---
phase: 05-dashboard-calendar
plan: 03
type: execute
wave: 3
depends_on: ["05-01", "05-02"]
requirements: [CAL-01, CAL-02, CAL-03, DASH-05]
files_modified:
  - apps/api/prisma/schema.prisma
  - apps/api/src/app.module.ts
  - apps/api/src/calendar/calendar.module.ts
  - apps/api/src/calendar/calendar.controller.ts
  - apps/api/src/calendar/calendar.service.ts
  - apps/api/src/calendar/crypto.service.ts
  - apps/api/src/calendar/providers/caldav.provider.ts
  - apps/api/src/calendar/providers/ics.provider.ts
  - apps/api/src/calendar/providers/exchange.provider.ts
  - apps/api/src/calendar/dto/create-calendar-source.dto.ts
  - apps/api/src/calendar/dto/update-calendar-source.dto.ts
  - apps/api/src/calendar/dto/calendar-events-query.dto.ts
  - apps/api/package.json
autonomous: true
user_setup:
  - service: calendar-encryption
    why: "AES-256-GCM key required to encrypt calendar credentials at rest"
    env_vars:
      - name: CALENDAR_ENCRYPTION_KEY
        source: "Generate a 32-byte hex key: openssl rand -hex 32 — add to apps/api .env and docker-compose api environment"
must_haves:
  truths:
    - "User can configure CalDAV, Exchange, and ICS calendar sources in Settings > Dashboard > Kalender"
    - "User can toggle which calendar sources are visible in the widget"
    - "Calendar widget shows upcoming events aggregated from selected sources"
    - "Calendar credentials are encrypted at rest and never returned in GET responses"
  artifacts:
    - path: "apps/api/prisma/schema.prisma"
      provides: "CalendarSource model"
      contains: "model CalendarSource"
    - path: "apps/api/src/calendar/calendar.service.ts"
      provides: "Event aggregation across provider types"
      exports: ["CalendarService"]
    - path: "apps/api/src/calendar/providers/ics.provider.ts"
      provides: "ICS event fetch + parse"
  key_links:
    - from: "apps/api/src/calendar/calendar.service.ts"
      to: "prisma.calendarSource"
      via: "user-scoped query with credential decryption"
      pattern: "prisma\\.calendarSource"
    - from: "apps/api/src/calendar/calendar.service.ts"
      to: "ICSProvider/CalDAVProvider/ExchangeProvider"
      via: "provider dispatch by source.type"
      pattern: "type === 'ics'"
---

<objective>
Deliver the calendar vertical slice end-to-end: a user configures one or more calendar sources (CalDAV via tsdav, ICS via node-ical, Exchange via ews/Graph) in Settings > Dashboard > Kalender, toggles which sources are visible, and the Calendar widget on the dashboard shows upcoming events aggregated and normalized across all visible sources. Credentials are encrypted at rest (AES-256-GCM) and never leave the backend.

Purpose: Implements CAL-01 (source integration), CAL-02 (visibility selection), CAL-03 (event previews for selected sources), and DASH-05 (calendar widget). This is the heaviest slice — calendar protocols carry the highest hidden complexity per RESEARCH.

Output: Working calendar widget backed by a multi-protocol aggregation service and a source-management settings page.
</objective>

<artifacts_this_phase_produces>
Symbols created by THIS plan (exclude from drift verification — they are new):

**Prisma models:** `CalendarSource`
**NestJS:** `CalendarModule`, `CalendarController`, `CalendarService`, `CalendarCryptoService`, `CalDAVProvider`, `ICSProvider`, `ExchangeProvider`, `CreateCalendarSourceDto`, `UpdateCalendarSourceDto`, `CalendarEventsQueryDto`
**Interfaces:** `CalendarEvent`, `CalendarProvider`
**API endpoints:** `GET /api/calendar/sources`, `POST /api/calendar/sources`, `PATCH /api/calendar/sources/:id`, `DELETE /api/calendar/sources/:id`, `POST /api/calendar/sources/:id/test`, `GET /api/calendar/events`
**npm:** `tsdav`, `node-ical`, `ews-javascript-api`, `@microsoft/microsoft-graph-client`
**env var:** `CALENDAR_ENCRYPTION_KEY`
</artifacts_this_phase_produces>

<execution_context>
@$HOME/.claude/gsd-core/workflows/execute-plan.md
@$HOME/.claude/gsd-core/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/phases/05-dashboard-calendar/05-CONTEXT.md
@.planning/phases/05-dashboard-calendar/05-RESEARCH.md
@.planning/phases/05-dashboard-calendar/05-PATTERNS.md
@.planning/phases/05-dashboard-calendar/05-UI-SPEC.md
@.planning/phases/05-dashboard-calendar/05-01-SUMMARY.md
@.planning/phases/05-dashboard-calendar/05-02-SUMMARY.md
</context>

<tasks>

<task type="auto">
  <name>Task 1: Calendar backend — model, crypto, source CRUD module</name>
  <files>apps/api/prisma/schema.prisma, apps/api/src/app.module.ts, apps/api/src/calendar/calendar.module.ts, apps/api/src/calendar/calendar.controller.ts, apps/api/src/calendar/calendar.service.ts, apps/api/src/calendar/crypto.service.ts, apps/api/src/calendar/dto/create-calendar-source.dto.ts, apps/api/src/calendar/dto/update-calendar-source.dto.ts, apps/api/src/calendar/dto/calendar-events-query.dto.ts, apps/api/package.json</files>
  <read_first>
    - apps/api/prisma/schema.prisma (CalendarSource model follows existing conventions; see CalendarSource example in RESEARCH lines 562-581)
    - apps/api/src/module-registry/module-registry.module.ts (module pattern)
    - apps/api/src/module-registry/module-registry.controller.ts (userId/tenant extraction)
    - apps/api/src/module-registry/module-registry.service.ts (PrismaService injection + CRUD)
    - apps/api/src/domaincheck/dto/check-domain.dto.ts (DTO pattern)
    - apps/api/src/app.module.ts (register CalendarModule)
    - .planning/phases/05-dashboard-calendar/05-RESEARCH.md lines 364-412 (anti-patterns: never fetch calendar in browser, encrypt credentials, never return passwords), lines 673-681 (encryption recommendation), lines 743-761 (Security Domain: SSRF, credential exposure)
    - .planning/phases/05-dashboard-calendar/05-UI-SPEC.md lines 161-166 (source list + form fields)
  </read_first>
  <action>
    Install calendar libs: `cd apps/api && pnpm add tsdav@2.2.2 node-ical@0.26.1 ews-javascript-api@0.15.3 @microsoft/microsoft-graph-client@3.0.7` (all Approved in RESEARCH Legitimacy Audit — no checkpoint).

    Add Prisma model `CalendarSource`: `id String @id @default(uuid())`, `userId String`, `tenantId String`, `name String`, `type String` ('caldav'|'ics'|'exchange'), `exchangeMode String?` ('ews'|'graph' — only for exchange, per RESEARCH open question 2), `url String`, `username String?`, `encryptedPassword String?` (AES-256-GCM ciphertext), `color String? @default("#3B82F6")`, `isVisible Boolean @default(true)`, `syncIntervalMin Int @default(15)`, `lastSyncAt DateTime?`, `lastSyncError String?`, `createdAt DateTime @default(now())`, `updatedAt DateTime @updatedAt`, `@@index([userId])`, `@@index([tenantId])`. Source config is per-user (D-09), not per-tenant.

    Create `crypto.service.ts` (`CalendarCryptoService`, injectable): AES-256-GCM using `CALENDAR_ENCRYPTION_KEY` (32-byte hex) from ConfigService. `encrypt(plaintext)` returns `iv:authTag:ciphertext` (hex-joined); `decrypt(stored)` reverses it. Throw a clear error at startup if the key is missing/wrong length.

    Create CalendarModule (controllers: [CalendarController], providers: [CalendarService, CalendarCryptoService, CalDAVProvider, ICSProvider, ExchangeProvider]); register in app.module.ts imports. Providers added in Task 2 — declare them in providers array now (stub provider files created in Task 2, but module references them; create minimal stubs here if needed so the module compiles, or sequence so Task 2 fills bodies).

    CalendarController `@Controller('calendar')`: `@Get('sources')` (returns sources WITHOUT password fields — use Prisma `select` excluding encryptedPassword, Pitfall 3), `@Post('sources')`, `@Patch('sources/:id')`, `@Delete('sources/:id')`, `@Post('sources/:id/test')` (testConnection), `@Get('events')` (aggregated events — implemented in Task 3). Every handler extracts userId + tenantId; all source mutations verify userId ownership.

    CalendarService (this task: source CRUD only): inject PrismaService + CalendarCryptoService. `getSources(userId)` → findMany with `select` that NEVER includes encryptedPassword (return a boolean `hasCredentials` instead). `addSource(userId, tenantId, dto)` → encrypt dto.password into encryptedPassword before create. `updateSource(id, userId, dto)` → ownership check, re-encrypt if password provided. `deleteSource(id, userId)` → ownership check + delete.

    DTOs: CreateCalendarSourceDto — `@IsString() @IsNotEmpty() name`, `@IsIn(['caldav','ics','exchange']) type`, `@IsUrl({ protocols: ['https'], require_protocol: true }) url` (https-only — SSRF mitigation, Security Domain), `@IsOptional() @IsString() username`, `@IsOptional() @IsString() password`, `@IsOptional() @IsIn(['ews','graph']) exchangeMode`, `@IsOptional() @IsHexColor() color`. UpdateCalendarSourceDto — all optional incl. `@IsOptional() @IsBoolean() isVisible` (CAL-02 toggle). CalendarEventsQueryDto — `@IsOptional() @IsDateString() from`, `@IsOptional() @IsDateString() to`.

    SSRF guard: in addSource/test, reject URLs resolving to private IP ranges (10.x, 192.168.x, 127.x, 169.254.x) in addition to https-only scheme.
  </action>
  <verify>
    <automated>cd apps/api && npx prisma validate && npx tsc --noEmit</automated>
  </verify>
  <acceptance_criteria>
    - apps/api/package.json contains tsdav, node-ical, ews-javascript-api, @microsoft/microsoft-graph-client
    - schema.prisma contains `model CalendarSource` with `encryptedPassword` and `isVisible`
    - calendar.controller.ts GET /sources uses Prisma `select` that excludes encryptedPassword (grep: no `encryptedPassword: true` in the sources select)
    - crypto.service.ts uses `aes-256-gcm`
    - create-calendar-source.dto.ts restricts url to https (`protocols: ['https']`)
    - app.module.ts imports CalendarModule
    - `npx prisma validate` and `npx tsc --noEmit` exit 0
  </acceptance_criteria>
  <done>Calendar source CRUD with encrypted credentials, https-only URLs, no password leakage in GET responses.</done>
</task>

<task type="auto">
  <name>Task 2: Calendar providers (CalDAV, ICS, Exchange)</name>
  <files>apps/api/src/calendar/providers/caldav.provider.ts, apps/api/src/calendar/providers/ics.provider.ts, apps/api/src/calendar/providers/exchange.provider.ts</files>
  <read_first>
    - apps/api/src/calendar/calendar.service.ts (from Task 1 — providers are injected here; match the CalendarProvider interface)
    - apps/api/src/calendar/crypto.service.ts (decrypt credentials before use)
    - .planning/phases/05-dashboard-calendar/05-RESEARCH.md lines 287-310 (CalendarEvent + CalendarProvider interface), lines 96-101 (library purposes), Assumptions A2/A3/A6 (date-range filter, exchange OAuth, recurring expansion)
    - .planning/phases/05-dashboard-calendar/05-PATTERNS.md lines 353-361 (no-analog — use RESEARCH library patterns)
  </read_first>
  <action>
    Define a shared `CalendarProvider` interface (in calendar.service.ts or a types file): `fetchEvents(source, from, to): Promise<CalendarEvent[]>` and `testConnection(source): Promise<boolean>`. `CalendarEvent { id, sourceId, title, start: Date, end: Date, allDay: boolean, location?, description? }`.

    `ics.provider.ts` (ICSProvider, injectable) — the simplest, implement fully: HTTPS GET the .ics URL (timeout ~8s, abort on timeout — Pitfall 4), parse with node-ical `async.fromURL` or `sync.parseICS`. Filter VEVENTs to the [from,to] window. Expand recurring events via node-ical RRULE support (Assumption A6 — if node-ical's expansion is insufficient, note the ical.js fallback but do not block). Map to CalendarEvent. testConnection: fetch + parse, return true if at least the request succeeds.

    `caldav.provider.ts` (CalDAVProvider, injectable): use tsdav `createDAVClient` with Basic auth (username + decrypted password). Login, fetch calendars, `fetchCalendarObjects` with the time-range filter (Assumption A2 — pass start/end so only the window is fetched). Parse returned iCal data with node-ical, map to CalendarEvent. testConnection: attempt login + list calendars.

    `exchange.provider.ts` (ExchangeProvider, injectable): dispatch on `source.exchangeMode`. For 'graph' use @microsoft/microsoft-graph-client to query `/me/calendarView` with start/end (Exchange Online, RESEARCH State of the Art prefers Graph). For 'ews' use ews-javascript-api FindAppointments over a CalendarView (on-premise). Map to CalendarEvent. Wrap both in try/catch; on auth failure surface a generic error (no credential details — Security V7). If Exchange integration cannot be fully realized for a given mode, return an empty array and set lastSyncError rather than throwing (graceful degradation; D-08 requires the source TYPE to be configurable and attempted — the widget must not crash).

    All providers: never log decrypted credentials; respect per-request timeouts.
  </action>
  <verify>
    <automated>cd apps/api && npx tsc --noEmit</automated>
  </verify>
  <acceptance_criteria>
    - ics.provider.ts imports node-ical and filters events by date window
    - caldav.provider.ts imports tsdav and passes a time-range to fetchCalendarObjects
    - exchange.provider.ts branches on exchangeMode ('graph' vs 'ews')
    - no provider logs decrypted passwords (grep: no `console.log` of password/credential vars)
    - all three implement fetchEvents + testConnection returning the CalendarEvent shape
    - `npx tsc --noEmit` exits 0
  </acceptance_criteria>
  <done>Three providers fetch + normalize events; Exchange degrades gracefully; no credential leakage.</done>
</task>

<task type="auto">
  <name>Task 3: Event aggregation + caching backend</name>
  <files>apps/api/src/calendar/calendar.service.ts, apps/api/src/calendar/calendar.controller.ts</files>
  <read_first>
    - apps/api/src/calendar/calendar.service.ts (from Task 1/2 — add aggregateEvents)
    - apps/api/src/calendar/providers/*.provider.ts (from Task 2 — dispatch by type)
    - .planning/phases/05-dashboard-calendar/05-RESEARCH.md lines 408-413 (caching with TTL Pitfall 4)
  </read_first>
  <action>
    Add `aggregateEvents(userId, from, to)` to CalendarService: load the user's `isVisible: true` sources (CAL-02/CAL-03), dispatch each to its provider by `source.type` (ics/caldav/exchange), decrypt credentials per source, fetch in parallel (`Promise.allSettled` so one failing source doesn't break others — set lastSyncError on failures), merge + sort by start ascending, return normalized CalendarEvent[] including each event's source color. Cache results per user in an in-memory Map with a 5-minute TTL (Pitfall 4) — serve cached immediately, refresh in background. Implement `GET /calendar/events` in the controller using CalendarEventsQueryDto (default window: now → now+30 days). Implement `POST /calendar/sources/:id/test` → provider.testConnection, update lastSyncAt/lastSyncError.
  </action>
  <verify>
    <automated>cd apps/api && npx tsc --noEmit</automated>
  </verify>
  <acceptance_criteria>
    - calendar.service.ts aggregateEvents uses `Promise.allSettled` and filters `isVisible`
    - calendar.service.ts caches events with a TTL (grep: a Map + timestamp/expiry check)
    - calendar.controller.ts contains `@Get('events')` and `@Post('sources/:id/test')`
    - `npx tsc --noEmit` exits 0
  </acceptance_criteria>
  <done>Event aggregation across providers with caching, test-connection endpoint.</done>
</task>

<task type="auto">
  <name>Task 4: [BLOCKING] Prisma schema push + encryption key check</name>
  <files>apps/api/prisma/schema.prisma</files>
  <read_first>
    - apps/api/prisma/schema.prisma (CalendarSource model from Task 1)
    - apps/api/src/calendar/crypto.service.ts (CALENDAR_ENCRYPTION_KEY consumer)
  </read_first>
  <action>
    Ensure `CALENDAR_ENCRYPTION_KEY` (32-byte hex, generate via `openssl rand -hex 32`) is present in apps/api `.env` and the docker-compose api service environment so the crypto service can start. Then push the schema to the running PostgreSQL container: `npx prisma db push` from apps/api, then `npx prisma generate`. MANDATORY — type checks pass without the push (false-positive). Only the new CalendarSource table is added; if data loss is reported, STOP and flag for manual review rather than passing `--accept-data-loss`.
  </action>
  <verify>
    <automated>cd apps/api && test -n "$(grep -s CALENDAR_ENCRYPTION_KEY .env)" && npx prisma db push --skip-generate && npx prisma generate</automated>
  </verify>
  <acceptance_criteria>
    - apps/api/.env contains CALENDAR_ENCRYPTION_KEY
    - `npx prisma db push` exits 0 and reports in sync on a second run
    - live DB contains the CalendarSource table
    - `npx prisma generate` exits 0
  </acceptance_criteria>
  <done>Live schema includes CalendarSource; encryption key configured; client regenerated.</done>
</task>

</tasks>

<threat_model>
## Trust Boundaries

| Boundary | Description |
|----------|-------------|
| Browser → Calendar API | User submits source config incl. credentials |
| API → External calendar servers | Backend fetches events from user-supplied URLs |
| API → PostgreSQL | Encrypted credentials stored at rest |

## STRIDE Threat Register

| Threat ID | Category | Component | Disposition | Mitigation Plan |
|-----------|----------|-----------|-------------|-----------------|
| T-05-09 | Information Disclosure | GET /calendar/sources | mitigate | Prisma `select` excludes encryptedPassword; return `hasCredentials` boolean only (Pitfall 3) |
| T-05-10 | Information Disclosure | CalendarSource at rest | mitigate | AES-256-GCM encryption via CalendarCryptoService + CALENDAR_ENCRYPTION_KEY |
| T-05-11 | Tampering / SSRF | source URL fetch (ics/caldav) | mitigate | DTO https-only (`protocols:['https']`) + block private IP ranges (10/192.168/127/169.254) + request timeouts |
| T-05-12 | Elevation of Privilege | source mutations + /events | mitigate | All endpoints scoped to userId from JWT; ownership check before update/delete; events per-user not per-tenant (D-09) |
| T-05-13 | Information Disclosure | connection error responses | mitigate | Generic error messages; no credential details in errors (ASVS V7) |
| T-05-SC | Tampering | npm installs (tsdav/node-ical/ews/graph) | mitigate | All Approved in RESEARCH Legitimacy Audit; no [ASSUMED]/[SUS] → no blocking checkpoint |
</threat_model>

<verification>
- `cd apps/api && npx prisma validate` exits 0
- `cd apps/api && npx tsc --noEmit` exits 0
- `cd apps/web && pnpm exec tsc --noEmit` exits 0
- `cd apps/web && pnpm vitest run src/components/dashboard/widgets/calendar-widget.test.tsx "src/app/(portal)/settings/dashboard/calendar/calendar-settings.test.tsx"` green
- `npx prisma db push` reports in sync; CALENDAR_ENCRYPTION_KEY present
</verification>

<success_criteria>
- User configures CalDAV, ICS, and Exchange sources in Settings > Dashboard > Kalender
- User toggles source visibility; only visible sources feed the widget (CAL-02/CAL-03)
- Calendar widget shows aggregated upcoming events with source color dots, read-only
- Credentials encrypted at rest, never returned in GET, https-only URLs enforced
- One failing source does not break the others (Promise.allSettled)
</success_criteria>

<output>
Create `.planning/phases/05-dashboard-calendar/05-03-SUMMARY.md` when done
</output>