feat(completion): add one-command completion setup

cmd/completion.go

@@ -7,6 +7,7 @@ import (
 )
 
 func init() {
+	completionCmd.AddCommand(completionInstallCmd)
 	completionCmd.AddCommand(completionBashCmd)
 	completionCmd.AddCommand(completionZshCmd)
 	completionCmd.AddCommand(completionFishCmd)
@@ -15,7 +16,7 @@ func init() {
 }
 
 var completionCmd = &cobra.Command{
-	Use:   "completion [bash|zsh|fish|powershell]",
+	Use:   "completion [install|bash|zsh|fish|powershell]",
 	Short: "Generate shell completion scripts",
 	Long: `Generate shell completion scripts for clime.
 

cmd/completion_install.go

@@ -0,0 +1,204 @@
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+const completionProfileMarker = "# clime completion"
+
+var completionInstallCmd = &cobra.Command{
+	Use:   "install [shell]",
+	Short: "Install TAB completion for your shell",
+	Long: `Install TAB completion with one command.
+
+This command writes completion scripts generated by Cobra and adds the
+required shell profile hook so completion works when you press TAB.`,
+	Args: cobra.MaximumNArgs(1),
+	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		if len(args) != 0 {
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		}
+		return []string{"bash", "zsh", "fish", "powershell"}, cobra.ShellCompDirectiveNoFileComp
+	},
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var (
+			shell string
+			err   error
+		)
+
+		if len(args) > 0 {
+			shell, err = detectShellFromEnv(args[0], false)
+		} else {
+			shell, err = detectShellFromEnv(os.Getenv("SHELL"), runtime.GOOS == "windows")
+		}
+		if err != nil {
+			return err
+		}
+
+		return installCompletion(shell)
+	},
+}
+
+func installCompletion(shell string) error {
+	script, err := generateCompletionScript(shell)
+	if err != nil {
+		return err
+	}
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("resolve home directory: %w", err)
+	}
+
+	if shell == "fish" {
+		path := filepath.Join(home, ".config", "fish", "completions", "clime.fish")
+		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+			return fmt.Errorf("prepare fish completions directory: %w", err)
+		}
+		if err := os.WriteFile(path, []byte(script), 0644); err != nil {
+			return fmt.Errorf("write fish completion file: %w", err)
+		}
+		terminal.Successf("Installed fish completion: %s", path)
+		return nil
+	}
+
+	if shell == "powershell" {
+		return fmt.Errorf("automatic install for powershell is not supported yet; use: clime completion powershell >> $PROFILE")
+	}
+
+	scriptPath := filepath.Join(home, ".clime", "completions", "clime."+shell)
+	if err := os.MkdirAll(filepath.Dir(scriptPath), 0755); err != nil {
+		return fmt.Errorf("prepare completion directory: %w", err)
+	}
+	if err := os.WriteFile(scriptPath, []byte(script), 0644); err != nil {
+		return fmt.Errorf("write completion file: %w", err)
+	}
+
+	rcPath, err := shellProfilePath(shell, home)
+	if err != nil {
+		return err
+	}
+	line := completionSourceLine(scriptPath)
+	changed, err := ensureLineInFile(rcPath, completionProfileMarker, line)
+	if err != nil {
+		return err
+	}
+
+	if changed {
+		terminal.Successf("Installed %s completion and updated profile: %s", shell, rcPath)
+		terminal.Info("Open a new shell or source your profile to enable completion.")
+		return nil
+	}
+	terminal.Successf("%s completion is already configured.", shell)
+	return nil
+}
+
+func generateCompletionScript(shell string) (string, error) {
+	var buf bytes.Buffer
+	switch shell {
+	case "bash":
+		if err := rootCmd.GenBashCompletionV2(&buf, true); err != nil {
+			return "", err
+		}
+	case "zsh":
+		if err := rootCmd.GenZshCompletion(&buf); err != nil {
+			return "", err
+		}
+	case "fish":
+		if err := rootCmd.GenFishCompletion(&buf, true); err != nil {
+			return "", err
+		}
+	case "powershell":
+		if err := rootCmd.GenPowerShellCompletionWithDesc(&buf); err != nil {
+			return "", err
+		}
+	default:
+		return "", fmt.Errorf("unsupported shell %q", shell)
+	}
+	return buf.String(), nil
+}
+
+func detectShellFromEnv(shellValue string, isWindows bool) (string, error) {
+	if isWindows {
+		return "powershell", nil
+	}
+
+	shell := normalizeShell(shellValue)
+	if shell == "" {
+		return "", fmt.Errorf("could not detect shell; run `clime completion install <bash|zsh|fish|powershell>`")
+	}
+	switch shell {
+	case "bash", "zsh", "fish", "powershell":
+		return shell, nil
+	default:
+		return "", fmt.Errorf("unsupported shell %q", shell)
+	}
+}
+
+func normalizeShell(shellValue string) string {
+	s := strings.ToLower(strings.TrimSpace(filepath.Base(shellValue)))
+	switch s {
+	case "bash":
+		return "bash"
+	case "zsh":
+		return "zsh"
+	case "fish":
+		return "fish"
+	case "powershell", "pwsh":
+		return "powershell"
+	default:
+		return ""
+	}
+}
+
+func shellProfilePath(shell, home string) (string, error) {
+	switch shell {
+	case "bash":
+		return filepath.Join(home, ".bashrc"), nil
+	case "zsh":
+		return filepath.Join(home, ".zshrc"), nil
+	default:
+		return "", fmt.Errorf("profile setup is unsupported for shell %q", shell)
+	}
+}
+
+func completionSourceLine(scriptPath string) string {
+	return fmt.Sprintf("[ -f '%s' ] && source '%s'", scriptPath, scriptPath)
+}
+
+func ensureLineInFile(path, marker, line string) (bool, error) {
+	existing, err := os.ReadFile(path)
+	if err != nil && !os.IsNotExist(err) {
+		return false, fmt.Errorf("read profile %s: %w", path, err)
+	}
+	if strings.Contains(string(existing), line) {
+		return false, nil
+	}
+
+	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+		return false, fmt.Errorf("prepare profile directory: %w", err)
+	}
+
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return false, fmt.Errorf("open profile %s: %w", path, err)
+	}
+	defer f.Close()
+
+	if len(existing) > 0 && !strings.HasSuffix(string(existing), "\n") {
+		if _, err := f.WriteString("\n"); err != nil {
+			return false, fmt.Errorf("write profile newline: %w", err)
+		}
+	}
+	if _, err := f.WriteString("\n" + marker + "\n" + line + "\n"); err != nil {
+		return false, fmt.Errorf("write profile hook: %w", err)
+	}
+	return true, nil
+}

cmd/completion_install_test.go

@@ -0,0 +1,88 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestNormalizeShell(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		in   string
+		want string
+	}{
+		{in: "/bin/bash", want: "bash"},
+		{in: "/bin/zsh", want: "zsh"},
+		{in: "/usr/bin/fish", want: "fish"},
+		{in: "pwsh", want: "powershell"},
+		{in: "powershell", want: "powershell"},
+		{in: "unknown", want: ""},
+	}
+
+	for _, tt := range tests {
+		if got := normalizeShell(tt.in); got != tt.want {
+			t.Fatalf("normalizeShell(%q) = %q, want %q", tt.in, got, tt.want)
+		}
+	}
+}
+
+func TestDetectShellFromEnv(t *testing.T) {
+	t.Parallel()
+
+	got, err := detectShellFromEnv("/bin/zsh", false)
+	if err != nil {
+		t.Fatalf("detectShellFromEnv() error = %v", err)
+	}
+	if got != "zsh" {
+		t.Fatalf("shell = %q, want %q", got, "zsh")
+	}
+
+	got, err = detectShellFromEnv("", true)
+	if err != nil {
+		t.Fatalf("windows detect should succeed: %v", err)
+	}
+	if got != "powershell" {
+		t.Fatalf("shell = %q, want %q", got, "powershell")
+	}
+
+	if _, err := detectShellFromEnv("unknown", false); err == nil {
+		t.Fatal("expected error for unknown shell")
+	}
+}
+
+func TestEnsureLineInFileIdempotent(t *testing.T) {
+	t.Parallel()
+
+	tmpDir := t.TempDir()
+	path := filepath.Join(tmpDir, ".bashrc")
+	marker := "# clime completion"
+	line := "[ -f '/tmp/clime' ] && source '/tmp/clime'"
+
+	changed, err := ensureLineInFile(path, marker, line)
+	if err != nil {
+		t.Fatalf("first ensureLineInFile() error = %v", err)
+	}
+	if !changed {
+		t.Fatal("first ensureLineInFile() should report changed")
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read profile: %v", err)
+	}
+	content := string(data)
+	if !strings.Contains(content, marker) || !strings.Contains(content, line) {
+		t.Fatalf("profile content missing marker/line: %q", content)
+	}
+
+	changed, err = ensureLineInFile(path, marker, line)
+	if err != nil {
+		t.Fatalf("second ensureLineInFile() error = %v", err)
+	}
+	if changed {
+		t.Fatal("second ensureLineInFile() should be idempotent")
+	}
+}