Improve highlighting and add QoL changes

markdown.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"strings"
+	"sync"
+
+	"github.com/charmbracelet/glamour"
+	"github.com/charmbracelet/glamour/styles"
+	"github.com/charmbracelet/lipgloss"
+)
+
+var commentMarkdownRenderers sync.Map
+var quoteRailStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("#777777"))
+
+func renderCommentMarkdown(markdown string, width int) []string {
+	if strings.TrimSpace(markdown) == "" {
+		return nil
+	}
+	width = max(10, width)
+	markdown = normalizeGitHubAlerts(markdown)
+	var (
+		result     []string
+		block      []string
+		blockQuote bool
+		haveBlock  bool
+	)
+	flush := func() {
+		if len(block) == 0 {
+			return
+		}
+		blockWidth := width
+		if blockQuote {
+			blockWidth = max(8, width-2)
+		}
+		lines := renderMarkdownFragment(strings.Join(block, "\n"), blockWidth)
+		if haveBlock && len(lines) > 0 {
+			result = append(result, "")
+		}
+		if blockQuote {
+			rail := quoteRailStyle.Render("│ ")
+			for i := range lines {
+				lines[i] = rail + lines[i]
+			}
+		}
+		result = append(result, lines...)
+		haveBlock = haveBlock || len(lines) > 0
+		block = nil
+	}
+
+	for _, line := range strings.Split(markdown, "\n") {
+		content, quoted := stripQuoteMarker(line)
+		if len(block) > 0 && quoted != blockQuote {
+			flush()
+		}
+		blockQuote = quoted
+		block = append(block, content)
+	}
+	flush()
+	return trimMarkdownLines(result)
+}
+
+func renderMarkdownFragment(markdown string, width int) []string {
+	if strings.TrimSpace(markdown) == "" {
+		return nil
+	}
+	renderer, err := commentMarkdownRenderer(width)
+	if err != nil {
+		return fallbackCommentLines(markdown, width)
+	}
+	rendered, err := renderer.Render(markdown)
+	if err != nil {
+		return fallbackCommentLines(markdown, width)
+	}
+	return trimMarkdownLines(strings.Split(strings.Trim(rendered, "\n"), "\n"))
+}
+
+func commentMarkdownRenderer(width int) (*glamour.TermRenderer, error) {
+	if cached, ok := commentMarkdownRenderers.Load(width); ok {
+		return cached.(*glamour.TermRenderer), nil
+	}
+	style := styles.DarkStyleConfig
+	zero := uint(0)
+	style.Document.Margin = &zero
+	style.Code.Prefix = ""
+	style.Code.Suffix = ""
+	renderer, err := glamour.NewTermRenderer(
+		glamour.WithStyles(style),
+		glamour.WithWordWrap(width),
+		glamour.WithTableWrap(true),
+		glamour.WithPreservedNewLines(),
+		glamour.WithEmoji(),
+	)
+	if err != nil {
+		return nil, err
+	}
+	actual, _ := commentMarkdownRenderers.LoadOrStore(width, renderer)
+	return actual.(*glamour.TermRenderer), nil
+}
+
+func stripQuoteMarker(line string) (string, bool) {
+	trimmed := strings.TrimLeft(line, " \t")
+	if !strings.HasPrefix(trimmed, ">") {
+		return line, false
+	}
+	content := strings.TrimPrefix(trimmed, ">")
+	content = strings.TrimPrefix(content, " ")
+	return content, true
+}
+
+func normalizeGitHubAlerts(markdown string) string {
+	alerts := map[string]string{
+		"[!NOTE]":      "ℹ **Note**",
+		"[!TIP]":       "◆ **Tip**",
+		"[!IMPORTANT]": "❗ **Important**",
+		"[!WARNING]":   "⚠ **Warning**",
+		"[!CAUTION]":   "⛔ **Caution**",
+	}
+	lines := strings.Split(markdown, "\n")
+	for i, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		if !strings.HasPrefix(trimmed, ">") {
+			continue
+		}
+		label := strings.TrimSpace(strings.TrimPrefix(trimmed, ">"))
+		if replacement, ok := alerts[strings.ToUpper(label)]; ok {
+			prefix := line[:strings.Index(line, ">")+1]
+			lines[i] = prefix + " " + replacement
+		}
+	}
+	return strings.Join(lines, "\n")
+}
+
+func fallbackCommentLines(markdown string, width int) []string {
+	return strings.Split(wrap(markdown, max(10, width)), "\n")
+}
+
+func trimMarkdownLines(lines []string) []string {
+	for len(lines) > 0 && strings.TrimSpace(lines[0]) == "" {
+		lines = lines[1:]
+	}
+	for len(lines) > 0 && strings.TrimSpace(lines[len(lines)-1]) == "" {
+		lines = lines[:len(lines)-1]
+	}
+	return lines
+}