using System;
using System.Linq;
using Dalamud.Plugin;
using Dalamud.Plugin.Services;
using Microsoft.Extensions.Logging;

namespace Questionable.External;

internal sealed class WigglyNavAvailability : IDisposable
{
	private const int SupportedMajorVersion = 1;

	private const string WigglyNavInternalName = "WigglyNav";

	private const long ReprobeIntervalMs = 5000L;

	private readonly IDalamudPluginInterface _pluginInterface;

	private readonly WigglyNavIpc _wigglyNavIpc;

	private readonly IFramework _framework;

	private readonly ILogger<WigglyNavAvailability> _logger;

	private readonly object _verdictLock = new object();

	private volatile bool _isCompatible;

	private long _lastProbeTicks;

	public bool IsCompatible => _isCompatible;

	public event Action? CompatibilityChanged;

	public WigglyNavAvailability(IDalamudPluginInterface pluginInterface, WigglyNavIpc wigglyNavIpc, IFramework framework, ILogger<WigglyNavAvailability> logger)
	{
		_pluginInterface = pluginInterface;
		_wigglyNavIpc = wigglyNavIpc;
		_framework = framework;
		_logger = logger;
		TryRefreshVerdict(respectThrottle: false);
		_logger.LogInformation("WigglyNav native surface is {State} at startup", DescribeVerdict(_isCompatible));
		_pluginInterface.ActivePluginsChanged += OnActivePluginsChanged;
		_framework.Update += OnFrameworkUpdate;
	}

	public void Dispose()
	{
		_framework.Update -= OnFrameworkUpdate;
		_pluginInterface.ActivePluginsChanged -= OnActivePluginsChanged;
	}

	private void OnActivePluginsChanged(IActivePluginsChangedEventArgs args)
	{
		if (args.AffectedInternalNames.Contains("WigglyNav") && TryRefreshVerdict(respectThrottle: false))
		{
			_logger.LogInformation("WigglyNav native surface is now {State} (plugin list change: {Kind})", DescribeVerdict(_isCompatible), args.Kind);
			this.CompatibilityChanged?.Invoke();
		}
	}

	private void OnFrameworkUpdate(IFramework framework)
	{
		if (!_isCompatible && TryRefreshVerdict(respectThrottle: true))
		{
			_logger.LogInformation("WigglyNav native surface is now {State} (periodic re-probe)", DescribeVerdict(_isCompatible));
			this.CompatibilityChanged?.Invoke();
		}
	}

	private bool TryRefreshVerdict(bool respectThrottle)
	{
		lock (_verdictLock)
		{
			long tickCount = Environment.TickCount64;
			if (respectThrottle && tickCount - _lastProbeTicks < 5000)
			{
				return false;
			}
			_lastProbeTicks = tickCount;
			(int, int)? tuple = _wigglyNavIpc.TryGetApiVersion();
			bool flag = tuple.HasValue && tuple.GetValueOrDefault().Item1 == 1;
			if (flag == _isCompatible)
			{
				return false;
			}
			_isCompatible = flag;
			return true;
		}
	}

	private static string DescribeVerdict(bool isCompatible)
	{
		if (!isCompatible)
		{
			return "unavailable or incompatible";
		}
		return "compatible";
	}
}