using System.Collections;
using System.Collections.Generic;
using System.Linq;
using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.Rendering;
using static UnityEditor.Experimental.GraphView.GraphView;

public class Minimax : MonoBehaviour
{
    int[] allowedSteps = {1, 2, 3};
    //List<string> positions = new List<string>();
    //int currentPosition = 0;
    MainGame game;
    float lastTime = 0;
    char opposite(char p) { return (p == 'N') ? 'X' : 'N'; }
    List<string> availableMoves(string stage) { 
        List<string> answers = new List<string>();
        //char player = stage[stage.Length-1];
        char player = stage[^1];
        int place=int.Parse(stage.Substring(0, stage.Length - 1));
        char newplayer=opposite(player);
        foreach(int stepLength in allowedSteps){
          if(place + stepLength <= game.N) { 
            answers.Add((place + stepLength).ToString() + newplayer);
          }
        }
        return answers;
    }

    float score(string stage, int depth=0)
    {
        char playerStr = stage[^1];
        int place = int.Parse(stage.Substring(0, stage.Length - 1));
        if (place == game.N) {
            if (playerStr == 'N') { return 1; }
            else { return -1; } 
        }
        //make game length to 20
        //find depth, where in some situations you can calcualate to end
        //and some situations not

        //try to find length of game and good depth, 
        //where calculation needs time, but not too mutch
        if (depth >= 6) { return 0; }
        //game not finished yet
        //print out all available moves from this point
        // Debug.Log(availableMoves(stage).ToSeparatedString(", "));
        List<string> moves = availableMoves(stage);
        var scores = moves.Select(move => score(move, depth+1));   
        return (playerStr=='N') ? scores.Min() : scores.Max();
    }

    string BestMove(string stage) {
        List<string> moves = availableMoves(stage);
        List<float> scores = moves.Select(move => score(move)).ToList();
        float bestScore=score(stage);
        int bestPosition = scores.IndexOf(bestScore);
        return moves[bestPosition];
    }

    void Start()
    {
        //Debug.Log(string.Join(",", availableMoves("2X")));
        game = GameObject.Find("GameObject").GetComponent<MainGame>();
       // positions = availableMoves("4X");
        //Change program, print out score for some starting position
        //example 2X
        //Debug.Log(positions.ToString());
        //Debug.Log(score("2X"));
        Debug.Log(BestMove("2X"));
    }

    void Update()
    {
            if (Time.time >= lastTime + 2)
        {
            if (game.sphere.GetComponent<Renderer>().material.color == game.player)
            {
                game.DisplayStage(BestMove(game.GetCurrentStage()));
            }
            //game.DisplayStage(positions[currentPosition]);

            //currentPosition++;
            //if (currentPosition == positions.Count) { currentPosition = 0; }
            //Debug.Log(score(positions[currentPosition]));
            lastTime=Time.time;
        }
    }
}