#!/usr/bin/env bash
# wave-guard.sh <sentinel-name> <task> [<task>...]
#
# Solves the real cause of the wave-3 loss: the sprite AUTO-SUSPENDS when idle
# ("When idle, sprites pause automatically" — /.sprite/llm.txt). Detached workers
# do NOT keep it awake; only services, live sessions, or a task lease do.
#
# Holds a sprite task lease (POST /v1/tasks, max expire 3600s) and renews it while
# workers run, so the box stays hot with no console attached. When the workers stop
# it writes the durable completion record AND releases the lease, so the sprite is
# free to suspend instead of burning money idling.
#
# WAVE 4 POST-MORTEM — why this file was rewritten:
# The previous lease_hold() did DELETE-then-POST with both results discarded, and
# logged "lease renewed" unconditionally. If that POST ever failed, the box was left
# with NO lease while the log claimed otherwise. That is exactly what wave 4 looks
# like: last "renewal" 11:39, workers dead by 11:46, box rebooted 12:55. So now:
#   - every acquire is VERIFIED against GET /v1/tasks before it is believed
#   - a failed acquire retries, and is logged as a failure, never as a success
#   - the lease is re-checked every POLL (cheap), not only every RENEW, so a lease
#     lost between renewals is noticed in seconds instead of never
set -u
SENT="$1"; shift
TASKS=("$@")
L="$HOME/bookshelf/logs"; OUT="$L/$SENT"; LEASE="bookshelf-wave"
RENEW="${RENEW:-900}"        # proactively renew every 15 min against a 60 min lease
POLL="${POLL:-30}"           # but CHECK completion + lease health every 30s
GUARD_LOG="$L/wave-guard.log"

log() { echo "[$(date -Is)] $*" >> "$GUARD_LOG"; }

lease_present() { sprite-env curl /v1/tasks 2>/dev/null | grep -q "\"$LEASE\""; }

# Acquire and VERIFY. Returns 0 only if the lease is actually live afterwards.
lease_acquire() {
  local attempt
  for attempt in 1 2 3; do
    sprite-env curl -X DELETE "/v1/tasks/$LEASE" >/dev/null 2>&1
    sprite-env curl -X POST /v1/tasks -H 'Content-Type: application/json' \
      -d "{\"name\":\"$LEASE\",\"expire\":\"3600s\"}" >/dev/null 2>&1
    if lease_present; then return 0; fi
    log "WARNING: lease acquire attempt $attempt did not take; retrying"
    sleep 5
  done
  return 1
}

lease_release() { sprite-env curl -X DELETE "/v1/tasks/$LEASE" >/dev/null 2>&1; }

trap 'lease_release; log "guard exiting, lease released"; exit 0' TERM INT

log "guard start: sentinel=$SENT tasks=${TASKS[*]} renew=${RENEW}s poll=${POLL}s"
if lease_acquire; then
  log "lease '$LEASE' acquired and VERIFIED (3600s)"
else
  log "FATAL: could not acquire lease '$LEASE' -- the sprite may suspend mid-wave"
fi
last_renew=$(date +%s)

while pgrep -f 'run-task\.sh|run-resume\.sh' >/dev/null; do
  sleep "$POLL"
  now=$(date +%s)
  if [ $(( now - last_renew )) -ge "$RENEW" ]; then
    if lease_acquire; then
      log "lease renewed and VERIFIED; workers still running"
    else
      log "ERROR: scheduled renewal FAILED; lease is not held"
    fi
    last_renew=$now
  elif ! lease_present; then
    # Lost between renewals (expiry race, API blip, someone else's DELETE).
    log "ERROR: lease disappeared between renewals -- re-acquiring now"
    if lease_acquire; then
      log "lease re-acquired and VERIFIED"
      last_renew=$now
    else
      log "ERROR: emergency re-acquire FAILED; sprite is unprotected"
    fi
  fi
done

log "workers stopped; writing $SENT"
{
  echo "=== $SENT written $(date -Is) ==="
  echo "Workers finished. The orchestrator was NOT necessarily alive for this."
  echo
  for t in "${TASKS[@]}"; do
    echo "--- $t ---"
    grep -hE 'SUCCESS|GIVING UP|WALL CLOCK|QUOTA' "$L/$t.state" 2>/dev/null | tail -3
    if [ -s "$L/$t.json" ]; then
      jq -r '"cost=$" + ((.total_cost_usd//0)|tostring) + " turns=" + ((.num_turns//0)|tostring)' "$L/$t.json" 2>/dev/null
    else
      echo "!! $t.json is 0 bytes -> worker was KILLED, not finished (hazard #3/#5)"
    fi
    echo
  done
  echo "NEXT: orchestrator must independently verify before accepting:"
  echo "  cd ~/bookshelf && ./tasks/gw assembleDebug && ./tasks/gw testDebugUnitTest"
  echo "  git status --porcelain   # boundary check: who touched what"
} > "$OUT"

lease_release; log "lease released; sprite may suspend"