feat(tui): replace Textual with a Go/Bubble Tea interface (#941)

strix/interface/tui/internal/render/code.go

@@ -0,0 +1,70 @@
+package render
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/alecthomas/chroma/v2"
+	"github.com/alecthomas/chroma/v2/formatters"
+	"github.com/alecthomas/chroma/v2/lexers"
+	"github.com/alecthomas/chroma/v2/styles"
+)
+
+// HighlightCode ports the Python renderers' pygments highlighting: colorize
+// code for the terminal using the "native" style, falling back to the plain
+// text when the language is unknown or the highlighter fails.
+func HighlightCode(code, language string) string {
+	if strings.TrimSpace(code) == "" {
+		return code
+	}
+	var lexer chroma.Lexer
+	if language != "" {
+		lexer = lexers.Get(language)
+	}
+	if lexer == nil {
+		lexer = lexers.Analyse(code)
+	}
+	if lexer == nil {
+		return Col(Text).Render(code)
+	}
+	lexer = chroma.Coalesce(lexer)
+	style := styles.Get("native")
+	formatter := formatters.Get("terminal256")
+	iterator, err := lexer.Tokenise(nil, code)
+	if err != nil {
+		return Col(Text).Render(code)
+	}
+	var out strings.Builder
+	if err := formatter.Format(&out, style, iterator); err != nil {
+		return Col(Text).Render(code)
+	}
+	return strings.TrimSuffix(out.String(), "\n")
+}
+
+// languageForPath resolves a chroma language name from a file path, returning
+// "" when the extension is unknown.
+func languageForPath(path string) string {
+	if path == "" {
+		return ""
+	}
+	lexer := lexers.Match(filepath.Base(path))
+	if lexer == nil {
+		return ""
+	}
+	return lexer.Config().Name
+}
+
+// ParseFencedCode ports parse_fenced_code: strip a surrounding ``` fence and
+// return the declared language (if any) and the inner code.
+func ParseFencedCode(raw string) (language, code string) {
+	trimmed := strings.TrimSpace(raw)
+	if !strings.HasPrefix(trimmed, "```") {
+		return "", raw
+	}
+	lines := strings.Split(trimmed, "\n")
+	if len(lines) < 2 || strings.TrimSpace(lines[len(lines)-1]) != "```" {
+		return "", raw
+	}
+	language = strings.TrimSpace(strings.TrimPrefix(lines[0], "```"))
+	return language, strings.Join(lines[1:len(lines)-1], "\n")
+}