using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using Microsoft.Extensions.Logging;
using SmartNav.Model.Navigation;

namespace SmartNav.Data;

internal static class ZoneBoundaryDerivation
{
	public static List<ZoneBoundary> Derive(IReadOnlyList<ExitRangeEntry> exitRanges, IReadOnlyDictionary<(ushort TerritoryId, uint InstanceId), PopRangeEntry> popRangeIndex, ILogger logger)
	{
		List<ZoneBoundary> list = new List<ZoneBoundary>();
		HashSet<(ushort, uint)> hashSet = new HashSet<(ushort, uint)>();
		List<ExitRangeEntry> list2 = new List<ExitRangeEntry>();
		foreach (ExitRangeEntry exitRange in exitRanges)
		{
			if (hashSet.Contains((exitRange.SourceTerritoryId, exitRange.InstanceId)) || exitRange.DestTerritoryId == 0)
			{
				continue;
			}
			Vector3? vector = null;
			if (popRangeIndex.TryGetValue((exitRange.DestTerritoryId, exitRange.DestInstanceId), out PopRangeEntry value))
			{
				vector = value.Position;
			}
			ExitRangeEntry exitRangeEntry = null;
			foreach (ExitRangeEntry exitRange2 in exitRanges)
			{
				if (exitRange2.SourceTerritoryId == exitRange.DestTerritoryId && exitRange2.DestTerritoryId == exitRange.SourceTerritoryId && !hashSet.Contains((exitRange2.SourceTerritoryId, exitRange2.InstanceId)) && ((exitRange2.DestInstanceId != 0 && exitRange2.DestInstanceId == exitRange.ReturnInstanceId) || (exitRange.DestInstanceId != 0 && exitRange.DestInstanceId == exitRange2.ReturnInstanceId) || (exitRange2.ReturnInstanceId != 0 && exitRange2.ReturnInstanceId == exitRange.InstanceId)))
				{
					exitRangeEntry = exitRange2;
					break;
				}
			}
			if (exitRangeEntry == null)
			{
				float num = float.MaxValue;
				ExitRangeEntry exitRangeEntry2 = null;
				foreach (ExitRangeEntry exitRange3 in exitRanges)
				{
					if (exitRange3.SourceTerritoryId != exitRange.DestTerritoryId || exitRange3.DestTerritoryId != exitRange.SourceTerritoryId || hashSet.Contains((exitRange3.SourceTerritoryId, exitRange3.InstanceId)))
					{
						continue;
					}
					if (popRangeIndex.TryGetValue((exitRange.SourceTerritoryId, exitRange3.DestInstanceId), out PopRangeEntry value2))
					{
						float num2 = Vector3.Distance(exitRange.SourcePosition, value2.Position);
						if (num2 < num)
						{
							num = num2;
							exitRangeEntry = exitRange3;
						}
					}
					else if ((object)exitRangeEntry2 == null)
					{
						exitRangeEntry2 = exitRange3;
					}
				}
				if ((object)exitRangeEntry == null)
				{
					exitRangeEntry = exitRangeEntry2;
				}
			}
			Vector3? vector2 = (((object)exitRangeEntry != null) ? new Vector3?(exitRangeEntry.SourcePosition) : vector);
			if (!vector2.HasValue)
			{
				list2.Add(exitRange);
				continue;
			}
			list.Add(new ZoneBoundary
			{
				Id = $"lgb-{exitRange.SourceTerritoryId}-{exitRange.DestTerritoryId}-{exitRange.InstanceId}",
				Side1 = new BoundarySide
				{
					TerritoryId = exitRange.SourceTerritoryId,
					Position = exitRange.SourcePosition,
					Trigger = TriggerOf(exitRange)
				},
				Side2 = new BoundarySide
				{
					TerritoryId = exitRange.DestTerritoryId,
					Position = vector2.Value,
					Trigger = ((exitRangeEntry == null) ? null : TriggerOf(exitRangeEntry))
				},
				OneWay = (exitRangeEntry == null)
			});
			hashSet.Add((exitRange.SourceTerritoryId, exitRange.InstanceId));
			if (exitRangeEntry != null)
			{
				hashSet.Add((exitRangeEntry.SourceTerritoryId, exitRangeEntry.InstanceId));
			}
		}
		HashSet<(ushort, ushort)> hashSet2 = new HashSet<(ushort, ushort)>();
		foreach (ZoneBoundary item in list)
		{
			hashSet2.Add((item.Side1.TerritoryId, item.Side2.TerritoryId));
			hashSet2.Add((item.Side2.TerritoryId, item.Side1.TerritoryId));
		}
		foreach (ExitRangeEntry item2 in list2)
		{
			if (hashSet2.Contains((item2.SourceTerritoryId, item2.DestTerritoryId)))
			{
				logger.LogDebug("Skipped redundant unresolvable ExitRange {InstanceId} in territory {SrcTerritory} -> {DestTerritory}", item2.InstanceId, item2.SourceTerritoryId, item2.DestTerritoryId);
			}
			else
			{
				logger.LogWarning("ExitRange {InstanceId} in territory {SrcTerritory} -> {DestTerritory}: could not resolve destination position (DestInstanceId={DestId})", item2.InstanceId, item2.SourceTerritoryId, item2.DestTerritoryId, item2.DestInstanceId);
			}
		}
		return list;
	}

	public static void ApplyOverrides(List<ZoneBoundary> boundaries, IReadOnlyCollection<(ushort TerritoryA, ushort TerritoryB)> flyingPairs, IReadOnlyList<ZoneBoundaryPositionOverride> positionOverrides, ILogger logger)
	{
		HashSet<(ushort, ushort)> hashSet = new HashSet<(ushort, ushort)>(flyingPairs);
		foreach (ZoneBoundary boundary in boundaries)
		{
			if (hashSet.Contains(PairKey(boundary.Side1.TerritoryId, boundary.Side2.TerritoryId)))
			{
				boundary.RequiresFlying = true;
			}
		}
		Dictionary<(ushort, ushort), List<ZoneBoundary>> dictionary = (from b in boundaries
			group b by PairKey(b.Side1.TerritoryId, b.Side2.TerritoryId)).ToDictionary((IGrouping<(ushort, ushort), ZoneBoundary> g) => g.Key, (IGrouping<(ushort, ushort), ZoneBoundary> g) => g.ToList());
		int num = 0;
		foreach (IGrouping<(ushort, ushort), ZoneBoundaryPositionOverride> item in from o in positionOverrides
			group o by (TerritoryA: o.TerritoryA, TerritoryB: o.TerritoryB))
		{
			List<ZoneBoundaryPositionOverride> list = item.ToList();
			if (!dictionary.TryGetValue(item.Key, out var value))
			{
				num += list.Count;
				logger.LogWarning("No derived boundary for override pair {TerritoryA}<->{TerritoryB} ({Count} overrides) - game data drift?", item.Key.Item1, item.Key.Item2, list.Count);
				continue;
			}
			List<(float, int, int)> list2 = new List<(float, int, int)>();
			for (int num2 = 0; num2 < value.Count; num2++)
			{
				for (int num3 = 0; num3 < list.Count; num3++)
				{
					list2.Add((OverrideDistance(value[num2], list[num3]), num2, num3));
				}
			}
			bool[] array = new bool[value.Count];
			bool[] array2 = new bool[list.Count];
			foreach (var item2 in list2.OrderBy<(float, int, int), float>(((float Distance, int GateIdx, int OverrideIdx) c) => c.Distance))
			{
				if (!array[item2.Item2] && !array2[item2.Item3])
				{
					array[item2.Item2] = true;
					array2[item2.Item3] = true;
					ZoneBoundary zoneBoundary = value[item2.Item2];
					ZoneBoundaryPositionOverride zoneBoundaryPositionOverride = list[item2.Item3];
					bool flag = zoneBoundary.Side1.TerritoryId == zoneBoundaryPositionOverride.TerritoryA;
					zoneBoundary.Side1.Position = (flag ? zoneBoundaryPositionOverride.PositionA : zoneBoundaryPositionOverride.PositionB);
					zoneBoundary.Side2.Position = (flag ? zoneBoundaryPositionOverride.PositionB : zoneBoundaryPositionOverride.PositionA);
				}
			}
			for (int num4 = 0; num4 < list.Count; num4++)
			{
				if (!array2[num4])
				{
					num++;
				}
			}
		}
		if (num > 0)
		{
			logger.LogWarning("{Count} position overrides had no gate to attach to", num);
		}
		static (ushort, ushort) PairKey(ushort a, ushort b)
		{
			if (a > b)
			{
				return (b, a);
			}
			return (a, b);
		}
	}

	private static TriggerBox? TriggerOf(ExitRangeEntry exit)
	{
		if (!(exit.HalfExtents == Vector3.Zero))
		{
			return new TriggerBox(exit.SourcePosition, exit.Rotation, exit.HalfExtents);
		}
		return null;
	}

	private static float OverrideDistance(ZoneBoundary gate, ZoneBoundaryPositionOverride ovr)
	{
		if (gate.Side1.TerritoryId != ovr.TerritoryA)
		{
			return Vector3.Distance(gate.Side1.Position, ovr.PositionB) + Vector3.Distance(gate.Side2.Position, ovr.PositionA);
		}
		return Vector3.Distance(gate.Side1.Position, ovr.PositionA) + Vector3.Distance(gate.Side2.Position, ovr.PositionB);
	}
}