feat(api): initial implementation of the auth system (#30)

Adds the auth system but does not add all required features. They will be handled in other tickets

server/routes/auth.ts

@@ -0,0 +1,65 @@
+import { Router } from 'express';
+import { getRepository } from 'typeorm';
+import { User } from '../entity/User';
+import PlexTvAPI from '../api/plextv';
+
+const authRoutes = Router();
+
+authRoutes.post('/login', async (req, res) => {
+  const userRepository = getRepository(User);
+  const body = req.body as { authToken?: string };
+
+  if (!body.authToken) {
+    return res.status(500).json({ error: 'You must provide an auth token' });
+  }
+  try {
+    // First we need to use this auth token to get the users email from plex tv
+    const plextv = new PlexTvAPI(body.authToken);
+    const account = await plextv.getUser();
+
+    // Next let's see if the user already exists
+    let user = await userRepository.findOne({
+      where: { email: account.email },
+    });
+
+    if (user) {
+      // Let's check if their plex token is up to date
+      if (user.plexToken !== body.authToken) {
+        user.plexToken = body.authToken;
+        await userRepository.save(user);
+      }
+    } else {
+      // Here we check if it's the first user. If it is, we create the user with no check
+      // and give them admin permissions
+      const totalUsers = await userRepository.count();
+
+      if (totalUsers === 0) {
+        user = new User({
+          email: account.email,
+          plexToken: account.authToken,
+          // TODO: When we add permissions in #52, set admin here
+        });
+        await userRepository.save(user);
+      }
+
+      // If we get to this point, the user does not already exist so we need to create the
+      // user _assuming_ they have access to the plex server
+      // (We cant do this until we finish the settings sytem and actually
+      // store the user token in ticket #55)
+    }
+
+    // Set logged in session
+    if (req.session && user) {
+      req.session.userId = user.id;
+    }
+
+    return res.status(200).json({ status: 'ok' });
+  } catch (e) {
+    console.error(e);
+    res
+      .status(500)
+      .json({ error: 'Something went wrong. Is your auth token valid?' });
+  }
+});
+
+export default authRoutes;