session

type ChildSession struct {
	// Key is the unique identifier for this child session.
	Key string

	// ParentKey is the key of the parent session.
	ParentKey string

	// AgentName is the sub-agent that owns this child session.
	AgentName string

	// History contains messages added during this child session.
	History []Message

	// Config holds the child session settings.
	Config ChildSessionConfig

	// CreatedAt is when this child session was forked.
	CreatedAt time.Time

	// MergedAt is set when the child session is merged back to parent.
	// Zero value means not yet merged.
	MergedAt time.Time
}

type ChildSessionConfig struct {
	// MaxMessages limits the child session's message history.
	// Zero means unlimited (inherits parent limit).
	MaxMessages int

	// InheritHistory copies the last N messages from parent.
	// Zero means start with empty history.
	InheritHistory int

	// SummarizeOnMerge applies a summarizer when merging back to parent.
	SummarizeOnMerge bool
}

type ChildSessionStore interface {
	// ForkChild creates a new child session from a parent session.
	// If cfg.InheritHistory > 0, the last N messages are copied from parent.
	ForkChild(parentKey, agentName string, cfg ChildSessionConfig) (*ChildSession, error)

	// MergeChild merges a child session's messages back into the parent.
	// The summary parameter, if non-empty, replaces the full child history
	// with a single assistant message containing the summary.
	MergeChild(childKey string, summary string) error

	// DiscardChild removes a child session without merging.
	DiscardChild(childKey string) error

	// GetChild retrieves a child session by key.
	GetChild(childKey string) (*ChildSession, error)

	// ChildrenOf returns all child sessions for a parent.
	ChildrenOf(parentKey string) ([]*ChildSession, error)
}

type ChildStoreOption func(*InMemoryChildStore)

type EntStore struct {
	// contains filtered or unexported fields
}

type InMemoryChildStore struct {
	// contains filtered or unexported fields
}

type Message struct {
	Role      types.MessageRole `json:"role"` // "user", "assistant", "tool"
	Content   string            `json:"content"`
	Timestamp time.Time         `json:"timestamp"`
	ToolCalls []ToolCall        `json:"toolCalls,omitempty"`
	Author    string            `json:"author,omitempty"` // ADK agent name for multi-agent routing
}

type RunContext struct {
	SessionType string
	WorkflowID  string
	RunID       string
}

type Session struct {
	Key         string            `json:"key"`
	AgentID     string            `json:"agentId,omitempty"`
	ChannelType string            `json:"channelType,omitempty"`
	ChannelID   string            `json:"channelId,omitempty"`
	History     []Message         `json:"history"`
	Metadata    map[string]string `json:"metadata,omitempty"`
	Model       string            `json:"model,omitempty"`
	CreatedAt   time.Time         `json:"createdAt"`
	UpdatedAt   time.Time         `json:"updatedAt"`
}

type SessionLifecycleEvent struct {
	Type      string // "fork", "merge", "discard"
	ChildKey  string
	ParentKey string
	AgentName string
}

type SessionSummary struct {
	Key       string
	CreatedAt time.Time
	UpdatedAt time.Time
}

type Store interface {
	// Create creates a new session
	Create(session *Session) error
	// Get retrieves a session by key
	Get(key string) (*Session, error)
	// Update updates an existing session
	Update(session *Session) error
	// Delete removes a session
	Delete(key string) error
	// AppendMessage adds a message to session history
	AppendMessage(key string, msg Message) error
	// AnnotateTimeout appends a synthetic assistant message to indicate that the
	// previous turn was interrupted by a timeout. This prevents incomplete history
	// from leaking into subsequent turns.
	// partial is any partial response text accumulated before the timeout.
	AnnotateTimeout(key string, partial string) error
	// Close closes the store
	Close() error

	// ListSessions returns lightweight summaries of all sessions,
	// ordered by most recent update first.
	ListSessions(ctx context.Context) ([]SessionSummary, error)

	// GetSalt retrieves the encryption salt for LocalCryptoProvider
	GetSalt(name string) ([]byte, error)
	// SetSalt stores the encryption salt for LocalCryptoProvider
	SetSalt(name string, salt []byte) error
}

type StoreOption func(*EntStore)

type ToolCall struct {
	ID               string `json:"id"`
	Name             string `json:"name"`
	Input            string `json:"input"`
	Output           string `json:"output,omitempty"`
	Thought          bool   `json:"thought,omitempty"`
	ThoughtSignature []byte `json:"thoughtSignature,omitempty"`
}