func loadGerritOriginInternal()

in git-codereview/api.go [73:136]
47 lines of code
9 McCabe index (conditional complexity)

func loadGerritOriginInternal(origin, remoteOrigin string) error {
	originUrl, err := url.Parse(remoteOrigin)
	if err != nil {
		return fmt.Errorf("failed to parse git's remote.origin.url %q as a URL: %v", remoteOrigin, err)
	} else {
		originUrl.User = nil
		remoteOrigin = originUrl.String()
	}
	hasGerritConfig := true
	if origin == "" {
		hasGerritConfig = false
		origin = remoteOrigin
	}
	if strings.Contains(origin, "github.com") {
		return fmt.Errorf("git origin must be a Gerrit host, not GitHub: %s", origin)
	}

	if googlesourceIndex := strings.Index(origin, ".googlesource.com"); googlesourceIndex >= 0 {
		if !strings.HasPrefix(origin, "https://") {
			return fmt.Errorf("git origin must be an https:// URL: %s", origin)
		}
		// https:// prefix and then one slash between host and top-level name
		if strings.Count(origin, "/") != 3 {
			return fmt.Errorf("git origin is malformed: %s", origin)
		}
		host := origin[len("https://"):strings.LastIndex(origin, "/")]

		// In the case of Google's Gerrit, host is go.googlesource.com
		// and apiURL uses go-review.googlesource.com, but the Gerrit
		// setup instructions do not write down a cookie explicitly for
		// go-review.googlesource.com, so we look for the non-review
		// host name instead.
		url := origin
		i := googlesourceIndex
		url = url[:i] + "-review" + url[i:]

		i = strings.LastIndex(url, "/")
		url, project := url[:i], url[i+1:]

		auth.host = host
		auth.url = url
		auth.project = project
		return nil
	}

	// Origin is not *.googlesource.com.
	//
	// If the Gerrit origin is set from the codereview.cfg file than we handle it
	// differently to allow for sub-path hosted Gerrit.
	auth.host = originUrl.Host
	if hasGerritConfig {
		if !strings.HasPrefix(remoteOrigin, origin) {
			return fmt.Errorf("Gerrit origin %q from %q different than git origin url %q", origin, configPath, originUrl)
		}

		auth.project = strings.Trim(strings.TrimPrefix(remoteOrigin, origin), "/")
		auth.url = origin
	} else {
		auth.project = strings.Trim(originUrl.Path, "/")
		auth.url = strings.TrimSuffix(remoteOrigin, originUrl.Path)
	}

	return nil
}