package markdown

import (
	"bytes"
	"io"

	chromahtml "github.com/alecthomas/chroma/formatters/html"
	"github.com/yuin/goldmark"
	emoji "github.com/yuin/goldmark-emoji"
	highlighting "github.com/yuin/goldmark-highlighting"
	"github.com/yuin/goldmark/extension"
	"github.com/yuin/goldmark/parser"
	"github.com/yuin/goldmark/renderer/html"
)

var gm = goldmark.New(
	goldmark.WithExtensions(
		extension.GFM,
		highlighting.NewHighlighting(
			highlighting.WithStyle("monokai"),
			highlighting.WithFormatOptions(
				chromahtml.WithLineNumbers(true),
				chromahtml.LinkableLineNumbers(true, "code-"),
				chromahtml.LineNumbersInTable(true),
			),
		),
		emoji.Emoji,
	),
	goldmark.WithParserOptions(
		parser.WithAutoHeadingID(),
	),
	goldmark.WithRendererOptions(
		html.WithHardWraps(),
	),
)

// Convert transforms a markdown document into HTML
func Convert(r io.Reader) (string, error) {
	content, err := io.ReadAll(r)
	if err != nil {
		return "", err
	}
	var buf bytes.Buffer
	if err := gm.Convert(content, &buf); err != nil {
		return "", err
	}
	return buf.String(), nil
}