Introduce processor

6 files changed, 168 insertions, 0 deletions

diff --git a/src/server/file/assets/avatar.jpg b/src/server/file/assets/avatar.jpg
new file mode 100644
index 0000000000..3c803f568e
--- /dev/null
+++ b/src/server/file/assets/avatar.jpg
diff --git a/src/server/file/assets/bad-egg.png b/src/server/file/assets/bad-egg.png
new file mode 100644
index 0000000000..a7c5930bd4
--- /dev/null
+++ b/src/server/file/assets/bad-egg.png
diff --git a/src/server/file/assets/dummy.png b/src/server/file/assets/dummy.png
new file mode 100644
index 0000000000..39332b0c1b
--- /dev/null
+++ b/src/server/file/assets/dummy.png
diff --git a/src/server/file/assets/not-an-image.png b/src/server/file/assets/not-an-image.png
new file mode 100644
index 0000000000..bf98b293f7
--- /dev/null
+++ b/src/server/file/assets/not-an-image.png
diff --git a/src/server/file/assets/thumbnail-not-available.png b/src/server/file/assets/thumbnail-not-available.png
new file mode 100644
index 0000000000..f960ce4d00
--- /dev/null
+++ b/src/server/file/assets/thumbnail-not-available.png
diff --git a/src/server/file/server.ts b/src/server/file/server.ts
new file mode 100644
index 0000000000..3bda5b14fe
--- /dev/null
+++ b/src/server/file/server.ts
@@ -0,0 +1,168 @@
+/**
+ * File Server
+ */
+
+import * as fs from 'fs';
+import * as express from 'express';
+import * as bodyParser from 'body-parser';
+import * as cors from 'cors';
+import * as mongodb from 'mongodb';
+import * as _gm from 'gm';
+import * as stream from 'stream';
+
+import DriveFile, { getGridFSBucket } from '../api/models/drive-file';
+
+const gm = _gm.subClass({
+	imageMagick: true
+});
+
+/**
+ * Init app
+ */
+const app = express();
+
+app.disable('x-powered-by');
+app.locals.cache = true;
+app.use(bodyParser.urlencoded({ extended: true }));
+app.use(cors());
+
+/**
+ * Statics
+ */
+app.use('/assets', express.static(`${__dirname}/assets`, {
+	maxAge: 1000 * 60 * 60 * 24 * 365 // 一年
+}));
+
+app.get('/', (req, res) => {
+	res.send('yee haw');
+});
+
+app.get('/default-avatar.jpg', (req, res) => {
+	const file = fs.createReadStream(`${__dirname}/assets/avatar.jpg`);
+	send(file, 'image/jpeg', req, res);
+});
+
+app.get('/app-default.jpg', (req, res) => {
+	const file = fs.createReadStream(`${__dirname}/assets/dummy.png`);
+	send(file, 'image/png', req, res);
+});
+
+interface ISend {
+	contentType: string;
+	stream: stream.Readable;
+}
+
+function thumbnail(data: stream.Readable, type: string, resize: number): ISend {
+	const readable: stream.Readable = (() => {
+		// 画像ではない場合
+		if (!/^image\/.*$/.test(type)) {
+			// 使わないことにしたストリームはしっかり取り壊しておく
+			data.destroy();
+			return fs.createReadStream(`${__dirname}/assets/not-an-image.png`);
+		}
+
+		const imageType = type.split('/')[1];
+
+		// 画像でもPNGかJPEGでないならダメ
+		if (imageType != 'png' && imageType != 'jpeg') {
+			// 使わないことにしたストリームはしっかり取り壊しておく
+			data.destroy();
+			return fs.createReadStream(`${__dirname}/assets/thumbnail-not-available.png`);
+		}
+
+		return data;
+	})();
+
+	let g = gm(readable);
+
+	if (resize) {
+		g = g.resize(resize, resize);
+	}
+
+	const stream = g
+		.compress('jpeg')
+		.quality(80)
+		.interlace('line')
+		.noProfile() // Remove EXIF
+		.stream();
+
+	return {
+		contentType: 'image/jpeg',
+		stream
+	};
+}
+
+const commonReadableHandlerGenerator = (req: express.Request, res: express.Response) => (e: Error): void => {
+	console.dir(e);
+	req.destroy();
+	res.destroy(e);
+};
+
+function send(readable: stream.Readable, type: string, req: express.Request, res: express.Response): void {
+	readable.on('error', commonReadableHandlerGenerator(req, res));
+
+	const data = ((): ISend => {
+		if (req.query.thumbnail !== undefined) {
+			return thumbnail(readable, type, req.query.size);
+		}
+		return {
+			contentType: type,
+			stream: readable
+		};
+	})();
+
+	if (readable !== data.stream) {
+		data.stream.on('error', commonReadableHandlerGenerator(req, res));
+	}
+
+	if (req.query.download !== undefined) {
+		res.header('Content-Disposition', 'attachment');
+	}
+
+	res.header('Content-Type', data.contentType);
+
+	data.stream.pipe(res);
+
+	data.stream.on('end', () => {
+		res.end();
+	});
+}
+
+async function sendFileById(req: express.Request, res: express.Response): Promise<void> {
+	// Validate id
+	if (!mongodb.ObjectID.isValid(req.params.id)) {
+		res.status(400).send('incorrect id');
+		return;
+	}
+
+	const fileId = new mongodb.ObjectID(req.params.id);
+
+	// Fetch (drive) file
+	const file = await DriveFile.findOne({ _id: fileId });
+
+	// validate name
+	if (req.params.name !== undefined && req.params.name !== file.filename) {
+		res.status(404).send('there is no file has given name');
+		return;
+	}
+
+	if (file == null) {
+		res.status(404).sendFile(`${__dirname}/assets/dummy.png`);
+		return;
+	}
+
+	const bucket = await getGridFSBucket();
+
+	const readable = bucket.openDownloadStream(fileId);
+
+	send(readable, file.contentType, req, res);
+}
+
+/**
+ * Routing
+ */
+
+app.get('/:id', sendFileById);
+app.get('/:id/:name', sendFileById);
+
+module.exports = app;