Snake ComputerCraft

local sx, sy = term.getSize()
local snakebody = {{5, 5}, {6, 5}, {7, 5}}
local snakehead = {snakebody[table.maxn(snakebody)][1], snakebody[table.maxn(snakebody)][2]}
local snakeface = "right"
local fed = false
local food = {10, 14}

local function tablecheck(tab, var)
    check = false

    for i, v in ipairs(tab) do
        if var == v then
            check = true
        end
    end

    return check
end

local function tabletablecheck(tab, var)
    check = false

    for i, v in ipairs(tab) do
        for i, v in ipairs(tab[i]) do
            if var == v then
                check = true
            end
        end
    end

    return check
end

local function poscheck(pos1, pos2)
    check = false

    if tabletablecheck(pos1, pos2[1]) and tabletablecheck(pos1, pos2[2]) then
        check = true
    end

    return check
end

local function snakeshow()
    term.setBackgroundColor(colors.white)
    term.clear()
    term.setBackgroundColor(colors.black)

    for a = 1, #snakebody do
        term.setCursorPos(snakebody[a][1], snakebody[a][2])
        term.blit(" ", "d", "d")
    end

    term.setCursorPos(food[1], food[2])
    term.blit(" ", "e", "e")
end

local function snakefeed()
    fed = true

    local cease = false

    while cease == false do
        food = {math.random(1, sx), math.random(1, sy)}

        if not poscheck(snakebody, food) then
            cease = true
        end
    end
end

local function snakemove()
    if fed == true then
        if snakeface == "up" then
            table.insert(snakebody, {snakehead[1], snakehead[2] - 1})
        elseif snakeface == "down" then
            table.insert(snakebody, {snakehead[1], snakehead[2] + 1})
        elseif snakeface == "right" then
            table.insert(snakebody, {snakehead[1] + 1, snakehead[2]})
        elseif snakeface == "left" then
            table.insert(snakebody, {snakehead[1] - 1, snakehead[2]})
        end

        fed = false
    elseif fed == false then
        if snakeface == "up" then
            table.insert(snakebody, {snakehead[1], snakehead[2] - 1})
            table.remove(snakebody, 1)
        elseif snakeface == "down" then
            table.insert(snakebody, {snakehead[1], snakehead[2] + 1})
            table.remove(snakebody, 1)
        elseif snakeface == "right" then
            table.insert(snakebody, {snakehead[1] + 1, snakehead[2]})
            table.remove(snakebody, 1)
        elseif snakeface == "left" then
            table.insert(snakebody, {snakehead[1] - 1, snakehead[2]})
            table.remove(snakebody, 1)
        end
    end

    snakehead = {snakebody[table.maxn(snakebody)][1], snakebody[table.maxn(snakebody)][2]}
end

local function snakelive()
    local check = true

    for a = 1, #snakebody - 1 do
        if snakehead[1] == snakebody[a][1] and snakehead[2] == snakebody[a][2] then
            check = false
        end
    end

    if snakehead[1] < 1 or snakehead[1] > sx or snakehead[2] < 1 or snakehead[2] > sy then
        check = false
    end

    return check
end

local function snaketime()
    local timer = os.startTimer(0.14)

    local face = snakeface

    while true do
        local event, par1 = os.pullEvent()

        if event == "timer" and par1 == timer then
            if face == "up" and snakeface ~= "down" then
                snakeface = face
            elseif face == "down" and snakeface ~= "up" then
                snakeface = face
            elseif face == "right" and snakeface ~= "left" then
                snakeface = face
            elseif face == "left" and snakeface ~= "right" then
                snakeface = face
            end

            snakemove()

            break
        elseif event == "key" and par1 == keys.up and face ~= "down" then
            face = "up"
        elseif event == "key" and par1 == keys.down and face ~= "up" then
            face = "down"
        elseif event == "key" and par1 == keys.right and face ~= "left" then
            face = "right"
        elseif event == "key" and par1 == keys.left and face ~= "right" then
            face = "left"
        end
    end
end

local function snakegame()
    while snakelive() == true do
        snakeshow()
        snaketime()

        if snakehead[1] == food[1] and snakehead[2] == food[2] then
            snakefeed()
        end
    end

    term.clear()
    term.setCursorPos(1, 1)

    print("Score : "..#snakebody - 3)

    sleep(1)
end

snakegame()