#!/bin/bash
# @file pane-launch.sh
# @description Server mode, one Linux user per account (S3): installed as
# /opt/agenthub/libexec/pane-launch. A member's pane starts as
# `pane-launch <launch file>`: the dashboard creates the session AS the member
# through sudo, and sudo logs its whole command line — so the pane's
# environment (a pane token, a pool account's token) and its argv (the prompt)
# are not in that command line but in the launch file, which `write-as`
# wrote as the member (0600) from stdin. This reads it, deletes it, exports
# the environment and execs the command; no shell ever parses a value.
#
# The file is NUL-separated: the number of environment entries, the
# NAME=value entries, then the argv (none = a login shell).
# @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
set -eu
f=${1:?usage: pane-launch <launch file>}
mapfile -d '' -t parts <"$f"
rm -f -- "$f"
n=${parts[0]}
[[ "$n" =~ ^[0-9]+$ ]] || { echo "pane-launch: malformed launch file" >&2; exit 2; }
for kv in "${parts[@]:1:n}"; do
  [[ "$kv" =~ ^[A-Za-z_][A-Za-z0-9_]*= ]] || { echo "pane-launch: bad variable" >&2; exit 2; }
  export "$kv"
done
argv=("${parts[@]:n+1}")
if [ ${#argv[@]} -eq 0 ]; then exec -l "${SHELL:-/bin/bash}"; fi
exec "${argv[@]}"