temp: initial large reorganization and polishing

+ Make as much private as possible.
+ Split distinct pieces into separate files.
+ Improve names.

internal/cli/app.go

@@ -1,13 +1,9 @@
+// Package cli creates and runs command line interfaces.
 package cli
 
 import (
-	"encoding/json"
-	"flag"
 	"fmt"
-	"io"
 	"os"
-	"path/filepath"
-	"slices"
 	"strings"
 )
 
@@ -18,102 +14,34 @@ const (
 	exitFailure    = 1
 )
 
-// App stores information about the application's state.
-type App struct {
-	HomeDir     string
-	CmdName     string
-	Usage       string
-	ExitValue   int
-	QuietWanted bool
+type appEnv struct {
+	homeDir     string
+	cmd         string
+	subCmd      string
+	usage       string
+	exitValue   int
+	quietWanted bool
 }
 
-// NoOp determines whether an App should bail out.
-func (app *App) NoOp() bool {
-	return app.ExitValue != exitSuccess
+func (app *appEnv) noOp() bool {
+	return app.exitValue != exitSuccess
 }
 
-// NewApp returns a new App pointer.
-func NewApp(cmdUsage string) *App {
+func newAppEnv(subCmd string) *appEnv {
 	homeDir, err := os.UserHomeDir()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s: %s\n", gitmirrorName, err)
-		return &App{ExitValue: exitFailure}
+		fmt.Fprintf(os.Stderr, "%s %s: %s\n", gitmirrorName, subCmd, err)
+		return &appEnv{exitValue: exitFailure}
 	}
-	return &App{
-		CmdName:   gitmirrorName,
-		Usage:     gitmirrorUsage,
-		ExitValue: exitSuccess,
-		HomeDir:   homeDir,
+	return &appEnv{
+		cmd:       gitmirrorName,
+		subCmd:    subCmd,
+		usage:     gitmirrorUsage,
+		exitValue: exitSuccess,
+		homeDir:   homeDir,
 	}
 }
 
-// Repo stores information about a git repository.
-type Repo struct {
-	URL  string
-	Name string
-}
-
-// Flags handles flags and options in my finicky way.
-func (app *App) Flags(args []string) (string, bool) {
-	if app.NoOp() {
-		return "", false
-	}
-	cmdFlags := flag.NewFlagSet("gitmirror", flag.ContinueOnError)
-	cmdFlags.SetOutput(io.Discard)
-	var helpWanted bool
-	cmdFlags.BoolVar(&helpWanted, "help", false, "")
-	cmdFlags.BoolVar(&helpWanted, "h", false, "")
-	cmdFlags.BoolVar(&app.QuietWanted, "quiet", false, "")
-	cmdFlags.BoolVar(&app.QuietWanted, "q", false, "")
-	var configFile string
-	var configIsDefault bool
-	cmdFlags.StringVar(&configFile, "config", "", "")
-	cmdFlags.StringVar(&configFile, "c", "", "")
-	err := cmdFlags.Parse(args)
-	switch {
-	// This must precede all other checks.
-	case err != nil:
-		fmt.Fprintf(os.Stderr, "%s: %s\n%s", app.CmdName, err, app.Usage)
-		app.ExitValue = exitFailure
-	case helpWanted:
-		fmt.Fprintf(os.Stderr, "%s: use 'help' not '-help' or '-h'\n", app.CmdName)
-		fmt.Fprint(os.Stderr, app.Usage)
-		app.ExitValue = exitFailure
-	case configFile == "":
-		configFile = defaultConfig
-		configIsDefault = true
-	}
-	return configFile, configIsDefault
-}
-
-// Unmarshal reads a configuration file and returns a slice of Repo.
-func (app *App) Unmarshal(configFile string, configIsDefault bool) []Repo {
-	if app.NoOp() {
-		return nil
-	}
-	if configIsDefault {
-		configFile = filepath.Join(app.HomeDir, configFile)
-	}
-	blob, err := os.ReadFile(configFile)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s: %s\n", app.CmdName, err)
-		app.ExitValue = exitFailure
-		return nil
-	}
-	repos := make([]Repo, 0, 20)
-	err = json.Unmarshal(blob, &repos)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s: %s\n", app.CmdName, err)
-		app.ExitValue = exitFailure
-		return nil
-	}
-	// Every repository must have a URL and a directory name.
-	return slices.DeleteFunc(repos, func(repo Repo) bool {
-		return repo.URL == "" || repo.Name == ""
-	})
-}
-
-// PrettyPath replaces a user's home directory with ~ in a string.
-func (app *App) PrettyPath(s string) string {
-	return strings.Replace(s, app.HomeDir, "~", 1)
+func (app *appEnv) prettyPath(s string) string {
+	return strings.Replace(s, app.homeDir, "~", 1)
 }

internal/cli/clone.go

@@ -7,37 +7,36 @@ import (
 	"path/filepath"
 )
 
-// Clone runs git repote update on a group of repositories.
-func (app *App) Clone(repos []Repo) {
-	if app.NoOp() {
+func (app *appEnv) clone(repos []Repo) {
+	if app.noOp() {
 		return
 	}
-	err := os.MkdirAll(filepath.Join(app.HomeDir, defaultStorage), os.ModePerm)
+	err := os.MkdirAll(filepath.Join(app.homeDir, defaultStorage), os.ModePerm)
 	if err != nil {
-		app.ExitValue = exitFailure
+		app.exitValue = exitFailure
 		return
 	}
 	ch := make(chan result)
 	for _, repo := range repos {
-		go app.clone(repo, ch)
+		go app.cloneOne(repo, ch)
 	}
 	for range repos {
 		res := <-ch
-		res.publish(app.QuietWanted)
+		res.publish(app.quietWanted)
 	}
 }
 
-func (app *App) clone(repo Repo, ch chan<- result) {
+func (app *appEnv) cloneOne(repo Repo, ch chan<- result) {
 	// Normally, it is a bad idea to check whether a directory exists
 	// before trying an operation.  However, this case is an exception.
 	// git clone --mirror /path/to/existing/repo.git will fail with an
 	// error, but for the purpose of this app, there is no error.
 	// If a directory with the repo's name exists, I simply want to send
 	// a result saying that the repo exists.
-	repoPath := filepath.Join(app.HomeDir, defaultStorage, repo.Name)
-	storagePath := filepath.Join(app.HomeDir, defaultStorage)
+	repoPath := filepath.Join(app.homeDir, defaultStorage, repo.Name)
+	storagePath := filepath.Join(app.homeDir, defaultStorage)
 	if _, err := os.Stat(repoPath); err == nil {
-		prettyPath := app.PrettyPath(storagePath)
+		prettyPath := app.prettyPath(storagePath)
 		ch <- result{
 			isErr: false,
 			msg:   fmt.Sprintf("%s: already present in %s", repo.Name, prettyPath),
@@ -49,10 +48,10 @@ func (app *App) clone(repo Repo, ch chan<- result) {
 	noGitPrompt := "GIT_TERMINAL_PROMPT=0"
 	env := append(os.Environ(), noGitPrompt)
 	cmd.Env = env
-	cmd.Dir = filepath.Join(app.HomeDir, defaultStorage)
+	cmd.Dir = filepath.Join(app.homeDir, defaultStorage)
 	err := cmd.Run()
 	if err != nil {
-		app.ExitValue = exitFailure
+		app.exitValue = exitFailure
 		ch <- result{
 			isErr: true,
 			msg:   fmt.Sprintf("%s: %s", repo.Name, err),
@@ -65,11 +64,10 @@ func (app *App) clone(repo Repo, ch chan<- result) {
 	}
 }
 
-// CmdClone clones requested repos locally for mirroring.
-func CmdClone(args []string) int {
-	app := NewApp(cloneUsage)
-	configFile, configIsDefault := app.Flags(args)
-	repos := app.Unmarshal(configFile, configIsDefault)
-	app.Clone(repos)
-	return app.ExitValue
+func cmdClone(args []string) int {
+	app := newAppEnv("clone")
+	configFile, configIsDefault := app.parse(args)
+	repos := app.getRepos(configFile, configIsDefault)
+	app.clone(repos)
+	return app.exitValue
 }

internal/cli/flags.go

@@ -0,0 +1,63 @@
+package cli
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+)
+
+func (app *appEnv) parse(args []string) (string, bool) {
+	if app.noOp() {
+		return "", false
+	}
+	cmdFlags := flag.NewFlagSet("gitmirror", flag.ContinueOnError)
+	cmdFlags.SetOutput(io.Discard)
+	var helpWanted bool
+	cmdFlags.BoolVar(&helpWanted, "help", false, "")
+	cmdFlags.BoolVar(&helpWanted, "h", false, "")
+	cmdFlags.BoolVar(&app.quietWanted, "quiet", false, "")
+	cmdFlags.BoolVar(&app.quietWanted, "q", false, "")
+	var configFile string
+	var configIsDefault bool
+	cmdFlags.StringVar(&configFile, "config", "", "")
+	cmdFlags.StringVar(&configFile, "c", "", "")
+	err := cmdFlags.Parse(args)
+	switch {
+	// This must precede all other checks.
+	case err != nil:
+		fmt.Fprintf(
+			os.Stderr,
+			"%s %s: %s\n%s",
+			app.cmd,
+			app.subCmd,
+			err,
+			app.usage,
+		)
+		app.exitValue = exitFailure
+	case helpWanted:
+		fmt.Fprintf(
+			os.Stderr,
+			"%s: use 'help' not '-help' or '-h'\n",
+			app.cmd,
+		)
+		fmt.Fprint(os.Stderr, app.usage)
+		app.exitValue = exitFailure
+	case configFile == "":
+		configFile = defaultConfig
+		configIsDefault = true
+	}
+	extraArgs := cmdFlags.Args()
+	if len(extraArgs) > 0 {
+		fmt.Fprintf(
+			os.Stderr,
+			"%s %s: unrecognized arguments: %+v\n",
+			app.cmd,
+			app.subCmd,
+			extraArgs,
+		)
+		fmt.Fprint(os.Stderr, app.usage)
+		app.exitValue = exitFailure
+	}
+	return configFile, configIsDefault
+}

internal/cli/gitmirror.go

@@ -10,29 +10,30 @@ const (
 	gitmirrorVersion = "v0.9.0"
 )
 
-// CmdWrapper turns, e.g., `gitmirror update -q` into `gitmirror-update -q`.
+// CmdGitmirror runs a subcommand and returns success or failure to the shell.
 func CmdGitmirror(args []string) int {
 	if len(args) < 1 {
 		fmt.Fprint(os.Stderr, gitmirrorUsage)
 		return exitFailure
 	}
-	// Give the user a hand if they try `gitmirror --help update`.
-	if args[0] == "--help" || args[0] == "-help" || args[0] == "-h" {
+	// Give users a hand if they try, e.g., `gitmirror -(-)help|-h update`.
+	subCmd := args[0]
+	if subCmd == "--help" || subCmd == "-help" || subCmd == "-h" {
 		args[0] = "help"
 	}
 	var exitValue int
-	switch args[0] {
+	switch subCmd {
 	case "clone":
-		exitValue = CmdClone(args[1:])
+		exitValue = cmdClone(args[1:])
 	case "update", "up":
-		exitValue = CmdUpdate(args[1:])
+		exitValue = cmdUpdate(args[1:])
 	case "version":
-		exitValue = CmdVersion(args[1:])
+		exitValue = cmdVersion(args[1:])
 	case "help":
 		// TODO: write the help in Asciidoc?
-		exitValue = CmdHelp(args[1:])
+		exitValue = cmdHelp(args[1:])
 	default:
-		fmt.Fprintf(os.Stderr, "gitmirror: unrecognized subcommand: \"%s\"\n", args[0])
+		fmt.Fprintf(os.Stderr, "gitmirror: unrecognized subcommand: \"%s\"\n", subCmd)
 		fmt.Fprint(os.Stderr, gitmirrorUsage)
 		exitValue = exitFailure
 	}

internal/cli/help.go

@@ -5,21 +5,20 @@ import (
 	"os"
 )
 
-// Help displays the help message for a command.
-func (app *App) Help(args []string) {
-	if app.NoOp() {
+func (app *appEnv) help(args []string) {
+	if app.noOp() {
 		return
 	}
 	if len(args) < 1 {
 		fmt.Fprintf(os.Stderr, "%s help: no subcommand given\n", gitmirrorName)
 		fmt.Fprint(os.Stderr, helpUsage)
-		app.ExitValue = exitFailure
+		app.exitValue = exitFailure
 		return
 	}
 	if len(args) > 1 {
 		fmt.Fprintf(os.Stderr, "%s help: too many arguments: %+v\n", gitmirrorName, args)
 		fmt.Fprint(os.Stderr, helpUsage)
-		app.ExitValue = exitFailure
+		app.exitValue = exitFailure
 		return
 	}
 	switch args[0] {
@@ -34,13 +33,12 @@ func (app *App) Help(args []string) {
 	default:
 		fmt.Fprintf(os.Stderr, "%s help: unrecognized subcommand: \"%s\"\n", gitmirrorName, args[0])
 		fmt.Fprint(os.Stderr, helpUsage)
-		app.ExitValue = exitFailure
+		app.exitValue = exitFailure
 	}
 }
 
-// CmdHelp clones requested repos locally for mirroring.
-func CmdHelp(args []string) int {
-	app := NewApp(helpUsage)
-	app.Help(args)
-	return app.ExitValue
+func cmdHelp(args []string) int {
+	app := newAppEnv("help")
+	app.help(args)
+	return app.exitValue
 }