package notify

import (
	"context"
	"errors"
)

// batchSenderQueueWaitError marks a request that expired or was canceled
// while waiting for the shared physical write gate. The transport is still
// healthy in this case, so the sender must not become permanently failed.
type batchSenderQueueWaitError struct {
	err error
}

func (e *batchSenderQueueWaitError) Error() string {
	if e == nil || e.err == nil {
		return "batch sender write queue wait failed"
	}
	return "batch sender write queue wait failed: " + e.err.Error()
}

func (e *batchSenderQueueWaitError) Unwrap() error {
	if e == nil {
		return nil
	}
	return e.err
}

func newBatchSenderQueueWaitError(err error) error {
	if err == nil {
		return nil
	}
	var existing *batchSenderQueueWaitError
	if errors.As(err, &existing) {
		return err
	}
	return &batchSenderQueueWaitError{err: err}
}

func isBatchSenderQueueWaitError(err error) bool {
	var queueErr *batchSenderQueueWaitError
	return errors.As(err, &queueErr)
}

func isBatchSenderQueueWaitCause(err error) bool {
	return errors.Is(err, context.Canceled) || isTimeoutLikeError(err)
}