feat(cli): add login command and refactor shared helpers

internal/cmd/login.go

@@ -0,0 +1,187 @@
+package cmd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"runtime"
+	"strings"
+
+	"github.com/charmbracelet/huh"
+	"github.com/fatih/color"
+	"github.com/google/uuid"
+	"github.com/spf13/cobra"
+	"github.com/torrentclaw/unarr/internal/agent"
+	"github.com/torrentclaw/unarr/internal/config"
+)
+
+func newLoginCmd() *cobra.Command {
+	var apiURL string
+
+	cmd := &cobra.Command{
+		Use:     "login",
+		Aliases: []string{"auth"},
+		Short:   "Authenticate with your torrentclaw account",
+		Long: `Log in to your torrentclaw account by opening the browser or pasting
+your API key manually. Use this when your API key has expired, been
+revoked, or you want to switch to a different account.
+
+Unlike 'unarr init', this command only updates your authentication
+credentials — it does not modify your download directory, daemon
+settings, or other configuration.`,
+		Example: `  unarr login
+  unarr login --api-url https://custom.server.com`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runLogin(apiURL)
+		},
+	}
+
+	cmd.Flags().StringVar(&apiURL, "api-url", "", "API URL override (default: https://torrentclaw.com)")
+
+	return cmd
+}
+
+func runLogin(apiURLOverride string) error {
+	if !isTerminal() {
+		return fmt.Errorf("interactive mode requires a terminal (use UNARR_API_KEY env var instead)")
+	}
+
+	bold := color.New(color.Bold)
+	green := color.New(color.FgGreen)
+	dim := color.New(color.FgHiBlack)
+
+	fmt.Println()
+	bold.Println("  unarr login")
+	fmt.Println()
+
+	cfg := loadConfig()
+
+	// Determine API URL
+	apiURL := cfg.Auth.APIURL
+	if apiURLOverride != "" {
+		apiURL = apiURLOverride
+	}
+	if apiURL == "" {
+		apiURL = "https://torrentclaw.com"
+	}
+
+	// ── Authenticate ────────────────────────────────────────────────
+
+	var apiKey string
+
+	// Try browser-based auth first
+	fmt.Println("  Opening browser to connect your account...")
+	fmt.Println()
+
+	browserKey, browserErr := browserAuth(apiURL)
+	if browserErr == nil && strings.HasPrefix(browserKey, "tc_") {
+		apiKey = browserKey
+		green.Println("  ✓ Connected via browser")
+		fmt.Println()
+	} else {
+		// Fallback to manual API key entry
+		if browserErr != nil {
+			dim.Printf("  Could not connect automatically: %s\n", browserErr)
+		}
+		fmt.Println("  Paste your API key instead:")
+		dim.Printf("  (get it from %s/profile?tab=apikey)\n", apiURL)
+		fmt.Println()
+
+		err := huh.NewForm(
+			huh.NewGroup(
+				huh.NewInput().
+					Title("API Key").
+					Placeholder("tc_...").
+					Value(&apiKey).
+					Validate(func(s string) error {
+						s = strings.TrimSpace(s)
+						if s == "" {
+							return fmt.Errorf("API key is required")
+						}
+						if !strings.HasPrefix(s, "tc_") {
+							return fmt.Errorf("API key should start with tc_")
+						}
+						return nil
+					}),
+			),
+		).Run()
+		if err != nil {
+			if errors.Is(err, huh.ErrUserAborted) {
+				fmt.Println("\n  Login cancelled.")
+				return nil
+			}
+			return err
+		}
+		apiKey = strings.TrimSpace(apiKey)
+	}
+
+	// ── Validate API key ────────────────────────────────────────────
+
+	fmt.Print("  Verifying API key... ")
+
+	agentID := cfg.Agent.ID
+	if agentID == "" {
+		agentID = uuid.New().String()
+	}
+
+	hostname, _ := os.Hostname()
+	agentName := cfg.Agent.Name
+	if agentName == "" {
+		agentName = hostname
+	}
+
+	ac := agent.NewClient(apiURL, apiKey, "unarr/"+Version)
+	resp, err := ac.Register(context.Background(), agent.RegisterRequest{
+		AgentID:     agentID,
+		Name:        agentName,
+		OS:          runtime.GOOS,
+		Arch:        runtime.GOARCH,
+		Version:     Version,
+		DownloadDir: cfg.Download.Dir,
+	})
+	if err != nil {
+		color.Red("FAILED")
+		fmt.Println()
+		return fmt.Errorf("API key validation failed: %w", err)
+	}
+
+	green.Println("OK")
+	fmt.Printf("  Connected as %s (%s) [%s]\n", resp.User.Name, resp.User.Email, strings.ToUpper(resp.User.Plan))
+	fmt.Println()
+
+	// ── Save config (auth fields only) ──────────────────────────────
+
+	cfg.Auth.APIKey = apiKey
+	cfg.Auth.APIURL = apiURL
+	cfg.Agent.ID = agentID
+	cfg.Agent.Name = agentName
+
+	configPath := config.FilePath()
+	if cfgFile != "" {
+		configPath = cfgFile
+	}
+
+	if err := config.Save(cfg, configPath); err != nil {
+		return fmt.Errorf("save config: %w", err)
+	}
+	appCfg = cfg
+
+	fmt.Println()
+	green.Println("  ✓ Credentials saved!")
+	fmt.Printf("  Config: %s\n", configPath)
+	fmt.Println()
+
+	// Features summary
+	if line := formatFeatures(resp.Features); line != "" {
+		color.New(color.FgCyan).Printf("  Available:  %s\n", line)
+		fmt.Println()
+	}
+
+	if cfg.Download.Dir == "" {
+		fmt.Println("  Run " + bold.Sprint("unarr init") + " to complete the setup (download directory, daemon).")
+		fmt.Println()
+	}
+
+	return nil
+}