#!/usr/bin/env bun
// s3-cleaner.js — Delete old versioned cache folders from S3/R2
// Usage: bun s3-cleaner.js <version>
// Example: bun s3-cleaner.js 235
//   Deletes all objects under api-cache/v-0/ through api-cache/v-234/

// ============================================================
// CREDENTIALS — replace with your actual values
// ============================================================
const S3_ACCESS_KEY_ID = 'YOUR_ACCESS_KEY_ID'
const S3_SECRET_ACCESS_KEY = 'YOUR_SECRET_ACCESS_KEY'
const S3_REGION = 'auto'              // 'us-east-1' for AWS, 'auto' for R2
const S3_ENDPOINT = 'https://your-account.r2.cloudflarestorage.com'  // S3 or R2 endpoint
const S3_BUCKET = 'your-bucket-name'
const API_CACHE_KEY = 'api-cache'     // matches API_CACHE_KEY env var in backend

// ============================================================

const threshold = parseInt(process.argv[2])
if (!threshold || isNaN(threshold) || threshold <= 0) {
  console.error('Usage: bun s3-cleaner.js <version>')
  console.error('Example: bun s3-cleaner.js 235')
  console.error('  Deletes all v-{n} folders where n < 235')
  process.exit(1)
}

const cachePrefix = API_CACHE_KEY.endsWith('/') ? API_CACHE_KEY : `${API_CACHE_KEY}/`
const versionPattern = new RegExp(`^${cachePrefix.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}v-(\\d+)/`)

console.log(`🧹 S3 Cache Cleaner — keeping v-${threshold}+, deleting v-0 through v-${threshold - 1}`)
console.log(`   Bucket: ${S3_BUCKET}`)
console.log(`   Prefix: ${cachePrefix}`)

const s3 = new Bun.S3Client({
  accessKeyId: S3_ACCESS_KEY_ID,
  secretAccessKey: S3_SECRET_ACCESS_KEY,
  region: S3_REGION,
  endpoint: S3_ENDPOINT,
  bucket: S3_BUCKET,
})

async function listAllObjects(prefix) {
  const allKeys = []
  let continuationToken

  do {
    const options = { prefix, maxKeys: 1000 }
    if (continuationToken) options.continuationToken = continuationToken

    const result = await s3.list(options)
    for (const obj of result.contents) {
      allKeys.push(obj.key)
    }
    continuationToken = result.nextContinuationToken

    process.stdout.write(`\r   Listed ${allKeys.length} objects...`)
  } while (continuationToken)

  console.log('')
  return allKeys
}

async function deleteObjects(keys) {
  let deleted = 0
  const batchSize = 1000

  for (let i = 0; i < keys.length; i += batchSize) {
    const batch = keys.slice(i, i + batchSize)
    const objects = batch.map((key) => ({ key }))

    const result = await s3.deleteObjects({ objects })
    deleted += result.deleted?.length ?? 0

    process.stdout.write(`\r   Deleted ${deleted}/${keys.length}...`)
  }

  console.log('')
  return deleted
}

// ============================================================
// MAIN
// ============================================================
try {
  console.log('\n📋 Listing objects...')
  const allObjects = await listAllObjects(cachePrefix)

  const toDelete = []
  const versionsSeen = new Set()
  for (const key of allObjects) {
    const match = key.match(versionPattern)
    if (match) {
      const ver = parseInt(match[1])
      if (ver < threshold) {
        toDelete.push(key)
      }
      versionsSeen.add(ver)
    }
  }

  const sortedVersions = [...versionsSeen].sort((a, b) => a - b)

  if (sortedVersions.length === 0) {
    console.log('\n✅ No cache objects found.')
    process.exit(0)
  }

  console.log(`\n📊 Found versions: v-${sortedVersions[0]} through v-${sortedVersions[sortedVersions.length - 1]}`)
  const oldVersionCount = sortedVersions.filter((v) => v < threshold).length
  console.log(`   To delete: ${toDelete.length} objects across ${oldVersionCount} version(s)`)
  console.log(`   To keep:   v-${threshold}+`)

  if (toDelete.length === 0) {
    console.log('\n✅ Nothing to delete.')
    process.exit(0)
  }

  console.log('\n❗ Proceeding with deletion...')
  const count = await deleteObjects(toDelete)
  console.log(`\n✅ Done — deleted ${count} objects.`)
} catch (error) {
  console.error(`\n❌ Error: ${error.message}`)
  process.exit(1)
}