#!/bin/sh
# Roll the production supervision promotion back to the incumbent detached pair.
#
# This restores the process-management arrangement that ran production before
# the supervision cutover: two nohup'd binaries entered into the anchor
# container's network namespace via nsenter, parented to init.
#
# It performs NO database or schema change, because the promotion it reverses
# performs none either. The economy is never at risk here.
#
# Run with --dry-run first; that prints the exact commands and touches nothing.
#
# usage: openfut-rollback-detached.sh [--dry-run]
set -eu

DRY=0
[ "${1:-}" = "--dry-run" ] && DRY=1

ANCHOR=openfut-fut-backend
ART=/home/alex/openfut-migration/promote-contract-20260822-184409/artifacts
ENVJSON=/home/alex/openfut-migration/promote-contract-20260822-184409/env.json
LOGDIR=/home/alex/openfut-promotion/logs

run() {
    if [ "$DRY" -eq 1 ]; then printf '  DRY  %s\n' "$*"; else printf '  RUN  %s\n' "$*"; sh -c "$*"; fi
}

echo "== 1. stop and remove supervision (units only; binaries, env and DB untouched) =="
run "systemctl disable --now openfut-host.service openfut-core.service openfut-netns.service openfut-netns-reconcile.timer || true"
run "/home/alex/OpenFUT/scripts/systemd/openfut-supervision-install.sh uninstall production"

echo "== 2. resolve the anchor's CURRENT namespace (never a remembered pid) =="
if [ "$DRY" -eq 1 ]; then
    APID="$(docker inspect -f '{{.State.Pid}}' "$ANCHOR" 2>/dev/null || echo '<anchor pid>')"
    echo "  DRY  anchor $ANCHOR pid=$APID ns=$(readlink "/proc/$APID/ns/net" 2>/dev/null || echo '<ns>')"
else
    APID="$(docker inspect -f '{{.State.Pid}}' "$ANCHOR")"
    [ -n "$APID" ] && [ "$APID" != "0" ] || { echo "anchor $ANCHOR is not running — cannot roll back into its namespace" >&2; exit 1; }
    echo "  anchor $ANCHOR pid=$APID ns=$(readlink "/proc/$APID/ns/net")"
fi

# The environment is replayed from the captured live process environment, never
# retyped. jq renders it as KEY=VALUE pairs for env(1).
CORE_ENV="$(jq -r '.core | to_entries[] | "\(.key)=\(.value)"' "$ENVJSON" | tr '\n' ' ')"
HOST_ENV="$(jq -r '.host | to_entries[] | "\(.key)=\(.value)"' "$ENVJSON" | tr '\n' ' ')"

echo "== 3. relaunch incumbent Core (the writer first) =="
run "mkdir -p $LOGDIR"
run "nsenter --net=/proc/$APID/ns/net env $CORE_ENV nohup $ART/openfut-core >> $LOGDIR/prod-core.log 2>&1 &"
run "/home/alex/OpenFUT/scripts/systemd/openfut-wait-tcp.sh 127.0.0.1 18080 30"

echo "== 4. relaunch incumbent host =="
run "nsenter --net=/proc/$APID/ns/net env $HOST_ENV nohup $ART/openfut-utas-host >> $LOGDIR/prod-host.log 2>&1 &"
run "/home/alex/OpenFUT/scripts/systemd/openfut-wait-tcp.sh 127.0.0.1 8099 30"

echo "== 5. verify =="
run "pgrep -af 'openfut-core|openfut-utas-host'"
echo "Rollback complete. No database or schema change was made."