# AGENTS.md

This file provides guidance to Codex (Codex.ai/code) when working with code in this repository.

## Commands

```bash
./mvnw spring-boot:run     # run app (default goal) — http://localhost:8080, ~30s first start
./mvnw compile              # compile only
./mvnw package               # production build → target/*.jar
java -jar target/*.jar       # run production jar
```

No test sources exist yet (`src/test` is empty) — `spring-boot-starter-test` and `browserless-test-spring` are on the classpath but unused.

**Java 25 toolchain required** (`pom.xml` sets `java.version=25`). If the default JDK on PATH is older (check `java -version`), point `JAVA_HOME` at a Java 25 install for the Maven build, e.g.:
```bash
JAVA_HOME="/path/to/jdk-25" ./mvnw compile
```

Port 8080 conflicts: a prior `spring-boot:run` left running in the background is the usual cause (Vaadin dev mode keeps a second process/thread alive under a different PID than the launching Maven process — killing the Maven process alone may not free the port). Find and stop the actual listener before restarting.

## Architecture

Vaadin Flow (server-side Java UI, no hand-written HTML/JS for views) on Spring Boot 4.1, using the **Aura** theme (not Lumo — no `@Theme` annotation; Aura is wired via `@StyleSheet(Aura.STYLESHEET)` in `Application.java`).

**Charts are ApexCharts, not Vaadin Charts.** The bridge lives in `components/`:
- `ApexChart` (abstract, `@Tag("apex-chart")`) — owns the JS module (`frontend/components/apex-chart.ts`, a Lit element rendering into light DOM), serializes an options `Map` to JSON via Jackson and calls `renderChart` client-side, and exposes point-click events back to the server via `@ClientCallable`.
- `AxisChart` (abstract) — builds `series`/`xaxis.categories` options for line/bar.
- `LineChart`, `BarChart` extend `AxisChart`; `PieChart` extends `ApexChart` directly (`series`/`labels` instead of axis-based).
- `DialectTheme` — single source of chart styling (categorical color palette, grid/legend/stroke option fragments). Every chart's `setData(...)` starts from `DialectTheme.baseOptions(chartType)` and merges in its data. Add new chart types here, not by duplicating option maps.

Since `apex-chart.ts` renders into light DOM (`createRenderRoot()` returns `this`), global CSS can reach into the chart markup — but series/legend/grid colors are driven entirely by the options JSON, not CSS, because ApexCharts renders its own SVG/canvas.

**Views** (`views/`): `MainLayout` (`@Layout`, applies to all routes) is the `AppLayout` shell — navbar + `SideNav` drawer, with one `SideNavItem` per route. Routes: `DashboardView` (`@Route("")`) wraps each chart in a `Card` (`components/Card.java`); `FormView` (`@Route("formular")`) demonstrates form controls bound via `Binder`; `TableView` (`@Route("tabelle")`) demonstrates a `Grid` over dummy data with a live text filter (`GridListDataView.addFilter`, `TextField` in `ValueChangeMode.EAGER`). New views should reuse `Card` to wrap their content rather than adding components directly, and get a matching `SideNavItem` in `MainLayout`.

**Styling**: `src/main/resources/META-INF/resources/styles.css` is the one project-level stylesheet (loaded via `@StyleSheet("styles.css")` in `Application.java`). It defines `--dialect-*` design tokens (Dialect design system: primary orange `#E86C00`, cool-gray background, card radius/shadow) and aliases them onto Aura's own CSS custom properties (`--aura-accent-color-*`, `--aura-background-color-*`, `--aura-orange`, `--aura-yellow`) rather than fighting the theme. Aura tokens use OKLCH + relative-color syntax and accept plain hex overrides. When restyling, prefer extending this alias layer over hardcoding new colors in components.

UI copy/data (chart labels, notifications) is in German.
