#!/bin/bash
# I, Ian Kelling, follow the GNU license recommendations at
# https://www.gnu.org/licenses/license-recommendations.en.html. They
# recommend that small programs, < 300 lines, be licensed under the
# Apache License 2.0. This file contains or is part of one or more small
# programs. If a small program grows beyond 300 lines, I plan to change
# to a recommended GPL license.

# Copyright 2024 Ian Kelling

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -e; . /usr/local/lib/bash-bear; set +e

script_name="${0##*/}"
usage() {
  cat <<EOF
Usage: $script_name [OPTIONS]

Turns on/off secondary monitor.

Sets resolution.

Alters i3 config.

-n  Dry run

-r  Restart secondary monitor

-s  No stream setup. Normally, split monitor into 2 virtual screens and
      set max resolution 2560x1440


-h|--help             Print help and exit.

Note: Uses GNU getopt options parsing style
EOF
  exit $1
}
edid() {
  card=$1
  sha256sum </sys/class/drm/$card/edid | grep -oE '^.{10}'
}

i3() {
  if [[ $I3SOCK ]]; then
    i3-msg "$@"
  fi
}

move-ws() {
  local target_out output tmps
  target_out=$1
  shift

  if [[ ! ${ws_out[*]} ]]; then
    declare -a ws_out
    tmps=$(i3 -t get_workspaces)
    if [[ ! $tmps ]]; then
      return 0
    fi
    tmps=$(jq -r '.[] | .num, .output' <<<"$tmps")
    while read -r ws; do
      read -r output || break
      ws_out["$ws"]=$output
    done <<<"$tmps"
  fi

  for ws; do
    if [[ ${ws_out[$ws]} && ${ws_out[$ws]} != "$target_out" ]]; then
      # if the workspace is already there, this will fail.
      # if the workspace doesn't exist yet, it fails with:
      # ERROR: No output matched
      m i3 '[workspace="'$ws'"]' move workspace to output $target_out
    fi
  done
}

date "+%A, %B %d, %r, %S seconds"

##### begin command line parsing ########

dry_run=false
stream=true
restart=false
temp=$(getopt -l help nrs "$@") || usage 1
eval set -- "$temp"
while true; do
  case $1 in
    -n) dry_run=true ;;
    -r) restart=true ;;
    -s) stream=false ;;
    -h|--help) usage 0 ;;
    --) shift; break ;;
    *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  esac
  shift
done

##### end command line parsing ########


xf=$(mktemp)
xrandr >$xf

m() { printf "$script_name: %s\n" "$*"; "$@"; }
if $dry_run; then
  m() { printf "$script_name: %s\n" "$*"; }
fi

for mon_suffix in LEFT RIGHT; do
  if xrandr --listmonitors | awk '$2 == "BIG-'$mon_suffix\" |grep . >/dev/null; then
    m xrandr --delmonitor BIG-$mon_suffix
  fi
done


secondary_out=$(awk '$2 == "connected" && $3 != "primary" {print $1}' $xf)
primary_info=$(awk '$2 == "connected" && $3 == "primary" {print $1,$4}' $xf)

# res_info eg: 3840x2160+1920+0
read -r primary_out primary_res_info <<<"$primary_info"

primary_res=${primary_res_info%%+*}
primary_x=${primary_res%x*}
primary_y=${primary_res#*x}


if [[ $secondary_out ]]; then

  # some monitors need off then on to become active
  if $restart; then
    m xrandr --output $secondary_out --off
    m sleep 2
  fi

  x_offset=$primary_x
  left_right_arg=--right-of
  if [[ $secondary_out == HDMI2 && $(edid card0-HDMI-A-2) == 192efbdcef ]] || \
       [[ $secondary_out == HDMI-1 && $(edid card1-HDMI-A-1 ) == 7c58f9ac1e ]] || \
       [[ $secondary_out == DP-1 && $(edid card1-DP-1 ) == f3364bc6c1 ]]; then
    left_right_arg=--left-of
    x_offset=0
  fi
  left_right_arg="$left_right_arg $primary_out"

  target_out=$secondary_out
  target_res=$(grep -A1 -E "^$secondary_out " $xf | tail -n1 | awk '{print $1}')
  target_x=${target_res%x*}
  target_y=${target_res#*x}
else
  # disables any leftover secondary.
  xrandr --auto
  target_out=$primary_out
  x_offset=0
  target_res=$primary_res
  target_x=$primary_x
  target_y=$primary_y
fi



if $stream && (( target_x > 1280 )); then

  if (( target_x > 2560 )); then
    target_x=2560
    target_y=1440
    target_res=${target_x}x$target_y
  fi

  if [[ $secondary_out || $primary_res != "$target_res" ]]; then
    m xrandr --output $target_out $left_right_arg --mode $target_res
  fi

  half_x=$(( target_x / 2 ))
  # 298 & 336 are millimeters. I took them from a monitor I was using. I
  # don't know if they are important, I assume not important enough to
  # change for different monitors.
  m xrandr --setmonitor BIG-LEFT $half_x/298x$target_y/336+$x_offset+0 $target_out
  m xrandr --setmonitor BIG-RIGHT $half_x/298x$target_y/336+$(( x_offset + half_x ))+0 none

  move-ws BIG-LEFT 2
  move-ws BIG-RIGHT 3 4 5 6 7 8 9 10

else
  m xrandr --output $target_out $left_right_arg --mode $target_res
  move-ws $target_out 2 3 5 6 7 8 9 10
fi

m /a/bin/ds/i3-sway/gen
m /a/exe/input-setup

echo -n "myx end: "
date "+%A, %B %d, %r, %S seconds"