import * as express from "express";
import * as session from "express-session";
import {
  DynamoDBClient,
  GetItemCommandOutput,
  ProvisionedThroughput,
  ScalarAttributeType,
} from "@aws-sdk/client-dynamodb";

export = ConnectDynamoDB;

declare function ConnectDynamoDB<Session extends Record<string, unknown>>(
  connect: (options?: session.SessionOptions) => express.RequestHandler
): ConnectDynamoDB.DynamoDBStore<Session>;

declare namespace ConnectDynamoDB {
  interface DynamoDBStoreOptions {
    /** A preconfigured client. If not supplied standard SDK environmental variables will be used. */
    client?: DynamoDBClient;
    /** Defaults to 'sessions' */
    table?: string;
    /** Defaults to 'sess:' */
    prefix?: string;
    /** Defaults to 'id' */
    hashKey?: string;
    readCapacityUnits?: ProvisionedThroughput["ReadCapacityUnits"];
    writeCapacityUnits?: ProvisionedThroughput["WriteCapacityUnits"];
    specialKeys?: DynamoDBStoreOptionsSpecialKey[];
    skipThrowMissingSpecialKeys?: boolean;
    /**
     * @deprecated
     * Upgrade to DynamoDB's TimeToLive configuration.
     */
    reapInterval?: number;
    /**
     * Disable initialization.
     * Useful if the table already exists or if you want to skip existence checks in a serverless environment such as AWS Lambda.
     */
    initialized?: boolean;
  }

  interface DynamoDBStoreOptionsSpecialKey {
    name: string; // The session key
    type: ScalarAttributeType | "B" | "N" | "S";
  }

  type DynamoDBStore<
    Session extends Record<string, unknown> = Record<string, unknown>
  > = session.Store & {
    readonly client: DynamoDBClient;
    new (options?: DynamoDBStoreOptions): DynamoDBStore<Session>;
    initialize(): Promise<void>;
    describeSessionsTable(): Promise<void>;
    createSessionsTable(): Promise<void>;
    get(
      id: string,
      callback: (err: CallbackError, session?: Session | null) => void
    ): void;
    getParsedSession(
      output: Pick<GetItemCommandOutput, "Item">
    ): Record<string, unknown>;
    set(id: string, callback: (err: CallbackError) => void): void;
    reap(callback?: (err: CallbackError) => void): void;
    destroy(id: string, callback?: (err: CallbackError) => void): void;
    getExpiresValue(): number;
    touch(
      id: string,
      callback?: (err: CallbackError, results: { expires: number }) => void
    ): void;
    clearInterval(): void;
  };

  type CallbackError = Error | undefined | null;
}