#!/usr/bin/env ruby -s
# randrmove [-rp] [CRTC...] - cycle windows between xrandr "screens"
# By default, cycle left-to-right.
#   -r to reverse the order
#   -p to try to keep proportions screen layout
# Needs xrandr, xdotool, xwininfo.

# TODO: 
# * fix negative offsets
# * resize windows?
# * base proportions on smallest distance to margin

cycle = ARGV

screens = {}

minfo = `xdotool getmouselocation`
mx = minfo[/x:(\d+)/, 1].to_i
my = minfo[/y:(\d+)/, 1].to_i

`xrandr --current`.each_line { |line|
  fields = line.split
  if fields[1] == "connected"
    screens[fields[0]] = fields[2].split(/[x+]/).map { |n| n.to_i }
  end
}

if cycle.empty?
  cycle = screens.sort_by { |_, (_, _, sx, sy)| [sx,sy] }.map { |s, _| s }
end

cycle.reverse!  if $r

abort "unknown screens: #{cycle-screens.keys}"  unless (cycle-screens.keys).empty?

`xdotool search --name --onlyvisible .`.each_line { |windowid|
  windowid.chomp!
  winfo = `xwininfo -id #{windowid}`

  info = []
  ["Absolute upper-left X", "Absolute upper-left Y", "Width", "Height"].each { |f|
    info << winfo[/#{f}: *(\d+)/, 1].to_i
  }
  
  x, y, w, h = *info
  
  # find screen where window occupies most space
  screen = screens.sort_by { |_, (sw, sh, sx, sy)|
    [0, [sx+sw, x+w].min - [sx, x].max].max *
    [0, [sy+sh, y+h].min - [sy, y].max].max
  }.first.first
  
  target = cycle[(cycle.index(screen)+1) % cycle.size]  rescue screen

  next  if screen == target

  sw,sh,sx,sy = screens[screen]
  tw,th,tx,ty = screens[target]

  if $p
    #  *(sw.to_f/tw)).to_i
    puts "windowmove #{windowid} #{(sx+(x-tx)*(sw.to_f/tw)).to_i} #{(sy+(y-ty)*(sw.to_f/tw)).to_i}  # #{sx-tx} #{sy-ty}"
  else
    puts "windowmove #{windowid} #{x+sx-tx} #{y+sy-ty}  # #{sx-tx} #{sy-ty}"
  end
}

mscreen = screens.sort_by { |_, (sw, sh, sx, sy)|
  [0, [sx+sw, mx+1].min - [sx, mx].max].max *
  [0, [sy+sh, my+1].min - [sy, my].max].max
}.first.first

mtarget = cycle[(cycle.index(mscreen)+1) % cycle.size]  rescue exit
  
_,_,sx,sy = screens[mscreen]
_,_,tx,ty = screens[mtarget]

puts "mousemove #{mx+sx-tx} #{my+sy-ty}  # #{sx-tx} #{sy-ty}"