#!/usr/bin/env lua

-- 1. CONFIGURATION

screen_width = 1150 -- FIXME... 
    -- The screen is actually 1280, but at that height
    -- 3 rows of videos is actually too tall, so this is a quick
    -- hack to make sure they all fit vertically
aspect_ratio = 1.5 -- a good default for dragonframe's typical 1620x1080 exports
-- menubar_height = 39
menubar_height = 22 -- at 1280x800 the menu bar is shorter


-- 2. UTILITY FUNCTIONS

function exec(cmd)
  local handle = io.popen(cmd)
  local result = handle:read("*a")
  handle:close()
  result = result:sub(1, #result - 1) -- remove trailing newline
  return result
end

function linesToTable(s)
  local t = {}
  for x in string.gmatch(s, "([^%s]+)") do
    table.insert(t, x)
  end
  return t
end

-- 3. COUNT WINDOWS + SET UP GRID

number_of_windows = tonumber(exec("osascript -e 'tell application \"System Events\" to count (windows of process \"QuickTime Player\" where value of attribute \"AXMinimized\" is false)'"))
print("There are currently "..number_of_windows.." non-minimized QuickTime windows")

-- FIXME:
if number_of_windows <= 9 then
  cols = 3
  rows = 3
elseif number_of_windows <= 12 then
  cols = 4
  rows = 3
-- elseif number_of_windows <= 16 then
--  cols = 5
--  rows = 3
--elseif number_of_windows <= 20 then
--  cols = 4
--  rows = 5
--elseif number_of_windows <= 25 then
--  cols = 5
--  rows = 5
--elseif number_of_windows <= 30 then
--  cols = 5
--  rows = 6
--elseif number_of_windows <= 36 then
--  cols = 6
--  rows = 6
else
  os.execute("osascript -e 'display dialog \"you have too many videos lol\"'")
  os.exit()
end

video_width = screen_width // cols -- "floor division" returns an integer
video_height = video_width // aspect_ratio


-- 4. PLAY + POSITION VIDEOS

-- For each QuickTime window we will:
-- 1. use AppleScript to play it on loop
-- 2. move it to the appropriate position

current_col = 1
current_row = 1
for i = 1, number_of_windows do
  -- Calculate position / dimensions
  local x1 = (current_col * video_width) - video_width
  local y1 = (current_row * video_height) - video_height + menubar_height
  local x2 = x1 + video_width
  local y2 = y1 + video_height
  local bounds = string.format("{%d, %d, %d, %d}", x1, y1, x2, y2)
  print(string.format("row %s, col %s: %s", current_row, current_col, bounds))

  -- Loop
  local loopCmd = string.format('tell application "QuickTime Player" to set the looping of document %d to true', i)
  os.execute("osascript -e '"..loopCmd.."'")

  -- Play
  local playCmd = string.format('tell application "QuickTime Player" to play document %d', i)
  os.execute("osascript -e '"..playCmd.."'")

  -- Move
  local moveCmd = string.format('tell application "QuickTime Player" to set the bounds of window %d to %s', i, bounds)
  os.execute("osascript -e '"..moveCmd.."'")

  -- Update grid positioning for the next iteration
  current_col = current_col + 1
  if current_col > cols then
    current_col = 1
    current_row = current_row + 1
  end
end