setup

os.pullEvent = os.pullEventRaw

local w,h = term.getSize()

--Print Centered Function
function printCentered(y,s,c)
    local x = math.floor((w - string.len(s)) /2)
    term.setCursorPos(x,y)
    term.setTextColor(c or colors.white)
    term.clearLine()
    term.write(s)
end

function printC(s,c)
    term.setTextColor(c or colors.white)
    print(s)
end

--Draw Menu Function

local nOption = 1

local function drawMenu()
    term.clear()
    term.setCursorPos(1,1)
    term.write("")

    term.setCursorPos(w-11,1)
    if nOption == 1 then
        term.write("Install")
    elseif nOption == 2 then
        term.write("Uninstall")
    else
        end
end

--Interface
term.clear()
local function drawFrontend()
    term.setCursorPos(1,1)
    printC("+-------------------------------------------------+", colors.yellow)
    printC("|                                                 |", colors.yellow)
    term.setCursorPos(22,2)
    printC("CharlieOS", colors.lime)
    printC("|                                                 |", colors.yellow)
    term.setCursorPos(23,3)
    printC("dev1.0b")
    printC("+-------------------------------------------------+", colors.yellow)
    printCentered(math.floor(h/2) + 0, ((nOption == 1 and "[ Install ]") or "Install"), colors.lime)
    printCentered(math.floor(h/2) + 1, ((nOption == 2 and "[ Uninstall ]") or "Uninstall"), colors.red)
    printCentered(math.floor(h/2) + 2, ((nOption == 3 and "[ About ]") or "About"), colors.purple)
end

--About
local function about()
    while true do
    term.clear()
    printCentered(math.floor(h/2) + 0, "CharlieOS is created by: Charlestone Maru")
    printCentered(math.floor(h/2) + 1, "Contact [email protected]")
    printCentered(math.floor(h/2) + 2, "To help me improve this OS.")
    term.setCursorPos(1,19)
    term.setTextColor(colors.yellow)
    print("Press Enter to go back...")
    local e,p = os.pullEvent()
    if e == "key" then
        local key = p
        if key == 28 then
        shell.run("setup")
        end
    end
end
end

--Install
local function install()
    while true do
    term.clear()
    term.setCursorPos(1,1)
    printC("Are you sure to install CharlieOS? (y/n)", colors.yellow)
    printC("Installation cannont be teminated...", colors.yellow)
    printC(">", colors.yellow)
    term.setCursorPos(3,3)
    term.setTextColor(colors.white)
    say = read()
    if say == "Y" or say == "y" then
        term.clear()
        term.setTextColor(colors.white)
        term.setCursorPos(1,1)
        shell.run("pastebin","run B2aetUKP")
    elseif say == "N" or say == "n" then
        printC("Installation Aborded.", colors.red)
        sleep(1)
        shell.run("setup")
    else
        printC("Invalid Choice...", colors.red)
        sleep(1)
    end
    end
end

--Uninstall
local function uninstall()
        while true do
        term.clear()
        term.setCursorPos(1,1)
        printC("Are you sure to Uninstall CharlieOS? (y/n)", colors.yellow)
        printC("Uninstallation cannont be teminated...", colors.yellow)
        printC(">", colors.yellow)
        term.setCursorPos(3,3)
        term.setTextColor(colors.white)
        say = read()
        if say == "Y" or say == "y" then
            term.clear()
            term.setTextColor(colors.white)
            term.setCursorPos(1,1)
            shell.run("pastebin","run eVLZwCy1")
        elseif say == "N" or say == "n" then
            printC("Uninstallation Aborded.", colors.red)
            sleep(1)
            shell.run("setup")
        else
            printC("Invalid Choice...", colors.red)
            sleep(1)
        end
    end
end

--Display
drawMenu()
drawFrontend()

while true do
    local e,p = os.pullEvent()
    if e == "key" then
        local key = p
        if key == 17 or key == 200 then
            if nOption > 1 then
                nOption = nOption - 1
                drawMenu()
                drawFrontend()
            end
            elseif key == 31 or key == 208 then
                if nOption < 3 then
                    nOption = nOption + 1
                    drawMenu()
                    drawFrontend()
                end

        elseif key == 28 then
            break
        end
    end
end
term.clear()

--Conditions
if nOption == 1 then
    install()
elseif nOption == 2 then
    uninstall()
elseif nOption == 3 then
    about()
end