#!/bin/sh
# backhaul-agent container entrypoint. Bootstraps the newest agent script, installs a
# once-a-minute cron job (heartbeat + poll for work + self-update), runs once immediately,
# then hands off to cron. All config comes from env passed to `docker run`.
set -eu
: "${BACKHAUL_URL:?set BACKHAUL_URL (e.g. https://backhaul.skui.io)}"
: "${BACKHAUL_TOKEN:?set BACKHAUL_TOKEN (from the backhaul admin)}"

APP=/app/backhaul-agent.py
LOG=/var/log/backhaul-agent.log
touch "$LOG"

# Cron jobs run with a bare environment, so persist the vars the agent needs to a file
# the cron command sources. Single-quoted to survive spaces/specials in values.
{
  printf "export BACKHAUL_URL='%s'\n" "$BACKHAUL_URL"
  printf "export BACKHAUL_TOKEN='%s'\n" "$BACKHAUL_TOKEN"
  printf "export BACKHAUL_TARGETS='%s'\n" "${BACKHAUL_TARGETS:-}"
  printf "export BACKHAUL_AUTOUPDATE='%s'\n" "${BACKHAUL_AUTOUPDATE:-1}"
} > /app/env
chmod 600 /app/env

# Bootstrap self-update: pull the current script from the app so a fresh container is already
# up to date. Compile-check and sanity-check before replacing; keep the bundled copy on any
# failure. Disable with BACKHAUL_AUTOUPDATE=0.
if [ "${BACKHAUL_AUTOUPDATE:-1}" != "0" ]; then
  if curl -fsS -H "X-Agent-Token: $BACKHAUL_TOKEN" "$BACKHAUL_URL/api/agent-script" \
       -o /tmp/agent.new 2>/dev/null \
     && python3 -c "compile(open('/tmp/agent.new').read(),'a','exec')" 2>/dev/null \
     && grep -q backhaul-agent /tmp/agent.new; then
    cp /tmp/agent.new "$APP"
    echo "bootstrap: fetched latest agent script"
  fi
fi

# Every-minute cron job (system crontab format needs the user field).
echo "* * * * * root . /app/env; /usr/bin/python3 $APP >> $LOG 2>&1" > /etc/cron.d/backhaul
chmod 0644 /etc/cron.d/backhaul

# Run once now so the first check-in doesn't wait a full minute.
( . /app/env; /usr/bin/python3 "$APP" >> "$LOG" 2>&1 ) || true

echo "backhaul-agent up — check-in every minute; logs at $LOG"
cron                    # daemonize the scheduler
exec tail -f "$LOG"     # keep PID 1 alive and surface activity in `docker logs`