Create base Google Drive Helper (#12)

Reviewed-on: https://gitea.vylpes.xyz/External/card-drop/pulls/12
Co-authored-by: Ethan Lane <ethan@vylpes.com>
Co-committed-by: Ethan Lane <ethan@vylpes.com>

src/helpers/GoogleDriveHelper.ts

@@ -0,0 +1,83 @@
+import { Auth, drive_v3, google } from "googleapis";
+import IGDriveFolderListing from "../contracts/IGDriveFolderListing";
+import path, { resolve } from "path";
+import os from 'os';
+import uuid, { v4 } from 'uuid';
+import { createWriteStream } from "fs";
+
+export default class GoogleDriveHelper {
+    private _auth: Auth.GoogleAuth;
+    private _drive: drive_v3.Drive;
+
+    constructor() {
+        this._auth = new google.auth.GoogleAuth({
+            keyFile: "gdrive-credentials.json",
+            scopes: [
+                "https://www.googleapis.com/auth/drive.readonly",
+                "https://www.googleapis.com/auth/drive.metadata.readonly",
+            ],
+        });
+
+        this._drive = google.drive( { version: "v3", auth: this._auth });
+    }
+
+    public async listFolder(folderId: string, pageSize: number): Promise<IGDriveFolderListing[]> {
+        const params = {
+            pageSize: pageSize,
+            fields: "nextPageToken, files(id, name)",
+            q: `'${folderId}' in parents and trashed=false`
+        }
+
+        const res = await this._drive.files.list(params);
+
+        return res.data.files as IGDriveFolderListing[];
+    }
+
+    public downloadFile(fileId: string) {
+        const res = this._drive.files.get({
+            fileId: fileId,
+            alt: 'media',
+        }, {
+            responseType: 'stream',
+        })
+        .then(res => {
+            return new Promise((resolve, reject) => {
+                const filePath = path.join(process.cwd(), 'temp', v4());
+                const dest = createWriteStream(filePath);
+                let progress = 0;
+
+                res.data
+                    .on('end', () => {
+                        resolve(filePath);
+                    })
+                    .on('error', err => {
+                        reject(err);
+                    })
+                    .on('data', d => {
+                        progress += d.length;
+                    })
+                    .pipe(dest);
+            });
+        })
+    }
+
+    public async exportFile(fileId: string, mimeType: string) {
+        const destPath = path.join(process.cwd(), 'temp', v4());
+        const dest = createWriteStream(destPath);
+
+        const res = await this._drive.files.export({
+            fileId: fileId,
+            mimeType: mimeType
+        }, {
+            responseType: 'stream',
+        });
+
+        await new Promise((resolve, reject) => {
+            res.data
+                .on('error', reject)
+                .pipe(dest)
+                .on('error', reject)
+                .on('finish', resolve);
+        })
+    }
+}