#!/bin/sh

usage() {
  echo "Asks for recording type via dmenu."
  echo "If there is already a running instance, user will be prompted to end it. "
  echo ""
  echo "Usage: ${0##*/} [-h] [-a|--audio|audio] [-k|--kill|kill] [-v|--video|video] [-s|--screencast|screencast]"
  echo ""
  echo "Options:"
  echo "  - audio         : Records only audio"
  echo "  - kill          : Kills existing recording"
  echo "  - video         : Records only screen"
  echo "  - screencast    : Records both audio and screen"
}

getdim() { xrandr | grep -oP '(?<=current ).*(?=,)' | tr -d ' '; }

updateicon() {
  echo "$1" >/tmp/recordingicon
  pkill -RTMIN+24 "${STATUSBAR:-dwmblocks}"
}

killrecording() {
  recpid="$(cat /tmp/recordingpid)"
  kill -15 "$recpid"
  rm -f /tmp/recordingpid
  updateicon ""
  pkill -RTMIN+24 "${STATUSBAR:-dwmblocks}"
}

getmonitor() {
  xrandr | awk '
    /^[^ ]+ connected/ {
      name=$1
      if (match($0, /([0-9]+)x([0-9]+)\+([0-9]+)\+([0-9]+)/, a)) {
        printf "%s %s %s+%s\n", name, a[1] "x" a[2], a[3], a[4]
      }
    }
  '
}

selectmonitor() {
  map=$(getmonitor)
  [ -n "$map" ] || exit 1

  names=$(printf "%s\n" "$map" | awk '{print $1}')
  monitor_count=$(printf "%s\n" "$names" | wc -l)

  if [ "$monitor_count" -ge 2 ]; then
    options=$(printf "%s\nall" "$names")
    choice=$(printf "%s\n" "$options" | dmenu -p "Select monitor to record:")
    [ -n "$choice" ] || exit 1

    if [ "$choice" = "all" ]; then
      echo "all"
    else
      line=$(printf "%s\n" "$map" | awk -v mon="$choice" '$1 == mon')
      [ -n "$line" ] || exit 1
      res=$(echo "$line" | awk '{print $2}')
      pos=$(echo "$line" | awk '{print $3}')
      echo "$res+$pos"
    fi
  else
    echo "all"
  fi
}

screencast() {
  ffmpeg -y \
    -f x11grab \
    -framerate 30 \
    -s "$(getdim)" \
    -i "$DISPLAY" \
    -r 24 \
    -use_wallclock_as_timestamps 1 \
    -f alsa -thread_queue_size 1024 -i default \
    -c:v h264 \
    -crf 0 -preset ultrafast -c:a aac \
    "$recordings/screencast-$(date '+%y%m%d-%H%M-%S').mp4" &
  echo $! >/tmp/recordingpid
  updateicon "⏺️🎙️"
}

screencastselected() {
  geometry=$(selectmonitor) || exit 1
  if [ "$geometry" = "all" ]; then
    screencast
  else
    ffmpeg -y \
      -f x11grab \
      -framerate 30 \
      -video_size "${geometry%%+*}" \
      -i "$DISPLAY+${geometry#*+}" \
      -r 24 \
      -use_wallclock_as_timestamps 1 \
      -f alsa -thread_queue_size 1024 -i default \
      -c:v h264 \
      -crf 0 -preset ultrafast -c:a aac \
      "$recordings/screencast-$(date '+%y%m%d-%H%M-%S').mp4" &
    echo $! >/tmp/recordingpid
    updateicon "⏺️🎙️"
  fi
}

video() {
  ffmpeg \
    -f x11grab \
    -framerate 30 \
    -s "$(getdim)" \
    -i "$DISPLAY" \
    -c:v libx264 -qp 0 -r 30 \
    "$recordings/video-$(date '+%y%m%d-%H%M-%S').mkv" &
  echo $! >/tmp/recordingpid
  updateicon "⏺️"
}

videoselected() {
  slop -f "%x %y %w %h" >/tmp/slop
  read -r X Y W H </tmp/slop
  rm /tmp/slop

  ffmpeg \
    -f x11grab \
    -framerate 30 \
    -video_size "$W"x"$H" \
    -i :0.0+"$X,$Y" \
    -c:v libx264 -qp 0 -r 30 \
    "$recordings/box-$(date '+%y%m%d-%H%M-%S').mkv" &
  echo $! >/tmp/recordingpid
  updateicon "⏺️"
}

webcamselect() {
  cameras=$(
    v4l2-ctl --list-devices | awk '
  BEGIN { RS=""; FS="\n" }
  {
    name = $1;
    sub(/ \(.*$/, "", name);
    gsub(/^[ \t]+|[ \t]+$/, "", name);
    for (i=2; i<=NF; i++) {
      if ($i ~ /\/dev\/video/) {
        gsub(/^[ \t]+/, "", $i);
        print name "|" $i;
        break;
      }
    }
  }'
  )
  names=$(echo "$cameras" | cut -d '|' -f1)
  choice=$(echo "$names" | dmenu -i -p 'Choose a camera:')
  camera=$(echo "$cameras" | awk -F '|' -v sel="$choice" '$1 == sel {print $2}')
}

webcamhidef() {
  [ -z "$camera" ] && exit
  ffmpeg \
    -display_hflip \
    -f v4l2 \
    -i "$camera" \
    -video_size 1920x1080 \
    "$recordings/webcam-$(date '+%y%m%d-%H%M-%S').mkv" &
  echo $! >/tmp/recordingpid
  updateicon "🎥"
}

webcam() {
  [ -z "$camera" ] && exit
  ffmpeg \
    -display_hflip \
    -f v4l2 \
    -i "$camera" \
    -video_size 640x480 \
    "$recordings/webcam-$(date '+%y%m%d-%H%M-%S').mkv" &
  echo $! >/tmp/recordingpid
  updateicon "🎥"
}

audio() {
  ffmpeg \
    -f alsa -i default \
    -c:a flac \
    "$recordings/audio-$(date '+%y%m%d-%H%M-%S').flac" &
  echo $! >/tmp/recordingpid
  updateicon "🎙️"
}

askrecording() {
  choice=$(printf "screencast\\nscreencast selected\\nvideo\\nvideo selected\\naudio\\nwebcam\\nwebcam (hi-def)" | dmenu -i -p "Select recording style:")
  case "$choice" in
  screencast) screencast ;;
  "screencast selected") screencastselected ;;
  audio) audio ;;
  video) video ;;
  "video selected") videoselected ;;
  webcam) webcamselect && webcam ;;
  "webcam (hi-def)") webcamselect && webcamhidef ;;
  *) exit ;;
  esac
}

asktoend() {
  response=$(printf "No\\nYes" | dmenu -i -p "Recording still active. End recording?")
  [ -z "$response" ] && exit
  [ "$response" = "Yes" ] && killrecording
}

recordings="${XDG_VIDEOS_DIR:-$HOME/Videos}/recordings"
[ -d "$recordings" ] || mkdir -p "$recordings"

case "$1" in
-h | --help | help) usage && exit 0 ;;
-a | --audio | audio) audio ;;
-k | --kill | kill) killrecording ;;
-s | --screencast | screencast) screencast ;;
-ss | --screencast-selected | "screencast selected") screencastselected ;;
-v | --video | video) video ;;
-vs | --video-selected | "video selected") videoselected ;;
*) ([ -f /tmp/recordingpid ] && asktoend && exit) || askrecording ;;
esac