feat: copy over the API function and install dependencies

functions/package.json

@@ -10,10 +10,14 @@
   },
   "main": "lib/index.js",
   "dependencies": {
+    "express": "^4.16.3",
     "firebase-admin": "~5.8.1",
-    "firebase-functions": "^0.8.1"
+    "firebase-functions": "^0.8.1",
+    "http-proxy": "^1.16.2"
   },
   "devDependencies": {
+    "@types/express": "^4.11.1",
+    "@types/http-proxy": "^1.16.0",
     "typescript": "^2.5.3"
   },
   "private": true

functions/src/index.ts

@@ -1,8 +1,36 @@
+import * as express from 'express';
 import * as functions from 'firebase-functions';
+import * as httpProxy from 'http-proxy';
 
-// // Start writing Firebase Functions
-// // https://firebase.google.com/docs/functions/typescript
-//
-// export const helloWorld = functions.https.onRequest((request, response) => {
-//  response.send("Hello from Firebase!");
-// });
+const app = express();
+
+const proxy = httpProxy
+  .createProxyServer({
+    changeOrigin: true,
+    headers: {
+      Authorization: `Bearer ${functions.config().twitter.token}`,
+    },
+    target: 'https://api.twitter.com',
+  });
+
+proxy.on('proxyRes', function(proxyRes, req, res) {
+  if (process.env.NODE_ENV === 'development') {
+    res.setHeader('Access-Control-Allow-Origin', '*');
+  } else {
+    res.setHeader('Access-Control-Allow-Origin', 'http://trumpymctweetface.com');
+  }
+});
+
+app.get('/1.1/statuses/user_timeline.json', function(req, res) {
+  if (req.query.screen_name === 'realDonaldTrump') {
+    proxy.web(req, res);
+  } else {
+    res.sendStatus(403);
+  }
+});
+
+app.get('/1.1/statuses/show.json', function(req, res) {
+  proxy.web(req, res);
+});
+
+export const api = functions.https.onRequest(app);