import {
  S3Client,
  PutObjectCommand,
  GetObjectCommand,
  HeadObjectCommand,
  DeleteObjectCommand,
  ListObjectsV2Command,
} from "@aws-sdk/client-s3";

// S3 설정 (RustFS) - 환경변수에서 로드
const s3Config = {
  endpoint: process.env.S3_ENDPOINT,
  accessKey: process.env.S3_ACCESS_KEY,
  secretKey: process.env.S3_SECRET_KEY,
  bucket: "minecraft",
  publicUrl: "https://s3.caadiq.co.kr",
};

// S3 클라이언트 생성
const s3Client = new S3Client({
  endpoint: s3Config.endpoint,
  region: "us-east-1",
  credentials: {
    accessKeyId: s3Config.accessKey,
    secretAccessKey: s3Config.secretKey,
  },
  forcePathStyle: true, // RustFS/MinIO용
});

/**
 * S3(RustFS)에 파일 업로드
 */
async function uploadToS3(
  bucket,
  key,
  data,
  contentType = "application/octet-stream"
) {
  const command = new PutObjectCommand({
    Bucket: bucket,
    Key: key,
    Body: data,
    ContentType: contentType,
  });

  await s3Client.send(command);
  // 공개 URL 반환 (key는 인코딩)
  const encodedKey = key
    .split("/")
    .map((s) => encodeURIComponent(s))
    .join("/");
  return `${s3Config.publicUrl}/${bucket}/${encodedKey}`;
}

/**
 * S3(RustFS)에서 파일 다운로드
 */
async function downloadFromS3(bucket, key) {
  const command = new GetObjectCommand({
    Bucket: bucket,
    Key: key,
  });

  const response = await s3Client.send(command);
  // ReadableStream을 Buffer로 변환
  const chunks = [];
  for await (const chunk of response.Body) {
    chunks.push(chunk);
  }
  return Buffer.concat(chunks);
}

/**
 * S3(RustFS)에 파일이 존재하는지 확인
 */
async function checkS3Exists(bucket, key) {
  try {
    const command = new HeadObjectCommand({
      Bucket: bucket,
      Key: key,
    });
    await s3Client.send(command);
    return true;
  } catch (err) {
    if (err.name === "NotFound" || err.$metadata?.httpStatusCode === 404) {
      return false;
    }
    throw err;
  }
}

/**
 * S3(RustFS)에서 파일 삭제
 */
async function deleteFromS3(bucket, key) {
  const command = new DeleteObjectCommand({
    Bucket: bucket,
    Key: key,
  });
  await s3Client.send(command);
}

/**
 * S3(RustFS)에서 prefix로 시작하는 모든 파일 삭제
 */
async function deleteByPrefix(bucket, prefix) {
  const listCommand = new ListObjectsV2Command({
    Bucket: bucket,
    Prefix: prefix,
  });

  const listResult = await s3Client.send(listCommand);
  const objects = listResult.Contents || [];

  let deletedCount = 0;
  for (const obj of objects) {
    try {
      await deleteFromS3(bucket, obj.Key);
      deletedCount++;
    } catch (err) {
      console.error(`[S3] 파일 삭제 실패: ${obj.Key} - ${err.message}`);
    }
  }

  return deletedCount;
}

export {
  s3Config,
  uploadToS3,
  downloadFromS3,
  checkS3Exists,
  deleteFromS3,
  deleteByPrefix,
};