tq0 refactor UI help rendering

1 files changed, 116 insertions, 0 deletions

diff --git a/internal/ui/help/help.go b/internal/ui/help/help.go
new file mode 100644
index 0000000..0d33279
--- /dev/null
+++ b/internal/ui/help/help.go
@@ -0,0 +1,116 @@
+package help
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"charm.land/lipgloss/v2"
+)
+
+// Item is a single key binding and description in a help section.
+type Item struct {
+	Key  string
+	Desc string
+}
+
+// Section groups related help items under a title.
+type Section struct {
+	Title string
+	Items []Item
+}
+
+// Palette contains the colors needed to render help content.
+type Palette struct {
+	HeaderFG string
+	HeaderBG string
+	KeyFG    string
+	DescFG   string
+	SearchFG string
+	SearchBG string
+}
+
+// Render converts help sections into styled terminal content.
+func Render(sections []Section, palette Palette, search *regexp.Regexp) string {
+	headerStyle, keyStyle, descStyle := styles(palette)
+	lines := make([]string, 0, len(sections)*4)
+	for i, section := range sections {
+		lines = append(lines, headerStyle.Render(section.Title))
+		for _, item := range section.Items {
+			lines = append(lines, formatLine(item.Key, item.Desc, keyStyle, descStyle))
+		}
+		if i < len(sections)-1 {
+			lines = append(lines, "")
+		}
+	}
+
+	if search != nil {
+		for i, line := range lines {
+			if search.MatchString(line) {
+				lines[i] = highlightLine(line, palette, search)
+			}
+		}
+	}
+
+	return strings.Join(lines, "\n")
+}
+
+// Lines returns plain text lines for searchable help content.
+func Lines(sections []Section) []string {
+	lines := make([]string, 0, len(sections)*4)
+	for i, section := range sections {
+		lines = append(lines, section.Title)
+		for _, item := range section.Items {
+			lines = append(lines, fmt.Sprintf("%s: %s", item.Key, item.Desc))
+		}
+		if i < len(sections)-1 {
+			lines = append(lines, "")
+		}
+	}
+	return lines
+}
+
+func styles(palette Palette) (lipgloss.Style, lipgloss.Style, lipgloss.Style) {
+	headerStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color(palette.HeaderFG)).
+		Background(lipgloss.Color(palette.HeaderBG)).
+		Padding(0, 1)
+
+	keyStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color(palette.KeyFG))
+
+	descStyle := lipgloss.NewStyle().
+		Foreground(lipgloss.Color(palette.DescFG))
+
+	return headerStyle, keyStyle, descStyle
+}
+
+func formatLine(key, desc string, keyStyle, descStyle lipgloss.Style) string {
+	paddedKey := fmt.Sprintf("%-12s", key)
+	return keyStyle.Render(paddedKey) + " " + descStyle.Render(desc)
+}
+
+func highlightLine(line string, palette Palette, search *regexp.Regexp) string {
+	matches := search.FindAllStringIndex(line, -1)
+	if len(matches) == 0 {
+		return line
+	}
+
+	highlightStyle := lipgloss.NewStyle().
+		Background(lipgloss.Color(palette.SearchBG)).
+		Foreground(lipgloss.Color(palette.SearchFG))
+
+	highlighted := line
+	offset := 0
+	for _, match := range matches {
+		start := match[0] + offset
+		end := match[1] + offset
+		rendered := highlightStyle.Render(highlighted[start:end])
+		highlighted = highlighted[:start] + rendered + highlighted[end:]
+		offset += len(rendered) - (end - start)
+	}
+
+	return highlighted
+}