-- Wrap monitor
local monitor = peripheral.wrap("monitor_1")
monitor.clear()
monitor.setTextScale(2)

-- Board setup
local board = {
    {" "," "," "},
    {" "," "," "},
    {" "," "," "}
}

local currentPlayer = "X"
local colorsMap = {X = colors.red, O = colors.blue}

-- Monitor dimensions
local width, height = monitor.getSize()
local topMargin = 3
local cellWidth = math.floor(width / 3)
local cellHeight = math.floor((height - topMargin) / 3)

-- Draw the grid and board
local function drawBoard()
    monitor.clear()
    monitor.setTextColor(colors.white)
    monitor.setCursorPos(1,1)
    monitor.write("=== Tic-Tac-Toe ===")

    -- Draw grid lines
    for i = 1, 2 do
        -- Vertical lines
        local x = i * cellWidth + 1
        for y = topMargin, height do
            monitor.setCursorPos(x, y)
            monitor.write("|")
        end
        -- Horizontal lines
        local y = topMargin + i * cellHeight - 1
        monitor.setCursorPos(1, y)
        monitor.write(string.rep("-", width))
    end

    -- Draw X and O
    for r = 1, 3 do
        for c = 1, 3 do
            local x = (c - 1) * cellWidth + math.floor(cellWidth / 2)
            local y = topMargin + (r - 1) * cellHeight + math.floor(cellHeight / 2)
            monitor.setCursorPos(x, y)
            monitor.setTextColor(colorsMap[board[r][c]] or colors.white)
            monitor.write(board[r][c])
        end
    end

    -- Display current player
    monitor.setTextColor(colors.white)
    monitor.setCursorPos(1, height)
    monitor.write("Player "..currentPlayer.."'s turn     ")
end

-- Check for win
local function checkWin()
    for i=1,3 do
        if board[i][1] ~= " " and board[i][1] == board[i][2] and board[i][2] == board[i][3] then return true end
        if board[1][i] ~= " " and board[1][i] == board[2][i] and board[2][i] == board[3][i] then return true end
    end
    if board[1][1] ~= " " and board[1][1] == board[2][2] and board[2][2] == board[3][3] then return true end
    if board[1][3] ~= " " and board[1][3] == board[2][2] and board[2][2] == board[3][1] then return true end
    return false
end

-- Check for draw
local function checkDraw()
    for r=1,3 do
        for c=1,3 do
            if board[r][c] == " " then return false end
        end
    end
    return true
end

-- Convert touch coordinates to row/column
local function touchToCell(x, y)
    local col = math.ceil(x / cellWidth)
    local row = math.ceil((y - topMargin + 1) / cellHeight)
    if row < 1 then row = 1 end
    if row > 3 then row = 3 end
    if col < 1 then col = 1 end
    if col > 3 then col = 3 end
    return row, col
end

-- Main loop
drawBoard()
while true do
    local event, side, x, y = os.pullEvent("monitor_touch")
    local row, col = touchToCell(x, y)

    if row >= 1 and row <= 3 and col >= 1 and col <= 3 then
        if board[row][col] == " " then
            board[row][col] = currentPlayer
            drawBoard()

            if checkWin() then
                monitor.setCursorPos(1, height)
                monitor.setTextColor(colors.green)
                monitor.write("Player "..currentPlayer.." wins!     ")
                break
            elseif checkDraw() then
                monitor.setCursorPos(1, height)
                monitor.setTextColor(colors.yellow)
                monitor.write("It's a draw!     ")
                break
            else
                currentPlayer = (currentPlayer == "X") and "O" or "X"
                drawBoard()
            end
        end
    end
end