// Personal notes
//
//      const ACTION_LEFT       = 0;               
//      const ACTION_RIGHT      = 1;
//      const ACTION_UP         = 2;             
//      const ACTION_DOWN       = 3;
//      const ACTION_STAYSTILL  = 4;
//
// Grid = 20 * 20, but only 18 * 18 is playable
// state = (x1, y1, x2, y2)

function Mind()  {
    
    // Creating an x, y grid with each position having a counter
    // Example: x, y : 0
    // 0 being the counter for the number of moves
    // moves starts at (1, 1) and ends at (18, 18)
    
    var moves = {};
    var x = 1;
    var y = 1;
        
    while (y < 19) {
        while (x < 19) {
            let tmp_xy = [x, y];
            moves[tmp_xy] = 0;
            x++;
        }
        x = 1;      // Reset x
        y++;
    }
	// moves is now properly initialized
	
	function newMove(agent) {
	    // Generate new move
        var new_move = Math.floor(Math.random() * 5);
        var original_agent = agent;
        
        // Check whether new move (coordinate) is valid
        if (new_move === 0) {                       // LEFT: (x-1, y)
            agent = [agent[0]-1, agent[1]];
        } else if (new_move === 1) {                // RIGHT: (x+1, y)
            agent = [agent[0]+1, agent[1]];
        } else if(new_move === 2) {                 // UP: (x, y+1)
            agent = [agent[0], agent[1]+1];
        } else if (new_move === 3) {                // DOWN: (x, y-1)
            agent = [agent[0], agent[1-1]];
        }
        
        try {
            xy_move_count = moves[agent];           // moves[agent] is the counter of agent coordinate
        } catch(e) {
            if (e instanceof TypeError) {
                return newMove(original_agent);     // If coordinate out of range, call newMove again
            }
        }
        
        if (xy_move_count < 3) {                    // This integer specifies maximum allowed duplicate moves
            moves[agent]++;
            return new_move;
        } else {
            return newMove(original_agent);
        }
	}
	
	this.newRun = function() {
	};

	
	this.getAction = function (state) {
        let agent = [state[0], state[1]];
        let [x1, y1] = agent;                   // agent = (x1, y1)
        
        let enemy = [state[2], state[3]];
        let [x2, y2] = enemy;                   // enemy = (x2, y2)
        
        return newMove(agent);
	};

		 
	this.endRun = function() {
	};

}