#!/usr/bin/env bash
# Keeps the shared checkout's observer and public API in step with origin/master, so a change an agent pushed to
# tools/observer or site/api is running here within five minutes (4 October 2026: the live API said "observer has
# not reported the proving layer" for an hour because the shared checkout was three commits behind origin).
# Fast-forwards only; if the shared checkout is ahead or dirty in those paths it logs and waits for a human.
# The observer is restarted whenever the checked-out observer.mjs or run.sh differs from what the running observer
# started from, whoever moved HEAD (4 October 2026, 19:35: a pull by hand moved HEAD past an observer fix and the
# observer kept the old code for ten minutes, because only this loop's own fast-forward used to restart it).
# Loop: tools/observer/autosync.sh   (log: /tmp/igneum-devnet/autosync.out)
# Check: tools/observer/autosync.sh check   prints the observer tree, the marker and whether a restart is due; exit 3 when due
cd "$(dirname "$0")/../.." || exit 1
LOG=/tmp/igneum-devnet/autosync.out
MARK="${OBSERVER_TREE_MARK:-/tmp/igneum-devnet/observer.tree}"   # tree id of tools/observer the running observer was started from
PATHS="tools/observer site/api"
# the code the running observer executes: observer.mjs and its restart loop (not autosync.sh or the README, whose
# changes used to restart it for nothing, 20:15 on 4 October 2026)
observer_tree() { git rev-parse "HEAD:tools/observer/observer.mjs" "HEAD:tools/observer/run.sh" 2>/dev/null | tr -d '\n' | shasum | cut -c1-40; }
marker() { cat "$MARK" 2>/dev/null || echo none; }
restart_due() { local t; t="$(observer_tree)"; [ -n "$t" ] && [ "$(marker)" != "$t" ]; }
restart_observer() { # <reason>
  local pid
  pid=$(pgrep -f "[n]ode tools/observer/observer.mjs" | head -1)
  if [ -n "$pid" ]; then kill "$pid" && echo "$(date -u +%FT%TZ) observer $pid restarted: $1"
  else echo "$(date -u +%FT%TZ) no observer process to restart ($1): is tools/observer/run.sh running?"; fi
  observer_tree > "$MARK"
}
if [ "${1:-}" = check ]; then
  echo "observer tree $(observer_tree | cut -c1-12), marker $(marker | cut -c1-12), restart $(restart_due && echo due || echo "not due")"
  restart_due && exit 3; exit 0
fi
mkdir -p "$(dirname "$LOG")"; exec >>"$LOG" 2>&1
while :; do
  git fetch -q origin master 2>/dev/null
  local_sha=$(git rev-parse HEAD); remote_sha=$(git rev-parse origin/master)
  if [ "$local_sha" != "$remote_sha" ]; then
    if [ -z "$(git status --porcelain -- $PATHS)" ] && git merge-base --is-ancestor HEAD origin/master; then
      if git merge -q --ff-only origin/master 2>/tmp/igneum-devnet/autosync-ff.err; then
        echo "$(date -u +%FT%TZ) fast-forwarded to $(git rev-parse --short HEAD)"
      else
        # name what blocks it: files dirty here that the incoming commits also change (4 October 2026, 20:05: results
        # files edited in the shared checkout against a commit of the same files; the observer sat behind master)
        blocking=$(comm -12 <(git status --porcelain | awk '{print $2}' | sort) <(git diff --name-only HEAD origin/master | sort) | head -5 | tr '\n' ' ')
        echo "$(date -u +%FT%TZ) fast-forward failed (local ${local_sha:0:7}, origin ${remote_sha:0:7}): $(head -c 200 /tmp/igneum-devnet/autosync-ff.err | tr '\n' ' ') blocking: ${blocking:-none found}"
      fi
    else
      echo "$(date -u +%FT%TZ) not fast-forwardable or dirty in $PATHS (local $local_sha, origin $remote_sha); waiting"
    fi
  fi
  if restart_due; then restart_observer "tools/observer tree $(observer_tree | cut -c1-12) (was $(marker | cut -c1-12))"; fi
  sleep 300
done