#!/usr/bin/env bun
// s3-sync.js — Ensure all objects in the source bucket exist in the dest bucket
// Usage: bun s3-sync.js
//   Lists all objects in SOURCE and DEST, then copies only the objects that
//   are missing from DEST. Direction is one-way: SOURCE -> DEST.

// ============================================================
// CREDENTIALS — replace with your actual values
// ============================================================
const SOURCE = {
  accessKeyId: '8fab47503efb9547b50e4fb317e35cc7',
  secretAccessKey: '47c2eb5636843cf568dda7ad0959a3e42071303f26dbdff94bd45a3c33dcd950',
  region: 'auto',           // 'us-east-1' for AWS, 'auto' for R2
  endpoint: 'https://da9b1aa7c1951c23e2c0c3246ba68a58.r2.cloudflarestorage.com',             // S3 or R2 endpoint
  bucket: 'meatfarmer',
}

const DEST = {
  accessKeyId: '8fab47503efb9547b50e4fb317e35cc7',
  secretAccessKey: '47c2eb5636843cf568dda7ad0959a3e42071303f26dbdff94bd45a3c33dcd950',
  region: 'auto',
  endpoint: 'https://da9b1aa7c1951c23e2c0c3246ba68a58.r2.cloudflarestorage.com',
  bucket: 'meatfarmer-dev',
}
// ============================================================

const CONCURRENCY = 20

if (!SOURCE.endpoint || !SOURCE.bucket || !DEST.endpoint || !DEST.bucket) {
  console.error('Fill in the SOURCE and DEST credentials at the top of the script first.')
  process.exit(1)
}

const source = new Bun.S3Client(SOURCE)
const dest = new Bun.S3Client(DEST)

async function listAllObjects(s3) {
  const allKeys = []
  let continuationToken

  do {
    const options = { 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
}

// ============================================================
// MAIN
// ============================================================
try {
  console.log(`🔁 S3 Sync — ${SOURCE.bucket} -> ${DEST.bucket}`)

  console.log('\n📋 Listing SOURCE...')
  const sourceKeys = await listAllObjects(source)

  console.log('\n📋 Listing DEST...')
  const destKeys = await listAllObjects(dest)

  const destSet = new Set(destKeys)
  const toCopy = sourceKeys.filter((key) => !destSet.has(key))

  console.log(`\n📊 SOURCE objects: ${sourceKeys.length}`)
  console.log(`   DEST objects:   ${destKeys.length}`)
  console.log(`   To copy:        ${toCopy.length} (present in SOURCE, missing in DEST)`)

  if (toCopy.length === 0) {
    console.log('\n✅ DEST already has everything from SOURCE.')
    process.exit(0)
  }

  console.log('\n🚚 Copying missing objects...')
  let copied = 0
  for (let i = 0; i < toCopy.length; i += CONCURRENCY) {
    const batch = toCopy.slice(i, i + CONCURRENCY)
    await Promise.all(
      batch.map(async (key) => {
        await dest.write(key, source.file(key))
        copied++
      })
    )
    process.stdout.write(`\r   Copied ${copied}/${toCopy.length}...`)
  }

  console.log(`\n✅ Done — copied ${copied} objects to ${DEST.bucket}.`)
} catch (error) {
  console.error(`\n❌ Error: ${error.message}`)
  process.exit(1)
}