package proxy

import (
	"io"
	"net/http"
	"net/http/httptest"
	"testing"

	"sneak.berlin/go/smallwebwaf/internal/config"
)

func TestAnAnswerWithoutAContentTypeGetsNone(t *testing.T) {
	t.Parallel()

	srv := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			rq := &request{
				h:   &handler{config: &config.Config{}},
				out: &responseWriter{ResponseWriter: w},
			}
			app := &http.Response{
				StatusCode: http.StatusOK,
				Header:     http.Header{},
				Body:       http.NoBody,
			}

			err := rq.modifyResponse(app)
			if err != nil {
				t.Errorf("modifyResponse: %v", err)
			}

			// The headers go out with this, the first part of the body,
			// which Go's server would guess a Content-Type from.
			_, _ = io.WriteString(w, "<!doctype html><title>page</title>")
		}))
	t.Cleanup(srv.Close)

	req, err := http.NewRequestWithContext(t.Context(), http.MethodGet, srv.URL,
		http.NoBody)
	if err != nil {
		t.Fatalf("new request: %v", err)
	}

	res, err := srv.Client().Do(req)
	if err != nil {
		t.Fatalf("get: %v", err)
	}

	_ = res.Body.Close()

	if res.Header.Values("Content-Type") != nil {
		t.Errorf("client got Content-Type %q, want none",
			res.Header.Get("Content-Type"))
	}
}