compaction

type ClassicCompactor struct{}

type Compactor interface {
	Compact(ctx context.Context, messages []protocol.ChatMessage, cfg Config) (Report, error)
}

type CompositeCompactor struct {
	Primary  Compactor
	Fallback Compactor
}

type Config struct {
	MaxMessages      int
	MaxTextPartBytes int
	// MaxTokens, when > 0, drops the oldest messages until the estimated token
	// count fits the budget (applied after the message-count/byte reductions).
	MaxTokens int
	// WorldState carries deterministic local state that must survive compaction.
	WorldState WorldState
}

type ContextBudget struct {
	MaxTokens         int `json:"max_tokens,omitempty"`
	EstimatedTokens   int `json:"estimated_tokens"`
	RemainingTokens   int `json:"remaining_tokens"`
	MessageCount      int `json:"message_count"`
	CompactedMessages int `json:"compacted_messages,omitempty"`
}

type EvictingCompactor struct {
	Sink                  EvictionSink
	ToolResultEvictTokens int
	KeepRecent            int
	PreviewHeadLines      int
	PreviewTailLines      int
}

type EvictionSink interface {
	Put(ctx context.Context, key string, content []byte) (ref string, err error)
}

type FileMetadata struct {
	Path     string `json:"path"`
	Kind     string `json:"kind,omitempty"` // write | edit
	Digest   string `json:"digest,omitempty"`
	Bytes    int64  `json:"bytes,omitempty"`
	LastTurn int    `json:"last_turn,omitempty"`
}

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

type PlanRef struct {
	ID       string `json:"id"`
	Path     string `json:"path,omitempty"`
	Status   string `json:"status,omitempty"`
	LastTurn int    `json:"last_turn,omitempty"`
}

type RecoveryResult struct {
	Source     string                 `json:"source"`
	Compacted  bool                   `json:"compacted"`
	Messages   []protocol.ChatMessage `json:"messages"`
	WorldState WorldState             `json:"world_state,omitempty"`
	Budget     ContextBudget          `json:"budget,omitempty"`
	Warnings   []RecoveryWarning      `json:"warnings,omitempty"`
}

type RecoveryWarning struct {
	Kind    string `json:"kind"`
	Segment int    `json:"segment,omitempty"`
	Detail  string `json:"detail,omitempty"`
}

type Report struct {
	Messages   []protocol.ChatMessage
	WorldState WorldState
	Budget     ContextBudget
}

type SkillRef struct {
	Name string `json:"name"`
	// Source is the skill's origin (e.g. path or catalog).
	Source string `json:"source,omitempty"`
	// LastTurn is the WorldState.Turn at which the skill was last invoked (via
	// load_skill). Age = current WorldState.Turn - LastTurn.
	LastTurn int `json:"last_turn,omitempty"`
}

type SubagentHandle struct {
	// ID is the child sub-agent's thread_id — the re-addressable handle returned
	// from spawn_subagent (pass it back as the `thread` arg to resume that child).
	// It is the dedup/merge key in MergeWorldState.
	ID       string `json:"id"`
	Name     string `json:"name,omitempty"`
	Task     string `json:"task,omitempty"`
	Status   string `json:"status,omitempty"`
	Summary  string `json:"summary,omitempty"`
	LastTurn int    `json:"last_turn,omitempty"`
}

type Summarizer interface {
	Summarize(ctx context.Context, messages []protocol.ChatMessage) (summary string, err error)
}

type SummarizingCompactor struct {
	Summarizer Summarizer
	Sink       EvictionSink
	KeepRecent int
}

type TaskState struct {
	ID        string   `json:"id"`
	Title     string   `json:"title,omitempty"`
	Status    string   `json:"status,omitempty"`
	BlockedBy []string `json:"blocked_by,omitempty"`
	LastTurn  int      `json:"last_turn,omitempty"`
}

type TodoState struct {
	ID       string `json:"id"`
	Content  string `json:"content,omitempty"`
	Status   string `json:"status,omitempty"`
	LastTurn int    `json:"last_turn,omitempty"`
}

type TranscriptSegment struct {
	ID         string                 `json:"id"`
	Compacted  bool                   `json:"compacted,omitempty"`
	Messages   []protocol.ChatMessage `json:"messages"`
	WorldState WorldState             `json:"world_state,omitempty"`
	Budget     ContextBudget          `json:"budget,omitempty"`
}

type WorldState struct {
	// Turn is a monotonic per-thread turn counter that survives compaction (it
	// rides the WorldState meta). Used to age InvokedSkills: a skill's staleness
	// is Turn - SkillRef.LastTurn.
	Turn int `json:"turn,omitempty"`
	// Compactions is a monotonic per-thread count of context-compaction events (each
	// provider call whose context Build dropped messages). Survives compaction via the
	// WorldState meta. Record-keeping today (no behavioral effect); a future signal
	// source — e.g. a hint that older detail was compacted out and should be searched
	// in history/memory rather than assumed gone.
	Compactions     int              `json:"compactions,omitempty"`
	PlanRefs        []PlanRef        `json:"plan_refs,omitempty"`
	Tasks           []TaskState      `json:"tasks,omitempty"`
	Todos           []TodoState      `json:"todos,omitempty"`
	InvokedSkills   []SkillRef       `json:"invoked_skills,omitempty"`
	RecentFiles     []FileMetadata   `json:"recent_files,omitempty"`
	DynamicTools    []string         `json:"dynamic_tools,omitempty"`
	ActiveSubagents []SubagentHandle `json:"active_subagents,omitempty"`
	Extra           json.RawMessage  `json:"extra,omitempty"`
}