// ── Event types ──────────────────────────────────────────────

export type EventType = 'put' | 'delete';

export interface SyncEvent {
  type: EventType;
  store: string;       // "kv" | collection name
  key: string;
  id?: string;         // present for collection documents
  ts: number;          // millisecond Unix epoch
  clientId: string;
  data?: unknown;      // absent on deletes
  rev?: number;
}

// ── Index / collection options ───────────────────────────────

export interface IndexDefinition<T = unknown> {
  name: string;
  fields: (keyof T & string)[] | string[];
}

export interface StoreOptions<T = unknown> {
  name: string;
  indexes?: IndexDefinition<T>[];
}

export interface OpenOptions {
  dbName?: string;
  autoSyncIntervalMs?: number;
  clientId?: string;
  conflictResolver?: (current: unknown, incoming: unknown) => unknown;
  /** Passed to sqlite3InitModule(). Use locateFile to override .wasm loading. */
  sqlite3Config?: Record<string, unknown>;
}

// ── Store record shapes ──────────────────────────────────────

export interface KVRecord {
  key: string;
  value: unknown;
  ts: number;
  rev: number;
}

export interface DocRecord {
  store: string;
  id: string;
  data: unknown;
  ts: number;
  rev: number;
  deleted?: boolean;
}

// ── Index range (replaces IDBKeyRange for SQLite) ────────────

export interface IndexRange {
  gt?: unknown;
  gte?: unknown;
  lt?: unknown;
  lte?: unknown;
}

// ── Event emitter ────────────────────────────────────────────

export type SyncDBEventName =
  | 'sync:start'
  | 'sync:end'
  | 'change'
  | 'conflict'
  | 'folder:lost-permission';

export type SyncDBEventHandler = (...args: unknown[]) => void;

// ── KV API surface ───────────────────────────────────────────

export interface KVApi {
  get<T = unknown>(key: string): Promise<T | undefined>;
  set<T = unknown>(key: string, value: T): Promise<void>;
  delete(key: string): Promise<void>;
  has(key: string): Promise<boolean>;
  keys(): Promise<string[]>;
  entries<T = unknown>(): Promise<Array<[string, T]>>;
}

// ── Collection API surface ───────────────────────────────────

export interface CollectionApi<T extends { id: string }> {
  get(id: string): Promise<T | undefined>;
  put(doc: T): Promise<void>;
  delete(id: string): Promise<void>;
  all(): Promise<T[]>;
  findByIndex(indexName: string, value: unknown): Promise<T[]>;
  queryByIndex(indexName: string, range: IndexRange): Promise<T[]>;
}