gastown/internal/cmd/session.go

package cmd

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/spf13/cobra"
	"github.com/steveyegge/gastown/internal/config"
	"github.com/steveyegge/gastown/internal/git"
	"github.com/steveyegge/gastown/internal/rig"
	"github.com/steveyegge/gastown/internal/session"
	"github.com/steveyegge/gastown/internal/style"
	"github.com/steveyegge/gastown/internal/tmux"
	"github.com/steveyegge/gastown/internal/workspace"
)

// Session command flags
var (
	sessionIssue     string
	sessionForce     bool
	sessionLines     int
	sessionMessage   string
	sessionFile      string
	sessionRigFilter string
	sessionListJSON  bool
)

var sessionCmd = &cobra.Command{
	Use:   "session",
	Short: "Manage polecat sessions",
	Long: `Manage tmux sessions for polecats.

Sessions are tmux sessions running Claude for each polecat.
Use the subcommands to start, stop, attach, and monitor sessions.`,
}

var sessionStartCmd = &cobra.Command{
	Use:   "start <rig>/<polecat>",
	Short: "Start a polecat session",
	Long: `Start a new tmux session for a polecat.

Creates a tmux session, navigates to the polecat's working directory,
and launches claude. Optionally inject an initial issue to work on.

Examples:
  gt session start wyvern/Toast
  gt session start wyvern/Toast --issue gt-123`,
	Args: cobra.ExactArgs(1),
	RunE: runSessionStart,
}

var sessionStopCmd = &cobra.Command{
	Use:   "stop <rig>/<polecat>",
	Short: "Stop a polecat session",
	Long: `Stop a running polecat session.

Attempts graceful shutdown first (Ctrl-C), then kills the tmux session.
Use --force to skip graceful shutdown.`,
	Args: cobra.ExactArgs(1),
	RunE: runSessionStop,
}

var sessionAtCmd = &cobra.Command{
	Use:     "at <rig>/<polecat>",
	Aliases: []string{"attach"},
	Short:   "Attach to a running session",
	Long: `Attach to a running polecat session.

Attaches the current terminal to the tmux session. Detach with Ctrl-B D.`,
	Args: cobra.ExactArgs(1),
	RunE: runSessionAttach,
}

var sessionListCmd = &cobra.Command{
	Use:   "list",
	Short: "List all sessions",
	Long: `List all running polecat sessions.

Shows session status, rig, and polecat name. Use --rig to filter by rig.`,
	RunE: runSessionList,
}

var sessionCaptureCmd = &cobra.Command{
	Use:   "capture <rig>/<polecat>",
	Short: "Capture recent session output",
	Long: `Capture recent output from a polecat session.

Returns the last N lines of terminal output. Useful for checking progress.`,
	Args: cobra.ExactArgs(1),
	RunE: runSessionCapture,
}

var sessionInjectCmd = &cobra.Command{
	Use:   "inject <rig>/<polecat>",
	Short: "Send message to session",
	Long: `Send a message to a polecat session.

Injects text into the session via tmux send-keys. Useful for nudges or notifications.

Examples:
  gt session inject wyvern/Toast -m "Check your mail"
  gt session inject wyvern/Toast -f prompt.txt`,
	Args: cobra.ExactArgs(1),
	RunE: runSessionInject,
}

func init() {
	// Start flags
	sessionStartCmd.Flags().StringVar(&sessionIssue, "issue", "", "Issue ID to work on")

	// Stop flags
	sessionStopCmd.Flags().BoolVarP(&sessionForce, "force", "f", false, "Force immediate shutdown")

	// List flags
	sessionListCmd.Flags().StringVar(&sessionRigFilter, "rig", "", "Filter by rig name")
	sessionListCmd.Flags().BoolVar(&sessionListJSON, "json", false, "Output as JSON")

	// Capture flags
	sessionCaptureCmd.Flags().IntVarP(&sessionLines, "lines", "n", 100, "Number of lines to capture")

	// Inject flags
	sessionInjectCmd.Flags().StringVarP(&sessionMessage, "message", "m", "", "Message to inject")
	sessionInjectCmd.Flags().StringVarP(&sessionFile, "file", "f", "", "File to read message from")

	// Add subcommands
	sessionCmd.AddCommand(sessionStartCmd)
	sessionCmd.AddCommand(sessionStopCmd)
	sessionCmd.AddCommand(sessionAtCmd)
	sessionCmd.AddCommand(sessionListCmd)
	sessionCmd.AddCommand(sessionCaptureCmd)
	sessionCmd.AddCommand(sessionInjectCmd)

	rootCmd.AddCommand(sessionCmd)
}

// parseAddress parses "rig/polecat" format.
func parseAddress(addr string) (rigName, polecatName string, err error) {
	parts := strings.SplitN(addr, "/", 2)
	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
		return "", "", fmt.Errorf("invalid address format: expected 'rig/polecat', got '%s'", addr)
	}
	return parts[0], parts[1], nil
}

// getSessionManager creates a session manager for the given rig.
func getSessionManager(rigName string) (*session.Manager, *rig.Rig, error) {
	// Find town root
	townRoot, err := workspace.FindFromCwdOrError()
	if err != nil {
		return nil, nil, fmt.Errorf("not in a Gas Town workspace: %w", err)
	}

	// Load rigs config
	rigsConfigPath := filepath.Join(townRoot, "config", "rigs.json")
	rigsConfig, err := config.LoadRigsConfig(rigsConfigPath)
	if err != nil {
		rigsConfig = &config.RigsConfig{Rigs: make(map[string]config.RigEntry)}
	}

	// Get rig
	g := git.NewGit(townRoot)
	rigMgr := rig.NewManager(townRoot, rigsConfig, g)
	r, err := rigMgr.GetRig(rigName)
	if err != nil {
		return nil, nil, fmt.Errorf("rig '%s' not found", rigName)
	}

	// Create session manager
	t := tmux.NewTmux()
	mgr := session.NewManager(t, r)

	return mgr, r, nil
}

func runSessionStart(cmd *cobra.Command, args []string) error {
	rigName, polecatName, err := parseAddress(args[0])
	if err != nil {
		return err
	}

	mgr, r, err := getSessionManager(rigName)
	if err != nil {
		return err
	}

	// Check polecat exists
	found := false
	for _, p := range r.Polecats {
		if p == polecatName {
			found = true
			break
		}
	}
	if !found {
		return fmt.Errorf("polecat '%s' not found in rig '%s'", polecatName, rigName)
	}

	opts := session.StartOptions{
		Issue: sessionIssue,
	}

	fmt.Printf("Starting session for %s/%s...\n", rigName, polecatName)
	if err := mgr.Start(polecatName, opts); err != nil {
		return fmt.Errorf("starting session: %w", err)
	}

	fmt.Printf("%s Session started. Attach with: %s\n",
		style.Bold.Render("✓"),
		style.Dim.Render(fmt.Sprintf("gt session at %s/%s", rigName, polecatName)))

	return nil
}

func runSessionStop(cmd *cobra.Command, args []string) error {
	rigName, polecatName, err := parseAddress(args[0])
	if err != nil {
		return err
	}

	mgr, _, err := getSessionManager(rigName)
	if err != nil {
		return err
	}

	fmt.Printf("Stopping session for %s/%s...\n", rigName, polecatName)
	if err := mgr.Stop(polecatName); err != nil {
		return fmt.Errorf("stopping session: %w", err)
	}

	fmt.Printf("%s Session stopped.\n", style.Bold.Render("✓"))
	return nil
}

func runSessionAttach(cmd *cobra.Command, args []string) error {
	rigName, polecatName, err := parseAddress(args[0])
	if err != nil {
		return err
	}

	mgr, _, err := getSessionManager(rigName)
	if err != nil {
		return err
	}

	// Attach (this replaces the process)
	return mgr.Attach(polecatName)
}

// SessionListItem represents a session in list output.
type SessionListItem struct {
	Rig       string `json:"rig"`
	Polecat   string `json:"polecat"`
	SessionID string `json:"session_id"`
	Running   bool   `json:"running"`
}

func runSessionList(cmd *cobra.Command, args []string) error {
	// Find town root
	townRoot, err := workspace.FindFromCwdOrError()
	if err != nil {
		return fmt.Errorf("not in a Gas Town workspace: %w", err)
	}

	// Load rigs config
	rigsConfigPath := filepath.Join(townRoot, "config", "rigs.json")
	rigsConfig, err := config.LoadRigsConfig(rigsConfigPath)
	if err != nil {
		rigsConfig = &config.RigsConfig{Rigs: make(map[string]config.RigEntry)}
	}

	// Get all rigs
	g := git.NewGit(townRoot)
	rigMgr := rig.NewManager(townRoot, rigsConfig, g)
	rigs, err := rigMgr.DiscoverRigs()
	if err != nil {
		return fmt.Errorf("discovering rigs: %w", err)
	}

	// Filter if requested
	if sessionRigFilter != "" {
		var filtered []*rig.Rig
		for _, r := range rigs {
			if r.Name == sessionRigFilter {
				filtered = append(filtered, r)
			}
		}
		rigs = filtered
	}

	// Collect sessions from all rigs
	t := tmux.NewTmux()
	var allSessions []SessionListItem

	for _, r := range rigs {
		mgr := session.NewManager(t, r)
		infos, err := mgr.List()
		if err != nil {
			continue
		}

		for _, info := range infos {
			allSessions = append(allSessions, SessionListItem{
				Rig:       r.Name,
				Polecat:   info.Polecat,
				SessionID: info.SessionID,
				Running:   info.Running,
			})
		}
	}

	// Output
	if sessionListJSON {
		enc := json.NewEncoder(os.Stdout)
		enc.SetIndent("", "  ")
		return enc.Encode(allSessions)
	}

	if len(allSessions) == 0 {
		fmt.Println("No active sessions.")
		return nil
	}

	fmt.Printf("%s\n\n", style.Bold.Render("Active Sessions"))
	for _, s := range allSessions {
		status := style.Bold.Render("●")
		if !s.Running {
			status = style.Dim.Render("○")
		}
		fmt.Printf("  %s %s/%s\n", status, s.Rig, s.Polecat)
		fmt.Printf("    %s\n", style.Dim.Render(s.SessionID))
	}

	return nil
}

func runSessionCapture(cmd *cobra.Command, args []string) error {
	rigName, polecatName, err := parseAddress(args[0])
	if err != nil {
		return err
	}

	mgr, _, err := getSessionManager(rigName)
	if err != nil {
		return err
	}

	output, err := mgr.Capture(polecatName, sessionLines)
	if err != nil {
		return fmt.Errorf("capturing output: %w", err)
	}

	fmt.Print(output)
	return nil
}

func runSessionInject(cmd *cobra.Command, args []string) error {
	rigName, polecatName, err := parseAddress(args[0])
	if err != nil {
		return err
	}

	// Get message
	message := sessionMessage
	if sessionFile != "" {
		data, err := os.ReadFile(sessionFile)
		if err != nil {
			return fmt.Errorf("reading file: %w", err)
		}
		message = string(data)
	}

	if message == "" {
		return fmt.Errorf("no message provided (use -m or -f)")
	}

	mgr, _, err := getSessionManager(rigName)
	if err != nil {
		return err
	}

	if err := mgr.Inject(polecatName, message); err != nil {
		return fmt.Errorf("injecting message: %w", err)
	}

	fmt.Printf("%s Message sent to %s/%s\n",
		style.Bold.Render("✓"), rigName, polecatName)
	return nil
}