package httpclient

import (
	"context"
	"io"
	"net/http"
	"testing"
)

type endlessRetryBody struct {
	read   int
	closed bool
}

func (b *endlessRetryBody) Read(p []byte) (int, error) {
	for i := range p {
		p[i] = 'x'
	}
	b.read += len(p)
	return len(p), nil
}
func (b *endlessRetryBody) Close() error { b.closed = true; return nil }

type retryTransport func(*http.Request) (*http.Response, error)

func (f retryTransport) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }

func TestRetryDrainBoundsEndlessErrorBody(t *testing.T) {
	b := &endlessRetryBody{}
	c := &http.Client{Transport: retryTransport(func(*http.Request) (*http.Response, error) {
		return &http.Response{StatusCode: 503, Status: "503 Service Unavailable", Body: b, Header: make(http.Header)}, nil
	})}
	req, err := http.NewRequest(http.MethodGet, "http://agent.example/bundle", nil)
	if err != nil {
		t.Fatal(err)
	}
	if _, err = DoWithRetry(context.Background(), c, req, 1); err == nil {
		t.Fatal("upstream failure accepted")
	}
	if b.read != 64<<10 || !b.closed {
		t.Fatalf("retry consumed %d bytes, closed=%v", b.read, b.closed)
	}
	var _ io.ReadCloser = b
}