-- 1. CONFIGURATION

screen_width = 1000 -- FIXME
aspect_ratio = 1.5 -- a good default for dragonframe's typical 1620x1080 exports
window_titlebar_height = 39


-- 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. GET FILE LIST
-- TODO: get these some other way that's easier to use...
-- maybe args passed in from an Automater script?

local cd = exec("pwd")
local files = exec('stat -f "%N" *.mp4')

-- Create a table containing the complete path to every video:
local filetable = linesToTable(files)
for k, file in ipairs(filetable) do
  print("k "..k.." v "..file)
  filetable[k] = cd.."/"..file
  print(filetable[k])
end


-- 4. PREP FOR PLAYING

-- FIXME:
if #filetable <= 9 then
  cols = 3
  rows = 3
end

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


-- 5. PLAY + POSITION VIDEOS

-- We're going to loop through the list of videos.
-- For each video we will:
-- 1. use AppleScript to open it, playing on loop
-- 2. move it to the appropriate position

current_col = 1
current_row = 1
for _, file in ipairs(filetable) do
  print("opening "..file)
  print(string.format("  col: %s, row: %s", current_col, current_row))

  -- Calculate position / dimensions
  local x1 = (current_col * video_width) - video_width
  local y1 = (current_row * video_height) - video_height + (current_row * window_titlebar_height) - window_titlebar_height
  local x2 = x1 + video_width
  local y2 = y1 + video_height
  local bounds = string.format("{%d, %d, %d, %d}", x1, y1, x2, y2)

  print("  "..bounds)
  print()

  -- Open the video + play it on loop
  os.execute(
      string.format(
      [[osascript -e '
      set f to POSIX file "%s"
      tell application "QuickTime Player"
        set theMovie to open file f
        tell theMovie
          set the looping of theMovie to true
          play
        end tell
      end tell'
      ]], file))

  -- Move it to the correct spot on the screen
  os.execute(string.format("osascript -e 'tell application \"%s\" to set the bounds of the front window to %s'", "QuickTime Player", bounds))

  -- 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