import {
  BlobServiceClient,
  ContainerClient,
  StorageSharedKeyCredential,
} from "@azure/storage-blob";
import {
  BLOB_STORAGE_REGION_AU,
  BLOB_STORAGE_REGION_EU,
  BLOB_STORAGE_REGION_US,
} from "../constants";
import { InvocationContext } from "@azure/functions";

export class AudioBlobStorageService {
  private readonly sharedKeyCredentialUS: StorageSharedKeyCredential;
  private readonly sharedKeyCredentialEU: StorageSharedKeyCredential;
  private readonly sharedKeyCredentialAU: StorageSharedKeyCredential;

  private readonly blobServiceClientUS: BlobServiceClient;
  private readonly blobServiceClientEU: BlobServiceClient;
  private readonly blobServiceClientAU: BlobServiceClient;

  constructor() {
    if (
      !process.env.STORAGE_ACCOUNT_ENDPOINT_US ||
      !process.env.STORAGE_ACCOUNT_ENDPOINT_AU ||
      !process.env.STORAGE_ACCOUNT_ENDPOINT_EU ||
      !process.env.STORAGE_ACCOUNT_NAME_US ||
      !process.env.STORAGE_ACCOUNT_KEY_US ||
      !process.env.STORAGE_ACCOUNT_NAME_AU ||
      !process.env.STORAGE_ACCOUNT_KEY_AU ||
      !process.env.STORAGE_ACCOUNT_NAME_EU ||
      !process.env.STORAGE_ACCOUNT_KEY_EU
    ) {
      throw new Error("Storage account information is missing");
    }

    // リージョンごとのSharedKeyCredentialを生成
    this.sharedKeyCredentialUS = new StorageSharedKeyCredential(
      process.env.STORAGE_ACCOUNT_NAME_US,
      process.env.STORAGE_ACCOUNT_KEY_US
    );
    this.sharedKeyCredentialAU = new StorageSharedKeyCredential(
      process.env.STORAGE_ACCOUNT_NAME_AU,
      process.env.STORAGE_ACCOUNT_KEY_AU
    );
    this.sharedKeyCredentialEU = new StorageSharedKeyCredential(
      process.env.STORAGE_ACCOUNT_NAME_EU,
      process.env.STORAGE_ACCOUNT_KEY_EU
    );

    // Audioファイルの保存先のリージョンごとにBlobServiceClientを生成
    this.blobServiceClientUS = new BlobServiceClient(
      process.env.STORAGE_ACCOUNT_ENDPOINT_US,
      this.sharedKeyCredentialUS
    );
    this.blobServiceClientAU = new BlobServiceClient(
      process.env.STORAGE_ACCOUNT_ENDPOINT_AU,
      this.sharedKeyCredentialAU
    );
    this.blobServiceClientEU = new BlobServiceClient(
      process.env.STORAGE_ACCOUNT_ENDPOINT_EU,
      this.sharedKeyCredentialEU
    );
  }

  /**
   * 指定されたファイルを削除します。
   * @param context
   * @param accountId
   * @param country
   * @param fileName
   * @returns file
   */
  async deleteFile(
    context: InvocationContext,
    accountId: number,
    country: string,
    fileName: string
  ): Promise<void> {
    context.log(
      `[IN] ${this.deleteFile.name} | params: { ` +
        `accountId: ${accountId} ` +
        `country: ${country} ` +
        `fileName: ${fileName} };`
    );

    try {
      // 国に応じたリージョンでコンテナ名を指定してClientを取得
      const containerClient = this.getContainerClient(
        context,
        accountId,
        country
      );
      // コンテナ内のBlobパス名を指定してClientを取得
      const blobClient = containerClient.getBlobClient(fileName);

      const { succeeded, errorCode, date } = await blobClient.deleteIfExists();
      context.log(
        `succeeded: ${succeeded}, errorCode: ${errorCode}, date: ${date}`
      );

      // 失敗時、Blobが存在しない場合以外はエラーとして例外をスローする
      // Blob不在の場合のエラーコードは「BlobNotFound」以下を参照
      // https://learn.microsoft.com/ja-jp/rest/api/storageservices/blob-service-error-codes
      if (!succeeded && errorCode !== "BlobNotFound") {
        throw new Error(
          `delete blob failed. succeeded: ${succeeded}, errorCode: ${errorCode}, date: ${date}`
        );
      }
    } catch (e) {
      context.error(`error=${e}`);
      throw e;
    } finally {
      context.log(`[OUT] ${this.deleteFile.name}`);
    }
  }

  /**
   * 指定してアカウントIDと国に応じたリージョンのコンテナクライアントを取得します。
   * @param context
   * @param accountId
   * @param country
   * @returns
   */
  private getContainerClient(
    context: InvocationContext,
    accountId: number,
    country: string
  ): ContainerClient {
    context.log(
      `[IN] ${this.getContainerClient.name} | params: { ` +
        `accountId: ${accountId}; country: ${country} };`
    );

    const containerName = `account-${accountId}`;
    if (BLOB_STORAGE_REGION_US.includes(country)) {
      return this.blobServiceClientUS.getContainerClient(containerName);
    } else if (BLOB_STORAGE_REGION_AU.includes(country)) {
      return this.blobServiceClientAU.getContainerClient(containerName);
    } else if (BLOB_STORAGE_REGION_EU.includes(country)) {
      return this.blobServiceClientEU.getContainerClient(containerName);
    } else {
      throw new Error("invalid country");
    }
  }
}