package credhelper

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

func TestUserAgent_Format(t *testing.T) {
	old := cfg
	cfg = Config{
		BinaryName: "docker-credential-test",
		Version:    "0.0.0",
		Commit:     "abc1234deadbeef",
	}
	t.Cleanup(func() { cfg = old })

	ua := userAgent()
	if !strings.HasPrefix(ua, "docker-credential-test/") {
		t.Errorf("UA missing product prefix: %q", ua)
	}
	if !strings.Contains(ua, "commit abc1234)") {
		t.Errorf("UA should truncate commit to 7 chars, got %q", ua)
	}
	if strings.Contains(ua, "Go-http-client") {
		t.Errorf("UA leaked default Go client string: %q", ua)
	}
}

func TestHTTPClient_SetsUserAgent(t *testing.T) {
	old := cfg
	cfg = Config{
		BinaryName: "docker-credential-test",
		Version:    "0.0.0",
		Commit:     "abc1234",
	}
	t.Cleanup(func() { cfg = old })

	var got string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		got = r.Header.Get("User-Agent")
		w.WriteHeader(http.StatusNoContent)
	}))
	t.Cleanup(srv.Close)

	resp, err := httpClient().Get(srv.URL)
	if err != nil {
		t.Fatalf("get: %v", err)
	}
	resp.Body.Close()

	want := userAgent()
	if got != want {
		t.Errorf("server saw User-Agent %q, want %q", got, want)
	}
}

func TestHTTPClient_RespectsExplicitUserAgent(t *testing.T) {
	old := cfg
	cfg = Config{BinaryName: "docker-credential-test"}
	t.Cleanup(func() { cfg = old })

	var got string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		got = r.Header.Get("User-Agent")
		w.WriteHeader(http.StatusNoContent)
	}))
	t.Cleanup(srv.Close)

	req, err := http.NewRequest("GET", srv.URL, nil)
	if err != nil {
		t.Fatalf("new request: %v", err)
	}
	req.Header.Set("User-Agent", "explicit-test/1.0")

	resp, err := httpClient().Do(req)
	if err != nil {
		t.Fatalf("do: %v", err)
	}
	resp.Body.Close()

	if got != "explicit-test/1.0" {
		t.Errorf("explicit UA was overwritten: got %q", got)
	}
}