func main()

in cmd/zoekt-mirror-github/main.go [55:183]
117 lines of code
27 McCabe index (conditional complexity)

func main() {
	dest := flag.String("dest", "", "destination directory")
	githubURL := flag.String("url", "", "GitHub Enterprise url. If not set github.com will be used as the host.")
	org := flag.String("org", "", "organization to mirror")
	user := flag.String("user", "", "user to mirror")
	token := flag.String("token",
		filepath.Join(os.Getenv("HOME"), ".github-token"),
		"file holding API token.")
	forks := flag.Bool("forks", false, "also mirror forks.")
	deleteRepos := flag.Bool("delete", false, "delete missing repos")
	namePattern := flag.String("name", "", "only clone repos whose name matches the given regexp.")
	excludePattern := flag.String("exclude", "", "don't mirror repos whose names match this regexp.")
	topics := topicsFlag{}
	flag.Var(&topics, "topic", "only clone repos whose have one of given topics. You can add multiple topics by setting this more than once.")
	excludeTopics := topicsFlag{}
	flag.Var(&excludeTopics, "exclude_topic", "don't clone repos whose have one of given topics. You can add multiple topics by setting this more than once.")

	flag.Parse()

	if *dest == "" {
		log.Fatal("must set --dest")
	}
	if *githubURL == "" && *org == "" && *user == "" {
		log.Fatal("must set either --org or --user when github.com is used as host")
	}

	var host string
	var apiBaseURL string
	var client *github.Client
	if *githubURL != "" {
		rootURL, err := url.Parse(*githubURL)
		if err != nil {
			log.Fatal(err)
		}
		host = rootURL.Host
		apiPath, err := url.Parse("/api/v3/")
		if err != nil {
			log.Fatal(err)
		}
		apiBaseURL = rootURL.ResolveReference(apiPath).String()
		client, err = github.NewEnterpriseClient(apiBaseURL, apiBaseURL, nil)
		if err != nil {
			log.Fatal(err)
		}
	} else {
		host = "github.com"
		apiBaseURL = "https://github.com/"
		client = github.NewClient(nil)
	}
	destDir := filepath.Join(*dest, host)
	if err := os.MkdirAll(destDir, 0o755); err != nil {
		log.Fatal(err)
	}

	if *token != "" {
		content, err := ioutil.ReadFile(*token)
		if err != nil {
			log.Fatal(err)
		}

		ts := oauth2.StaticTokenSource(
			&oauth2.Token{
				AccessToken: strings.TrimSpace(string(content)),
			})
		tc := oauth2.NewClient(context.Background(), ts)
		if *githubURL != "" {
			client, err = github.NewEnterpriseClient(apiBaseURL, apiBaseURL, tc)
			if err != nil {
				log.Fatal(err)
			}
		} else {
			client = github.NewClient(tc)
		}
	}

	reposFilters := reposFilters{
		topics:        topics,
		excludeTopics: excludeTopics,
	}
	var repos []*github.Repository
	var err error
	if *org != "" {
		repos, err = getOrgRepos(client, *org, reposFilters)
	} else if *user != "" {
		repos, err = getUserRepos(client, *user, reposFilters)
	} else {
		log.Printf("no user or org specified, cloning all repos.")
		repos, err = getUserRepos(client, "", reposFilters)
	}

	if err != nil {
		log.Fatal(err)
	}

	if !*forks {
		trimmed := repos[:0]
		for _, r := range repos {
			if r.Fork == nil || !*r.Fork {
				trimmed = append(trimmed, r)
			}
		}
		repos = trimmed
	}

	filter, err := gitindex.NewFilter(*namePattern, *excludePattern)
	if err != nil {
		log.Fatal(err)
	}

	{
		trimmed := repos[:0]
		for _, r := range repos {
			if filter.Include(*r.Name) {
				trimmed = append(trimmed, r)
			}
		}
		repos = trimmed
	}

	if err := cloneRepos(destDir, repos); err != nil {
		log.Fatalf("cloneRepos: %v", err)
	}

	if *deleteRepos {
		if err := deleteStaleRepos(*dest, filter, repos, *org+*user); err != nil {
			log.Fatalf("deleteStaleRepos: %v", err)
		}
	}
}