/**
 * Context Compression Utility
 *
 * Provides automatic context compression for Hive when context reaches threshold.
 * Similar to DCP (Dynamic Context Pruning) or oh-my-openagent's context management.
 *
 * Features:
 * - Automatic compression at 50% context threshold
 * - Trimming unnecessary tool outputs
 * - Deduplication, write superseding, and error purging strategies
 * - Zero-cost automatic pruning strategies
 */
interface MessageContent {
    type: "text";
    text?: string;
}
interface ToolCall {
    id?: string;
    name: string;
    arguments?: Record<string, unknown>;
}
interface Message {
    role: "user" | "assistant" | "tool" | "system";
    content?: string | MessageContent[];
    tool_calls?: ToolCall[];
    tool_call_id?: string;
    name?: string;
}
export interface CompressionConfig {
    /** Context threshold to trigger compression (0-1, default: 0.5 = 50%) */
    threshold?: number;
    /** Enable automatic compression */
    enabled?: boolean;
    /** Protected tool output patterns (glob) */
    protectedTools?: string[];
    /** Protect user messages from compression */
    protectUserMessages?: boolean;
    /** Maximum tool calls to keep after compression */
    maxToolCalls?: number;
}
/**
 * Estimate token count from messages (rough approximation)
 * ~4 characters per token on average
 */
export declare function estimateTokens(messages: Message[]): number;
/**
 * Calculate context usage ratio (0-1)
 */
export declare function getContextUsage(messages: Message[], contextLimit: number): number;
/**
 * Check if context compression is needed
 */
export declare function needsCompression(messages: Message[], contextLimit: number, config?: CompressionConfig): boolean;
/**
 * Main compression function
 * Applies all strategies to reduce context size
 */
export declare function compressContext(messages: Message[], config?: CompressionConfig, contextLimit?: number): {
    compressed: Message[];
    stats: CompressionStats;
};
export interface CompressionStats {
    originalTokens: number;
    compressedTokens: number;
    reductionRatio: number;
    originalMessages: number;
    compressedMessages: number;
}
/**
 * Build a compression hint prompt
 * This is injected into context to guide the LLM
 */
export declare function buildCompressionHint(): string;
/**
 * Create a session compaction hook for Hive
 * This can be used with experimental.session.compacting hook
 */
export declare function createCompactionHook(config?: CompressionConfig): (input: {
    sessionID: string;
    messages?: Message[];
    contextLimit?: number;
}, output: {
    context: string[];
    prompt?: string;
}) => void;
export {};