using System;
using Dalamud.Plugin.Services;
using Lumina.Excel;
using Lumina.Excel.Sheets;

namespace LLib.GameData;

public sealed class WeatherHelper
{
	public const double WeatherPeriodSeconds = 1400.0;

	private readonly IDataManager _dataManager;

	public WeatherHelper(IDataManager dataManager)
	{
		_dataManager = dataManager;
	}

	public Weather? GetCurrentWeather(uint territoryId)
	{
		return GetWeatherAtTime(territoryId, DateTimeOffset.UtcNow.ToUnixTimeSeconds());
	}

	public Weather? GetPreviousWeather(uint territoryId)
	{
		return GetWeatherAtTime(territoryId, DateTimeOffset.UtcNow.ToUnixTimeSeconds() - 1400);
	}

	public Weather? GetNextWeather(uint territoryId)
	{
		return GetWeatherAtTime(territoryId, DateTimeOffset.UtcNow.ToUnixTimeSeconds() + 1400);
	}

	public static double GetSecondsUntilWeatherChange()
	{
		long num = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
		return 1400.0 - (double)(num % 1400);
	}

	public Weather? GetWeatherAtTime(uint territoryId, long unixSeconds)
	{
		TerritoryType? rowOrDefault = _dataManager.GetExcelSheet<TerritoryType>().GetRowOrDefault(territoryId);
		if (!rowOrDefault.HasValue)
		{
			return null;
		}
		if (!rowOrDefault.Value.WeatherRate.IsValid)
		{
			return null;
		}
		WeatherRate value = rowOrDefault.Value.WeatherRate.Value;
		uint target = CalculateTarget(unixSeconds);
		return ResolveWeather(value, target);
	}

	internal static uint CalculateTarget(long unixSeconds)
	{
		long num = unixSeconds / 175;
		uint num2 = (uint)((num + 8 - num % 8) % 24);
		uint num3 = (uint)((int)(unixSeconds / 4200) * 100) + num2;
		uint num4 = (num3 << 11) ^ num3;
		return ((num4 >> 8) ^ num4) % 100;
	}

	private static Weather? ResolveWeather(WeatherRate weatherRate, uint target)
	{
		Weather? result = null;
		int num = 0;
		for (int i = 0; i < weatherRate.Rate.Count; i++)
		{
			if (weatherRate.Rate[i] <= 0)
			{
				continue;
			}
			RowRef<Weather> rowRef = weatherRate.Weather[i];
			if (rowRef.IsValid)
			{
				result = rowRef.Value;
			}
			num += weatherRate.Rate[i];
			if (target < num)
			{
				if (!rowRef.IsValid)
				{
					return null;
				}
				return rowRef.Value;
			}
		}
		return result;
	}
}