-- credit: osmarks https://pastebin.com/ZP9Q1HCT

local Sound = require('sound')

local modules = _G.peripheral.wrap('back')
local os = _G.os
local parallel = _G.parallel

if not modules.launch or not modules.getMetaOwner then
  error([[Required:
* Kinetic augment
* Introspection module]])
end

local function run()
  local launchCounter = 0

  while true do
    local meta = modules.getMetaOwner()

    if not meta.isSneaking and meta.isElytraFlying then

      if meta.pitch < 0 then -- looking up
        modules.launch(meta.yaw, meta.pitch, -meta.pitch / 22.5)
        Sound.play('entity.bobber.throw', .6)
        os.sleep(0.1)

      elseif meta.motionY < -0.5 then -- falling fast
        modules.launch(0, 270, -meta.motionY + 1)
        Sound.play('entity.bat.takeoff')
        os.sleep(0)

      else
        os.sleep(0.1)
      end

    elseif meta.isSneaking and not meta.isElytraFlying and meta.pitch == -90 then
      if launchCounter < 2 then
        launchCounter = launchCounter + 1
        Sound.play('block.note.pling', .5)
        os.sleep(0.5)

      else
        Sound.play('entity.bobber.throw', 1)
        modules.launch(0, 270, 4)
        os.sleep(0.2)
      end

    elseif not meta.isSneaking and meta.motionY < -0.8 then
      print('falling...')
      modules.launch(0, 270, -meta.motionY + 1)
      Sound.play('entity.bat.takeoff')
      os.sleep(0)

    else
      launchCounter = 0
      os.sleep(0.4)
    end
  end
end

parallel.waitForAny(
  function()
    print('\nFlight control initialized')
    print('\nSneak and look straight up for launch')
    print('Sneak to deactivate during flight')
    print('\nPress any key to exit')
    os.pullEvent('char')
  end,
  function()
    while true do
    local _, m = pcall(run)
      if m then
        print(m)
      end
      print('Waiting for 5 seconds before restarting')
      os.sleep(5)
    end
  end)