kit/internal/session/manager.go

package session

import (
	"fmt"
	"sync"

	"charm.land/fantasy"
)

// Manager manages session state and auto-saving functionality.
// It provides thread-safe operations for managing a conversation session,
// including automatic persistence to disk after each modification.
type Manager struct {
	session  *Session
	filePath string
	mutex    sync.RWMutex
}

// NewManager creates a new session manager with a fresh session.
func NewManager(filePath string) *Manager {
	return &Manager{
		session:  NewSession(),
		filePath: filePath,
	}
}

// NewManagerWithSession creates a new session manager with an existing session.
func NewManagerWithSession(session *Session, filePath string) *Manager {
	return &Manager{
		session:  session,
		filePath: filePath,
	}
}

// AddMessage adds a fantasy message to the session and auto-saves.
func (m *Manager) AddMessage(msg fantasy.Message) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	sessionMsg := ConvertFromFantasyMessage(msg)
	m.session.AddMessage(sessionMsg)

	if m.filePath != "" {
		return m.session.SaveToFile(m.filePath)
	}

	return nil
}

// AddMessages adds multiple fantasy messages to the session and auto-saves.
func (m *Manager) AddMessages(msgs []fantasy.Message) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	for _, msg := range msgs {
		sessionMsg := ConvertFromFantasyMessage(msg)
		m.session.AddMessage(sessionMsg)
	}

	if m.filePath != "" {
		return m.session.SaveToFile(m.filePath)
	}

	return nil
}

// ReplaceAllMessages replaces all messages in the session with the provided messages.
func (m *Manager) ReplaceAllMessages(msgs []fantasy.Message) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	// Clear existing messages
	m.session.Messages = []Message{}

	// Add all new messages
	for _, msg := range msgs {
		sessionMsg := ConvertFromFantasyMessage(msg)
		m.session.AddMessage(sessionMsg)
	}

	if m.filePath != "" {
		return m.session.SaveToFile(m.filePath)
	}

	return nil
}

// SetMetadata sets the session metadata.
func (m *Manager) SetMetadata(metadata Metadata) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	m.session.SetMetadata(metadata)

	if m.filePath != "" {
		return m.session.SaveToFile(m.filePath)
	}

	return nil
}

// GetMessages returns all messages as fantasy.Message slice.
func (m *Manager) GetMessages() []fantasy.Message {
	m.mutex.RLock()
	defer m.mutex.RUnlock()

	messages := make([]fantasy.Message, len(m.session.Messages))
	for i, msg := range m.session.Messages {
		messages[i] = msg.ConvertToFantasyMessage()
	}

	return messages
}

// GetSession returns a copy of the current session.
func (m *Manager) GetSession() *Session {
	m.mutex.RLock()
	defer m.mutex.RUnlock()

	sessionCopy := *m.session
	sessionCopy.Messages = make([]Message, len(m.session.Messages))
	copy(sessionCopy.Messages, m.session.Messages)

	return &sessionCopy
}

// Save manually saves the session to file.
func (m *Manager) Save() error {
	m.mutex.RLock()
	defer m.mutex.RUnlock()

	if m.filePath == "" {
		return fmt.Errorf("no file path specified for session manager")
	}

	return m.session.SaveToFile(m.filePath)
}

// GetFilePath returns the file path for this session.
func (m *Manager) GetFilePath() string {
	return m.filePath
}

// MessageCount returns the number of messages in the session.
func (m *Manager) MessageCount() int {
	m.mutex.RLock()
	defer m.mutex.RUnlock()

	return len(m.session.Messages)
}