexToken;
        }

        private string GetSequence()
        {
            var sequenceIndexToken = Functions.GetConfigItem("sequence");
            if (sequenceIndexToken.Type == JTokenType.Boolean)
            {
                SaveToConfig("sequence", "");
                return "";
            }
            return sequenceIndexToken.ToString();
        }

        private void SaveToConfig(string key, string data)
        {
            var config = Functions.GetConfig();
            config[key] = data;
            Functions.SaveConfig(config);
        }
    }
}