package busretry

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"testing"
	"time"

	"github.com/nats-io/nats.go"
	"github.com/nats-io/nats.go/jetstream"
)

// Issue 774 (bus blackouts at every user-list reload): only a request that reached no one is asked again, within the
// bound; a blackout probe that says the bus answers ends the wait at once.
func TestABusThatAnswersNothingIsWaitedOut(t *testing.T) {
	Bound, FirstWait, MostWait = 60*time.Millisecond, time.Millisecond, 4*time.Millisecond
	for _, row := range []struct {
		name      string
		errs      []error // what each try answers; the last repeats
		blackout  func() bool
		tries     int // at least
		atMost    int
		delivered bool
	}{
		{"no responders, then an answer", []error{nats.ErrNoResponders, nats.ErrNoResponders, nil}, nil, 3, 3, true},
		{"jetstream not enabled, then an answer", []error{jetstream.ErrJetStreamNotEnabled, nil}, nil, 2, 2, true},
		{"said in words by a runtime", []error{errors.New("nats: no responders available for request"), nil}, nil, 2, 2, true},
		{"a timeout may have been delivered: never asked again", []error{context.DeadlineExceeded}, nil, 1, 1, false},
		{"an answer that refuses is an answer", []error{errors.New("refused")}, nil, 1, 1, false},
		{"nobody answers on a bus that answers: the callee is not running", []error{nats.ErrNoResponders}, func() bool { return false }, 1, 1, false},
		{"blacked out past the bound: said", []error{jetstream.ErrJetStreamNotEnabledForAccount}, func() bool { return true }, 3, 1000, false},
	} {
		tries := 0
		_, err := Do("the test", func() (int, error) {
			e := row.errs[min(tries, len(row.errs)-1)]
			tries++
			return tries, e
		}, row.blackout)
		if tries < row.tries || tries > row.atMost || (err == nil) != row.delivered {
			t.Errorf("%s: %d tries, %v", row.name, tries, err)
		}
		if strings.HasPrefix(row.name, "blacked out") && (!Undelivered(err) || !strings.Contains(fmt.Sprint(err), "the bus answered nothing")) {
			t.Errorf("%s: %v", row.name, err)
		}
	}
}