/**
 * Core type definitions for Pi-DCP
 */

import type { AgentMessage, } from "@mariozechner/pi-agent-core";
import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";

/**
 * Message with pruning metadata attached
 */
export interface MessageWithMetadata {
	/** Original message from pi */
	message: AgentMessage;
	/** Pruning metadata annotated by rules */
	metadata: MessageMetadata;
}

/**
 * Metadata attached to messages during prepare/process phases
 */
export interface MessageMetadata {
	/** Content hash for deduplication */
	hash?: string;
	/** File path for superseded writes tracking */
	filePath?: string;
	/** File content version for superseded writes */
	fileVersion?: string;
	/** Whether message is an error */
	isError?: boolean;
	/** Whether error was resolved by later success */
	errorResolved?: boolean;
	/** Recency score (distance from end) */
	recencyScore?: number;
	/** Whether protected by recency rule */
	protectedByRecency?: boolean;
	/** Final decision: should this message be pruned? */
	shouldPrune?: boolean;
	/** Reason for pruning (for debugging) */
	pruneReason?: string;
	/** Extensible: custom rule metadata */
	[key: string]: any;
}

/**
 * Context provided to prepare phase
 */
export interface PrepareContext {
	/** All messages being prepared */
	messages: MessageWithMetadata[];
	/** Current message index */
	index: number;
	/** Extension configuration */
	config: DcpConfigWithPruneRuleObjects
}

/**
 * Context provided to process phase
 */
export interface ProcessContext {
	/** All messages with metadata from prepare phase */
	messages: MessageWithMetadata[];
	/** Current message index */
	index: number;
	/** Extension configuration */
	config: DcpConfigWithPruneRuleObjects;
}

/**
 * Pruning rule definition
 */
export interface PruneRule {
	/** Unique rule identifier */
	name: string;
	/** Human-readable description */
	description?: string;
	/** Prepare phase: annotate metadata */
	prepare?: (msg: MessageWithMetadata, context: PrepareContext) => void;
	/** Process phase: make pruning decisions */
	process?: (msg: MessageWithMetadata, context: ProcessContext) => void;
}
export const isPruneRuleObject = (obj: unknown): obj is PruneRule => {
	return typeof obj === 'object'
		&& obj !== null
		&& 'name' in obj
		&& ('prepare' in obj || 'process' in obj)
		&& typeof (obj as any).name === 'string'
		&& (
			typeof (obj as any).prepare === 'function'
			|| typeof (obj as any).process === 'function'
		);
}

/**
 * Extension configuration
 */
export interface DcpConfig {
	/** Master enable/disable toggle */
	enabled?: boolean;
	/** Enable debug logging */
	debug?: boolean;
	/** Always keep last N messages */
	keepRecentCount: number;
	/** Optional log directory override */
	logDir?: string;
}
export type DcpConfigWithPruneRuleObjects = DcpConfig & {
	rules: PruneRule[];
};
export type DcpConfigWithRuleRefs = DcpConfig & {
	rules: (string | PruneRule)[];
};

export type CommandDefinition = Parameters<ExtensionAPI['registerCommand']>[1];

/**
 * Stats tracker for pruning statistics
 */
export interface StatsTracker {
	/** Total messages pruned */
	totalPruned: number;
	/** Total messages processed */
	totalProcessed: number;
}