# Role: Senior .NET Developer
# Goal: Build a Transparent & Pilot-Ready ASP.NET Core latest Sync App

## Context:
A prototype for Microsoft Graph Calendar Sync that makes the background process visible via a Web Dashboard.

## Core Tech:
- .NET 10.0 MVC + EF Core SQLite.
- Microsoft.Identity.Web (Confidential Client flow).

## Key Requirements:

1. **Database Schema (SQLite):**
   - 'UserConfigs': Tracks 'UserId', 'Email', 'SubscriptionId', 'Expiration', 'LastDeltaToken'.
   - 'WebhookLogs': Tracks 'Id', 'ReceivedAt', 'Payload' (raw JSON), 'Type' (Notification/Lifecycle).

2. **Webhook Controller ('/api/notifications'):**
   - Implement '/listen' and '/lifecycle'.
   - **Crucial:** Log every incoming request body into 'WebhookLogs' before processing.
   - Return 'validationToken' as text/plain (not JSON).

3. **Management Dashboard ('/Sync/Dashboard'):**
   - Create a Razor View that displays:
     - A table of all rows in 'UserConfigs'.
     - A table of the last 20 rows in 'WebhookLogs' (ordered by newest).
     - A "Sync Now" button that triggers a manual Delta query for a specific user.

4. **Background Logic:**
   - 'SubscriptionManagerService': A background worker that checks for expiring subscriptions every 12 hours.
   - When a webhook hits, trigger a 'SyncTask' that performs the Delta query and writes updates to the 'SyncResults.xlsx' file.

5. **Transparency/Feedback:**
   - Use 'ILogger' to print the specific Subject and ChangeType of every event processed to the console.
   - Ensure the 'validationToken' handshake is logged so I can see it succeed.

## Instructions:
- Provide placeholders for ClientId, TenantId, ClientSecret, and BaseUrl.
- Ensure the app can run on macOS using 'dotnet run'.

## Implementation Status (Updated: 2026-02-20)

### Completed Tasks:

1.  **Project Initialization:**
    -   Created ASP.NET Core MVC project targeting .NET 10.0.
    -   Added required NuGet packages:
        -   `Microsoft.EntityFrameworkCore.Sqlite`
        -   `Microsoft.EntityFrameworkCore.Design`
        -   `Microsoft.Identity.Web`
        -   `ClosedXML` (for Excel)
        -   `Microsoft.Graph` & `Azure.Identity`

2.  **Database Implementation:**
    -   Created `UserConfig` and `WebhookLog` models in `Models/`.
    -   Configured `AppDbContext` in `Data/`.
    -   Configured SQLite connection string in `appsettings.json`.
    -   Added logic in `Program.cs` to automatically ensure the database is created (`EnsureCreated`).

3.  **Webhook Handling:**
    -   Implemented `WebhookController` (`/api/notifications`).
    -   `[HttpPost("listen")]` and `[HttpPost("lifecycle")]` endpoints created.
    -   **Validation:** Handles `validationToken` query parameter and returns it as `text/plain`.
    -   **Logging:** Logs all request payloads to `WebhookLogs` table before processing.

4.  **Sync Logic & Excel Reporting:**
    -   Implemented `SyncService` (`ISyncService`) to encapsulate synchronization logic.
    -   Configured `GraphServiceClient` with `ClientSecretCredential`.
    -   Added logic to perform (simulated) Delta queries.
    -   Implemented `ClosedXML` logic to write/append sync results to `SyncResults.xlsx`.

5.  **Dashboard:**
    -   Created `SyncController` with `Dashboard` action.
    -   Implemented Razor View `Views/Sync/Dashboard.cshtml` displaying:
        -   `UserConfigs` table.
        -   Last 20 `WebhookLogs`.
        -   "Sync Now" button triggering manual sync via `SyncService`.

6.  **Background Services:**
    -   Implemented `SubscriptionManagerService` as an `IHostedService`.
    -   Checks for expiring subscriptions every 12 hours (and on startup).

7.  **Configuration:**
    -   Updated `appsettings.json` with placeholders for Azure AD credentials (`ClientId`, `TenantId`, `ClientSecret`, `BaseUrl`).

### How to Run:

1.  Navigate to the project directory:
    ```bash
    cd GraphCalendarSync
    ```
2.  Update `appsettings.json` with your actual Azure AD credentials.
3.  Run the application:
    ```bash
    dotnet run
    ```
4.  Access the dashboard at `https://localhost:7197/Sync/Dashboard` (port may vary, check console output).