#!/usr/bin/env bash
#
# Register an additional autofirmer instance on this device: same checkout,
# same build, its own PM2 process, port and database.
#
#   ./scripts/add-instance.sh <N> [--name <instance_name>] [--master <url>]
#                                 [--port <port>] [--token <backup_token>]
#                                 [--restore-from <instance_uuid>]
#
#   N            instance number, 2 or higher (1 is the legacy install:
#                pm2 name `autofirmer`, port 3000, ./autotrader.sqlite —
#                registered by install-autostart.sh, never by this script)
#   --name       instance_name to seed (default: <hostname>-N)
#   --master     master dashboard url to seed (default: leave the app's seed)
#   --port       listen port (default: 3000 + N - 1; NOTE the master dev
#                server uses 3001 — pick another port on a dev machine)
#   --token      master_backup_token to seed
#   --restore-from  pull that instance's backup from the master before first
#                boot and adopt its identity (requires --master and --token)
#
# The instance lands in scripts/instances.json, which start-all.mjs and
# update-check.mjs iterate. The first run of this script also records the
# legacy instance 1 there so updates keep restarting it.
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
REGISTRY="$ROOT/scripts/instances.json"

info() { printf '  %s\n' "$1"; }
die()  { printf '  [X] %s\n' "$1" >&2; exit 1; }

[ $# -ge 1 ] || die "usage: $0 <N> [--name ...] [--master ...] [--port ...] [--token ...] [--restore-from ...]"
N="$1"; shift
case "$N" in (*[!0-9]*|'') die "N must be a number, got: $N" ;; esac
[ "$N" -ge 2 ] || die "N starts at 2 — instance 1 is the legacy install (install-autostart.sh)"

NAME="$(hostname)-$N"
MASTER=""
PORT=$((3000 + N - 1))
TOKEN=""
RESTORE_FROM=""

while [ $# -gt 0 ]; do
    case "$1" in
        --name)         NAME="$2"; shift 2 ;;
        --master)       MASTER="$2"; shift 2 ;;
        --port)         PORT="$2"; shift 2 ;;
        --token)        TOKEN="$2"; shift 2 ;;
        --restore-from) RESTORE_FROM="$2"; shift 2 ;;
        *) die "unknown option: $1" ;;
    esac
done

PM2_NAME="autofirmer-$N"
DB_REL=".data/instance-$N/autotrader.sqlite"
DB_ABS="$ROOT/$DB_REL"

if [ -n "$RESTORE_FROM" ]; then
    [ -n "$MASTER" ] || die "--restore-from needs --master"
    [ -n "$TOKEN" ]  || die "--restore-from needs --token"
fi

NEXT_BIN="$ROOT/node_modules/next/dist/bin/next"
[ -f "$NEXT_BIN" ] || die "next not found at $NEXT_BIN - run npm install first"
[ -d "$ROOT/.next" ] || die "no production build - run npm run build first"
command -v pm2 >/dev/null 2>&1 || die "PM2 not installed - run install-autostart.sh first"

# ── registry: create with the legacy entry, refuse duplicates, append ───────
node - "$REGISTRY" "$PM2_NAME" "$PORT" "$DB_REL" <<'NODE'
const { existsSync, readFileSync, writeFileSync } = require('node:fs');
const [, file, name, port, db] = process.argv;
const entries = existsSync(file)
    ? JSON.parse(readFileSync(file, 'utf8'))
    : [{ name: 'autofirmer', port: 3000, db: 'autotrader.sqlite' }];
for (const e of entries) {
    if (e.name === name)         { console.error(`  [X] ${name} is already registered`); process.exit(1); }
    if (e.port === Number(port)) { console.error(`  [X] port ${port} is already used by ${e.name}`); process.exit(1); }
    if (e.db === db)             { console.error(`  [X] db ${db} is already used by ${e.name}`); process.exit(1); }
}
entries.push({ name, port: Number(port), db });
writeFileSync(file, JSON.stringify(entries, null, 4) + '\n');
console.log(`  registry: ${name} on :${port} -> ${db}`);
NODE

mkdir -p "$(dirname "$DB_ABS")"

# ── seed (and optionally restore) the new database ──────────────────────────
cd "$ROOT"
SEED_ARGS=()
[ -n "$TOKEN" ] && SEED_ARGS+=(--token "$TOKEN")
[ -n "$RESTORE_FROM" ] && SEED_ARGS+=(--restore-from "$RESTORE_FROM")
AUTOFIRMER_DB="$DB_ABS" node scripts/seed-settings.js "$MASTER" "$NAME" ${SEED_ARGS[@]+"${SEED_ARGS[@]}"}

# ── PM2 ─────────────────────────────────────────────────────────────────────
pm2 delete "$PM2_NAME" >/dev/null 2>&1 || true
PORT="$PORT" AUTOFIRMER_DB="$DB_ABS" pm2 start "$NEXT_BIN" --name "$PM2_NAME" --interpreter node --update-env -- start
pm2 save >/dev/null
info "pm2: $PM2_NAME registered and saved"

echo
info "instance $N is up: http://localhost:$PORT"
info "database: $DB_REL"
if [ -n "$RESTORE_FROM" ]; then
    info "restored from backup $RESTORE_FROM - stop the old machine if it is still running"
fi
info "remove later with: ./scripts/remove-instance.sh $N"