Add shell completion

main.go

@@ -11,31 +11,47 @@ import (
 )
 
 func main() {
+	if handled, err := handleCompletionCommand(os.Args[1:], os.Stdout); handled {
+		if err != nil {
+			exitf("%v", err)
+		}
+		return
+	}
 	defaults := defaultConfig()
 	defaultConfigPath, err := configPath()
 	if err != nil {
 		exitf("configuration: %v", err)
 	}
+	flag.Usage = func() {
+		writeCLIHelp(flag.CommandLine.Output(), defaults, defaultConfigPath)
+	}
+	if len(os.Args) == 2 && os.Args[1] == "help" {
+		flag.Usage()
+		return
+	}
 	var (
 		configFile     = flag.String("config", defaultConfigPath, "TOML configuration file")
-		repo           = flag.String("repo", "", "optional GitHub repository filter as owner/name (or GH_REPO)")
-		poll           = flag.Duration("poll", defaults.RefreshInterval.Duration, "refresh interval")
-		showAll        = flag.Bool("all", defaults.ShowAll, "show all open PRs in --repo, not only PRs assigned to you")
-		limit          = flag.Int("limit", defaults.Limit, "maximum open PRs to load (1-1000)")
-		endpoint       = flag.String("endpoint", defaults.Endpoint, "GitHub GraphQL endpoint")
-		theme          = flag.String("theme", defaults.Theme, "color theme name (including custom, catppuccin, gruvbox, one-dark-pro, and github)")
-		foldResolved   = flag.Bool("fold-resolved", defaults.Display.FoldResolved, "start resolved threads folded")
-		listWidth      = flag.Int("thread-list-width", defaults.Display.ThreadListWidthPercent, "thread list width as terminal percentage (20-60)")
-		dashboardMode  = flag.String("dashboard-mode", defaults.Display.DashboardMode, "dashboard navigation: intermediate or hotkey")
-		compactReviews = flag.Bool("compact-reviews", defaults.Display.CompactReviews, "aggregate submitted review history")
-		pathScroll     = flag.Bool("path-scroll", defaults.Paths.Scroll, "scroll truncated paths")
-		pathScrollRate = flag.Duration("path-scroll-interval", defaults.Paths.ScrollInterval.Duration, "path scrolling interval")
-		cacheEnabled   = flag.Bool("cache", defaults.Cache.Enabled, "enable local read cache fallback")
-		cacheMaxAge    = flag.Duration("cache-max-age", defaults.Cache.MaxAge.Duration, "maximum offline cache age (0 disables expiry)")
-		cacheDir       = flag.String("cache-dir", defaults.Cache.Directory, "local read cache directory")
-		editorMode     = flag.String("editor-mode", defaults.Editing.Mode, "description editor mode: standard or vim")
+		repo           = flag.String("repo", "", "limit pull requests to an owner/repository")
+		poll           = flag.Duration("poll", defaults.RefreshInterval.Duration, "base interval between GitHub refreshes")
+		showAll        = flag.Bool("all", defaults.ShowAll, "show every open PR in --repo instead of only assigned PRs")
+		limit          = flag.Int("limit", defaults.Limit, "maximum number of open pull requests to load")
+		endpoint       = flag.String("endpoint", defaults.Endpoint, "GitHub GraphQL API endpoint")
+		theme          = flag.String("theme", defaults.Theme, "built-in or custom color theme")
+		foldResolved   = flag.Bool("fold-resolved", defaults.Display.FoldResolved, "start resolved review threads folded")
+		listWidth      = flag.Int("thread-list-width", defaults.Display.ThreadListWidthPercent, "thread-list width as a percentage of the terminal")
+		dashboardMode  = flag.String("dashboard-mode", defaults.Display.DashboardMode, "open the dashboard by hotkey or as an intermediate screen")
+		compactReviews = flag.Bool("compact-reviews", defaults.Display.CompactReviews, "aggregate repeated submitted-review entries")
+		pathScroll     = flag.Bool("path-scroll", defaults.Paths.Scroll, "scroll file paths that do not fit")
+		pathScrollRate = flag.Duration("path-scroll-interval", defaults.Paths.ScrollInterval.Duration, "interval between file-path scroll steps")
+		cacheEnabled   = flag.Bool("cache", defaults.Cache.Enabled, "enable the local read cache and offline fallback")
+		cacheMaxAge    = flag.Duration("cache-max-age", defaults.Cache.MaxAge.Duration, "oldest cache entry accepted for offline fallback")
+		cacheDir       = flag.String("cache-dir", defaults.Cache.Directory, "local read-cache directory")
+		editorMode     = flag.String("editor-mode", defaults.Editing.Mode, "description editor mode")
 	)
 	flag.Parse()
+	if flag.NArg() != 0 {
+		exitf("unexpected argument %q; run 'diple --help' for usage", flag.Arg(0))
+	}
 
 	visited := map[string]bool{}
 	flag.Visit(func(item *flag.Flag) { visited[item.Name] = true })