import Database from 'better-sqlite3';

/**
 * entity-name-dedup.ts — one-time destructive migration for the v0.26
 * canonical-key fix.
 *
 * Pre-v0.26 `upsertEntity` keyed on (LOWER(name), entity_type, namespace),
 * so the same real-world entity accumulated one row per extractor-assigned
 * type ("NeuroMCP" as project + concept + tool). v0.26 drops entity_type
 * from the key for NEW writes; this pass merges the duplicates that already
 * exist.
 *
 * Winner selection per duplicate group (same LOWER(TRIM(name)) + namespace):
 *   most memory_entities links wins; ties go to the oldest row (it has the
 *   longest provenance). Losers' memory links and relations are re-pointed
 *   to the winner, then the losers are soft-deleted (tombstoned, not
 *   physically removed — reversible by hand if a merge was wrong).
 *
 * DESTRUCTIVE in the sense that the merge collapses rows; always run with
 * dryRun: true first and review the proposed plan (the CLI wrapper in
 * scripts/ defaults to dry-run).
 */

interface NameDedupPair {
    readonly key: string;
    readonly winnerId: string;
    readonly winnerName: string;
    readonly winnerType: string;
    readonly loserId: string;
    readonly loserType: string;
}
interface NameDedupResult {
    readonly proposed: readonly NameDedupPair[];
    readonly merged: number;
    readonly relinked_memory_entities: number;
    readonly relinked_relations: number;
}
declare function mergeDuplicateEntityNames(db: Database.Database, options?: {
    dryRun?: boolean;
}): NameDedupResult;

export { type NameDedupPair, type NameDedupResult, mergeDuplicateEntityNames };