julie-ng/blocklift-js

const { BlobServiceClient, StorageSharedKeyCredential } = require('@azure/storage-blob')
const BlobUploadOptions = require('./blob-upload-options')

/**
 *
 * Abstracts all the chaining required to use Azure SDK
 * and converts iterables to standard objects. For example,
 * as a developer, a single method is easier to understand and therefore preferred:
 *
 * ```javascript
 * // Blocklift API - simple and preferred:
 * service.uploadFile('local-file.png', 'destination.png')
 * ```
 *
 * As a developer, dealing with the internal interfaces is _not_ preferred
 *
 * ```javascript
 * // Azure SDK API - clunky and not preferred
 * service
 *   .getContainerClient('container')
 *   .getBlockBlobClient('destination.png')
 *   .uploadFile('local-file.png')
 * ```
 *
 * @private
 */
class AzureSDK {

    /**
     *
     * @param {Object} opts
     * @param {String} opts.account
     */
    constructor (opts = {}) {
        const sharedKeyCredential = new StorageSharedKeyCredential(opts.account, opts.accessKey)

        /**
         * Azure Storage Account name for reference
         *
         * @readonly
         * @type {String}
         */
        this.account = opts.account

        /**
         * Default container name, used if no container is specified when calling the API
         *
         * @readonly
         * @type {String|null}
         */
        this.defaultContainer = opts.defaultContainer || null

        /**
         * Reference to [Blob Service Client from Azure SDK](https://azuresdkdocs.blob.core.windows.net/$web/javascript/azure-storage-blob/12.0.2/classes/blobserviceclient.html)
         *
         * @readonly
         * @type {BlobServiceClient}
         */
        this.service = new BlobServiceClient(
            `https://${opts.account}.blob.core.windows.net`,
            sharedKeyCredential
        )
    }

    // ---- Containers ----

    /**
     * @param {String} name - name of container to create
     * @returns {Promise}
     */
    async createContainer (name) {
        return await this.service
            .getContainerClient(name)
            .create()
    }

    /**
     * @param {String} name - name of container to delete
     * @returns {Promise}
     */
    async deleteContainer (name) {
        return await this.service
            .getContainerClient(name)
            .delete()
    }

    /**
     * @returns {Promise<Array>} list of containers
     * @returns {Promise<Object>} Error
     */
    async listContainers () {
        const containers = []
        const iter = this.service.listContainers()

        for await (const c of iter) {
            containers.push(c)
        }

        return containers
    }

    // ---- Blobs ----

    /**
     *
     * @param {String} container - containername
     * @return {Array}
     */
    async listBlobs (container) {
        const blobs = []
        const containerClient = this.service.getContainerClient(container)
        const iter = await containerClient.listBlobsFlat()

        for await (const b of iter) {
            blobs.push(b)
        }

        return blobs
    }

    /**
     * Uploads Raw Content
     * Todo: add options, e.g. parallel upload block size
     *
     * @param {String} params.container
     * @param {String} params.pathname - path name for blob without container prefix
     * @param {String} params.content
     * @param {String} [opts.contentType] - content type
     * @return {Promise}
     */
    async upload (params, opts = {}) {
        const blobOpts = new BlobUploadOptions(opts)

        return this.service
            .getContainerClient(params.container)
            .getBlockBlobClient(params.pathname)
            .upload(params.content, params.content.length, blobOpts)
    }

    /**
     * Uploads file
     *
     * Todo: add options, e.g. parallel upload block size
     * For more blob upload options see
     * [official SDK Docs](https://azuresdkdocs.blob.core.windows.net/$web/javascript/azure-storage-blob/12.0.2/classes/blockblobclient.html#uploadfile).
     *
     * @param {String} params.container
     * @param {String} params.filePathname - pathname of of source file
     * @param {String} params.blobPathname - pathname for destination blob without container prefix
     * @param {String} [opts.contentType] - content type
     * @return {Promise}
     */
    async uploadFile (params, opts = {}) {
        const blobOpts = new BlobUploadOptions(opts)

        return this.service
            .getContainerClient(params.container)
            .getBlockBlobClient(params.blobPathname)
            .uploadFile(params.filePathname, blobOpts)
    }

    /**
     * @param {String} params.container - container name
     * @param {String} params.blobPathname - pathname for destination blob without container prefix
     * @return {Promise}
     */
    async deleteBlob (params, opts = {}) {
        return this.service
            .getContainerClient(params.container)
            .getBlockBlobClient(params.pathname)
            .delete()
    }
}

module.exports = AzureSDK