chore: rewrite /login page for OAuth, write createUser for the database

server/db/database.ts

@@ -2,7 +2,7 @@ import crypto from 'crypto'
 
 import { readFile, writeFile, access, constants } from 'fs/promises'
 
-import { MetadataProps as MetaProps, Problem, ProblemId, Solution, SolutionId, User } from '../../shared/model'
+import { MetadataProps as MetaProps, Problem, ProblemId, Solution, SolutionId, User, UserId, UserRole } from '../../shared/model'
 
 function once<T extends (...args: any) => any>(fn: T, message: string): T {
     let flag = false
@@ -53,7 +53,7 @@ function createMutex(): Mutex {
     return { lock }
 }
 
-type DatabaseConnection = {
+export type DatabaseConnection = {
     path: string
     initialValue: Database
     mu: Mutex
@@ -110,6 +110,11 @@ export const getUser: (db: DatabaseConnection, id: string) => Promise<User | nul
         return state.users[id] ?? null
     })
 
+export const createUser: (db: DatabaseConnection, user: User) => Promise<void> = (db, user) =>
+    withDatabase(db, state => {
+        state.users[user.id] = user
+    })
+
 //
 // Problems
 //