ollie/cmd/olliesrv/internal/session/session.go

package session

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"ollie/cmd/olliesrv/internal/agent"
	"ollie/cmd/olliesrv/internal/backend"
	"ollie/cmd/olliesrv/internal/toolclient"
	olog "ollie/log"
	toolsrvclient "ollie/toolsrv/client"
	"ollie/toolsrv/protocol"
	"ollie/util"
)

// Session owns all session-level state: identity, agents, tool server lifecycle.
type Session struct {
	// Identity (immutable after creation)
	ID    string // UUID
	Uname string // user principal (numeric UID)

	// Context lifecycle
	Ctx    context.Context
	Cancel context.CancelFunc

	// Tool server lifecycle (set during setup/teardown, not raced)
	Proc   *toolclient.Process
	Keeper *toolclient.ProcessKeeper
	Remote string

	// Agent state
	agents []*agent.Agent
	log    *olog.Logger

	// Mutable state protected by mu
	mu        sync.RWMutex
	name      string              // friendly name
	toolsConn *toolsrvclient.Conn // multiplexed RPC connection
	paused    bool

	// Autosave
	saveMu    sync.Mutex
	saveDirty bool
	saveTimer *time.Timer

	// Models cache (per-session, refreshed every 24h)
	modelsMu      sync.Mutex
	modelsCache   string
	modelsCacheAt time.Time
}

var sweepTmpOnce sync.Once

func ollieTmpDir() string {
	return filepath.Join(util.DataDir(), "tmp")
}

func sweepStaleTmpDirs() {
	sweepTmpOnce.Do(func() {
		base := ollieTmpDir()
		os.RemoveAll(base)      //nolint:errcheck
		os.MkdirAll(base, 0700) //nolint:errcheck
	})
}

// --- Mutable field accessors (only for fields that race) ---

// Name returns the mutable friendly name.
func (s *Session) Name() string {
	s.mu.RLock()
	defer s.mu.RUnlock()
	return s.name
}

// SetName sets the friendly name.
func (s *Session) SetName(name string) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.name = name
}

// ToolsConn returns the tool server connection.
func (s *Session) ToolsConn() *toolsrvclient.Conn {
	s.mu.RLock()
	defer s.mu.RUnlock()
	return s.toolsConn
}

// DialToolServer dials a fresh toolsrv connection via the keeper.
// Caller is responsible for closing the returned conn.
func (s *Session) DialToolServer() *toolsrvclient.Conn {
	s.mu.RLock()
	k := s.Keeper
	s.mu.RUnlock()
	if k == nil {
		return nil
	}
	conn, err := k.Dial()
	if err != nil {
		return nil
	}
	return conn
}

// SetToolsConn sets the tool server connection.
func (s *Session) SetToolsConn(conn *toolsrvclient.Conn) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.toolsConn = conn
}

// BypassNotifyFunc is called when a bypass request arrives.
// It receives the request, session ID, and a dial function to get a connection for resolution.
type BypassNotifyFunc func(req *protocol.BypassRequest, sessionID string, dialFn func() *toolsrvclient.Conn)

// StartBypassLoop starts a goroutine that reads bypass requests from toolsrv
// and calls notifyFn for each one. This should be called after SetToolsConn.
func (s *Session) StartBypassLoop(notifyFn BypassNotifyFunc) {
	go s.runBypassLoop(notifyFn)
}

func (s *Session) runBypassLoop(notifyFn BypassNotifyFunc) {
	for {
		// Get a fresh connection for each request (blocking reads don't multiplex well)
		conn := s.DialToolServer()
		if conn == nil {
			select {
			case <-s.Ctx.Done():
				return
			case <-time.After(1 * time.Second):
				continue
			}
		}

		req, err := conn.ReadBypassPending(s.Ctx)
		conn.Close()
		if err != nil {
			select {
			case <-s.Ctx.Done():
				return
			default:
				s.log.Debug("bypass read error: %v", err)
				time.Sleep(100 * time.Millisecond)
				continue
			}
		}

		// Notify (non-blocking) - the notifier will write resolution when user responds
		if notifyFn != nil {
			notifyFn((*protocol.BypassRequest)(req), s.ID, s.DialToolServer)
		}
	}
}

// IsPaused returns true if the session is paused.
func (s *Session) IsPaused() bool {
	s.mu.RLock()
	defer s.mu.RUnlock()
	return s.paused
}

// FindAgent returns the agent matching the given name or ID, or nil.
func (s *Session) FindAgent(nameOrID string) *agent.Agent {
	for _, ag := range s.agents {
		if ag.Name() == nameOrID || ag.ID() == nameOrID {
			return ag
		}
	}
	return nil
}

// Agents returns the full agent slice.
func (s *Session) Agents() []*agent.Agent { return s.agents }

// AddAgent appends an agent to the session.
func (s *Session) AddAgent(ag *agent.Agent) {
	s.agents = append(s.agents, ag)
	if s.Ctx != nil {
		go agent.ConsumeFeed(s.Ctx, ag)
	}
}

// RemoveAgent removes an agent by ID and closes it.
func (s *Session) RemoveAgent(id string) bool {
	idx := -1
	for i, ag := range s.agents {
		if ag.ID() == id {
			idx = i
			break
		}
	}
	if idx < 0 {
		return false
	}
	s.agents[idx].Close()
	s.agents = append(s.agents[:idx], s.agents[idx+1:]...)
	return true
}

// Close releases resources for this session.
func (s *Session) Close() {
	s.log.Debug("Close() session=%q", s.ID)
	s.flushSave()
	for _, ag := range s.agents {
		ag.Close()
	}
	if s.ID != "" {
		os.RemoveAll(filepath.Join(ollieTmpDir(), s.ID)) //nolint:errcheck
	}
}

// SetEnv stores a session-scoped variable and propagates to all agents.
func (s *Session) SetEnv(key, value string) {
	for _, ag := range s.agents {
		ag.SetEnv(key, value)
	}
}

// SetSessionID renames the session.
func (s *Session) SetSessionID(newID string) error {
	oldID := s.ID
	if oldID == newID {
		return nil
	}
	if pkgSessionsDir != "" && oldID != "" {
		for _, suffix := range []string{".json", ".compaction.jsonl"} {
			oldPath := s.activeSessionPath(oldID, suffix)
			if _, err := os.Stat(oldPath); err == nil {
				if err := os.Rename(oldPath, s.activeSessionPath(newID, suffix)); err != nil {
					return fmt.Errorf("rename %s: %w", suffix, err)
				}
			}
		}
	}
	s.ID = newID
	oldTemp := filepath.Join(ollieTmpDir(), oldID)
	newTemp := filepath.Join(ollieTmpDir(), newID)
	if _, err := os.Stat(oldTemp); err == nil {
		os.Rename(oldTemp, newTemp) //nolint:errcheck
	}
	for _, ag := range s.agents {
		ag.SetSessionEnv(newID)
	}
	return nil
}

// Pause stops the tool server to save resources.
func (s *Session) Pause() error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.paused {
		return fmt.Errorf("session already paused")
	}
	if s.Cancel != nil {
		s.Cancel()
	}
	if s.Keeper != nil {
		s.Keeper.Close()
	} else if s.Proc != nil {
		s.Proc.Close()
	}
	if s.toolsConn != nil {
		s.toolsConn.Close()
		s.toolsConn = nil
	}
	s.paused = true
	go s.saveSession()
	PublishEvent("session."+s.ID+".pause", "")
	return nil
}

// Resume restarts the tool server after a Pause.
func (s *Session) Resume() error {
	s.mu.Lock()
	defer s.mu.Unlock()
	if !s.paused {
		return fmt.Errorf("session not paused")
	}

	ctx, cancel := context.WithCancel(serverCtx)
	s.Ctx = ctx
	s.Cancel = cancel

	// Ensure we always have a Keeper. If the session was restored from disk
	// without infra, spawn a new tool server now.
	if s.Keeper == nil {
		cwd := ""
		if len(s.agents) > 0 {
			cwd = s.agents[0].Cwd()
		}
		if cwd == "" {
			cwd, _ = os.Getwd()
		}
		infra, err := SetupToolServer(ToolServerConfig{
			Ctx:          ctx,
			CWD:          cwd,
			RemoteTarget: s.Remote,
			SessionID:    s.ID,
			Yolo:         pkgYolo,
		})
		if err != nil {
			return fmt.Errorf("resume: %w", err)
		}
		s.Proc = infra.Proc
		s.Keeper = infra.Keeper
		s.toolsConn = infra.ToolsConn
		for _, ag := range s.agents {
			ag.SetToolServer(infra.NewToolServer, infra.NewToolServer())
			ag.SetSessionEnv(s.ID)
		}
	} else {
		// Keeper exists — just re-dial.
		s.Keeper.SetContext(ctx)
		conn, err := s.Keeper.Dial()
		if err != nil {
			return fmt.Errorf("resume failed: %w", err)
		}
		s.toolsConn = conn
		// Update agent connections with fresh dials
		for _, ag := range s.agents {
			agConn, err := s.Keeper.Dial()
			if err != nil {
				return fmt.Errorf("resume agent dial: %w", err)
			}
			ag.SetToolServer(func() *toolsrvclient.Conn {
				c, _ := s.Keeper.Dial()
				return c
			}, agConn)
			ag.SetSessionEnv(s.ID)
		}
	}

	s.paused = false

	// Rebuild full runtimes for restored agents (they have stub runtimes from persist).
	for _, ag := range s.agents {
		if err := rebuildAgentRuntime(ag, s.ID); err != nil {
			pkgLog.Error("resume agent %s: %v", ag.ID(), err)
		}
	}

	// Start feed consumers for restored agents (context now available).
	for _, ag := range s.agents {
		go agent.ConsumeFeed(ctx, ag)
	}
	go s.saveSession()
	PublishEvent("session."+s.ID+".resume", "")
	return nil
}

// rebuildAgentRuntime rebuilds the full runtime for an agent (used on resume).
func rebuildAgentRuntime(ag *agent.Agent, sessID string) error {
	cfg := agent.LoadConfig(pkgAgentsDir, ag.Profile(), os.Open)
	layers := BuildPromptLayers(cfg, ag.Cwd(), sessID, ag.ID(), "linux", false, "")
	env := []string{"OLLIE_SESSION_ID=" + sessID, "OLLIE_UNAME=" + ag.ID()}
	rt := agent.BuildRuntime(cfg, ag.ToolServer(), ag.Cwd(), env, layers.SystemPrompt, layers.EnvBlock)
	be, err := backend.NewWithName(cfg.Backend)
	if err != nil {
		return fmt.Errorf("backend: %w", err)
	}
	if cfg.Model != "" {
		be.SetModel(cfg.Model)
	}
	rt.Backend = be
	ag.SetRuntime(rt)
	LoadAutoLoadTools(cfg, ag.ToolServer(), sessID, ag.ID(), func(f string, a ...any) {
		pkgLog.Error("session %s agent %s: "+f, append([]any{sessID, ag.ID()}, a...)...)
	})
	return nil
}

// --- Tool loading ---

// LoadTool loads a tool into the tool server.
func (s *Session) LoadTool(name string, ag *agent.Agent) error {
	name = strings.TrimSpace(name)
	if name == "" {
		return nil
	}
	conn := s.ToolsConn()
	if conn == nil {
		return nil
	}
	// Ensure session ID is set on toolsrv before loading - the server uses this
	// to scope the tool registry. Required because conn may have been reconnected.
	conn.SetEnv("OLLIE_SESSION_ID", s.ID)
	return LoadToolOnConn(conn, name)
}

// LoadToolOnConn loads a tool on the given connection.
func LoadToolOnConn(conn *toolsrvclient.Conn, name string) error {
	if conn == nil {
		return nil
	}
	return conn.LoadTool(name)
}

// --- Autosave ---

func (s *Session) activeSessionPath(id, suffix string) string {
	return filepath.Join(pkgSessionsDir, "active", id+suffix)
}

func (s *Session) saveSession() {
	s.saveMu.Lock()
	s.saveDirty = true
	if s.saveTimer == nil {
		s.saveTimer = time.AfterFunc(2*time.Second, s.flushSave)
	}
	s.saveMu.Unlock()
}

func (s *Session) flushSave() {
	s.saveMu.Lock()
	dirty := s.saveDirty
	s.saveDirty = false
	if s.saveTimer != nil {
		s.saveTimer.Stop()
		s.saveTimer = nil
	}
	s.saveMu.Unlock()
	if !dirty || s.ID == "" || pkgSessionsDir == "" {
		return
	}
	if err := PersistSession(s.Name()); err != nil {
		s.log.Error("session save: %v", err)
	}
}

// Save writes the current session state via PersistSession.
func (s *Session) Save() error {
	return PersistSession(s.Name())
}

// --- Constructor for empty session ---

// NewEmpty creates an empty session without an agent.
func NewEmpty(id string, ctx context.Context, cancel context.CancelFunc) *Session {
	name := id
	if idx := strings.IndexByte(id, '-'); idx > 0 {
		name = id[:idx]
	}
	log := pkgSink.NewLogger("session")
	return &Session{
		ID:     id,
		name:   name,
		Ctx:    ctx,
		Cancel: cancel,
		agents: make([]*agent.Agent, 0),
		log:    log,
	}
}

// --- Models cache ---

const modelsCacheTTL = 24 * time.Hour

// CachedListModels returns a cached model list for this session.
func (s *Session) CachedListModels() string {
	s.modelsMu.Lock()
	if s.modelsCache != "" && time.Since(s.modelsCacheAt) < modelsCacheTTL {
		result := s.modelsCache
		s.modelsMu.Unlock()
		return result
	}
	s.modelsMu.Unlock()

	agents := s.Agents()
	if len(agents) == 0 {
		return ""
	}
	models := agents[0].ListModels()
	result := strings.Join(models, "\n")
	s.modelsMu.Lock()
	s.modelsCache = result
	s.modelsCacheAt = time.Now()
	s.modelsMu.Unlock()
	return result
}

// InvalidateModelsCache clears the cached model list.
func (s *Session) InvalidateModelsCache() {
	s.modelsMu.Lock()
	s.modelsCache = ""
	s.modelsCacheAt = time.Time{}
	s.modelsMu.Unlock()
}