const { S3Client, PutObjectCommand } = require("@aws-sdk/client-s3")

function createR2Client() {
  const endpoint = process.env.R2_ENDPOINT
  const accessKeyId = process.env.R2_ACCESS_KEY_ID
  const secretAccessKey = process.env.R2_SECRET_ACCESS_KEY

  if (!endpoint || !accessKeyId || !secretAccessKey) {
    throw new Error("R2 config missing (R2_ENDPOINT/R2_ACCESS_KEY_ID/R2_SECRET_ACCESS_KEY)")
  }

  return new S3Client({
    region: process.env.R2_REGION || "auto",
    endpoint,
    credentials: { accessKeyId, secretAccessKey },
  })
}

let r2Client = null

function getR2Client() {
  if (!r2Client) r2Client = createR2Client()
  return r2Client
}

function encodeObjectKey(key) {
  return String(key)
    .split("/")
    .map((part) => encodeURIComponent(part))
    .join("/")
}

function toStoredPath(key) {
  const normalized = String(key || "").replace(/^\/+/, "")
  return `/${encodeObjectKey(normalized)}`
}

async function uploadImage({ bucket, path, fileBuffer, contentType }) {
  if (!path || !fileBuffer) throw new Error("uploadImage params missing")

  const targetBucket = bucket || process.env.R2_BUCKET_NAME
  if (!targetBucket) throw new Error("R2 bucket missing (R2_BUCKET_NAME)")

  const r2 = getR2Client()

  await r2.send(
    new PutObjectCommand({
      Bucket: targetBucket,
      Key: path,
      Body: fileBuffer,
      ContentType: contentType || "image/webp",
    })
  )

  return toStoredPath(path)
}

module.exports = { uploadImage }