--- type: architecture title: Key Files Index description: One-line responsibility for important source and contract-test files, including strict event-window validation, the public bootstrap SSE listener, the challenges full-replace import flow, the authenticated player-facing challenges board, and the per-user `solvedByMe` reset on the session boundary. tags: [architecture, key-files, event-window, validation, default-challenge-ip, sse, bootstrap, migrations, challenges, import, board, notifications, per-user, session] timestamp: 2026-07-23T04:05:00Z --- # Backend | File | Responsibility | |---|---| | `backend/src/main.ts` | Bootstraps Nest, middleware, OpenAPI, static assets, and SPA fallback. | | `backend/src/app.module.ts` | Wires feature modules and global providers. | | `backend/src/config/env.schema.ts` | Zod-validated runtime config; canonical defaults for `DATABASE_PATH` (`./data/db.sqlite`) and `UPLOAD_DIR` (`./data/uploads`). | | `backend/src/database/database.module.ts` | Configures TypeORM with SQLite. | | `backend/src/database/database-init.service.ts` | Initializes the database and runs migrations; `verifySeed()` also asserts the canonical six system-category keys and reports missing/duplicate rows. | | `backend/src/database/migrations/1700000000400-RepairCategorySchemaAndSystemCategories.ts` | Forward-only repair migration: adds `created_at`/`updated_at` to legacy six-column `category` tables, deletes obsolete `FOR`/`OSI` system rows, rewrites canonical row metadata, inserts any missing canonical key, and re-asserts unique indexes. Exports `CANONICAL_SYSTEM_CATEGORIES`. | | `backend/src/common/guards/jwt-auth.guard.ts` | Global JWT authorization guard. | | `backend/src/common/middleware/csrf.middleware.ts` | Double-submit CSRF protection. | | `backend/src/common/services/event-status.service.ts` | Computes the event-window state machine. | | `backend/src/common/services/sse-hub.service.ts` | In-process pub/sub for server-sent event streams. | | `backend/src/modules/system/system.controller.ts` | Registers bootstrap, event status, settings, and SSE endpoints. | | `backend/src/modules/system/system.service.ts` | Builds the public bootstrap payload from admin existence, settings, the theme loader, and password-policy configuration. | | `backend/src/modules/admin/admin-general.controller.ts` | Registers admin general-settings and available-theme endpoints. | | `backend/src/modules/admin/general.service.ts` | Reads/writes global settings, filters available theme files, and publishes the `general` SSE notification after updates. | | `backend/src/modules/auth/auth.controller.ts` | Registers authentication and account endpoints. | | `backend/src/modules/auth/auth.service.ts` | Handles sessions, authentication, registration, and password changes. | | `backend/src/modules/uploads/uploads.controller.ts` | Registers admin-only multipart uploads, including Sharp-backed site-logo format validation and strict category-icon decode (rejects undecodable / non-image buffers with HTTP 400 before any filesystem write so existing icons are preserved). | | `backend/src/modules/admin/dto/general.dto.ts` | Zod contract for `PUT /api/v1/admin/general/settings`; both event timestamps are required ISO-8601 values and end must be strictly after start. | | `tests/backend/admin-general-event-window.spec.ts` | Focused contract tests for valid, empty, malformed, equal, and reversed event-window timestamps. | | `tests/backend/admin-general-service.spec.ts` | General-settings schema and service tests, including per-field empty datetime failures and settings-event emission. | | `tests/backend/admin-challenges-import-replace.spec.ts` | Contract tests for the confirmed-import full-replace: wipes unrelated pre-existing challenges, unlinks wiped disk files, empty archive, unknown-category skip-then-wipe. | | `backend/src/modules/challenges/challenges.module.ts` | Wires `ChallengesController`, `ChallengesEventsController`, `ChallengesService`, and the four TypeORM entities (`ChallengeEntity`, `CategoryEntity`, `SolveEntity`, `UserEntity`). | | `backend/src/modules/challenges/challenges.controller.ts` | Registers `/api/v1/challenges/{board,status,:id,:id/solves}` (all JWT-protected). | | `backend/src/modules/challenges/events.controller.ts` | Authenticated SSE `/api/v1/events` merging status ticks + hub `general` pushes + `scoreboard$` solve frames. | | `backend/src/modules/challenges/challenges.service.ts` | `getBoard` / `getDetail` / `submitFlag` + `dataSource.transaction` for race-safe idempotent solves; publishes `solve` SSE frames on success. | | `backend/src/modules/challenges/dto/challenges.dto.ts` | zod contracts (`SolveSubmitBodySchema`, `BoardQuerySchema`, `ChallengeIdParamSchema`) + DTO types for the player-facing board. | | `backend/src/modules/challenges/scoring.util.ts` | Pure `computeLivePoints`, `rankBonusForPosition`, `compareDifficulty`, and constant-time `safeEqualString` for flag comparison. | | `backend/src/common/errors/error-codes.ts` | Canonical error code map (now includes `EVENT_NOT_RUNNING`, `FLAG_INCORRECT`, `CHALLENGE_DISABLED`). | # Frontend | File | Responsibility | |---|---| | `frontend/src/main.ts` | Bootstraps Angular and registers HTTP interceptors. | | `frontend/proxy.conf.json` | Angular dev-server proxy: forwards `/api` and `/uploads` to `http://localhost:3000`. | | `frontend/angular.json` | Angular workspace config; the `serve` target references `proxy.conf.json`. | | `package.json` (root) | Root npm scripts; `dev` runs both workspaces via `concurrently`, `dev:backend` / `dev:frontend` run one at a time. | | `setup.sh` | Idempotent setup: installs root + workspace deps, builds both packages, creates `./data/uploads`. | | `frontend/src/app/app.routes.ts` | Defines public, shell, child, and admin routes. | | `frontend/src/app/core/services/bootstrap.service.ts` | Caches and exposes bootstrap state, refreshes it after admin updates, and applies the resolved theme. | | `frontend/src/app/core/services/bootstrap.types.ts` | Defines bootstrap/theme payload types and maps theme tokens to CSS custom properties. | | `frontend/src/app/core/services/admin.service.ts` | Calls admin settings, theme-list, category, and upload APIs. | | `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services; on logout and on session invalidation also calls `challengesStore.reset()` to flush any per-user board cache before navigating to `/login`. | | `frontend/src/app/core/services/auth.service.ts` | Signal-backed access token and current-user state; owns the cross-tab invalidation `BroadcastChannel` + `storage`-event fallback. | | `frontend/src/app/core/services/auth-session-events.pure.ts` | Pure cross-tab message encoding/validation and namespaced constants used by the auth broadcast channel. | | `frontend/src/app/core/services/authenticated-event-source.service.ts` | Fetch-based authenticated SSE transport with frame parsing, abort support, and a separate `'unauthorized'` event for `401`/`403`. | | `frontend/src/app/core/services/bootstrap-event.service.ts` | Root-provided public SSE listener that subscribes to `/api/v1/event/stream`, filters `topic === 'general'` frames, and triggers `BootstrapService.refresh()` so the landing modal stays in sync with admin general-settings updates. | | `frontend/src/app/core/services/bootstrap-event.pure.ts` | Pure helpers for the public bootstrap SSE listener: `isBootstrapGeneralFrame` predicate, SSE line parser, and the `makeBootstrapEventSource` factory (fetch + `ReadableStream` opener with frame buffering and idempotent `close()`). | | `frontend/src/app/core/services/event-status.store.ts` | Event state signal store, one-second countdown timer, and the optional `onUnauthorized` callback wiring; exposes `start()`/`stop()`/`closeTransport()` for transport lifecycle and `subscribeReloadAtCountdownZero(handler)` (with `reloadAtCountdownZero(handler)` kept as a back-compat wrapper) so the reload handler is owned by its subscriber rather than the transport. | | `frontend/src/app/core/services/event-status.pure.ts` | Event payload types, transport interface (including `'unauthorized'` listener), pure countdown helpers (`formatDdHhMm` returns `DD:HH:mm:ss` and `deriveCountdownText`), and the `LED_COLOR_BY_STATE` map used by the shell LED. | | `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services, subscribes to peer invalidation, resets both `UserStore` and `ChallengesStore`, and navigates to `/login` when the session is invalidated elsewhere. | | `frontend/src/app/features/shell/header/shell-header.component.ts` | Shell title, status LED (size/shape only — color comes from the pure map via `[style.background-color]`), countdown, and user menu. | | `frontend/src/app/features/shell/tabs/quick-tabs.component.ts` | Main shell navigation tabs. | | `frontend/src/app/features/shell/change-password/change-password-modal.component.ts` | Change-password form modal. | | `frontend/src/app/features/admin/general.component.ts` | `AdminGeneralComponent` reactive form for `/admin/general` — per-field inline error rendering (page-title + event-start + event-end), logo upload wiring, welcome Markdown preview, event-state derivation, and SSE `general` event handling. | | `frontend/src/app/features/admin/categories/category-form-modal.component.ts` | Standalone OnPush modal for create + edit; owns the `CategoryFormGroup`, exposes the pure `syncCategoryForm` helper, binds `[formGroup]` on its template `
`, accepts `errorMessage` + `saving` parent inputs (renders `cf-error` and disables OK while saving), and reacts to `open` / `mode` / `category` signal inputs via a `markForCheck` effect so edit prefill reaches the DOM. | | `frontend/src/app/features/admin/general.pure.ts` | Pure General Settings helpers, including required datetime validation, field messages, UTC conversion, end-after-start validation, and the default-challenge-address IPv4/hostname validator/normalizer/message trio. | | `tests/frontend/admin-general-pure.spec.ts` | Pure client-contract tests for required event timestamps, datetime messaging, UTC conversion, event-window ordering, and default-challenge-address validation, error mapping, and normalization. | | `tests/frontend/admin-categories-form-modal.spec.ts` | Tests the pure `syncCategoryForm` helper that drives the edit/create prefill in `CategoryFormModalComponent`: system-row abbreviation lock, user-row unlock, re-population on second invocation, clearing on create, and iconPreview passthrough. | | `tests/frontend/authenticated-event-source.spec.ts` | Tests SSE authorization, frame transport behavior, and the `401`/`403` unauthorized path. | | `tests/frontend/auth-session-events.spec.ts` | Pure tests for cross-tab invalidation message encoding, payload validation, and `storage`-event filtering. | | `tests/frontend/admin-challenges-import-autoclose.spec.ts` | Pure helpers (`summarizeImportResult`, `importErrorMessage`) and modal auto-close branch for the confirmed-import handler. | | `frontend/src/app/features/challenges/challenges.page.ts` | `/challenges` smart page: gate logic (countdown/running/stopped/unconfigured), modal lifecycle, SSE wiring on `/api/v1/events`, and the page-owned countdown-zero reload (handler registered in the constructor with the disposer wired into `DestroyRef`). | | `frontend/src/app/features/challenges/challenges.store.ts` | Signal store: board, event state, per-card solve listeners, SSE solve-frame mutation, submit response application, stop() lifecycle, public `reset()` for the session-boundary flush, and `setMyUserId(id)` which now returns the previous id and clears the cache whenever the cached state belongs to an unknown or different user. | | `frontend/src/app/features/challenges/challenges.service.ts` | HTTP service for `/api/v1/challenges/{board,status,:id,:id/solves}` returning typed `ApiErrorEnvelope`s. `getDetail` always requests `?include=solvers` so the modal can render the solvers list in one round-trip; `getBoard` only attaches `include=solvers` when the caller opts in. | | `frontend/src/app/features/challenges/challenges.pure.ts` | Pure types and helpers (`BoardCard`, `SolverRow`, `SolveEventPayload`, `parseSolveEvent`, `mergeSolveEventIntoSolvers`, `messageForSolveError`, `formatDdHhMm`). | | `frontend/src/app/features/challenges/category-column.component.ts` | Renders a single category column (header + cards) on the challenges board. | | `frontend/src/app/features/challenges/challenge-card.component.ts` | Renders a single challenge card on the board as a semantic `