1package http
 2
 3import (
 4	"strings"
 5)
 6
 7// UserAgentBuilder is a builder for a HTTP User-Agent string.
 8type UserAgentBuilder struct {
 9	sb strings.Builder
10}
11
12// NewUserAgentBuilder returns a new UserAgentBuilder.
13func NewUserAgentBuilder() *UserAgentBuilder {
14	return &UserAgentBuilder{sb: strings.Builder{}}
15}
16
17// AddKey adds the named component/product to the agent string
18func (u *UserAgentBuilder) AddKey(key string) {
19	u.appendTo(key)
20}
21
22// AddKeyValue adds the named key to the agent string with the given value.
23func (u *UserAgentBuilder) AddKeyValue(key, value string) {
24	u.appendTo(key + "/" + value)
25}
26
27// Build returns the constructed User-Agent string. May be called multiple times.
28func (u *UserAgentBuilder) Build() string {
29	return u.sb.String()
30}
31
32func (u *UserAgentBuilder) appendTo(value string) {
33	if u.sb.Len() > 0 {
34		u.sb.WriteRune(' ')
35	}
36	u.sb.WriteString(value)
37}