using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Threading;
using Microsoft.Extensions.Logging;
using SmartNav.Model.Navigation;

namespace SmartNav.Data;

public sealed class WaterMapService
{
	private readonly Lazy<IReadOnlyDictionary<ushort, TerritoryWaterMap>> _maps;

	public WaterMapService(SmartNavDataOptions dataOptions, ILogger<WaterMapService> logger)
	{
		_maps = new Lazy<IReadOnlyDictionary<ushort, TerritoryWaterMap>>(delegate
		{
			try
			{
				var (text, readOnlyDictionary) = AssemblyWaterMapLoader.GetWaterMaps(dataOptions.DevSourceDirectory?.FullName);
				logger.LogInformation("WaterMapService: {Count} territories with water maps loaded (game version {GameVersion})", readOnlyDictionary.Count, text ?? "<none>");
				return readOnlyDictionary;
			}
			catch (Exception exception)
			{
				logger.LogError(exception, "Water cache could not be loaded - routing proceeds without water data");
				return new Dictionary<ushort, TerritoryWaterMap>();
			}
		}, LazyThreadSafetyMode.ExecutionAndPublication);
	}

	internal WaterMapService(IReadOnlyDictionary<ushort, TerritoryWaterMap> maps)
	{
		_maps = new Lazy<IReadOnlyDictionary<ushort, TerritoryWaterMap>>(maps);
	}

	public bool TryGetMap(uint territoryId, [NotNullWhen(true)] out TerritoryWaterMap? map)
	{
		if (territoryId > 65535)
		{
			map = null;
			return false;
		}
		return _maps.Value.TryGetValue((ushort)territoryId, out map);
	}
}