# CLAUDE.md

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

## Project Overview

Go library for rendering data tables as PNG images. Provides two APIs:
- `DrawTableWarm()` — renders a single table with header and rows
- `RenderDocument()` — renders a multi-block document with titled table sections

## Build & Test Commands

```bash
go test ./...            # run all tests
go test -run TestDrawTable   # run single test
go test -run TestDocument    # run document rendering test
```

Tests output PNG files to `test-data/` (gitignored). Verify rendering by inspecting the generated images visually.

## Architecture

- **`image_table.go`** — Core rendering engine. `DrawTableWarm()` draws a single table image. Contains font initialization (`init()`), text measurement/drawing utilities, rounded rect helper, and row-to-string conversion via reflection. Embeds `assets/jb.ttf` (JetBrains font) at compile time.
- **`document.go`** — `RenderDocument()` composes multiple `TableBlock`s into a single document image with titles, using a larger font face for block headings.
- **`table_block.go`** — `TableBlock` struct: a titled table with header and rows.
- **`tablle_block_style.go`** — `TableBlockStyle` implements `ITableRow` to allow per-row background colors.
- **`itablerow.go`** — `ITableRow` interface for custom row rendering (cells + background color).

## Key Patterns

- Rows accept `any` type: slices, structs (via reflection), or `ITableRow` implementors for custom styling.
- Column widths are auto-calculated from content measurement.
- Two `init()` functions parse the embedded TTF font at different sizes (10pt for table cells, 12pt for document titles).
- Comments and identifiers are in Russian.