using Bobo.System.Maze.Bot.Interface;
using HightechICT.Amazeing.Client.Rest;
using Microsoft.Extensions.Logging;

namespace Bobo.System.Maze.Bot
{
    public class SimpleBot : BaseBot
    {
        private Stack<Direction> Directions { get; set; } = new Stack<Direction>();
        private List<List<Direction>> ExitDirections { get; set; } = new List<List<Direction>>();
        private List<List<Direction>> CollectionPointDirections { get; set; } = new List<List<Direction>>();

        public SimpleBot(AmazeingClient mazeClient, ILogger logger) : base(mazeClient, logger)
        {  }

        public override async Task<int> Run(MazeInfo maze)
        {
            if (MazeClient == null)
                throw new ArgumentException(nameof(MazeClient));

            if (string.IsNullOrWhiteSpace(maze.Name))
                throw new ArgumentException(nameof(maze.Name));

            Random random = new Random();
            Logger.Log(LogLevel.Information, "Entering maze '{MazeName}'", maze.Name);
            PossibleActionsAndCurrentScore result = await MazeClient.EnterMaze(maze.Name);
            int collected = 0;

            do
            {
                if (result.PossibleMoveActions.All(m => m.HasBeenVisited))
                {
                    Logger.Log(LogLevel.Debug, "All adjacent tiles have been visited! Going back.");
                    result = await MoveBackOne();
                }
                else
                {
                    MoveAction[] notVisited = result.PossibleMoveActions.Where(m => !m.HasBeenVisited).ToArray();
                    Logger.Log(LogLevel.Debug, $"{string.Join(", ", notVisited.Select(m => m.Direction.ToString()))} have not been visited, selecting next move.");
                    int selected = random.Next(notVisited.Length - 1);
                    MoveAction moveAction = notVisited[selected];

                    Logger.Log(LogLevel.Debug, $"Moving {moveAction.Direction}, I have {(!moveAction.HasBeenVisited ? "not" : string.Empty)} been here.");

                    result = await MazeClient.Move(moveAction.Direction);

                    Directions.Push(moveAction.Direction);
                }


                // if this is an exit, copy the path so we know how to get there
                if (result.CanExitMazeHere)
                {
                    ExitDirections.Add(new List<Direction>(Directions));
                }

                // if this is a collection point, copy the path so we know how to get there
                if (result.CanCollectScoreHere)
                {
                    CollectionPointDirections.Add(new List<Direction>(Directions));

                    List<Direction> list = new List<Direction>(Directions);
                }

                Logger.Log(LogLevel.Debug, $"New tile has {(!result.CanExitMazeHere ? "no" : string.Empty)} exit.");

            } while (maze.PotentialReward != result.CurrentScoreInHand
                    && CollectionPointDirections.Any()
                    && ExitDirections.Any());



            do
            {
                // create a list of the directions to the current point
                List<Direction> fromStart = new List<Direction>(Directions);

                // see what collection point is closest (if multiple)
                List<Direction> collectionPointDirections = CollectionPointDirections.First();
                int collectionCommonPointFromStart = int.MaxValue;
                foreach(List<Direction> cdp in CollectionPointDirections)
                {
                    int lowest = fromStart.Count() < cdp.Count() ? fromStart.Count() : cdp.Count();
                    int lastCommonIndex = 0;

                    // start from index 0 and work up to the lowest size
                    for (lastCommonIndex = 0; lastCommonIndex < lowest; lastCommonIndex++)
                    {
                        if (fromStart[lastCommonIndex] != cdp[lastCommonIndex])
                        {
                            // not common, break loop
                            break;
                        }
                    }

                    if (lastCommonIndex < collectionCommonPointFromStart)
                    {
                        collectionPointDirections = cdp;
                        collectionCommonPointFromStart = lastCommonIndex;
                    }
                }

                // first go back to the common index
                for (int returnMoves = 0; returnMoves < fromStart.Count - collectionCommonPointFromStart; returnMoves ++)
                {
                    await MoveBackOne();
                }

                for (int toCollectionIndex = collectionCommonPointFromStart + 1; toCollectionIndex < collectionPointDirections.Count(); toCollectionIndex++)
                {
                    result = await MazeClient.Move(collectionPointDirections[toCollectionIndex]);
                }

                // go to collection
                if (result.CanCollectScoreHere)
                {
                    collected += result.CurrentScoreInHand;
                    await MazeClient.CollectScore();
                }

                // go to exit
            }
            while (!result.CanExitMazeHere);

            await MazeClient.ExitMaze();

            Logger.Log(LogLevel.Information, "Collected {Collected}!", collected);
            Logger.Log(LogLevel.Information, "Exited maze {MazeName}!", maze.Name);

            return collected;
        }
        
        private Task<PossibleActionsAndCurrentScore> MoveBackOne()
        {
            Direction direction = Directions.Pop();

            switch (direction)
            {
                case Direction.Left:
                    direction = Direction.Right;
                    break;
                case Direction.Right:
                    direction = Direction.Left;
                    break;
                case Direction.Up:
                    direction = Direction.Down;
                    break;
                case Direction.Down:
                    direction = Direction.Up;
                    break;

            }

            Logger.Log(LogLevel.Debug, "Moving {Direction}, I have been here.", direction);

            return MazeClient.Move(direction);
        }
    }
}