import type { WrpcRoomCommand } from "./wrpcRoomCommand";
import type { Maybe, Shape } from "./wrpcSchema";

export type ExtractCommandNames<Commands extends Maybe<Record<string, WrpcRoomCommand>>> =
  Commands extends Record<string, WrpcRoomCommand> ? keyof Commands : never;

export type ExtractCommandInput<
  Commands extends Maybe<Record<string, WrpcRoomCommand>>,
  Name extends ExtractCommandNames<Commands>,
  Fallback = unknown,
> =
  Commands extends Record<string, WrpcRoomCommand>
    ? Commands[Name] extends WrpcRoomCommand<infer Input, unknown>
      ? Input extends Shape
        ? Input
        : Fallback
      : Fallback
    : Fallback;

export type ExtractCommandOutput<
  Commands extends Maybe<Record<string, WrpcRoomCommand>>,
  Name extends ExtractCommandNames<Commands>,
  Fallback = unknown,
> =
  Commands extends Record<string, WrpcRoomCommand>
    ? Commands[Name] extends WrpcRoomCommand<unknown, infer Output>
      ? Output extends Shape
        ? Output
        : Fallback
      : Fallback
    : Fallback;