import { copyFileSync, readdirSync, unlinkSync, mkdirSync, existsSync } from 'fs'
import { join, dirname } from 'path'
import { fileURLToPath } from 'url'
import { logger } from '../lib/logger.js'

const __dirname = dirname(fileURLToPath(import.meta.url))
const DB_PATH = process.env.DB_PATH || join(__dirname, '..', '..', 'data', 'botfights.db')
const BACKUP_DIR = join(dirname(DB_PATH), 'backups')
const MAX_BACKUPS = 7

/** Create a timestamped backup of the database */
export function createBackup(): string {
  mkdirSync(BACKUP_DIR, { recursive: true })

  const timestamp = new Date().toISOString().slice(0, 10)
  const backupPath = join(BACKUP_DIR, `botfights-${timestamp}.db`)

  copyFileSync(DB_PATH, backupPath)
  logger.info('backup', `created backup: ${backupPath}`)

  // Rotate: keep only the latest MAX_BACKUPS
  rotateBackups()

  return backupPath
}

/** Remove old backups beyond MAX_BACKUPS */
function rotateBackups(): void {
  if (!existsSync(BACKUP_DIR)) return

  const files = readdirSync(BACKUP_DIR)
    .filter(f => f.startsWith('botfights-') && f.endsWith('.db'))
    .sort()
    .reverse()

  for (let i = MAX_BACKUPS; i < files.length; i++) {
    const path = join(BACKUP_DIR, files[i])
    try {
      unlinkSync(path)
      logger.info('backup', `rotated out: ${files[i]}`)
    } catch { /* ok */ }
  }
}

/** Start daily backup timer */
export function startDailyBackups(): void {
  // Run first backup after 1 minute, then every 24 hours
  setTimeout(() => {
    createBackup()
    setInterval(() => createBackup(), 24 * 60 * 60 * 1000)
  }, 60_000)
  logger.info('backup', 'daily backups scheduled')
}