TicTacToe

os.loadAPI("button")
local mainMonitor = "top"
GamePanel = peripheral.wrap(mainMonitor)
GamePanel.clear()
ControlPanel = peripheral.wrap("right")

function writeMessage(message, monitor)
    local xc, yc = ControlPanel.getSize()
    ControlPanel.clear()
    ControlPanel.setCursorPos(math.floor((xc - string.len(message))/2+1),yc/2 + 1)
    ControlPanel.write(message)
end

local xo, yo = GamePanel.getSize()
print("Width: "..xo)
print("Height: "..yo)
local width = math.floor((xo-2)/3)
local height = math.floor((yo-2)/3)
print("Box width: "..width)
print("Box height: "..height)

function getEnemy(pPlayer)
    if pPlayer == "x" then
        return "o"
    elseif pPlayer == "o" then
        return "x"
    else
        print("Player \""..pPlayer.."\" has no opponent! (returning nil)")
        return nil
    end
end

activePlayer = "x"
nextGameActivePlayer = getEnemy(activePlayer)
winner = "empty"

function newGame()
    winner = "empty"
    clearAll()
    fillTable()
    activePlayer = nextGameActivePlayer
    nextGameActivePlayer = getEnemy(nextGameActivePlayer)
end

function getPlayerTable()
    local tbl = {}
    for x = 0,2 do
        tbl[x] = {}
        for y = 0,2 do
            tbl[x][y] = button.getPlayer(x..y)
        end
    end
    return tbl
end

function checkGameOver()
    local p1 = "x"
    local p2 = "o"
    local p3 = "empty"

    --Get player information
    local tbl = getPlayerTable()

    --Check draw
    local countNotEmpty = 0
    for x = 0,2 do
        for y = 0,2 do
            if tbl[x][y] ~= p3 then
                countNotEmpty = countNotEmpty + 1
            end
        end
    end
    if countNotEmpty == 9 then
        return true, p3, {}
    end

    -- Check win
    local countColumns = {[p1] = 0, [p2] = 0}
    local countRows = {[p1] = 0, [p2] = 0}
    local countDiagonal1 = {[p1] = 0, [p2] = 0}
    local countDiagonal2 = {[p1] = 0, [p2] = 0}

    for a = 0,2 do
        countColumns = {[p1] = 0, [p2] = 0}
        countRows = {[p1] = 0, [p2] = 0}
        for b = 0,2 do
            if tbl[a][b] ~= p3 then
                countColumns[tbl[a][b]] = countColumns[tbl[a][b]] + 1
            end
            if tbl[b][a] ~= p3 then
                countRows[tbl[b][a]] = countRows[tbl[b][a]] + 1
            end
        end

        if tbl[a][a] ~= p3 then
            countDiagonal1[tbl[a][a]] = countDiagonal1[tbl[a][a]] + 1
        end
        if tbl[a][2 - a] ~= p3 then
            countDiagonal2[tbl[a][2 - a]] = countDiagonal2[tbl[a][2 - a]] + 1
        end

        if countColumns[p1] == 3 then
            return true, p1, {{["x"] = a, ["y"] = 0},{["x"] = a, ["y"] = 1},{["x"] = a, ["y"] = 2}}
        elseif  countColumns[p2] == 3 then
            return true, p2, {{["x"] = a, ["y"] = 0},{["x"] = a, ["y"] = 1},{["x"] = a, ["y"] = 2}}
        end
        if countRows[p1] == 3 then
            return true, p1, {{["x"] = 0, ["y"] = a},{["x"] = 1, ["y"] = a},{["x"] = 2, ["y"] = a}}
        elseif  countRows[p2] == 3 then
            return true, p2, {{["x"] = 0, ["y"] = a},{["x"] = 1, ["y"] = a},{["x"] = 2, ["y"] = a}}
        end
    end

    if countDiagonal1[p1] == 3 then
        return true, p1, {{["x"] = 0, ["y"] = 0},{["x"] = 1, ["y"] = 1},{["x"] = 2, ["y"] = 2}}
    elseif  countDiagonal1[p2] == 3 then
        return true, p2, {{["x"] = 0, ["y"] = 0},{["x"] = 1, ["y"] = 1},{["x"] = 2, ["y"] = 2}}
    end
    if countDiagonal2[p1] == 3 then
        return true, p1, {{["x"] = 0, ["y"] = 2},{["x"] = 1, ["y"] = 1},{["x"] = 2, ["y"] = 0}}
    elseif  countDiagonal2[p2] == 3 then
        return true, p2, {{["x"] = 0, ["y"] = 2},{["x"] = 1, ["y"] = 1},{["x"] = 2, ["y"] = 0}}
    end

    return false, p3, {}
end

function getPlayerName(pPlayer)
    if pPlayer == "x" then
        return "Cross"
    elseif pPlayer == "o" then
        return "Circle"
    elseif pPlayer == "empty" then
        print("Player \"empty\" has no name! (returning \"empty\")")
        return "empty"
    else
        print("Player \""..pPlayer.."\" has is invalid! (returning nil)")
        return nil
    end
end

function fx(params)
    local x = params["x"]
    local y = params["y"]
    print("Field at "..x..","..y.." was clicked")
    if button.getPlayer(x..y) == "empty" then
        print(getPlayerName(activePlayer).." occupied the field at "..x..","..y..".")
        button.setPlayer(x..y, activePlayer)
        activePlayer = getEnemy(activePlayer)
        local gameOver, winner, wInformation = checkGameOver()
        if gameOver then
            print("Game over: "..getPlayerName(winner).." has won.")
            for a,b in pairs(wInformation) do
                button.setState(b["x"]..b["y"], true)
            end
            if winner == "empty" then
                writeMessage("Draw! Try again...")
            else
                writeMessage(getPlayerName(winner).." has won!", ControlPanel)
            end
        else
            writeMessage(getPlayerName(activePlayer).."\'s turn!", ControlPanel)
        end
    else
        print(getPlayerName(activePlayer).." cannot occupy the field at "..x..","..y..". It is already occupied by "..getPlayerName(button.getPlayer(x..y))..".")
    end
end

function fillTable()
    for x = 0,2 do
        for y = 0,2 do
         -- local pos = fieldIndex * FieldWidth + borderIndex * borderWidth(=1) + monitorIndex (0,1,2,3 -> 1,2,3,4)
            local xPos = x * width + x + 1
            local yPos = y * height + y + 1
            print("Drawing button "..x..","..y.." at "..xPos..","..yPos.." to the monitor on the top...")
            button.setTable(x..y, fx, {["x"] = x, ["y"] = y}, xPos, xPos + width - 1, yPos, yPos + height - 1, "top")
        end
    end
    button.screen()
end

function getClick()
    event,side,x,y = os.pullEvent("monitor_touch")
    button.checkxy(x, y, side)
end

fillTable()

while true do
    getClick()
end