# CLAUDE.md

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

## Project Overview

TRMNLc is a self-hosted server that serves rendered displays to [TRMNL](https://usetrmnl.com/) e-ink devices. It renders plugin UIs as HTML using React SSR, screenshots with Puppeteer (Firefox), dithers with ImageMagick for e-ink, and serves via the TRMNL device API.

## Running

```bash
bun install

# Run the server (requires Firefox and ImageMagick in PATH)
FIREFOX=/path/to/firefox CONFIG_FILE=config.json COLORMAP=./colormap.png bun run src/web.ts

# Run tests
bun test
```

The server runs on port 2300 by default (`BUN_PORT` env var). See `config.sample.json` for the config format.

## Architecture

### Plugin system

Each device is configured with a `plugin` name and `settings` object. The plugin registry (`src/plugins.ts`) maps names to factory functions that return a `Renderable`. The `Renderable` interface (`src/template.ts`) requires `hash`, `nextEvent?`, and `async render()`.

Available plugins:

- **`calendar`** — Full-screen ICS calendar view with current/next/later event slots. UI is in Dutch ("VRIJ", "BEZET", "VOLGENDE"). Implementation: `src/xlcalendar.tsx`.
- **`today`** — Daily dashboard with date header, focus/success lines, agenda timeline, chores checklist, and due/overdue tasks. Implementation: `src/todayview.tsx`.

### Data sources (`src/sources/`)

The today plugin fetches from external services during `render()`, all in parallel:

- **`tana.ts`** — Fetches daily focus/success text and due/overdue tasks from a Tana server. Focus: calendar node → markdown field parsing. Tasks: single search query (`lt` tomorrow), split client-side by due date.
- **`ics.ts`** — Fetches today's non-full-day events from ICS feeds, returns `AgendaEvent[]`. Note: `location` lives on `instance.event.location`, not on the expanded instance directly.
- **`donetick.ts`** — Fetches chores from a Donetick instance (defaults to `app.donetick.com`). Filters by `user_id` and `isActive`. Done status: `nextDueDate > today` means completed.

### Config structure

```json
{
  "base_url": "http://host:2300",
  "devices": {
    "DEVICE_MAC": {
      "plugin": "today",
      "settings": { ... },
      "refresh": 300,
      "model": "inkplate_10"
    }
  }
}
```

### Render pipeline

1. **`src/web.ts`** — Bun HTTP server. Routes: `/api/setup`, `/api/display` (PNG), `/api/display/html` (raw HTML), `/api/render/:id/:ignore` (cached PNGs).
2. **`src/template.ts`** — Wraps plugin HTML in a full page with TRMNL's CSS/JS framework.
3. **`src/render.ts`** — Puppeteer (Firefox) screenshots the HTML, then ImageMagick dithers to 2-bit grayscale PNG.
4. **`src/devices.ts`** — Fetches device model definitions (screen dimensions, CSS classes) from `trmnl.com/api/models` at startup.

## Deployment

Deployed as a NixOS module via `flake.nix` / `default.nix`. The `default.nix` defines a systemd service with `DynamicUser=true`. The Nix derivation copies source directly (no build step — runs with `bun run` at runtime).

## Formatting

Uses Prettier: single quotes, trailing commas (es5), 2-space indent, bracket same line.