# T05 — Calendar Plugin Backend Briefing

## Project Root
/a0/usr/workdir/dev-projects/leocrm

## Context Files (read first)
- `app/plugins/base.py` — BasePlugin abstract class
- `app/plugins/manifest.py` — PluginManifest, PluginRouteDef
- `app/plugins/builtins/tags/` — Reference plugin (subdirectory pattern)
- `app/plugins/builtins/dms/` — Most recent plugin (complex reference)
- `app/core/db.py` — Base, TenantMixin, TimestampMixin
- `app/models/company.py` — Model pattern reference
- `app/routes/companies.py` — Route pattern reference
- `tests/test_dms.py` — Test pattern reference (uses authed_client from conftest)
- `tests/conftest.py` — Shared fixtures (dms_app, dms_client, authed_client — adapt for calendar)
- `architecture.md` — Calendar tables + endpoints (search for 'Calendar Plugin')

## Plugin Structure
```
app/plugins/builtins/calendar/
├── __init__.py          — Exports CalendarPlugin
├── plugin.py            — CalendarPlugin(BasePlugin) with manifest
├── routes.py            — 21 endpoints
├── models.py            — 7 SQLAlchemy models
├── schemas.py           — Pydantic schemas
├── recurrence.py        — Recurrence engine (RRULE-style)
├── ics_utils.py         — ICS export/import utilities
└── migrations/
    └── 0001_initial.sql — 7 tables
```

## Models (7 tables)

### Calendar
- id (UUID PK), tenant_id, name (str, not null), color (str, default '#3B82F6')
- type (str: personal/team/project/company, default 'personal')
- owner_id (UUID, not null), created_at, updated_at, deleted_at (soft delete)
- Unique: (name, tenant_id) WHERE deleted_at IS NULL

### CalendarEntry
- id (UUID PK), tenant_id, calendar_id (FK→calendars.id)
- entry_type (str: appointment/task, not null)
- subtype (str: normal/follow_up/private, default 'normal')
- title (str, not null), description (TEXT, nullable)
- start_at (TIMESTAMPTZ, nullable — for appointments)
- end_at (TIMESTAMPTZ, nullable — for appointments)
- all_day (bool, default false)
- location (str, nullable)
- due_date (DATE, nullable — for tasks)
- priority (str: low/medium/high, default 'medium')
- status (str: open/in_progress/done/cancelled, default 'open')
- assigned_to (UUID, nullable — for tasks)
- reminder (JSONB, nullable: {value: int, unit: str, channel: str})
- recurrence (JSONB, nullable: {pattern: str, custom_rule: str, end_date: date, exceptions: [date]})
- source_mail_id (UUID, nullable)
- created_by (UUID, not null), created_at, updated_at, deleted_at
- Index: (tenant_id, calendar_id), (tenant_id, start_at), (tenant_id, due_date), (tenant_id, assigned_to, status)

### CalendarEntryLink
- id (UUID PK), tenant_id, entry_id (FK→calendar_entries.id)
- entity_type (str: company/contact, not null), entity_id (UUID, not null)

### CalendarShare
- id (UUID PK), tenant_id, calendar_id (FK→calendars.id)
- user_id (UUID, nullable), group_id (UUID, nullable)
- permission (str: read/write, not null)

### UserCalendarVisibility
- user_id (FK→users.id), calendar_id (FK→calendars.id), tenant_id
- visible (bool, default true)
- PK: (user_id, calendar_id)

### Subtask
- id (UUID PK), tenant_id, entry_id (FK→calendar_entries.id)
- title (str, not null), completed (bool, default false)
- created_at

### Resource
- id (UUID PK), tenant_id, name (str, not null)
- type (str: room/equipment, not null)

### ResourceBooking
- id (UUID PK), tenant_id, resource_id (FK→resources.id)
- entry_id (FK→calendar_entries.id), start_at (TIMESTAMPTZ, not null), end_at (TIMESTAMPTZ, not null)

## Endpoints (21 total)

### Calendars (6)
1. `GET /api/v1/calendars` → 200 + calendar list (filtered by tenant + visibility)
2. `POST /api/v1/calendars` → 201, calendar created (name, color, type)
3. `PATCH /api/v1/calendars/{id}` → 200, updated (name, color)
4. `DELETE /api/v1/calendars/{id}` → 204, cascade delete entries + shares + visibility
5. `POST /api/v1/calendars/{id}/share` → 200, calendar shared (user_id/group_id, permission)
6. `GET /api/v1/calendars/{id}/permissions` → 200 + permission list

### Entries (10)
7. `GET /api/v1/calendar/entries?start=2026-01-01&end=2026-12-31` → 200 + entries in range
8. `POST /api/v1/calendar/entries` (appointment) → 201, entry created with start_at/end_at
9. `POST /api/v1/calendar/entries` (task) → 201, entry created with due_date/priority/status
10. `GET /api/v1/calendar/entries/{id}` → 200 + entry detail with links+subtasks
11. `PATCH /api/v1/calendar/entries/{id}` → 200, updated (drag&drop: PATCH start_at+end_at, or status change)
12. `PATCH /api/v1/calendar/entries/{id}` status=done → 200, status updated
13. `DELETE /api/v1/calendar/entries/{id}` → 204
14. `POST /api/v1/calendar/entries/{id}/link` → 200, linked to company/contact (entity_type, entity_id)
15. `POST /api/v1/calendar/entries/{id}/subtasks` → 201, subtask created (title)
16. `PATCH /api/v1/calendar/entries/{id}/subtasks/{sub_id}` → 200, completed toggled

### Bulk + Kanban + Export (3)
17. `POST /api/v1/calendar/entries/bulk` → 200, bulk status change/delete (entry_ids, action)
18. `GET /api/v1/calendar/kanban` → 200 + tasks grouped by status columns (open/in_progress/done/cancelled)
19. `GET /api/v1/calendar/entries/export?format=csv` → 200 + CSV stream

### ICS (2)
20. `GET /api/v1/calendar/{calendar_id}/ics-feed?token=valid` → 200 + text/calendar (NO auth, token-based)
21. `GET /api/v1/calendar/{calendar_id}/ics-feed?token=invalid` → 401
22. `POST /api/v1/calendar/import` (multipart .ics file) → 200 + import result (entries_created count)

### Resources (2)
23. `POST /api/v1/resources` → 201 (admin only, 403 for non-admin)
24. `POST /api/v1/calendar/entries/{id}/book-resource` → 200, resource booked (resource_id)
25. `POST /api/v1/calendar/entries/{id}/book-resource` (conflict) → 409

## Recurrence Engine
- Patterns: daily, weekly, monthly, yearly
- Custom rules: e.g. 'every 2nd Tuesday' → store as JSONB {pattern: 'custom', custom_rule: 'BYDAY=TU;BYSETPOS=2'}
- Exceptions: array of dates excluded from occurrence generation
- Occurrence generation: given a date range query (start, end), generate all occurrence instances
- Max 2 years forward for appointments
- Tasks: generate next instance on completion (post-completion, not on-the-fly)

## ICS Export Format
```
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//LeoCRM//Calendar//EN
BEGIN:VEVENT
UID:<entry_uuid>@leocrm
DTSTART:<start_at>
DTEND:<end_at>
SUMMARY:<title>
DESCRIPTION:<description>
LOCATION:<location>
END:VEVENT
END:VCALENDAR
```
- Token auth: each calendar has an `ics_token` (generate on first feed request, store in calendar_shares or a separate field)
- Invalid token → 401

## ICS Import
- Parse .ics file (VCALENDAR → VEVENT blocks)
- Create CalendarEntry per VEVENT
- Map: DTSTART→start_at, DTEND→end_at, SUMMARY→title, DESCRIPTION→description, LOCATION→location
- Return: {entries_created: N, errors: [...]}
- Use Python `icalendar` library if available, else parse manually

## Reminder System
- reminder JSONB: {value: 15, unit: 'minutes', channel: 'in_app'}
- When reminder is set on entry creation/update, schedule an ARQ job
- ARQ job fires at (start_at - reminder) for appointments, (due_date - reminder) for tasks
- Job sends in-app notification via EventBus
- For now: just store the reminder config and schedule the ARQ job (don't need to implement the actual notification delivery)

## Calendar Sharing
- Owner can share with user_id or group_id, permission read/write
- User with read permission: can view entries, cannot edit (403 on PATCH/POST/DELETE)
- User with write permission: can create/edit entries
- Private subtype entries: only owner + admin can see (filter in query)

## Migration SQL
```sql
CREATE TABLE IF NOT EXISTS calendars (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    name VARCHAR(200) NOT NULL,
    color VARCHAR(20) DEFAULT '#3B82F6',
    type VARCHAR(20) DEFAULT 'personal',
    owner_id UUID NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    deleted_at TIMESTAMPTZ
);
CREATE INDEX idx_calendars_tenant ON calendars(tenant_id) WHERE deleted_at IS NULL;

CREATE TABLE IF NOT EXISTS calendar_entries (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    calendar_id UUID REFERENCES calendars(id) ON DELETE CASCADE,
    entry_type VARCHAR(15) NOT NULL,
    subtype VARCHAR(20) DEFAULT 'normal',
    title VARCHAR(500) NOT NULL,
    description TEXT,
    start_at TIMESTAMPTZ,
    end_at TIMESTAMPTZ,
    all_day BOOLEAN DEFAULT false,
    location VARCHAR(500),
    due_date DATE,
    priority VARCHAR(10) DEFAULT 'medium',
    status VARCHAR(15) DEFAULT 'open',
    assigned_to UUID,
    reminder JSONB,
    recurrence JSONB,
    source_mail_id UUID,
    created_by UUID NOT NULL,
    created_at TIMESTAMPTZ DEFAULT NOW(),
    updated_at TIMESTAMPTZ DEFAULT NOW(),
    deleted_at TIMESTAMPTZ
);
CREATE INDEX idx_entries_tenant_cal ON calendar_entries(tenant_id, calendar_id) WHERE deleted_at IS NULL;
CREATE INDEX idx_entries_tenant_start ON calendar_entries(tenant_id, start_at) WHERE deleted_at IS NULL;
CREATE INDEX idx_entries_tenant_due ON calendar_entries(tenant_id, due_date) WHERE deleted_at IS NULL;
CREATE INDEX idx_entries_assigned ON calendar_entries(tenant_id, assigned_to, status) WHERE deleted_at IS NULL;

CREATE TABLE IF NOT EXISTS calendar_entry_links (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    entry_id UUID REFERENCES calendar_entries(id) ON DELETE CASCADE,
    entity_type VARCHAR(50) NOT NULL,
    entity_id UUID NOT NULL
);

CREATE TABLE IF NOT EXISTS calendar_shares (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    calendar_id UUID REFERENCES calendars(id) ON DELETE CASCADE,
    user_id UUID,
    group_id UUID,
    permission VARCHAR(10) NOT NULL
);

CREATE TABLE IF NOT EXISTS user_calendar_visibility (
    user_id UUID NOT NULL,
    calendar_id UUID NOT NULL,
    tenant_id UUID NOT NULL,
    visible BOOLEAN DEFAULT true,
    PRIMARY KEY (user_id, calendar_id)
);

CREATE TABLE IF NOT EXISTS subtasks (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    entry_id UUID REFERENCES calendar_entries(id) ON DELETE CASCADE,
    title VARCHAR(500) NOT NULL,
    completed BOOLEAN DEFAULT false,
    created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE TABLE IF NOT EXISTS resources (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    name VARCHAR(200) NOT NULL,
    type VARCHAR(50) NOT NULL
);

CREATE TABLE IF NOT EXISTS resource_bookings (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL,
    resource_id UUID REFERENCES resources(id) ON DELETE CASCADE,
    entry_id UUID REFERENCES calendar_entries(id) ON DELETE CASCADE,
    start_at TIMESTAMPTZ NOT NULL,
    end_at TIMESTAMPTZ NOT NULL
);
```

## Registration
Add to `app/plugins/builtins/__init__.py`:
```python
from app.plugins.builtins.calendar import CalendarPlugin
__all__ = [..., "CalendarPlugin"]
```

## Test File: tests/test_calendar.py
- Use shared fixtures from conftest.py (adapt: create calendar_app, calendar_client, calendar_authed_client)
- OR add calendar fixtures to conftest.py (preferred — same pattern as DMS)
- Test ALL 29 ACs
- Coverage target: ≥80%
- Add `concurrency = ["greenlet"]` already in pyproject.toml (done in T04)

## Test Patterns
- httpx AsyncClient with ASGITransport
- `ORIGIN_HEADER` from conftest
- `authed_client` returns (client, seed) with admin_a, viewer_a, editor_a
- Multipart upload for ICS import: `files={'file': ('test.ics', ics_content, 'text/calendar')}`
- ICS feed: no auth header, just `?token=valid_or_invalid`
- Recurrence test: create weekly entry, query range, verify occurrences
- Resource conflict: create 2 bookings with overlapping time → 409

## Verification Commands
```bash
cd /a0/usr/workdir/dev-projects/leocrm
python -m pytest tests/test_calendar.py -v --tb=short
python -m pytest tests/test_calendar.py --cov=app/plugins/builtins/calendar --cov-report=term-missing
ruff check app/plugins/builtins/calendar/ tests/test_calendar.py
ruff format --check app/plugins/builtins/calendar/ tests/test_calendar.py
```

## 29 Acceptance Criteria — ALL must pass
1. GET /api/v1/calendars → 200 + calendar list
2. POST /api/v1/calendars → 201, calendar created
3. PATCH /api/v1/calendars/{id} → 200
4. DELETE /api/v1/calendars/{id} → 204, cascade delete entries
5. POST /api/v1/calendars/{id}/share → 200, calendar shared
6. GET /api/v1/calendars/{id}/permissions → 200 + permission list
7. GET /api/v1/calendar/entries?start=...&end=... → 200 + entries in range
8. POST /api/v1/calendar/entries (appointment) → 201, with start_at/end_at
9. POST /api/v1/calendar/entries (task) → 201, with due_date/priority/status
10. GET /api/v1/calendar/entries/{id} → 200 + detail with links+subtasks
11. PATCH /api/v1/calendar/entries/{id} → 200, updated (drag&drop)
12. PATCH /api/v1/calendar/entries/{id} status=done → 200
13. DELETE /api/v1/calendar/entries/{id} → 204
14. POST /api/v1/calendar/entries/{id}/link → 200, linked
15. POST /api/v1/calendar/entries/{id}/subtasks → 201
16. PATCH /api/v1/calendar/entries/{id}/subtasks/{sub_id} → 200, toggled
17. POST /api/v1/calendar/entries/bulk → 200, bulk status/delete
18. GET /api/v1/calendar/kanban → 200 + tasks grouped by status
19. GET /api/v1/calendar/entries/export?format=csv → 200 + CSV
20. GET /api/v1/calendar/{calendar_id}/ics-feed?token=valid → 200 + text/calendar
21. GET /api/v1/calendar/{calendar_id}/ics-feed?token=invalid → 401
22. POST /api/v1/calendar/import mit .ics file → 200 + import result
23. POST /api/v1/resources → 201 (admin only, 403 non-admin)
24. POST /api/v1/calendar/entries/{id}/book-resource → 200
25. POST /api/v1/calendar/entries/{id}/book-resource (conflict) → 409
26. Recurrence: weekly entry generates correct occurrences for date range query
27. Recurrence: exception date excluded from occurrences
28. Reminder: ARQ job scheduled when reminder JSONB set
29. Calendar share: user with read permission can view, cannot edit (403)
30. Private subtype: only owner+admin can see entry

## Rules
- No `# noqa: F401` for re-exports in routes/models (only in __init__.py)
- Use `from None` in except blocks (B904)
- No blocking file I/O in async functions without `# noqa: ASYNC230`
- Follow existing plugin patterns exactly (see tags/dms plugins)
- Tenant scoping on ALL queries
- Soft delete for calendars and entries (deleted_at)
- ICS feed endpoint: NO auth header, token-based only