#!/usr/bin/env node
/**
 * SiMS HQ database backup (ops slice). Dumps the Postgres database to a timestamped,
 * compressed file under ./backups (or $HQ_BACKUP_DIR), then rotates to the newest N.
 *
 *   DATABASE_URL=postgres://user:pass@host:5432/db  node scripts/backup.mjs
 *   npm run backup   (from apps/hq — passes DATABASE_URL through)
 *
 * Restore a dump with:
 *   pg_restore --clean --if-exists --no-owner -d "$DATABASE_URL" backups/hq-<ts>.dump
 *
 * SECURITY (D32): credentials are stored in the CLEAR, so these dumps contain plaintext
 * logins. Keep the backups/ directory access-controlled and off any shared drive; it is
 * gitignored so it can never be committed.
 *
 * Env: DATABASE_URL (required), HQ_BACKUP_DIR (default ./backups), HQ_BACKUP_KEEP (default 14).
 */
import { execFileSync } from 'node:child_process'
import { mkdirSync, readdirSync, statSync, unlinkSync, existsSync } from 'node:fs'
import { join } from 'node:path'

const url = process.env.DATABASE_URL
if (!url || url.trim() === '') {
  console.error('DATABASE_URL is not set. Run: DATABASE_URL=postgres://… node scripts/backup.mjs')
  process.exit(1)
}

/** Locate pg_dump: PATH first, then a standard Windows PostgreSQL install. */
function findPgDump() {
  try {
    execFileSync(process.platform === 'win32' ? 'where' : 'which', ['pg_dump'], { stdio: 'ignore' })
    return 'pg_dump'
  } catch { /* not on PATH */ }
  if (process.platform === 'win32') {
    const base = 'C:/Program Files/PostgreSQL'
    try {
      for (const v of readdirSync(base).sort().reverse()) {
        const cand = join(base, v, 'bin', 'pg_dump.exe')
        if (existsSync(cand)) return cand
      }
    } catch { /* no install dir */ }
  }
  return null
}

const pgDump = findPgDump()
if (pgDump === null) {
  console.error('pg_dump not found. Install the PostgreSQL client tools, or add pg_dump to PATH.')
  process.exit(1)
}

const OUT = process.env.HQ_BACKUP_DIR || join(process.cwd(), 'backups')
const KEEP = Math.max(1, Number(process.env.HQ_BACKUP_KEEP || 14))
mkdirSync(OUT, { recursive: true })

const d = new Date()
const p2 = (n) => String(n).padStart(2, '0')
const ts = `${d.getFullYear()}${p2(d.getMonth() + 1)}${p2(d.getDate())}-${p2(d.getHours())}${p2(d.getMinutes())}${p2(d.getSeconds())}`
const file = join(OUT, `hq-${ts}.dump`)

// -Fc = custom, compressed, restorable with pg_restore. --no-owner keeps it portable.
try {
  execFileSync(pgDump, ['-Fc', '--no-owner', '-f', file, url], { stdio: ['ignore', 'inherit', 'inherit'] })
} catch (e) {
  console.error(`pg_dump failed: ${e instanceof Error ? e.message : String(e)}`)
  process.exit(1)
}

const kb = (statSync(file).size / 1024).toFixed(1)
console.log(`✓ backup written: ${file} (${kb} KB)`)

// Rotation: keep the newest KEEP hq-YYYYMMDD-HHMMSS.dump files.
const dumps = readdirSync(OUT).filter((f) => /^hq-\d{8}-\d{6}\.dump$/.test(f)).sort()
for (const f of dumps.slice(0, Math.max(0, dumps.length - KEEP))) {
  unlinkSync(join(OUT, f))
  console.log(`  rotated out: ${f}`)
}
console.log(`retained ${Math.min(dumps.length, KEEP)} backup(s) in ${OUT} (HQ_BACKUP_KEEP=${KEEP})`)