# EnvelopeGenerator - Agent Guide

## Must Read First
- **`COPILOT_CONTEXT.md`** - Architecture, coordinate systems, migration status
- **`FORM_APPLICATION_CONTEXT.md`** - Legacy VB.NET features to migrate

## Active Architecture (Post-Migration)

**Frontend:** Blazor Auto (Server+WASM hybrid)
- **WebUI** (Server): `@rendermode InteractiveServer` - PDF viewers requiring DevExpress backend
- **WebUI.Client** (WASM): `@rendermode InteractiveWebAssembly` - Login, dashboards, business logic

**Backend:** EnvelopeGenerator.API (ASP.NET Core 8.0)

**Proxy:** YARP in WebUI routes `/api/*` → `localhost:8088` (API)

### Deprecated Projects - DO NOT USE
- `EnvelopeGenerator.ReceiverUI` - Pure WASM (migrated to WebUI)
- `EnvelopeGenerator.Web` - Razor Pages (replaced by WebUI)
- **VB.NET projects** (`Form`, `Service`, `BBTests`) - Legacy, read-only for reference

## Development Commands

### Run Both Projects (Required)
```powershell
# Terminal 1 - API Backend
cd EnvelopeGenerator.API
dotnet run

# Terminal 2 - Blazor Frontend
cd EnvelopeGenerator.WebUI\EnvelopeGenerator.WebUI
dotnet run
```

**Critical:** Both must run simultaneously. WebUI proxy forwards `/api/*` to API.

### Build
```powershell
dotnet build EnvelopeGenerator.sln
```

## Project Boundaries

```
EnvelopeGenerator.Domain/          # Entities (Envelope, Receiver, Document, etc.)
EnvelopeGenerator.Application/     # MediatR CQRS (Commands, Queries, Handlers)
EnvelopeGenerator.Infrastructure/  # EF Core, SQL executors, repositories
EnvelopeGenerator.API/             # Controllers, endpoints
EnvelopeGenerator.WebUI/           # Server-side Blazor components
  ├─ Components/Pages/             # @rendermode InteractiveServer
EnvelopeGenerator.WebUI.Client/    # Client-side WASM components
  ├─ Pages/                        # @rendermode InteractiveWebAssembly
  ├─ Services/                     # HTTP API clients
  ├─ Models/                       # DTOs
```

## Route Structure (Critical)

| Route | File Location | Render Mode | Purpose |
|-------|--------------|-------------|---------|
| `/` | `WebUI.Client/Pages/Index.razor` | WASM | Landing page |
| `/sender/login` | `WebUI.Client/Pages/LoginSenderPage.razor` | WASM | Sender auth |
| `/sender` | `WebUI.Client/Pages/EnvelopeSenderPage.razor` | WASM | Sender dashboard |
| `/envelope/login/{key}` | `WebUI.Client/Pages/LoginReceiverPage.razor` | WASM | Receiver auth |
| `/envelope/{key}` | `WebUI/Components/Pages/EnvelopeReceiverPage.razor` | **Server** | PDF viewer + signing |

**Rule:** PDF viewers MUST use `@rendermode InteractiveServer` (DevExpress backend requirement). Everything else uses WASM.

## Coordinate System (CRITICAL)

**Database stores INCHES** (GdPicture14 native). Origin: top-left, Y-axis down.

### Conversions
```csharp
// Database (INCHES) → PDF Points
float points = inches * 72;

// Database (INCHES) → DevExpress DX
float dx = inches * 100;

// PDF.js Pixels → Database (INCHES)
float inches = (pixelX / canvasWidth) * pageWidthInches;
```

**A4 Page:** 8.27" wide × 11.69" tall = 595pt × 842pt

**Signature Field Size:** 1.77" × 1.96" (FIXED, do not change)

**Evidence:** See `COPILOT_CONTEXT.md` lines 158-185, `EnvelopeGenerator.Form/frmFieldEditor.vb`

## API Architecture Quirks

### Monolithic Endpoint (Avoid for UI)
`POST /api/EnvelopeReceiver` - Creates envelope+document+receivers+fields atomically.
- **Use case:** External API consumers
- **Not suitable for:** Step-by-step UI workflow (no draft support, no partial updates)

### Missing Granular Endpoints (Need to Create)
```
POST /api/Envelope/draft          # Create draft envelope
PUT /api/Envelope/{id}            # Update metadata
DELETE /api/Envelope/{id}         # Delete with reason
POST /api/Envelope/{id}/document  # Upload PDF
POST /api/Envelope/{id}/receivers # Add receiver
POST /api/Envelope/{id}/signature-fields  # Place signature field
POST /api/Envelope/{id}/send      # Send to receivers
```

See `FORM_APPLICATION_CONTEXT.md` for detailed workflow requirements.

## Status Color Coding

Form app uses DevExpress `CustomDrawCell`. WebUI needs CSS:

```css
.envelope-row.status-partly-signed { background-color: #81C784; } /* GREEN_300 */
.envelope-row.status-queued,
.envelope-row.status-sent { background-color: #FFB74D; } /* ORANGE_300 */
.envelope-row.status-completed { background-color: #81C784; }
.envelope-row.status-deleted,
.envelope-row.status-rejected { background-color: #E57373; } /* RED_300 */
```

## Configuration

### YARP Proxy (`WebUI/yarp.json`)
Routes `/api/*`, `/swagger/*`, `/openapi/*`, `/scalar/*` → `https://localhost:8088`

### PDF.js Settings (`WebUI/wwwroot/appsettings.json`)
```json
{
  "PdfViewerOptions": {
    "ThumbnailBaseScale": 0.75,
    "ThumbnailEnableHiDPI": true,
    "MainCanvasEnableHiDPI": true,
    "ZoomStepPercentage": 5
  }
}
```

### API Config (`API/appsettings.json`)
- `ConnectionStrings:Default` - SQL Server DB
- `AllowedOrigins` - CORS (includes `http://localhost:5131`, `http://localhost:7192`)
- `Cache:SignatureCacheExpiration` - Signature persistence timeout
- `PSPDFKitLicenseKey` - **DEPRECATED** (use PDF.js instead)

## Migration Status

### Complete ✅
- Receiver login/authentication
- PDF viewing with PDF.js (HiDPI, zoom, thumbnails)
- Signature capture (draw/type/image)
- Signature caching (Redis/SQL)
- Sender login

### Missing (High Priority) ❌
- Sender dashboard (`/sender`) - Empty stub
- Envelope editor (`/sender/envelope/{id}`)
- Signature field placement tool (PDF.js + draggable overlays)
- Granular API endpoints (draft, receivers, fields)
- Master-detail grids for receivers/history

## Common Mistakes (DO NOT REPEAT)

| Mistake | Why Wrong |
|---------|-----------|
| Using iText7 in receiver pages | GPL license issue. Use PDF.js overlays. |
| Using PSPDFKit | Removed from architecture. Use PDF.js + DevExpress. |
| `@rendermode InteractiveWebAssembly` on PDF viewers | DevExpress DxPdfViewer requires server-side rendering. |
| Hardcoded quality in PDF.js | Use `appsettings.json` `PdfViewerOptions`. |
| Coordinates in points/pixels for DB | Database uses INCHES. Convert before save. |
| `BottomMarginBand` for signatures | Repeats on every page. Use `DetailBand`. |

## Testing

**No automated tests exist yet.**

Manual testing workflow:
1. Start API (`dotnet run` in `EnvelopeGenerator.API`)
2. Start WebUI (`dotnet run` in `EnvelopeGenerator.WebUI\EnvelopeGenerator.WebUI`)
3. Navigate to `https://localhost:5131` (or check console output for port)
4. Test sender login at `/sender/login`
5. Test receiver flow at `/envelope/login/{envelopeKey}`

## Database

**SQL Server** (DD_ECM)
- Connection string in `API/appsettings.json`
- EF Core migrations NOT used (manual SQL scripts)
- Stored procedures: `PRSIG_*` prefix

**Key Tables:**
- `TBSIG_ENVELOPE` - Envelope metadata
- `TBSIG_ENVELOPE_RECEIVER` - Receiver assignments
- `TBSIG_DOC_RECEIVER_ELEMENT` - Signature fields (X, Y in INCHES)
- `TBSIG_RECEIVER` - Receiver registry
- `TBSIG_DOCUMENT` - PDF binary data
- `TBSIG_ENVELOPE_HISTORY` - Audit trail

## DevExpress

**License:** Commercial (v25.2.3)
**Components Used:**
- `DxGrid` - Master-detail grids
- `DxPdfViewer` - Server-side PDF rendering
- `DxPopup` - Modal dialogs
- `DxToolbar` - Action bars
- `DxFormLayout` - Forms

**Theme:** Blazing Berry (default)

## JavaScript Interop

**PDF Viewer:** `wwwroot/js/pdf-viewer.js`
```javascript
window.pdfViewer = {
    initialize(canvasId, pdfDataUrl, dotNetRef),
    renderPage(num),
    renderSignatureButtons(signatures, pageNum, dotNetRef),
    applySignature(signatureId, dataUrl, fullName, position, place),
    zoomIn(), zoomOut(), dispose()
}
```

**Signature Pad:** `wwwroot/js/receiver-signature.js`
```javascript
window.receiverSignature = {
    initializeDrawPad(canvasId, dotNetRef),
    getSignatureDataUrl(canvasId),
    clearPad(canvasId)
}
```

## Multi-Envelope Support

Receivers can login to **multiple envelopes simultaneously** via per-envelope cookies:
```
AuthTokenSignFLOWReceiver.{envelopeKey}
```

Each envelope maintains independent authentication state.

## External Dependencies

**CDN:**
- PDF.js 3.11.174: `https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.min.js`

**NuGet (WebUI.Client):**
- `DevExpress.Blazor.*` 25.2.3
- `SkiaSharp.*` 3.119.1 (WASM rendering)

**External Services:**
- LDAP/AD authentication (optional)
- GTX Messaging (SMS 2FA)
- Email dispatcher (signFlow)

## Environment Variables

None required. All config in `appsettings.json`.

**Local dev ports:**
- API: `https://localhost:8088`
- WebUI: `https://localhost:5131` or `http://localhost:7192`