From fc80e5334b147ef940b1ec21d9c625f7f26e0bca Mon Sep 17 00:00:00 2001
From: Alexey Yerin <yyp@disroot.org>
Date: Mon, 18 Jan 2021 23:08:57 +0300
Subject: [PATCH] Add --user-agent option

---
 README.md    |  1 -
 main.go      |  5 +++--
 translate.go | 14 ++++++++++----
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 510b905..8fb5b55 100644
--- a/README.md
+++ b/README.md
@@ -34,5 +34,4 @@ templates and static directories:
 
 # TODO
 - Proper language selector
-- Change `User-Agent`
 - Dark theme
diff --git a/main.go b/main.go
index 810cfd0..a64f068 100644
--- a/main.go
+++ b/main.go
@@ -33,6 +33,7 @@ func main() {
 	templateDir := pflag.String("template-dir", "./templates", "Templates directory")
 	staticDir := pflag.String("static-dir", "./static", "Static files directory")
 	proxy := pflag.String("proxy", "", "Proxy URL, with no scheme http is assumed")
+	userAgent := pflag.String("user-agent", "", "User-Agent header to use")
 	pflag.Parse()
 
 	var proxyUrl *url.URL
@@ -60,7 +61,7 @@ func main() {
 		to := req.FormValue("to")
 		text := req.FormValue("text")
 
-		translation, err := Translate(from, to, text, proxyUrl)
+		translation, err := Translate(from, to, text, *userAgent, proxyUrl)
 		if err != nil {
 			writeError(w, 500, err)
 		}
@@ -92,7 +93,7 @@ func main() {
 			return
 		}
 
-		translation, err := Translate(from, to, text, proxyUrl)
+		translation, err := Translate(from, to, text, *userAgent, proxyUrl)
 		if err != nil {
 			writeError(w, 500, err)
 		}
diff --git a/translate.go b/translate.go
index 1f136e1..f3b35cd 100644
--- a/translate.go
+++ b/translate.go
@@ -10,7 +10,7 @@ import (
 	"golang.org/x/net/html"
 )
 
-func getWithProxy(url string, proxy *url.URL) (*http.Response, error) {
+func getWithProxy(url string, userAgent string, proxy *url.URL) (*http.Response, error) {
 	client := &http.Client{}
 
 	if proxy != nil {
@@ -18,13 +18,19 @@ func getWithProxy(url string, proxy *url.URL) (*http.Response, error) {
 		client.Transport = tr
 	}
 
-	resp, err := client.Get(url)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header["User-Agent"] = []string{userAgent}
+
+	resp, err := client.Do(req)
 
 	return resp, err
 }
 
 // Requests and parses translation from Google
-func Translate(fromLang, toLang, text string, proxy *url.URL) (string, error) {
+func Translate(fromLang, toLang, text string, userAgent string, proxy *url.URL) (string, error) {
 	// Escape parameters before embedding in URL
 	fromLang = url.QueryEscape(fromLang)
 	toLang = url.QueryEscape(toLang)
@@ -32,7 +38,7 @@ func Translate(fromLang, toLang, text string, proxy *url.URL) (string, error) {
 
 	url := fmt.Sprintf("https://translate.google.com/m?sl=%s&tl=%s&q=%s", fromLang, toLang, text)
 
-	resp, err := getWithProxy(url, proxy)
+	resp, err := getWithProxy(url, userAgent, proxy)
 	if err != nil {
 		return "", fmt.Errorf("Request failed: %v", err)
 	}