using GameModel.DeathGame;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GameHandler.DeathGame
{
    public delegate void CoffinCompleted(Coffin coffin);
    public class DeathGameHandler
    {
        const int MIN_PLAYER_COUNT = 3;
        const int MAX_PLAYER_COUNT = 12;
        const int MIN_COFFIN_SIZE = 6;
        const int MAX_COFFIN_SIZE = 12;

        public event CoffinCompleted CoffinCompleted;

        private static Random random = new Random();

        
        private void ValidatePlayerCount(int playerCount)
        {
            if (playerCount < MIN_PLAYER_COUNT)
            {
                throw new InvalidDataException($"MaxPlayerCount must be at least {MIN_PLAYER_COUNT}");
            }
            if (playerCount > MAX_PLAYER_COUNT)
            {
                throw new InvalidDataException($"MaxPlayerCount cannot be greater than {MAX_PLAYER_COUNT}");
            }
        }

        private void ValidateGameSettings(DeathGameSettings deathGameSettings)
        {
            if (deathGameSettings.MaxCoffinSize < MIN_COFFIN_SIZE || deathGameSettings.MaxCoffinSize > MAX_COFFIN_SIZE )
            {
                throw new InvalidDataException($"Max coffin size must be from {MIN_COFFIN_SIZE} to {MAX_COFFIN_SIZE}");
            }
        }

        public DeathGameHandler()
        {                       
        }

        public DeathGameModel InitGameModel(int[] playerIds, DeathGameSettings deathGameSettings)
        {
            ValidatePlayerCount(playerIds.Count());
            ValidateGameSettings(deathGameSettings);

            var coffins = new List<Coffin>();
            foreach (var playerId in playerIds)
            {
                if (coffins.Any(_ => _.PlayerId.Equals(playerId)))
                {
                    throw new InvalidDataException($"player {playerId} already exists");
                }
                coffins.Add(new Coffin(playerId,0,0));
            }
            return new DeathGameModel(1, coffins.OrderBy(_ => random.Next()).ToList().ToArray(), deathGameSettings);
        }

        public DeathGameModel CalcNextModel(DeathGameModel gm, int pinCount, bool isTrowIntoAllPins, bool boardCleared)
        {
            var incLine = false;
            var incX = false;
            if (gm.Id == 1) // first round in game
            {
                incX = true;
                if (pinCount < 3)
                {
                    incLine = true;
                }
            }

            if (isTrowIntoAllPins) 
            {
                incX = true;
            }

            if (pinCount == 0)
            {
                incLine = true;
            }

            var current = gm.Coffins.First();
            var next = gm.Coffins.Skip(1).First();
            var previous = gm.Coffins.Last();
            Coffin? currentUpdated = null;
            Coffin? nextUpdated = next;
            Coffin? previousUpdated = previous;


            var xCount = current.XCount;
            var lineCount = current.LineCount;


            if ((current.XCount == 2) && incX)
            {
                xCount = 0;
                lineCount++;
            }

            if (incLine)
            {
                lineCount++;
            }

            if (incX)
            {
                xCount++;
            }
            currentUpdated = current with { LineCount = lineCount, XCount = xCount };

            if (lineCount > gm.deathGameSettings.MaxCoffinSize)
            {
                CoffinCompleted?.Invoke(currentUpdated);
                currentUpdated = null;
            }
            

            if (boardCleared)
            {
                previousUpdated = previous with { LineCount = previous.LineCount + 1 };
               if (previousUpdated.LineCount > gm.deathGameSettings.MaxCoffinSize)
               {
                    CoffinCompleted?.Invoke(previousUpdated);
                    previousUpdated = null;
               }


                if (next.XCount < 2)
                {
                    nextUpdated = next with { XCount = next.XCount + 1 };
                }
                else
                {
                    nextUpdated = next with { LineCount = previous.LineCount + 1, XCount = 0 };                    
                    if (nextUpdated.LineCount > gm.deathGameSettings.MaxCoffinSize)
                    {
                        CoffinCompleted?.Invoke(nextUpdated);
                        nextUpdated = null;
                    }
                }
                
            }

            var coffins = gm.Coffins.Skip(1).ToList();
            if (currentUpdated != null)
            {
                coffins.Add(currentUpdated);
            }
            
            if (nextUpdated == null) 
            {
                coffins.Remove(next);
            }

            if (previousUpdated == null)
            {
                coffins.Remove(previous);
            }
            else
            {
                var idx = coffins.IndexOf(previous);

                coffins.Remove(previous);
                coffins.Insert(idx, previousUpdated);
            }




            var result = gm with { Coffins = coffins.ToArray(), Id = gm.Id + 1 };

            return result;
        }
    }
}