compaction

type CompactionResult struct {
	Summary      string   // the generated summary text
	FileOps      *FileOps // accumulated file operations
	TokensBefore int      // estimated tokens before compaction
	TokensAfter  int      // estimated tokens after compaction
	CutIndex     int      // index of first kept message
	MessagesKept int      // number of messages preserved verbatim
	Warning      string   // degradation warning, if any
}

type Config struct {
	// Enabled controls whether automatic compaction runs. Default: true.
	Enabled bool

	// ContextWindow is the model's context window in tokens.
	ContextWindow int

	// ReserveTokens is the budget reserved for the model response.
	ReserveTokens int

	// KeepRecentTokens is how many tokens of recent messages to keep verbatim.
	KeepRecentTokens int

	// MaxToolResultChars is the max chars per tool result in summarization input.
	MaxToolResultChars int

	// EffectivePercent is the percentage of ContextWindow to actually use (0-100).
	EffectivePercent int

	// SummarizationModel overrides the model used for summarization.
	SummarizationModel string

	// SummarizationProvider overrides the provider for summarization.
	SummarizationProvider agent.Provider

	// SummarizationFocus is optional text appended to the summarization prompt.
	SummarizationFocus string

	// UserMessageTailTokens is the token budget for re-including recent real
	// user messages after compaction alongside the summary. This gives the model
	// actual request context rather than only the summary.
	// Default: 20000. Zero means disabled.
	UserMessageTailTokens int

	// StuckThreshold is the number of consecutive compaction attempts (where
	// ShouldCompact returns true) that fail to produce a compacted history
	// before the compactor returns agent.ErrCompactionStuck. Zero uses
	// DefaultStuckThreshold.
	StuckThreshold int
}

type FileOps struct {
	Read     map[string]bool
	Modified map[string]bool
}