# HotlinePlanner Sync — Dev Log

## Stack
- **Runtime**: ASP.NET Core 10.0 (net10.0)
- **Auth**: Microsoft.Identity.Web 4.3.0 — Confidential Client / OIDC
- **Graph**: Microsoft.Graph 5.103.0 (SDK v5)
- **Database**: SQLite + EF Core 10.0.3
- **Real-time**: ASP.NET Core SignalR (built-in)
- **Token cache**: In-memory (prototype) — lost on restart

---

## Setup Checklist

### 1. Azure App Registration
1. Go to [https://portal.azure.com](https://portal.azure.com) → App registrations → New registration
2. Name: `HotlinePlannerSync` | Supported account types: **Single tenant** (or multitenant as needed)
3. Redirect URI: `https://YOUR-NGROK-URL.ngrok-free.app/signin-oidc` (Web)
4. After creation, note: **Application (client) ID** and **Directory (tenant) ID**
5. Certificates & secrets → New client secret → copy the **Value** (not the ID)
6. API permissions → Add: `Calendars.Read` (Delegated), `offline_access` (Delegated) → Grant admin consent

### 2. ngrok (local webhook exposure)
```bash
# Install ngrok from https://ngrok.com
ngrok http 5001 --scheme https
# Copy the HTTPS URL, e.g. https://abc123.ngrok-free.app
```
Update `appsettings.Development.json`:
```json
"Webhook": {
  "BaseUrl": "https://abc123.ngrok-free.app",
  "ClientState": "your-random-secret-string"
}
```
**Important**: ngrok URL changes on each restart unless you have a paid plan with a static domain.

### 3. Fill appsettings
In `appsettings.Development.json` (or use `dotnet user-secrets`):
```json
"AzureAd": {
  "TenantId":     "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "ClientId":     "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "ClientSecret": "your~client~secret~value"
}
```

Prefer **user-secrets** to keep credentials out of source control:
```bash
dotnet user-secrets set "AzureAd:TenantId"     "xxx"
dotnet user-secrets set "AzureAd:ClientId"     "xxx"
dotnet user-secrets set "AzureAd:ClientSecret" "xxx"
dotnet user-secrets set "Webhook:BaseUrl"       "https://xxx.ngrok-free.app"
dotnet user-secrets set "Webhook:ClientState"   "my-secret-state"
```

### 4. Run
```bash
dotnet run
# App starts on https://localhost:5001 (or http://localhost:5000)
```

---

## Architecture

```
Browser ──── OIDC login ──────────────────► Microsoft Entra ID
             │                                     │
             │ ◄─── redirect + tokens ─────────────┘
             │
             ▼
      HomeController.Onboard()
         ├─ Upsert UserConfig (SQLite)
         ├─ SubscriptionService.CreateSubscription()  ──► Graph POST /subscriptions
         └─ DeltaSyncService.Sync() [initial]          ──► Graph GET /me/calendarView/delta

Microsoft Graph ──── POST /api/notifications/listen ──────► NotificationsController
                          │
                          ├─ Handshake? → return validationToken as text/plain
                          ├─ Log to WebhookLogs (FIRST)
                          ├─ Verify ClientState
                          ├─ Return 202 Accepted
                          └─ Fire & forget: DeltaSyncService.Sync(userId)
                                                │
                                                └─► Graph GET /me/calendarView/delta?$deltaToken=...
                                                    ├─ Page through results
                                                    ├─ Deduplicate (SHA-256 of Subject+Start+End)
                                                    └─ Save new DeltaLink to UserConfig

SubscriptionRenewalBackgroundService (every 12h)
  └─ Find subscriptions expiring < 24h
  └─ PATCH /subscriptions/{id} with new ExpirationDateTime

DashboardHub (SignalR)
  └─ All events flow through ActivityLogger → SignalR push → live feed in browser
```

---

## Database Tables

### UserConfigs
| Column | Type | Notes |
|---|---|---|
| UserId | TEXT PK | Azure AD Object ID |
| Email | TEXT | preferred_username claim |
| DisplayName | TEXT | name claim |
| SubscriptionId | TEXT | Graph subscription ID |
| SubscriptionExpiration | DATETIME | When subscription expires |
| SubscriptionStatus | TEXT | None / Active / Expiring / Expired |
| LastDeltaLink | TEXT | Full delta URL for incremental sync |
| CreatedAt | DATETIME | First login |
| LastSyncAt | DATETIME | Last successful delta sync |
| TotalEventsSynced | INT | Running count |
| TenantId | TEXT | Azure AD Tenant ID |

### WebhookLogs
| Column | Type | Notes |
|---|---|---|
| Id | INT PK | Auto-increment |
| ReceivedAt | DATETIME | UTC timestamp |
| RawPayload | TEXT | Full JSON body |
| EndpointType | TEXT | Listen / Lifecycle |
| IsHandshake | BOOL | Validation token request |
| ClientState | TEXT | Received client state |
| SubscriptionId | TEXT | From notification |
| UserId | TEXT | Extracted from resource path |
| ChangeType | TEXT | created / updated / deleted |
| LifecycleEvent | TEXT | reauthorizationRequired etc. |
| ProcessingStatus | TEXT | Received / Processing / Completed / Failed / Skipped |
| ErrorMessage | TEXT | If failed |
| EventsProcessed | INT | New/updated from delta |
| EventsDeduplicated | INT | Filtered by hash |

---

## Key Endpoints

| Endpoint | Auth | Description |
|---|---|---|
| `GET /` | Public | Landing page |
| `GET /Home/Login` | Public | Triggers OIDC flow |
| `GET /Home/Onboard` | Authenticated | Post-login onboarding |
| `GET /Sync` | Authenticated | Live dashboard |
| `GET /sync/data` | Authenticated | JSON data for dashboard AJAX |
| `POST /sync/manual` | Authenticated | Trigger manual delta sync |
| `GET /sync/log/{id}` | Authenticated | Raw payload for a log entry |
| `POST /api/notifications/listen` | **Anonymous** | Graph change notifications |
| `POST /api/notifications/lifecycle` | **Anonymous** | Graph lifecycle notifications |

---

## Delta Query Notes

- **Initial sync**: `GET /me/calendarView/delta?startDateTime=now-30d&endDateTime=now+90d`
- **Incremental sync**: `GET {stored_delta_link}` (URL already contains all params)
- Delta link stored per-user in `UserConfigs.LastDeltaLink`
- If delta link is gone (410 Gone), the code will log an error; manually clear `LastDeltaLink` to force a full re-sync

## Token Cache Notes

- `AddInMemoryTokenCaches()` stores tokens in RAM — lost on app restart
- Users must re-login after restart for tokens to repopulate
- For production: replace with `AddDistributedTokenCaches()` + Redis/SQL

---

## Changes from Original Spec
- Target: **.NET 10.0** (not 8.0 — SDK 10.0.102 is installed)
- Excel/OneDrive output: **removed** (per user request)
- Real-time dashboard: **SignalR** push (not polling)
- Dashboard shows everything: auth events, subscription creation, webhook handshakes, delta syncs, renewals