# Architecture

## Request Flow

```
HTTP Request
  → public/index.php
  → bootstrap/app.php         (loads config, registers PDO, services)
  → Application::boot()        (loads routes/web.php)
  → Router::dispatch(Request)  (matches URL, runs middleware pipeline)
  → [Middleware]               (AuthMiddleware, ApiKeyMiddleware)
  → Controller::method()       (parse input → call repository/service → render)
  → Template::render()         (PHP native, layout composition)
  → Response::send()
```

## Layer Map

| Layer | Location | Responsibility |
|-------|----------|----------------|
| Entry | `public/index.php` | Bootstrap only |
| Routes | `routes/web.php` (581 lines) | All ~80 routes; manual DI wiring |
| Core | `src/Core/` (25 files) | Framework infrastructure |
| Controllers | `src/Modules/*/Controller.php` | Request parsing → response |
| Services | `src/Modules/*/Service.php` | Business logic |
| Repositories | `src/Modules/*/Repository.php` | PDO data access (34+ repos) |
| Views | `resources/views/` | PHP templates with `$e()` / `$t()` |
| Components | `resources/views/components/` | Reusable UI blocks |

## Module Inventory (`src/Modules/`)

| Module | Files | Key Classes | Purpose |
|--------|-------|-------------|---------|
| **Auth** | 3 | `AuthController`, `AuthMiddleware`, `AuthService` | Login/logout, session |
| **Users** | 2 | `UserController`, `UserRepository` | User CRUD |
| **Orders** | 3 | `OrdersController` (1187 LOC), `OrdersRepository` (1221 LOC) | Order list, detail, status, payment, correlated subquery for return-risk |
| **Shipments** | 17 | `ShipmentController`, provider services + tracking services | Shipment creation, label download, tracking polling |
| **Accounting** | 5 | `AccountingController`, `ReceiptService`, `ReceiptRepository` | Receipts, invoices, PDF, Excel export |
| **Email** | 3 | `EmailSendingService`, `VariableResolver`, `AttachmentGenerator` | Template-based email with PDF attachments |
| **Automation** | 6 | `AutomationService` (834 LOC), `AutomationRepository`, `AutomationExecutionLogRepository` | Event→condition→action rules, email triggers |
| **Settings** | 51+ | Integration controllers, OAuth clients, API clients, mappers | Allegro/shopPRO/Apaczka/InPost config, status mappings |
| **Cron** | 12 | `CronRepository`, `CronHandlerFactory`, handler classes | Scheduled imports, syncs, token refresh |
| **Printing** | 4 | `PrintApiController`, `PrintJobRepository`, `ApiKeyMiddleware` | REST API for Windows print client |
| **Statistics** | 2 | `OrdersStatisticsController`, `OrdersStatisticsRepository` | Dashboard aggregates |
| **Info** | 1 | `InfoController` | Health check |

## Key Data Flows

### Order Lifecycle
1. **Import** — Cron handler → API client → `OrderImportService` → `OrdersRepository::insertOrder()` → `AutomationService::executeForNewOrder()`
2. **Status update** — `OrdersController::updateStatus()` → `OrdersRepository::updateStatus()` → automation check
3. **Status sync** — Cron → `AllegroStatusSyncService` / `ShopproStatusSyncService` → carrier API

### Shipment Flow
1. **Create** — `ShipmentController::create()` → `ShipmentProviderRegistry` → carrier `ShipmentService::createShipment()` → `ShipmentPackageRepository::insert()`
2. **Track** — Cron `ShipmentTrackingHandler` → `ShipmentTrackingRegistry` → carrier tracking API → `ShipmentPackageRepository::updateDeliveryStatus()`

### Receipt / Invoice
1. **Generate** — `ReceiptController::store()` → `ReceiptService::generateReceipt()` → `ReceiptRepository::insert()` + Dompdf PDF
2. **Email** — `EmailSendingService::send()` → `VariableResolver::resolve()` → `AttachmentGenerator::generatePdf()` → PHPMailer SMTP

### Automation Rules
1. **Setup** — `AutomationController` → `AutomationRepository::insertRule()`
2. **Trigger** — `AutomationService::executeForOrder()` → evaluates trigger (`order_status_changed`, `order_status_aged`) → runs action (send email, update status)
3. **Log** — `AutomationExecutionLogRepository` tracks every run

### Cron Jobs

| Handler | Task |
|---------|------|
| `AllegroOrdersImportHandler` | Fetch new Allegro orders |
| `AllegroStatusSyncHandler` | Push status changes to Allegro |
| `AllegroTokenRefreshHandler` | OAuth token refresh (24h expiry) |
| `ShopproOrdersImportHandler` | Fetch new shopPRO orders |
| `ShopproStatusSyncHandler` | Push status to shopPRO |
| `ShopproPaymentStatusSyncHandler` | Sync payment statuses |
| `ShipmentTrackingHandler` | Poll carrier tracking APIs |
| `OrderStatusAgedHandler` | Trigger automation for stuck statuses |
| `AutomationHistoryCleanupHandler` | Purge old automation logs |

## Dependency Injection

Manual constructor injection in `routes/web.php` — no DI container library. Example:

```php
$ordersController = new OrdersController(
    $template, $translator, $auth,
    $app->orders(), $shipmentPackageRepository,
    $receiptRepository, $receiptConfigRepository, ...
);
```

All production classes are `final` — prevents accidental inheritance.

## Directory Structure

```
bootstrap/         app.php (service wiring, config loading)
bin/               migrate.php, cron.php (CLI entry points)
config/            app.php, database.php
database/
  migrations/      84 SQL files (YYYYMMDD_NNNNNN_description.sql)
  drafts/          WIP migrations
public/
  index.php        HTTP entry point
  .htaccess        Apache rewrite rules
  assets/css/      Compiled CSS (app.css, login.css, modules/)
  assets/js/       jquery-alerts.js, global-search.js, automation-form.js
resources/
  views/           PHP templates by module + components/ layouts/
  scss/            SCSS sources (app.scss, login.scss, modules/_*.scss)
  modules/         jquery-alerts JS+SCSS source
  lang/pl/         Polish translations
routes/
  web.php          All routes (581 lines)
src/
  Core/            Framework (25 files)
  Modules/         13 feature modules (~200+ PHP files)
storage/
  logs/            app.log
  sessions/        PHP session files
  cache/           PHPUnit cache, etc.
tests/
  Unit/            PHPUnit tests (7+ service test files)
  bootstrap.php    PSR-4 autoloader for tests
```