install

if not (string.sub(os.version(),1,8)=="TurtleOS") then
  print("Diese API ist nur fuer Turtles gedacht!")
  return
end

local startupFile = "turtle.startup"
local apiFolder = "customAPI"
local apiFile = "turtle.advanced"
local apiPath = fs.combine(apiFolder,apiFile)


local function getFileContent( path )
  local result
  if fs.exists(path) then
    local file = fs.open(path, "r")
    result = file.readAll()
    file.close()
  end
  return result
end


-- break if the api file is allready existing
if fs.exists(apiPath) then
  print("\""..apiPath.."\" existiert")
  print("  schon auf dem System!")
  return
end

local oldStartup = getFileContent("startup")
local newStartup = getFileContent("disk/"..startupFile)

-- break if defined startup file is not existant
if not newStartup then
  print("\"disk/"..startupFile.."\" konnte")
  print("  nicht gelesen werden!")
  return
end

-- break if api file could not be found
if not fs.exists("disk/"..apiFile) then
  print("\"disk/"..apiFile.."\" existiert nicht!")
  return
end

-- try copying api file
if not fs.exists(apiFolder) then
  fs.makeDir(apiFolder)
end
fs.copy("disk/"..apiFile, apiPath)

-- check if startup exists on system
if not oldStartup then
  -- if not, simply copy the startup file
  fs.copy("disk/"..startupFile, "startup")
else
  -- if it does, merge the new one in at the front
  local file = fs.open("startup", "w")
  file.writeLine("--- LOAD API ---")
  file.writeLine(newStartup)
  file.writeLine()
  file.writeLine("--- BEGIN OF STARTUP ---")
  file.writeLine(oldStartup)
  file.close()
end

-- print success message
textutils.slowPrint("Installation vollstaendig!")