package main

import (
	"bytes"
	"context"

	"git.dev.alexdunmow.com/block/core/blocks"
)

// TocBlockMeta defines metadata for the section TOC block.
var TocBlockMeta = blocks.BlockMeta{
	Key:         "toc",
	Title:       "Section TOC",
	Description: "Fixed left-rail table of contents for article pages",
	Source:      "terminal",
	Category:    blocks.CategoryNavigation,
}

// TocItem is a single TOC entry.
type TocItem struct {
	Label  string
	Anchor string
}

// TocData is the parsed content for the toc block.
type TocData struct {
	Heading string
	Items   []TocItem
}

// TocBlock renders the section TOC.
// Content shape: {heading, items[{label, anchor}]}.
func TocBlock(ctx context.Context, content map[string]any) string {
	items := getSlice(content, "items")
	tocItems := make([]TocItem, 0, len(items))
	for _, it := range items {
		tocItems = append(tocItems, TocItem{
			Label:  getString(it, "label"),
			Anchor: getString(it, "anchor"),
		})
	}
	data := TocData{
		Heading: getStringDefault(content, "heading", "Sections"),
		Items:   tocItems,
	}

	var buf bytes.Buffer
	_ = tocComponent(data).Render(ctx, &buf)
	return buf.String()
}