backend/auth: redo OAuth flow and "finish" DM auth flow

services/auth.js

@@ -3,6 +3,8 @@ import Service from './Service'
 import nanoid from 'nanoid'
 import moniker from 'moniker'
 import type { AppContext } from '../Roleypoly'
+import type { Context } from 'koa'
+// import type { UserPartial } from './discord'
 // import type { Models } from '../models'
 
 export type DMChallenge = {
@@ -12,6 +14,12 @@ export type DMChallenge = {
   issuedAt: Date
 }
 
+export type AuthTokens = {
+  access_token: string,
+  refresh_token: string,
+  expires_in: string
+}
+
 export default class AuthService extends Service {
   M: { AuthChallenge: any }
   monikerGen = moniker.generator([ moniker.adjective, moniker.adjective, moniker.noun ], { glue: ' ' })
@@ -20,6 +28,26 @@ export default class AuthService extends Service {
     this.M = ctx.M
   }
 
+  async isLoggedIn (ctx: Context, { refresh = false }: { refresh: boolean } = {}) {
+    const { userId, expiresAt, authType } = ctx.session
+    if (userId == null) {
+      return false
+    }
+
+    if (expiresAt < Date.now()) {
+      if (refresh && authType === 'oauth') {
+        const tokens = await this.ctx.discord.refreshOAuth(ctx.session)
+        this.injectSessionFromOAuth(ctx, tokens, userId)
+        return true
+      }
+
+      ctx.session = null // reset session as well
+      return false
+    }
+
+    return true
+  }
+
   async createDMChallenge (userId: string): Promise<DMChallenge> {
     const out: DMChallenge = {
       userId,
@@ -48,4 +76,27 @@ export default class AuthService extends Service {
 
     return challenge
   }
+
+  deleteDMChallenge (input: DMChallenge) {
+    return this.M.AuthChallenge.destroy({ where: { magic: input.magic } })
+  }
+
+  injectSessionFromChallenge (ctx: Context, chall: DMChallenge) {
+    ctx.session = {
+      userId: chall.userId,
+      authType: 'dm',
+      expiresAt: Date.now() + 1000 * 60 * 60 * 24
+    }
+  }
+
+  injectSessionFromOAuth (ctx: Context, tokens: AuthTokens, userId: string) {
+    const { expires_in: expiresIn, access_token: accessToken, refresh_token: refreshToken } = tokens
+    ctx.session = {
+      userId,
+      authType: 'oauth',
+      expiresAt: Date.now() + expiresIn,
+      accessToken,
+      refreshToken
+    }
+  }
 }