# CLAUDE.md

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

## What This Is

Potluck signup app. No accounts — share a link, people claim slots. Open like a shared Google Sheet.

## Commands

```bash
# Build and run
go build -o bbq . && ./bbq

# Docker
docker compose up -d --build

# Regenerate DB layer after editing schema.sql or db/queries.sql
$(go env GOPATH)/bin/sqlc generate
```

## Environment Variables

- `PORT` — Go server listen port (default `8080`)
- `BBQ_DB` — SQLite database path (default `bbq.db`)
- `BBQ_BASE_URL` — Absolute URL for OG images (e.g. `https://bbq.torrtle.co`)
- `HOST_PORT` — Compose host-side port mapping (default `8090`)

## Architecture

**Stack:** Go, chi router, sqlc + SQLite (mattn/go-sqlite3), html/template, HTMX + SSE

**Design:** Soft Brutalism — cream `#f5f0e8`, black borders/shadows, yellow `#f5e642` accents, Bricolage Grotesque + DM Mono fonts

### Data Flow

`schema.sql` defines tables (events, slots, claims, rsvps) → `db/queries.sql` has SQL queries → `sqlc generate` produces `db/` package (models.go, queries.sql.go, db.go). Never edit generated files in `db/` directly.

### Server (`main.go`)

`Server` struct holds `*db.Queries`, `*sql.DB`, `baseURL`, and SSE client channels. SSE uses `subscribe/unsubscribe/notify` pattern — any mutation calls `notify(slug)` to push updates to all viewers.

### Templates

Go template inheritance doesn't work with a single `ParseFS`, so each page is parsed separately into `pageTmpl` map:
- `pageTmpl["home"]` / `pageTmpl["event"]` — full pages, rendered via `.ExecuteTemplate(w, "layout", data)`
- `pageTmpl["slots"]` — partial for HTMX responses, rendered via `.ExecuteTemplate(w, "slots-inner", data)`

Template files: `layout.html` (shell + all CSS/JS), `slots.html` (shared partial), `event.html`, `home.html`. All CSS is inline in `layout.html`.

### Handlers (`handlers.go`)

`loadEventPage()` is the shared data loader — assembles `EventPageData` with event, slots+claims, rsvps, and counts. Used by both full page renders and HTMX partial responses.

### OG Image (`ogimage.go`)

Dynamic PNG generation at `/e/{slug}/og.png` using Go's `image` package with a custom 5x7 bitmap font. Renders event title, date/time/location in the app's visual style.

### Routes

- `GET /` — create event form
- `POST /events` — creates event + slots, redirects to admin URL
- `GET /e/{slug}` — guest view
- `POST /e/{slug}/claim` / `DELETE /e/{slug}/claim/{claimID}` — HTMX claim/unclaim
- `POST /e/{slug}/rsvp` / `DELETE /e/{slug}/rsvp/{rsvpID}` — HTMX RSVP
- `GET /e/{slug}/sse` — SSE stream for live updates
- `GET /e/{slug}/og.png` — dynamic OG image
- `GET /e/{slug}/admin/{token}` — admin view (same template, `IsAdmin=true`)
- `POST /e/{slug}/admin/{token}/slot` / `DELETE /e/{slug}/admin/{token}/slot/{slotID}` — manage slots

### Auth Model

No user auth. Admin access is via secret `admin_token` in the URL. Claims/RSVPs are open to anyone with the event link.