#!/bin/bash

_help() {
  echo 'Commands:
  -o [filename] -s [size] -p [pos] -r [framerate] -d [delay] -i
  default filename: '$filename'
  default size: '$size'
  default pos:  '$pos'
  default framerate:  '$framerate'
  default delay: '$delay'
  -i for interactive selection using "slop"
  --shell "[cmd]" to record current terminal, default cmd: bash

  Hit "q"  when finished (or exit shell in --shell)!
'
}
_helpexit(){
  _help
  exit
}

printf -v filename "grab-%(%FT%H-%M)T.mp4"
size=$( xdpyinfo  | awk "/dimensions/{print \$2}" )
pos="0,0"
framerate=15
delay=0
interact=0
new_shell=0
shell_command=bash
for (( i=1; i<=$#; i++ )); do
  [[ ${!i} = "-h"* ]] && _helpexit
  [[ ${!i} = "--h"* ]] && _helpexit
  [[ ${!i} = "help" ]] && _helpexit
done
for (( i=1; i<=$#; i++ )); do
  j=$(( $i + 1 ))
  if [[ ${!i} = "-o" ]]; then
    filename="${!j}"
    shift
  fi
  if [[ ${!i} = "-s" ]]; then
    size="${!j}"
    shift
  fi
  if [[ ${!i} = "-p" ]]; then
    pos="${!j}"
    shift
  fi
  if [[ ${!i} = "-r" ]]; then
    framerate="${!j}"
    shift
  fi
  if [[ ${!i} = "-d" ]]; then
    delay="${!j}"
    shift
  fi
  if [[ ${!i} = "-i" ]]; then
    interact=1
  fi
  if [[ ${!i} = "--shell" ]]; then
    new_shell=1
    shell_command="${!j}"
    shift
  fi
done
shell_command="${shell_command:-bash}"

if [[ $delay -gt 0 ]]; then
  echo Waiting.. for $delay seconds
  sleep $delay
fi

if [[ $new_shell -eq 0 ]]; then

  if [[ $interact -eq 1 ]]; then
    slop=$( slop -b 10 -c 1.0,0.8,0.1,0.8 )
    size=$( echo $slop | cut -d+ -f1 )
    pos=$( echo $slop | cut -d+ -f2-3 )
    pos=${pos/+/,}
  else
    convert -size 256x256 xc:red PNG8:- | timeout 5 feh --geometry $size+${pos//,/+} -
  fi
else
   eval $(xwininfo -id $(xdotool getactivewindow) |
    sed -n -e "s/^ \+Absolute upper-left X: \+\([0-9]\+\).*/x=\1/p" \
           -e "s/^ \+Absolute upper-left Y: \+\([0-9]\+\).*/y=\1/p" \
           -e "s/^ \+Width: \+\([0-9]\+\).*/w=\1/p" \
           -e "s/^ \+Height: \+\([0-9]\+\).*/h=\1/p" )
  size="${w}x${h}"
  pos="${x},${y}"
fi
echo Grabbing: $filename ${size}+$pos

rm -f "$filename"

if [[ $new_shell -eq 1 ]]; then

  echo Starting to record in 5 seconds, or press enter
  read -t 5 foo || true
  ffmpeg \
      -video_size $size \
      -framerate $framerate \
      -f x11grab \
      -i $DISPLAY+${pos} \
      -vf "pad=ceil(iw/2)*2:ceil(ih/2)*2" \
      -c:v libx264 -crf 23 -profile:v baseline -level 3.0 -pix_fmt yuv420p \
      -an \
      -movflags faststart \
      -loglevel panic \
      -hide_banner \
      "$filename" &
  ffpid=$!
  clear
  eval "$shell_command"
  kill -INT $ffpid
  trap - EXIT SIGINT SIGTERM
  tput init
  echo ""
else
  ffmpeg \
      -video_size $size \
      -framerate $framerate \
      -f x11grab \
      -i $DISPLAY+${pos} \
      -vf "pad=ceil(iw/2)*2:ceil(ih/2)*2" \
      -c:v libx264 -crf 23 -profile:v baseline -level 3.0 -pix_fmt yuv420p \
      -an \
      -movflags faststart \
      -loglevel panic \
      -hide_banner \
      "$filename"
fi

echo "Saved to: $filename"