#!/usr/bin/env bash
set -euo pipefail

TEXTFILE_DIR="${TEXTFILE_DIR:-/mnt/user/services/posture-check/textfile}"
OUTPUT_FILE="${OUTPUT_FILE:-$TEXTFILE_DIR/homelab.prom}"
BORG_CONTAINER="${BORG_CONTAINER:-borg-ui}"
CRITICAL_CONTAINERS="${CRITICAL_CONTAINERS:-traefik authelia postgresql17 gitea komodo-core komodo-mongo komodo-periphery vaultwarden borg-ui ntfy adguard unbound Tailscale-Docker monitoring-alertmanager monitoring-alertmanager-ntfy-bridge monitoring-blackbox-exporter monitoring-cadvisor monitoring-grafana monitoring-loki monitoring-node-exporter monitoring-promtail immich_server immich_postgres immich_redis paperless-ngx nextcloud nextcloud-postgres nextcloud-redis mealie mealie-postgres}"

mkdir -p "$TEXTFILE_DIR"
tmp="$(mktemp "$TEXTFILE_DIR/homelab.prom.XXXXXX")"
cleanup() {
  rm -f "$tmp"
}
trap cleanup EXIT

now="$(date +%s)"

emit_gitops_runtime_image_metrics() {
  cat <<'EOF'
# HELP homelab_gitops_runtime_image_match Whether a running Compose container uses the image currently declared by its Compose config.
# TYPE homelab_gitops_runtime_image_match gauge
EOF

  if ! command -v jq >/dev/null 2>&1; then
    return
  fi

  docker ps \
    --filter label=com.docker.compose.project \
    --format '{{.Names}}\t{{.Label "com.docker.compose.project"}}\t{{.Label "com.docker.compose.service"}}\t{{.Label "com.docker.compose.project.config_files"}}\t{{.Label "com.docker.compose.project.environment_file"}}' |
    while IFS="$(printf '\t')" read -r container project service config_files env_file; do
      [ -n "$container" ] || continue
      [ -n "$service" ] || continue
      [ -n "$config_files" ] || continue

      config_file="${config_files%%,*}"
      [ -f "$config_file" ] || continue

      compose_args=(-f "$config_file")
      if [ -n "$env_file" ] && [ -f "$env_file" ]; then
        compose_args+=(--env-file "$env_file")
      fi

      expected="$(
        docker compose "${compose_args[@]}" config --format json 2>/dev/null |
          jq -r --arg service "$service" '.services[$service].image // empty' 2>/dev/null || true
      )"
      [ -n "$expected" ] || continue

      running="$(docker inspect -f '{{.Config.Image}}' "$container" 2>/dev/null || true)"
      [ -n "$running" ] || continue

      match="0"
      if [ "$running" = "$expected" ]; then
        match="1"
      fi

      printf 'homelab_gitops_runtime_image_match{name="%s",project="%s",service="%s"} %s\n' \
        "$container" "$project" "$service" "$match"
    done
}

{
  cat <<'EOF'
# HELP homelab_textfile_exporter_last_run_timestamp_seconds Unix timestamp of the last successful homelab textfile exporter run.
# TYPE homelab_textfile_exporter_last_run_timestamp_seconds gauge
EOF
  printf 'homelab_textfile_exporter_last_run_timestamp_seconds %s\n' "$now"

  cat <<'EOF'
# HELP homelab_critical_container_running Whether a critical container is currently running according to docker inspect.
# TYPE homelab_critical_container_running gauge
EOF
  for container in $CRITICAL_CONTAINERS; do
    running="0"
    if docker inspect -f '{{.State.Running}}' "$container" 2>/dev/null | grep -qx true; then
      running="1"
    fi
    printf 'homelab_critical_container_running{name="%s"} %s\n' "$container" "$running"
  done

  emit_gitops_runtime_image_metrics

  cat <<'EOF'
# HELP homelab_borg_last_completed_timestamp_seconds Unix timestamp of the most recent completed Borg backup job known to Borg UI.
# TYPE homelab_borg_last_completed_timestamp_seconds gauge
# HELP homelab_borg_last_success Whether the most recent Borg backup job completed successfully.
# TYPE homelab_borg_last_success gauge
# HELP homelab_borg_last_job_warning Whether the most recent Borg backup job completed with warnings.
# TYPE homelab_borg_last_job_warning gauge
EOF

  if docker inspect "$BORG_CONTAINER" >/dev/null 2>&1; then
    docker exec -i "$BORG_CONTAINER" python3 - <<'PY'
import datetime as dt
import sqlite3

conn = sqlite3.connect("/data/borg.db")
conn.row_factory = sqlite3.Row
cur = conn.cursor()

latest = cur.execute("""
    select status, completed_at, archive_name
      from backup_jobs
     order by coalesce(started_at, created_at) desc
     limit 1
""").fetchone()

completed = cur.execute("""
    select completed_at, archive_name
      from backup_jobs
     where status in ('completed', 'completed_with_warnings')
       and completed_at is not null
     order by completed_at desc
     limit 1
""").fetchone()

def parse_ts(value):
    if not value:
        return 0
    value = value.replace("Z", "+00:00")
    try:
        parsed = dt.datetime.fromisoformat(value)
    except ValueError:
        try:
            parsed = dt.datetime.strptime(value, "%Y-%m-%d %H:%M:%S")
        except ValueError:
            return 0
    if parsed.tzinfo is None:
        parsed = parsed.replace(tzinfo=dt.timezone.utc)
    return int(parsed.timestamp())

def escape_label(value):
    return (value or "").replace("\\", "\\\\").replace('"', '\\"')

latest_status = latest["status"] if latest else "missing"
latest_success = 1 if latest_status in ("completed", "completed_with_warnings") else 0
latest_warning = 1 if latest_status == "completed_with_warnings" else 0
completed_ts = parse_ts(completed["completed_at"]) if completed else 0
latest_archive = escape_label(latest["archive_name"] if latest else "")
completed_archive = escape_label(completed["archive_name"] if completed else "")

print(f'homelab_borg_last_success{{status="{latest_status}",archive="{latest_archive}"}} {latest_success}')
print(f'homelab_borg_last_job_warning{{status="{latest_status}",archive="{latest_archive}"}} {latest_warning}')
print(f'homelab_borg_last_completed_timestamp_seconds{{archive="{completed_archive}"}} {completed_ts}')
PY
  else
    printf 'homelab_borg_last_success{status="container_missing",archive=""} 0\n'
    printf 'homelab_borg_last_job_warning{status="container_missing",archive=""} 0\n'
    printf 'homelab_borg_last_completed_timestamp_seconds{archive=""} 0\n'
  fi
} > "$tmp"

# 0644 statt mktemp-default 0600, damit der node-exporter-Textfile-Collector
# (laeuft als nobody:65534) die Datei lesen kann.
chmod 644 "$tmp"
mv "$tmp" "$OUTPUT_FILE"
trap - EXIT

printf '%s\n' "$OUTPUT_FILE"