first commit

output/formatter/formatter.go

@@ -0,0 +1,79 @@
+package formatter
+
+import (
+	"bytes"
+	"context"
+	"regexp"
+
+	"gitoa.ru/go-4devs/console/output/style"
+)
+
+//nolint: gochecknoglobals
+var re = regexp.MustCompile(`<(([a-z][^<>]+)|/([a-z][^<>]+)?)>`)
+
+func WithStyle(styles func(string) (style.Style, error)) func(*Formatter) {
+	return func(f *Formatter) {
+		f.styles = styles
+	}
+}
+
+func New(opts ...func(*Formatter)) *Formatter {
+	f := &Formatter{
+		styles: style.Find,
+	}
+
+	for _, opt := range opts {
+		opt(f)
+	}
+
+	return f
+}
+
+type Formatter struct {
+	styles func(string) (style.Style, error)
+}
+
+func (a *Formatter) Format(ctx context.Context, msg string) string {
+	var (
+		out bytes.Buffer
+		cur int
+	)
+
+	for _, idx := range re.FindAllStringIndex(msg, -1) {
+		tag := msg[idx[0]+1 : idx[1]-1]
+
+		if cur < idx[0] {
+			out.WriteString(msg[cur:idx[0]])
+		}
+
+		var (
+			st  style.Style
+			err error
+		)
+
+		switch {
+		case tag[0:1] == "/":
+			st, err = a.styles(tag[1:])
+			if err == nil {
+				out.WriteString(st.Set(style.ActionUnset))
+			}
+		default:
+			st, err = a.styles(tag)
+			if err == nil {
+				out.WriteString(st.Set(style.ActionSet))
+			}
+		}
+
+		if err != nil {
+			cur = idx[0]
+		} else {
+			cur = idx[1]
+		}
+	}
+
+	if len(msg) > cur {
+		out.WriteString(msg[cur:])
+	}
+
+	return out.String()
+}