export declare const COMPACTION_BUFFER = 20000;

export declare const COMPACTION_TRIGGER_RATIO = 0.55;

export declare function getCompactionTriggerRatio(contextLimit: number): number;

export declare const PRUNE_PROTECT = 40000;

export declare const PRUNE_MINIMUM = 20000;

export declare const COMPACTION_LLM_PROMPT_TEMPLATE: string;
interface ChatMessageLike {
    role: "system" | "user" | "assistant" | "tool";
    content: string | unknown[] | null;
    tool_call_id?: string;
    tool_calls?: unknown[];
}

export interface CompactionResult {
    
    strategy: "prune" | "summarize" | "prune+summarize" | "none";
    
    freedTokens: number;
    
    sizeBeforeKB: number;
    
    sizeAfterKB: number;
    
    tokensBefore: number;
    
    tokensAfter: number;
    
    messageCountBefore: number;
    
    messageCountAfter: number;
    
    prunedToolMessages: number;
    
    summarizedMessages: number;
}

export interface CompactionPhaseEvent {
    phase: "prune_start" | "prune_end" | "summarize_start" | "summarize_end";
    
    messageCount?: number;
    
    prunedCount?: number;
    
    freedTokens?: number;
    
    summarizedCount?: number;
    
    usedLLM?: boolean;
}

export type LLMSummarizer = (input: {
    conversationText: string;
    messageCount: number;
    contextLimit: number;
}) => Promise<string>;

export declare function calculateCompactionThreshold(contextLimit: number, maxOutput: number, inputLimit?: number): number;

export declare function lookupModelLimits(modelName: string, configOverrides?: {
    contextLimit?: number;
    maxOutput?: number;
}): {
    contextLimit: number;
    maxOutput: number;
};

export declare function estimateTextTokens(text: string): number;

export declare function estimateTokens(text: string): number;

export declare function estimateConversationTokens(messages: readonly ChatMessageLike[]): number;

export declare function conversationSizeKB(messages: readonly ChatMessageLike[]): number;

export declare function isOverflow(messages: readonly ChatMessageLike[], contextLimit: number, _maxOutput?: number): boolean;

export declare function isOverflowByActualUsage(accumulatedInput: number, accumulatedOutput: number, contextLimit: number): boolean;

export declare function pruneToolOutputs(messages: ChatMessageLike[], contextLimit?: number): {
    prunedCount: number;
    freedTokens: number;
};

export declare function summarizeConversation(messages: ChatMessageLike[], options?: {
    llmSummarizer?: LLMSummarizer;
    contextLimit?: number;
}): Promise<number>;

export declare function snipOldestMessageGroup(messages: ChatMessageLike[]): number;

export declare function performCompaction(messages: ChatMessageLike[], contextLimit: number, maxOutput?: number, options?: {
    llmSummarizer?: LLMSummarizer;
    onPhase?: (event: CompactionPhaseEvent) => void;
    
    actualUsedTokens?: number;
}): Promise<CompactionResult>;
export {};