cli/pkg/cmd/auth/shared/login_flow.go

package shared

import (
	"fmt"
	"net/http"
	"strings"

	"github.com/AlecAivazis/survey/v2"
	"github.com/MakeNowJust/heredoc"
	"github.com/cli/cli/api"
	"github.com/cli/cli/internal/authflow"
	"github.com/cli/cli/pkg/iostreams"
	"github.com/cli/cli/pkg/prompt"
)

type iconfig interface {
	Get(string, string) (string, error)
	Set(string, string, string) error
	Write() error
}

type LoginOptions struct {
	IO          *iostreams.IOStreams
	Config      iconfig
	HTTPClient  *http.Client
	Hostname    string
	Interactive bool
	Web         bool
	Scopes      []string
}

func Login(opts *LoginOptions) error {
	cfg := opts.Config
	hostname := opts.Hostname
	httpClient := opts.HTTPClient
	cs := opts.IO.ColorScheme()

	var gitProtocol string
	if opts.Interactive {
		var proto string
		err := prompt.SurveyAskOne(&survey.Select{
			Message: "What is your preferred protocol for Git operations?",
			Options: []string{
				"HTTPS",
				"SSH",
			},
		}, &proto)
		if err != nil {
			return fmt.Errorf("could not prompt: %w", err)
		}
		gitProtocol = strings.ToLower(proto)
	}

	minimumScopes := []string{"repo", "read:org"}

	var credentialHelper string
	var configureGitCredential bool
	if opts.Interactive && gitProtocol == "https" {
		credentialHelper, _ = gitCredentialHelper(hostname)
		if isOurCredentialHelper(credentialHelper) {
			minimumScopes = append(minimumScopes, "workflow")
		} else {
			err := prompt.SurveyAskOne(&survey.Confirm{
				Message: "Authenticate Git with your GitHub credentials?",
				Default: true,
			}, &configureGitCredential)
			if err != nil {
				return fmt.Errorf("could not prompt: %w", err)
			}
			if configureGitCredential {
				minimumScopes = append(minimumScopes, "workflow")
			}
		}
	}

	var keyToUpload string
	if opts.Interactive && gitProtocol == "ssh" {
		pubKeys, err := localPublicKeys()
		if err != nil {
			return err
		}

		if len(pubKeys) > 0 {
			var keyChoice int
			err := prompt.SurveyAskOne(&survey.Select{
				Message: "Upload your SSH public key to your GitHub account?",
				Options: append(pubKeys, "Skip"),
			}, &keyChoice)
			if err != nil {
				return fmt.Errorf("could not prompt: %w", err)
			}
			if keyChoice < len(pubKeys) {
				keyToUpload = pubKeys[keyChoice]
			}
		} else {
			var err error
			keyToUpload, err = generateSSHKey()
			if err != nil {
				return err
			}
		}
	}
	if keyToUpload != "" {
		minimumScopes = append(minimumScopes, "admin:public_key")
	}

	var authMode int
	if opts.Web {
		authMode = 0
	} else {
		err := prompt.SurveyAskOne(&survey.Select{
			Message: "How would you like to authenticate GitHub CLI?",
			Options: []string{
				"Login with a web browser",
				"Paste an authentication token",
			},
		}, &authMode)
		if err != nil {
			return fmt.Errorf("could not prompt: %w", err)
		}
	}

	var authToken string
	userValidated := false

	if authMode == 0 {
		var err error
		authToken, err = authflow.AuthFlowWithConfig(cfg, opts.IO, hostname, "", append(opts.Scopes, minimumScopes...))
		if err != nil {
			return fmt.Errorf("failed to authenticate via web browser: %w", err)
		}
		userValidated = true
	} else {
		fmt.Fprint(opts.IO.ErrOut, heredoc.Docf(`
			Tip: you can generate a Personal Access Token here https://%s/settings/tokens
			The minimum required scopes are %s.
		`, hostname, scopesSentence(minimumScopes)))

		err := prompt.SurveyAskOne(&survey.Password{
			Message: "Paste your authentication token:",
		}, &authToken, survey.WithValidator(survey.Required))
		if err != nil {
			return fmt.Errorf("could not prompt: %w", err)
		}

		if err := HasMinimumScopes(httpClient, hostname, authToken); err != nil {
			return fmt.Errorf("error validating token: %w", err)
		}

		if err := cfg.Set(hostname, "oauth_token", authToken); err != nil {
			return err
		}
	}

	var username string
	if userValidated {
		username, _ = cfg.Get(hostname, "user")
	} else {
		apiClient := api.NewClientFromHTTP(httpClient)
		var err error
		username, err = api.CurrentLoginName(apiClient, hostname)
		if err != nil {
			return fmt.Errorf("error using api: %w", err)
		}

		err = cfg.Set(hostname, "user", username)
		if err != nil {
			return err
		}
	}

	if gitProtocol != "" {
		fmt.Fprintf(opts.IO.ErrOut, "- gh config set -h %s git_protocol %s\n", hostname, gitProtocol)
		err := cfg.Set(hostname, "git_protocol", gitProtocol)
		if err != nil {
			return err
		}
		fmt.Fprintf(opts.IO.ErrOut, "%s Configured git protocol\n", cs.SuccessIcon())
	}

	err := cfg.Write()
	if err != nil {
		return err
	}

	if configureGitCredential {
		err := GitCredentialSetup(hostname, username, authToken, credentialHelper)
		if err != nil {
			return err
		}
	}

	if keyToUpload != "" {
		err := sshKeyUpload(httpClient, keyToUpload)
		if err != nil {
			return err
		}
		fmt.Fprintf(opts.IO.ErrOut, "%s Uploaded the SSH key to your GitHub account: %s\n", cs.SuccessIcon(), cs.Bold(keyToUpload))
	}

	fmt.Fprintf(opts.IO.ErrOut, "%s Logged in as %s\n", cs.SuccessIcon(), cs.Bold(username))
	return nil
}

func scopesSentence(scopes []string) string {
	quoted := make([]string, len(scopes))
	for i, s := range scopes {
		quoted[i] = fmt.Sprintf("'%s'", s)
	}
	// TODO: insert an "and" before the last element
	return strings.Join(quoted, ", ")
}