using Fusion;
using System.Collections.Generic;
using UnityEngine;

namespace TPSBR
{
	public class EliminationGameplayMode : GameplayMode
	{
		// PRIVATE MEMBERS

		[SerializeField]
		private int _extraLives = 4;

		private EliminationComparer _playerComparer = new EliminationComparer();

		// GameplayMode INTERFACE

		protected override void PreparePlayerStatistics(ref PlayerStatistics playerStatistics)
		{
			base.PreparePlayerStatistics(ref playerStatistics);

			// Do not add extra lives after reconnect
			if (playerStatistics.Deaths == 0 && playerStatistics.IsEliminated == false && playerStatistics.ExtraLives == 0)
			{
				playerStatistics.ExtraLives = (short)GetExtraLivesForNewPlayer();
			}
		}

		protected override float GetRespawnTime(PlayerStatistics playerStatistics)
		{
			if (playerStatistics.ExtraLives > 0)
				return base.GetRespawnTime(playerStatistics);

			return -1f;
		}

		protected override void AgentDeath(ref PlayerStatistics victimStatistics, ref PlayerStatistics killerStatistics)
		{
			base.AgentDeath(ref victimStatistics, ref killerStatistics);

			if (victimStatistics.ExtraLives > 0)
			{
				victimStatistics.ExtraLives -= 1;
			}
		}

		protected override void SortPlayers(List<PlayerStatistics> allStatistics)
		{
			allStatistics.Sort(_playerComparer);
		}

		protected override void CheckWinCondition()
		{
			var alivePlayers    = 0;
			var lastAlivePlayer = PlayerRef.None;

			foreach (var player in Context.NetworkGame.ActivePlayers)
			{
				if (player == null)
					continue;

				var statistics = player.Statistics;
				if (statistics.ExtraLives > 0 || statistics.IsAlive == true || statistics.RespawnTimer.IsRunning == true)
				{
					if (alivePlayers > 0)
						return;

					alivePlayers    += 1;
					lastAlivePlayer  = player.Object.InputAuthority;
				}
			}

			if (alivePlayers == 1)
			{
				FinishGameplay();
				Log.Info($"Player {lastAlivePlayer} won the match!");
			}
			else if (alivePlayers == 0)
			{
				Log.Error("No player alive, this should not happen");
				FinishGameplay();
			}
		}

		// PRIVATE METHODS

		private int GetExtraLivesForNewPlayer()
		{
			int minExtraLives = int.MaxValue;
			int maxExtraLives = int.MinValue;

			foreach (var player in Context.NetworkGame.ActivePlayers)
			{
				if (player == null)
					continue;

				var playerStatistics = player.Statistics;

				if (playerStatistics.Deaths == 0 && playerStatistics.ExtraLives == 0 && playerStatistics.IsEliminated == false)
					continue; // Player not yet initialized properly

				minExtraLives = Mathf.Min(minExtraLives, playerStatistics.ExtraLives);
				maxExtraLives = Mathf.Max(maxExtraLives, playerStatistics.ExtraLives);
			}

			int extraLives = _extraLives;

			if (minExtraLives < int.MaxValue && maxExtraLives > int.MinValue)
			{
				extraLives = Mathf.Clamp(Mathf.RoundToInt((minExtraLives + maxExtraLives) * 0.5f), 0, _extraLives);
			}

			return extraLives;
		}

		// HELPERS

		private class EliminationComparer : IComparer<PlayerStatistics>
		{
			public int Compare(PlayerStatistics x, PlayerStatistics y)
			{
				var result = x.IsEliminated.CompareTo(y.IsEliminated);
				if (result != 0)
					return result;

				result = y.ExtraLives.CompareTo(x.ExtraLives);
				if (result != 0)
					return result;

				result = y.Kills.CompareTo(x.Kills);
				if (result != 0)
					return result;

				return x.Deaths.CompareTo(y.Deaths);
			}
		}
	}
}