import * as fs from 'fs'; import * as Koa from 'koa'; import * as send from 'koa-send'; import * as mongodb from 'mongodb'; import DriveFile, { getDriveFileBucket } from '../../models/drive-file'; import DriveFileThumbnail, { getDriveFileThumbnailBucket } from '../../models/drive-file-thumbnail'; const commonReadableHandlerGenerator = (ctx: Koa.Context) => (e: Error): void => { console.error(e); ctx.status = 500; }; export default async function(ctx: Koa.Context) { // Validate id if (!mongodb.ObjectID.isValid(ctx.params.id)) { ctx.throw(400, 'incorrect id'); return; } const fileId = new mongodb.ObjectID(ctx.params.id); // Fetch drive file const file = await DriveFile.findOne({ _id: fileId }); if (file == null) { ctx.status = 404; await send(ctx, `${__dirname}/assets/dummy.png`); return; } if (file.metadata.deletedAt) { ctx.status = 410; await send(ctx, `${__dirname}/assets/tombstone.png`); return; } const sendRaw = async () => { const bucket = await getDriveFileBucket(); const readable = bucket.openDownloadStream(fileId); readable.on('error', commonReadableHandlerGenerator(ctx)); ctx.set('Content-Type', file.contentType); ctx.body = readable; }; if ('thumbnail' in ctx.query) { // 画像以外 if (!file.contentType.startsWith('image/')) { const readable = fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`); ctx.set('Content-Type', 'image/png'); ctx.body = readable; } else if (file.contentType == 'image/gif') { // GIF await sendRaw(); } else { const thumb = await DriveFileThumbnail.findOne({ 'metadata.originalId': fileId }); if (thumb != null) { ctx.set('Content-Type', 'image/jpeg'); const bucket = await getDriveFileThumbnailBucket(); ctx.body = bucket.openDownloadStream(thumb._id); } else { await sendRaw(); } } } else { if ('download' in ctx.query) { ctx.set('Content-Disposition', 'attachment'); } await sendRaw(); } }