Simplify connection flow, mobile transfer UI, and header actions

apps/server/src/app.ts

@@ -331,6 +331,7 @@ export async function createApp(cfg: Config, options: { mailer?: Mailer } = {})
         device: service.device(g.id),
         devices: service.peers(g),
         sameNetworkDiscoveryEnabled: cfg.discoveryEnabled,
+        spaceInviteCodeLength: cfg.spaceInviteCodeLength,
         locationDiscovery: {
           enabled: cfg.locationDiscoveryEnabled,
           radiusMeters: cfg.locationRadiusMeters,

apps/server/src/config.ts

@@ -18,6 +18,7 @@ export type Config = {
   requestSeconds: number;
   uploadStartHours: number;
   spaceMinutes: number;
+  spaceInviteCodeLength: number;
   spaceMax: number;
   offlineGraceMs: number;
   maxUrlBytes: number;
@@ -67,6 +68,9 @@ export function loadConfig(env: NodeJS.ProcessEnv = process.env): Config {
     throw Error('PROXY_DIAGNOSTIC_TOKEN must contain at least 32 characters');
   if (num('LOCATION_DISCOVERY_RADIUS_METERS', 100) > 1000)
     throw Error('LOCATION_DISCOVERY_RADIUS_METERS must not exceed 1000');
+  const spaceInviteCodeLength = num('SPACE_INVITE_CODE_LENGTH', 4);
+  if (![4, 6].includes(spaceInviteCodeLength))
+    throw Error('SPACE_INVITE_CODE_LENGTH must be 4 or 6');
   return {
     production,
     appUrl,
@@ -92,6 +96,7 @@ export function loadConfig(env: NodeJS.ProcessEnv = process.env): Config {
     requestSeconds: num('LOCAL_REQUEST_TIMEOUT_SECONDS', 60),
     uploadStartHours: num('ACCEPTED_UPLOAD_START_HOURS', 24),
     spaceMinutes: num('SPACE_RETENTION_MINUTES', 10),
+    spaceInviteCodeLength,
     spaceMax: num('SPACE_MAX_DEVICES', 10),
     offlineGraceMs: num('OFFLINE_GRACE_MS', 3000, 0),
     maxUrlBytes: num('MAX_URL_PAYLOAD_SIZE_KB', 1024) * 1024,

apps/server/src/inviteCode.js

@@ -0,0 +1,10 @@
+import { randomInt } from 'node:crypto';
+const alphabet = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';
+
+export function newInviteCode(length, isTaken, random = randomInt) {
+  for (let attempt = 0; attempt < 32; attempt++) {
+    const candidate = Array.from({ length }, () => alphabet[random(alphabet.length)]).join('');
+    if (!isTaken(candidate)) return candidate;
+  }
+  return null;
+}

apps/server/src/service.ts

@@ -5,7 +5,8 @@ import { Storage } from './storage.js';
 import { ResumableUploads } from './resumable.js';
 import { NearbyLocations } from './nearby.js';
 import { Vault } from './vault.js';
-import { randomInt, randomUUID } from 'node:crypto';
+import { randomUUID } from 'node:crypto';
+import { newInviteCode } from './inviteCode.js';
 import { and, eq, gt, isNull, or, desc, lt, inArray, sql } from 'drizzle-orm';
 import type { DB } from './db/index.js';
 import * as s from './db/schema.js';
@@ -380,8 +381,18 @@ export class Service {
     const now = Date.now(),
       id = randomUUID(),
       token = randomToken();
-    const alphabet = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';
-    const code = Array.from({ length: 8 }, () => alphabet[randomInt(alphabet.length)]).join('');
+    // The unique DB constraint includes historical spaces; never reuse their codes.
+    const code =
+      newInviteCode(this.cfg.spaceInviteCodeLength, (candidate: string) =>
+        Boolean(
+          this.db
+            .select({ id: s.spaces.id })
+            .from(s.spaces)
+            .where(eq(s.spaces.codeHash, hmac(this.cfg.discoverySecret, candidate)))
+            .get(),
+        ),
+      ) ??
+      fail(503, 'SPACE_CODE_BUSY', '초대 코드를 만들지 못했습니다. 잠시 후 다시 시도해 주세요.');
     this.db.transaction(() => {
       this.db
         .insert(s.spaces)