package lib

import (
	"html/template"
	"strings"

	"github.com/yuin/goldmark/v2/parser"
	"github.com/yuin/goldmark/v2/renderer/html"
)

var (
	markdownParser   = parser.New()
	markdownRenderer = html.New()
)

// optimizations props to claude opus 5
func FormatMarkdown(source []byte) (template.HTML, error) {
	var sb strings.Builder
	sb.Grow(len(source) + len(source)/2) // rendered html runs ~1.2-1.3x the source

	doc := markdownParser.Parse(source)
	if err := markdownRenderer.Render(&sb, source, doc); err != nil {
		return "", err
	}

	return template.HTML(sb.String()), nil
}