func getTagsToDelete()

in cmd/acr/purge.go [253:317]
54 lines of code
19 McCabe index (conditional complexity)

func getTagsToDelete(ctx context.Context,
	acrClient api.AcrCLIClientInterface,
	repoName string,
	filter *regexp2.Regexp,
	timeToCompare time.Time,
	lastTag string,
	keep int,
	skippedTagsCount int) (*[]acr.TagAttributesBase, string, int, error) {

	var matches bool
	var lastUpdateTime time.Time
	resultTags, err := acrClient.GetAcrTags(ctx, repoName, "timedesc", lastTag)
	if err != nil {
		if resultTags != nil && resultTags.Response.Response != nil && resultTags.StatusCode == http.StatusNotFound {
			fmt.Printf("%s repository not found\n", repoName)
			return nil, "", skippedTagsCount, nil
		}
		// An empty lastTag string is returned so there will not be any tag purged.
		return nil, "", skippedTagsCount, err
	}
	newLastTag := ""
	if resultTags != nil && resultTags.TagsAttributes != nil && len(*resultTags.TagsAttributes) > 0 {
		tags := *resultTags.TagsAttributes
		tagsEligibleForDeletion := []acr.TagAttributesBase{}
		for _, tag := range tags {
			matches, err = filter.MatchString(*tag.Name)
			if err != nil {
				// The only error that regexp2 will return is a timeout error
				return nil, "", skippedTagsCount, err
			}
			if !matches {
				// If a tag does not match the regex then it not added to the list no matter the LastUpdateTime
				continue
			}
			lastUpdateTime, err = time.Parse(time.RFC3339Nano, *tag.LastUpdateTime)
			if err != nil {
				return nil, "", skippedTagsCount, err
			}
			// If a tag did match the regex filter, is older than the specified duration and can be deleted then it is returned
			// as a tag to delete.
			if lastUpdateTime.Before(timeToCompare) && *(*tag.ChangeableAttributes).DeleteEnabled && *(*tag.ChangeableAttributes).WriteEnabled {
				tagsEligibleForDeletion = append(tagsEligibleForDeletion, tag)
			}
		}

		newLastTag = common.GetLastTagFromResponse(resultTags)
		// No more tags to keep
		if keep == 0 || skippedTagsCount == keep {
			return &tagsEligibleForDeletion, newLastTag, skippedTagsCount, nil
		}

		tagsToDelete := []acr.TagAttributesBase{}
		for _, tag := range tagsEligibleForDeletion {
			// Keep at least the configured number of tags
			if skippedTagsCount < keep {
				skippedTagsCount++
			} else {
				tagsToDelete = append(tagsToDelete, tag)
			}
		}
		return &tagsToDelete, newLastTag, skippedTagsCount, nil
	}
	// In case there are no more tags return empty string as lastTag so that the purgeTags function stops
	return nil, "", skippedTagsCount, nil
}