#!/usr/bin/env bash
# Opens a remote desktop session to the shell server as Administrator, for when SSH is down. The session runs
# headless on a virtual display, so it can be driven from the command line:
#
#   server/scripts/rdp.sh         opens the session (and closes one that is still open)
#   server/scripts/rdp.sh stop    closes it
#
# - look:   DISPLAY=:73 import -window root shot.png
# - type:   printf 'text' > $XDG_RUNTIME_DIR/kik-rdp/keys, and special keys with DISPLAY=:73 xdotool key Return
# - files:  $XDG_RUNTIME_DIR/kik-rdp/share is \\tsclient\kik in the session
#
# The password is read from .password.txt in the root of the repository and handed to the client on stdin, so it
# shows up neither on a command line nor in a log.
set -euo pipefail

repo=$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)
dir=${XDG_RUNTIME_DIR:-/tmp}/kik-rdp
display=:73

for pid in "$dir"/*.pid; do
    [ -e "$pid" ] || continue
    kill "$(cat "$pid")" 2>/dev/null || true
    rm -f "$pid"
done
if [ "${1:-}" = stop ]; then exit; fi

bin() { echo "$(nix build --no-link --print-out-paths "nixpkgs#$1")/bin/$2"; }
mkdir -p "$dir/share"
# the client creates the pipe itself and refuses one that is left over
rm -f "$dir/keys"

setsid "$(bin xorg.xvfb Xvfb)" "$display" -screen 0 1280x800x24 -nolisten tcp > "$dir/xvfb.log" 2>&1 < /dev/null &
echo $! > "$dir/xvfb.pid"
sleep 2

{
    printf '%s\n' /v:nowhere.wirs.ing /u:Administrator /cert:tofu /size:1280x800 +auto-reconnect \
        "/drive:kik,$dir/share" "/kbd:unicode:on,pipe:$dir/keys" /log-level:WARN
    printf '/p:%s\n' "$(cat "$repo/.password.txt")"
} | DISPLAY=$display setsid "$(bin freerdp xfreerdp)" /args-from:stdin > "$dir/xfreerdp.log" 2>&1 &
echo $! > "$dir/xfreerdp.pid"

sleep 15
if kill -0 "$(cat "$dir/xfreerdp.pid")" 2>/dev/null; then
    printf 'The session is open on display %s; %s/share is \\\\tsclient\\kik in it.\n' "$display" "$dir"
else
    echo 'The client ended:' >&2
    tail -5 "$dir/xfreerdp.log" >&2
    exit 1
fi