import { StorageClient, PutObjectOptions, HeadObjectResult } from '../../core/StorageClient';
import { HuaweiObsConfig } from '../../config/types';

// 华为 OBS Node.js SDK（CommonJS）
const ObsClient = require('esdk-obs-nodejs');

/**
 * 华为 OBS 的 StorageClient 实现（Adapter）。
 * 通过 SDK 的 getObjectMetadata 查元数据判断是否存在，putObject 上传对象。
 */
export class HuaweiObsClient implements StorageClient {
  private readonly client: InstanceType<typeof ObsClient>;
  private readonly whiteList: string[];
  constructor(private readonly config: HuaweiObsConfig) {
    this.client = new ObsClient({
      access_key_id: config.accessKey,
      secret_access_key: config.secretKey,
      server: config.endpoint,
    });
    this.whiteList = JSON.parse(process.env.FILE_RE_WHITE_LIST as string)
  }

  /**
   * 按前缀列举对象 key（分页拉全），用于上传前一次拉取、内存判断存在，避免每个文件都 head。
   */
  async listObjectKeys(bucket: string, prefix: string): Promise<string[]> {
    const keys: string[] = [];
    let marker: string | undefined;
    const pageSize = 1000;
    do {
      const param: Record<string, unknown> = {
        Bucket: bucket,
        MaxKeys: pageSize,
        Prefix: prefix || undefined,
      };
      if (marker) param.Marker = marker;
      const result = await this.client.listObjects(param);
      if (result.CommonMsg.Status > 300) {
        throw new Error(
          `OBS listObjects 失败: ${result.CommonMsg.Status} ${result.CommonMsg.Code} ${result.CommonMsg.Message}`,
        );
      }
      const contents = result.InterfaceResult?.Contents ?? [];
      for (const item of contents) {
        if (item.Key) keys.push(item.Key);
      }
      const truncated = result.InterfaceResult?.IsTruncated === 'true';
      marker = truncated ? result.InterfaceResult?.NextMarker : undefined;
    } while (marker);
    return keys;
  }

  /**
   * 调用 OBS getObjectMetadata 查元数据，判断对象是否存在（同路径即跳过上传）。
   * 当使用 listObjectKeys 时，上传流程会优先用内存 Set 判断，不再逐文件调用本方法。
   */
  async headObject(bucket: string, key: string): Promise<HeadObjectResult> {
    try {
      if(this.whiteList.some(item => key.includes(item))) {
        return { exists: false };
      }
      const result = await this.client.getObjectMetadata({
        Bucket: bucket,
        Key: key,
      });
      if (result.CommonMsg.Status <= 300) {
        return { exists: true };
      }

      // 对象不存在
      if (result.CommonMsg.Status === 404 || result.CommonMsg.Code === 'NoSuchKey' || result.CommonMsg.Code === 'NotFound') {
        return { exists: false };
      }

      throw new Error(`OBS getObjectMetadata 失败: ${result.CommonMsg.Status} ${result.CommonMsg.Code} ${result.CommonMsg.Message}`);
    } catch (err: unknown) {
      const msg = err && typeof (err as any).message === 'string' ? (err as Error).message : String(err);
      const code = (err as any)?.Code ?? (err as any)?.code;
      if (code === 'NoSuchKey' || code === 'NotFound' || msg.includes('404') || msg.includes('NoSuchKey')) {
        return { exists: false };
      }
      throw err;
    }
  }

  /** 调用 OBS putObject 上传对象（支持 Body 或 SourceFile 本地路径，SourceFile 由 SDK 直接读文件避免 Buffer 问题） */
  async putObject(options: PutObjectOptions): Promise<void> {
    const { bucket, key, contentType } = options;
    const param: Record<string, unknown> = {
      Bucket: bucket,
      Key: key,
      ContentType: contentType,
    };
    if (options.sourceFile) {
      param.SourceFile = options.sourceFile;
    } else if (options.body) {
      param.Body = options.body;
    } else {
      throw new Error('putObject 需要 body 或 sourceFile');
    }

    const result = await this.client.putObject(param);

    if (result.CommonMsg.Status > 300) {
      const { Status, Code, Message, RequestId } = result.CommonMsg;
      const detail = [Status, Code, Message, RequestId].filter(Boolean).join(' ');
      throw new Error(
        `OBS putObject 失败 (${detail || '无详情'}). ` +
          '请检查: 1) 桶名是否正确且已创建 2) OBS_ENDPOINT 是否与该桶所在区域一致，如 https://obs.xx-xx-1.myhuaweicloud.com'
      );
    }
  }
}