const direction = [[-1, 0], [1, 0], [0, 1], [0, -1], [0, 0]];

class Node {
    constructor(state, move, player) {
        this.player = player;
        this.state = state;
        this.move = move;
        this.value = Math.abs(state[0] - state[2]) + Math.abs(state[1] - state[3]);
        this.child = [];
    }
    
    addDepth(map) {
        var x;
        var y;
        var c;
        var i = 0;
        if (this.child.length) {
            for (c = 0; c < this.child.length; ++c) {
                this.child[c].addDepth(map);
            }
        }
        else
        {
        if (this.player) {
            for (i = 0; i < 5; ++i) {
                x = this.state[0] + direction[i][0];
                y = this.state[1] + direction[i][1];
                
                if (!map[y][x]) {
                    this.child.push(new Node([x, y, this.state[2], this.state[3]], i, !this.player));
                }
            }
        }
        else {
            for (i = 0; i < 5; ++i) {
                x = this.state[2] + direction[i][0];
                y = this.state[3] + direction[i][1];
                
                if (!map[y][x]) {
                    this.child.push(new Node([this.state[0], this.state[1], x, y], i, !this.player));
                }
            }
        }
        }
    }
    
    getBest() {
        if (!this.child.length || this.value === 0) {
            return [this.value, this.move];
        }
        
        var cur;
        var c;
        var tmp;
        if (this.player) {
            cur = [0, 0];
            for (c = 0; c < this.child.length; ++c) {
                tmp = this.child[c].getBest();
                if (tmp[0] > cur[0]) {
                    cur = [tmp[0], this.child[c].move];
                }
            }
        }
        else
        {
            cur = [100, 0];
            for (c = 0; c < this.child.length; ++c) {
                tmp = this.child[c].getBest();
                if (tmp[0] < cur[0]) {
                    cur = [tmp[0], this.child[c].move];
                }
            }
        }
        return cur;
    }
}

function Mind() 
{
	this.newRun = function()                  
	{
	    this.map = [];
	    for (var i = 0; i < 20; ++i) {
	        this.map.push([]);
	        for (var j = 0; j < 20; ++j) {
	            if (i === 0 || i === 19 || j === 0 || j === 19) {
	                this.map[i].push(1);
	            }
	            else {
	            this.map[i].push(0);    
	            }
	        }
	    }
	    this.dir = 0;
	    this.last = [0, 0];
	};

    this.setWall = function(state) {
        if (state[0] != this.last[0] || state[1] != this.last[1]) {
            return false;
        }
        x = state[0] + direction[this.dir][0];
        y = state[1] + direction[this.dir][1];
        if (x == state[3] || y == state[4]) {
            return false;
        }
        this.map[y][x] = 1;
        return true;
    };
    
    this.moveTree = function(state) {
        var i;
        var reset = true;
      for (i = 0; i < this.tree.child.length; ++i) {
          if (this.tree.child[i].state[0] == state[0] && this.tree.child[i].state[1] == state[1]) {
              this.tree = this.tree.child[i];
              reset = false;
              break;
          }
      }
      if (reset) {
          return false;
      }
      reset = true;
      for (i = 0; i < this.tree.child.length; ++i) {
          if (this.tree.child[i].state[2] == state[2] && this.tree.child[i].state[3] == state[3]) {
              this.tree = this.tree.child[i];
              reset = false;
              break;
          }
      }
      return !reset;
    };
    
    this.printMap = function() {
        for (var i = 0; i < this.map.length; ++i) {
            console.log(i, this.map[i].join(' '));
        }
    };
    
    this.reset = function( state ) {
        this.tree = new Node(state, 4, true);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
            this.tree.addDepth(this.map);
    };
    
	this.getAction = function ( state )		 
	{
	    if (this.last[0] === 0) {
            this.reset(state);
            this.last = [state[0], state[1]];
            return (1);
        }
        if (!this.moveTree(state)) {
            this.reset(state);
        }
        if (this.setWall(state)) {
            this.reset(state);
        }
        else
        {
        this.tree.addDepth(this.map);
        this.tree.addDepth(this.map);
        }
        this.last = [state[0], state[1]];
        this.dir = this.tree.getBest()[1];
        return ( this.dir );
	};

		 
	this.endRun = function()                
	{
	};

}