Aperture Science OS System - AppStore_AppPage

--AppPage
--this program shows the details of the Choosen App, and allows the User to either "Download", "Exit", or "Uninstall"
--this program is for Minecraft 1.16.5, CC Tweaked


local tArg = {..}
local AppName = tArg[1]
local AppDataCode = tArg[2]
local AppAuthor = nil
local AppDiscription = nil
local AppLauncher = nil
local ClientAppRelation = "Not Installed"
local PageScroll = 1
local AppDownloadCode = nil
local y,h = term.getSize()


term.clear()
term.setcursorPos(1,1)
print("APP PAGE")

function CenterText(y,text)
  local x = math.floor((y - string.len(text)) /2)
  term.setCursorPos(x,y)
  term.clearLine()
  term.write(text)
end

function Download()
fs.delete("Temp_AppData")
shell.run(AppDownloadCode)
local Apps = fs.open("AppList","a")
local i = #AppList.list()
AppList.setCursorPos(1,i+1)
AppList.writeLine(AppName)
AppList.writeLine(AppLauncher)
AppList.close()
shell.run(".ApertureOS_AppMenu")
end

function GetAppData()
shell.run("pastebin","get",AppDataCode,"Temp_AppData")
local file = fs.open("Temp_AppData","r")
AppAuthor = file.readLine(3)
AppDiscription = file.readLine(4)
AppLauncher = file.readLine(5)
AppDownloadCode = file.readLine(7)
file.close()
end

function DrawMenu()
term.setBackground(colors.white)
paintutils.drawFilledBox(40,3,48,5,colors.green)
term.setCursorPos(41,4)
term.write("Download")
CenterText(4,AppName)
CenterText(6,AppAuthor)
paintutils.drawFilledBox(1,1,3,3,colors.red)
paintutils.drawLine(1,1,3,3,colors.black)
paintutils.drawLine(1,3,3,1,colors.black)
paintutils.drawFilledBox(2,8,49,30,colors.white)
local Lines = require"cc.strings".wrap(AppDiscription, 45)
for i = 1 #Lines do
  term.setCursorPos(3,i+9)
  term.write(Lines[i])
end
end

GetAppData()
DrawMenu()

while true do
  local event, Item, x, y = os.pullEvent()
  if event == "mouse_click" and x > 40 and x < 48 and y > 3 and y < 5 and ClientAppRelation == "Not Installed" then --clicked on Download Button
    paintutils.drawFilledBox(10,4,40,8,colors.gray)
    CenterText(6,"DOWNLOADING APPLICATION, PLEASE WAIT")
    term.setCursorPos(10,7)
    textutils.slowWrite("==============================")
    sleep(20)
    Download()
    break
  elseif event == "mouse_click" and x < 3 and y < 3 then --returns back to Store Menu, not the browser
    shell.run(".ApertureOS_AppStore")
    break
  elseif event == "key" and Item == keys.down and PageScroll < 40 then
    PageScroll = PageScroll + 1
    term.scroll(1)
  elseif event == "key" and Item == keys.up and Page Scroll > 1 then
    PageScroll = PageScroll - 1
    term.scroll(-1)
  end
  DrawMenu()
end