#!/bin/sh -eu

program=$(basename "$0")
directory=$HOME/.config/seance
session=$directory/session
spirits=$directory/spirits

Help() {
printf \
"
Usage: %s [FLAGS]... [ARGUMENT]...

The program $program shall save and restore
running programs in a desktop session according
to a specified configuration file.

Add a program command, one per line, in
$spirits
to save to current session.

Session: $session
Config:  $spirits

  Command List:

   $program commit        Saves programs in config to session.
   $program list          List session commands.
   $program config        View programs to be saved to session.
   $program windows       List running programs
   $program search        Search for a running program.
   $program start         Restore previous session.
   $program edit session  Edit session commands.
   $program edit config   Edit programs in config.
   $program -h --help     Show this help menu.

" "$program";
}

Commit() {

windows=$(wmctrl -Glp)
date=$(date --utc '+%a-%b-%d-%H:%M:%S-%Y')

IFS='
'

mv "$1" "$1-$date"

true > "$1"

for window in $windows; do

pid=$(printf "%s" "$window" | awk '{ print $3 }')
desktop=$(printf "%s" "$window" | awk '{ print $2 }')
title=$(printf "%s" "$window" | tr -s ' ' | cut -d ' ' -f 9-)
dimensions=$(printf "%s" "$window" | awk '{ print $4, ",", $5, ",", $6, ",", $7 }' | tr -d ' ')
[ "$pid" = "0" ] && continue;
process=$(ps -ww -p "$pid" -o command | tail -n 1)

while read -r spirit; do
  case "$process" in
  *$spirit*) process=$spirit ;;
  esac
done < "$spirits"

commands=$(printf "%s" "$title" | cut -d ' ' -f 3- | sed "s|'|'\\\\\\\''|g")

[ -z "$commands" ] && commands="true"

mime="$(file --mime-type "$title" | awk '{ print $2 }')"
directory=$(printf "%s" "$title" | cut -d ' ' -f 2)

case "$mime" in
application/pdf) process="zathura $title" ;;
esac

case "$title" in
*term:*) process="\$TERMINAL -e sh -c 'cd $directory && $commands; \$SHELL'" ;;
esac

case "$title" in
*vim:*) process="\$TERMINAL -e sh -c '\$EDITOR $directory; \$SHELL'" ;;
esac

case "$title" in
*\[Scratch\]*) continue ;;
esac

case "$commands" in
*$program*) continue ;;
esac

grep "$process" "$1" > /dev/null 2>&1 && continue

printf "%s\n" "$process"

printf "\
$process > /dev/null 2>&1 & disown
i=0; until wmctrl -Glp | grep -i \"\$!\"; do i=\$((i+1)); [ \$i -gt 150 ] && break; done
wmctrl -i -r \"\$(wmctrl -Glp | awk -v pid=\"\$!\" '\$0 ~ pid { print \$1 }')\" -t $desktop
wmctrl -i -r \"\$(wmctrl -Glp | awk -v pid=\"\$!\" '\$0 ~ pid { print \$1 }')\" -e '0,$dimensions'

" >> "$1"
done
}

{ [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ] || [ "$#" = 0 ]; } && Help && exit;

mkdir --parents "$directory"

touch "$spirits"

[ "${1:-}" = "commit" ] \
  && { Commit "$session" || printf "Warning empty or failed session file!\n"; } \
  && printf '\nSession %s canonized.\n\n' "$session" \
  && exit

[ "${1:-}" = "list" ]    && cat "$session" && exit;

[ "${1:-}" = "config" ]  && cat "$spirits" && exit;

[ "${1:-}" = "windows" ] && wmctrl -Glp && exit;

[ "${1:-}" = "search" ]  && wmctrl -Glp | grep --ignore-case -- "$2" && exit;

[ "${1:-}" = "start" ]   && sh "$session" && exit;

[ "${1:-}" = "edit" ] && [ "${2:-}" = "session" ] && $EDITOR "$session" && exit;

[ "${1:-}" = "edit" ] && [ "${2:-}" = "config" ]  && $EDITOR "$spirits" && exit;

Help && printf "Error: Unknown argument '%s'.\n\n" "$@" && exit 1;