MiniMax algorithm in Kotlin - Nim Game

Question

I have a question regarding my implementation of the minimax algorithm for the game called "nim game" in kotlin. It is based on the minimax algorithm that is described in wikipedia.

I do not really know why it is not working. I think the problem is in the evaluate method. If the player is +1 the algorithm should link a great move with a high value and if the player is -1 it should link a great move with a low value.

To understand the Code you may need to know what some methods and variables do:

rows -> IntArray of the current board. If rows = (2,3) the board has 2 matches in the first row and 3 in the second

createAllMoves -> takes rows and creates all possible Moves. If rows = (1,1) there are two Moves: (0,1) take one match out of the first row, or (1,0) take one match out of the second row

play(Move) -> if Move = (3,1) and rows (1,2,3) the output is: rows = (1,2,2) because the Move took 1 match out of the third row

desiredDepth = 5

I'd be pleased if you know how to improve my code. Thanks in advance.

fun evaluate(player: Int) : Int {
    if (player == 1) {
        return 1
    } else if (player == -1) {
        return -1
    }
    return 0
}

fun max(player: Int, depth: Int): Int{

    var tmpAllMoves: MutableList<Move> = createAllMoves(rows)   

    if(depth == 0 || tmpAllMoves.isEmpty()){
        return evaluate(player)
    }

    var maxValue: Int = Int.MIN_VALUE

    while(!tmpAllMoves.isEmpty()){

        var randomMove: Move = tmpAllMoves.random();

        play(randomMove)

        tmpAllMoves.remove(randomMove)

        var value: Int = min(-1*player, depth-1)

        undoMove()

        if(value > maxValue){
            maxValue = value
            if(depth == desiredDepth){
                var savedMove: Move = randomMove
            }
        }
    }
    return maxValue
}

fun min(player: Int, depth: Int): Int{

    var tmpAllMoves: MutableList<Move> = createAllMoves(rows)

    if(depth == 0 || tmpAllMoves.isEmpty()){
        return evaluate(player)
    }

    var minValue: Int = Int.MAX_VALUE

    while(!tmpAllMoves.isEmpty()){

        var randomMove: Move = tmpAllMoves.random();

        play(randomMove)

        tmpAllMoves.remove(randomMove)

        var value: Int = max(-1*player, depth-1)

        undoMove()

        if(value < minValue){
            minValue = value
        }
    }
    return minValue
}