# Connections Dashboard with Background Health Checks

## Context

Users currently access Evotor connection via a dedicated `/evotor` page linked from the navbar. As more integrations are planned, we need a unified **Connections** page where users can manage all their connections: add new ones, view status, edit, and delete. The dashboard starts empty — users explicitly add each connection they need.

Supported connection types: **Evotor**, **VK** (one per type per user).

## Data Design

### Current state (separate models)

`EvotorConnection` and `VkConnection` remain as-is — they hold service-specific fields (store_id/store_name for Evotor, vk_user_id/first_name/last_name for VK). The connections dashboard reads from both tables.

No new unified "connection" table needed. The dashboard builds a virtual list by querying both tables. The "add" flow is just a gateway to the existing per-service OAuth pages.

### Model additions (both `EvotorConnection` and `VkConnection`)

Already planned:
- `is_online` (Boolean, default=False, server_default="0")
- `last_checked_at` (DateTime, nullable)

## Plan

### 1. Model Changes — `web/models.py`

Add `is_online` and `last_checked_at` to both `EvotorConnection` and `VkConnection`.

### 2. Alembic Migration

Add health check fields to both connection tables.

### 3. Config Addition — `web/config.py`

Add `HEALTH_CHECK_INTERVAL_SECONDS: int = 600` (10 minutes default).

### 4. Background Health Checker — `web/health_checker.py` (new)

- `check_evotor_connection(access_token) -> bool` — async, `GET https://api.evotor.ru/stores` with Bearer token
- `check_vk_connection(access_token) -> bool` — async, `GET https://api.vk.com/method/users.get` with token
- `run_health_checks()` — queries all connection rows, checks each, updates `is_online` and `last_checked_at`
- `health_check_loop(interval)` — infinite loop with `asyncio.sleep`

### 5. Wire Background Task — `web/main.py`

Add FastAPI lifespan context manager:
- On startup: `asyncio.create_task(health_check_loop(...))`
- On shutdown: cancel the task
- Register connections router

### 6. Connections Route — `web/routes/connections.py` (new)

**`GET /connections`** — Main dashboard. Requires auth.

Queries both `EvotorConnection` and `VkConnection` for the current user. Builds a list of available service types and their connection state:

```python
SERVICE_TYPES = [
    {"type": "evotor", "name": "Эвотор", "icon": "bi-shop", "connect_url": "/evotor", "disconnect_url": "/evotor/disconnect"},
    {"type": "vk", "name": "ВКонтакте", "icon": "bi-chat-dots", "connect_url": "/vk", "disconnect_url": "/vk/disconnect"},
]
```

For each type, attach the connection record (or None). Template renders based on state.

**`GET /connections/add`** — "Add connection" page.

Shows only service types the user has NOT yet connected:
- Card per available type with service name, icon, short description
- "Подключить" button linking to the service's OAuth page (`/evotor` or `/vk`)
- If all types already connected — message "Все доступные сервисы подключены"
- Back link to `/connections`

**`POST /connections/delete?type=evotor|vk`** — Delete a connection.

Same as existing disconnect endpoints but accessed from the dashboard. Deletes the connection record, redirects to `/connections`.

(The existing `/evotor/disconnect` and `/vk/disconnect` routes remain as aliases.)

### 7. Templates

**`web/templates/connections.html`** — Dashboard:

```
┌─────────────────────────────────────────────────┐
│  Подключения                 [+ Добавить]       │
├─────────────────────────────────────────────────┤
│                                                 │
│  ┌─ Card ─────────────────────────────────────┐ │
│  │ 🏪 Эвотор          ● (green)              │ │
│  │ Магазин "Чайная"                           │ │
│  │ Последняя проверка: 06.03.2026 14:30       │ │
│  │                                            │ │
│  │    [Настроить]  [Отключить]                │ │
│  └────────────────────────────────────────────┘ │
│                                                 │
│  ┌─ Card ─────────────────────────────────────┐ │
│  │ 💬 ВКонтакте       ● (green)              │ │
│  │ Иван Иванов                                │ │
│  │ Последняя проверка: 06.03.2026 14:30       │ │
│  │                                            │ │
│  │    [Настроить]  [Отключить]                │ │
│  └────────────────────────────────────────────┘ │
│                                                 │
│  (Нет подключений — нажмите «Добавить»)         │
│                                                 │
└─────────────────────────────────────────────────┘
```

Each connection card:
- Icon + service name + status indicator (green/red/grey)
- Details line (store name for Evotor, profile name for VK)
- Last checked timestamp in card footer
- "Настроить" button → links to service page (`/evotor` or `/vk`) for reconnect/details
- "Отключить" button → POST to `/connections/delete?type=...` with confirmation

Empty state: message prompting user to add their first connection.

**`web/templates/connections_add.html`** — Add connection page:

```
┌─────────────────────────────────────────────────┐
│  Добавить подключение                           │
├─────────────────────────────────────────────────┤
│                                                 │
│  ┌─ Card ─────────────────────────────────────┐ │
│  │ 🏪 Эвотор                                 │ │
│  │ Подключите кассу Эвотор для синхронизации  │ │
│  │ каталога товаров.                          │ │
│  │                         [Подключить →]     │ │
│  └────────────────────────────────────────────┘ │
│                                                 │
│  ┌─ Card ─────────────────────────────────────┐ │
│  │ 💬 ВКонтакте                               │ │
│  │ Подключите аккаунт ВКонтакте для           │ │
│  │ публикации товаров в вашу группу.          │ │
│  │                         [Подключить →]     │ │
│  └────────────────────────────────────────────┘ │
│                                                 │
│  ← Вернуться к подключениям                     │
│                                                 │
└─────────────────────────────────────────────────┘
```

### 8. Navbar Update — `web/templates/base.html`

Replace "Эвотор" link with "Подключения" → `/connections`.

### 9. Evotor/VK Callback Updates

On successful OAuth callback in both `/evotor/callback` and `/vk/callback`:
- Set `is_online=True` and `last_checked_at=now()`
- Redirect to `/connections` (already done for Evotor)

### 10. Evotor/VK Template Back Links

Change back links on `/evotor` and `/vk` pages: "Вернуться к подключениям" → `/connections`.

### 11. Delete Confirmation

The "Отключить" button on the dashboard uses a simple JS `confirm()` dialog: "Вы уверены, что хотите отключить {service name}?" before submitting the POST form.

## Files Summary

| File | Action |
|------|--------|
| `web/models.py` | Modify — add `is_online`, `last_checked_at` to both connection models |
| `web/config.py` | Modify — add `HEALTH_CHECK_INTERVAL_SECONDS` |
| `web/main.py` | Modify — lifespan + register connections router |
| `web/routes/evotor.py` | Modify — set online on callback, redirect to /connections |
| `web/routes/vk.py` | Modify — set online on callback, redirect to /connections |
| `web/routes/connections.py` | Create — dashboard, add page, delete endpoint |
| `web/health_checker.py` | Create — background checks for both Evotor and VK |
| `web/templates/connections.html` | Create — dashboard with cards |
| `web/templates/connections_add.html` | Create — add connection page |
| `web/templates/base.html` | Modify — navbar link |
| `web/templates/evotor.html` | Modify — back link to /connections |
| `web/templates/vk.html` | Modify — back link to /connections |
| Alembic migration | Create |

## Verification

1. Run `alembic upgrade head`
2. Start the app, verify background task logs appear
3. Visit `/connections` — empty state, "Добавить" button visible
4. Click "Добавить" → shows Evotor and VK as available services
5. Add Evotor → goes through OAuth → returns to `/connections` with green status card
6. Add VK → same flow → both connections visible
7. Click "Добавить" again → shows "Все доступные сервисы подключены"
8. Click "Отключить" on Evotor → confirmation dialog → connection removed → card disappears
9. Click "Добавить" → Evotor is available again
10. Wait for health check cycle → verify `is_online` and `last_checked_at` update on remaining connections