TIC TAC TOE

import java.lang.NumberFormatException

var nameUser = "no name"
var nameBot = "bot no name"

val NAME_BOTS = arrayOf("Mike", "Alex", "Anna", "Sara", "Lucas")

var sizeField = 0

var sizeLineForWin = 0

var gameField = arrayOf<Array<Char>>()

const val POINT: Char = '*'

const val FLAG_USER: Char = 'X'
var USER_MOVE_X: Int = 0
var USER_MOVE_Y: Int = 0

const val FLAG_BOT: Char = 'O'
var BOT_MOVE_X: Int = 0
var BOT_MOVE_Y: Int = 0

fun main() {
    welcomeToTheGame()
    initGameSettings()
    println("Start game!")
    startGame()

}

fun welcomeToTheGame() {
    println("Hello, welcome to tic tac toe!")
    print("What's your name? Please enter it: ")
    nameUser = readLine().toString()
    nameBot = NAME_BOTS[(Math.random() * NAME_BOTS.size).toInt()]
    println("You opponent is $nameBot")
}

fun initGameSettings() {

    sizeField =
        checkInputCorrectData("Enter to size on the field: ",
            0,
            99,
            "WARNING!!! Minimal and maximum size game field may be 3 - 99 cells, pls repeat!",
            "WARNING!!! You entered incorrect data, pls repeat!")

    sizeLineForWin =
        checkInputCorrectData("Enter the line size for win: ",
            3,
            sizeField,
            "WARNING!!! Minimal and maximum length line for win 3 - $sizeField, pls repeat!",
            "WARNING!!! You entered incorrect data, pls repeat!")

    gameField = Array(sizeField) { Array(sizeField) { POINT } }
}

fun checkInputCorrectData(msgForUser: String,
                          min: Int,
                          max: Int,
                          msgWarningIncorrectData: String,
                          msgWarningNumberFormatException: String): Int {
    var inputUser: Int

    while (true) {
        print(msgForUser)
        try {
            inputUser = readLine()!!.toInt()
            if (inputUser in min..max) {
                return inputUser
            } else {
                println(msgWarningIncorrectData)
            }
        } catch (e: NumberFormatException) {
            println(msgWarningNumberFormatException)
        }
    }
}

fun startGame() {
    while (true) {
        printField()
        if (!playUser()) {
            break
        }
        if (checkForWin(FLAG_USER)) {
            printNameWinner(nameUser)
            break
        }
        if (!playBot()) {
            break
        }
        if (checkForWin(FLAG_BOT)) {
            printNameWinner(nameBot)
            break
        }
    }
}

fun printField() {
    for (i in 0..gameField[0].size) {
        if (i != 0) {
            print("${i}\t")
        } else {
            print(" \t")
        }
    }
    println()

    for (i in gameField.indices) {
        print("${i + 1}\t")
        for (element in gameField[i]) {
            print("${element}\t")
        }
        println()
    }
}

fun printNameWinner(nameUser: String) {
    printField()
    println("Game over! $nameUser is winner! ^_^")
}

fun checkForWin(FLAG_GAMER: Char): Boolean {
    if (searchWinHorizontal(FLAG_GAMER)) return true
    if (searchWinVertical(FLAG_GAMER)) return true
    if (searchWinDiagonalToRightBottom(FLAG_GAMER)) return true
    if (searchWinDiagonalToLeftBottom(FLAG_GAMER)) return true

    return false
}

fun searchWinHorizontal(FLAG_GAMER: Char): Boolean {
    var buffer = 0

    for (i in 0..gameField.size - 1) {

        for (j in 0..gameField[0].size - 1) {
            if (gameField[i][j] != FLAG_GAMER) {
                buffer = 0
            } else {
                buffer += 1
                if (buffer == sizeLineForWin) return true
            }
        }

        buffer = 0
    }
    return false
}

fun searchWinVertical(FLAG_GAMER: Char): Boolean {
    var buffer = 0

    for (i in 0..gameField[0].size - 1) {

        for (j in 0..gameField.size - 1) {
            if (gameField[j][i] != FLAG_GAMER) {
                buffer = 0
            } else {
                buffer += 1
                if (buffer == sizeLineForWin) return true
            }
        }

        buffer = 0
    }
    return false

}

fun searchWinDiagonalToRightBottom(FLAG_GAMER: Char): Boolean {
    var buffer = 0

    for (i in 0..gameField.size - 1) {
        for (j in 0..gameField[0].size - 1) {

            if (gameField[i][j] == FLAG_GAMER) {
                buffer += 1

                for (n in 1..sizeLineForWin) {

                    if (i + n > gameField.size - 1 || j + n > gameField[0].size - 1) {
                        buffer = 0
                        break
                    } else {

                        if (gameField[i + n][j + n] == FLAG_GAMER) {
                            buffer += 1
                            if (buffer == sizeLineForWin) return true
                        } else {
                            buffer = 0
                            break
                        }
                    }
                }
            }
        }
        buffer = 0
    }
    return false
}

fun searchWinDiagonalToLeftBottom(FLAG_GAMER: Char): Boolean {
    var buffer = 0

    for (i in 0..gameField.size - 1) {
        for (j in 0..gameField[0].size - 1) {

            if (gameField[i][j] == FLAG_GAMER) {
                buffer += 1

                for (n in 1..sizeLineForWin) {

                    if (i + n > gameField.size - 1 || j - n < 0) {
                        buffer = 0
                        break
                    } else {

                        if (gameField[i + n][j - n] == FLAG_GAMER) {
                            buffer += 1
                            if (buffer == sizeLineForWin) return true
                        } else {
                            buffer = 0
                            break
                        }
                    }
                }
            }
        }
        buffer = 0
    }
    return false
}

fun playUser(): Boolean {
    return if (!checkForEmptyField()) {
        false
    } else {

        USER_MOVE_Y =
            checkInputCorrectData("Walk User: Enter to coordinate >> 'X' <<: ",
                0,
                sizeField,
                "WARNING!!! You entered incorrect data, pls repeat!",
                "WARNING!!! You entered incorrect data, pls repeat!")

        USER_MOVE_X =
            checkInputCorrectData("Walk User: Enter to coordinate >> 'Y' <<: ",
                0,
                sizeField,
                "WARNING!!! You entered incorrect data, pls repeat!",
                "WARNING!!! You entered incorrect data, pls repeat!")

        gameField[USER_MOVE_X - 1][USER_MOVE_Y - 1] = FLAG_USER

        true
    }
}

fun playBot(): Boolean {
    return if (!checkForEmptyField()) {
        false
    } else {

        while (true) {
            BOT_MOVE_Y = (Math.random() * sizeField + 1).toInt() - 1
            BOT_MOVE_X = (Math.random() * sizeField + 1).toInt() - 1
            if (gameField[BOT_MOVE_X][BOT_MOVE_Y] == POINT) {
                gameField[BOT_MOVE_X][BOT_MOVE_Y] = FLAG_BOT
                break;
            }
        }

        true
    }
}

fun checkForEmptyField(): Boolean {
    for (elStr in gameField) {
        for (elColumn in elStr) {
            if (elColumn == POINT) {
                return true
            }
        }
    }

    printField()
    println("Game over. Draw!")
    return false
}