import {
  type AutocompleteInteraction,
  type User,
  type Attachment,
  type Role,
  type GuildBasedChannel,
  type ApplicationCommandOptionChoiceData,
} from "discord.js";

export const OPTION_TYPES = {
  subcommand: 1,
  subcommandGroup: 2,
  string: 3,
  integer: 4,
  boolean: 5,
  user: 6,
  channel: 7,
  role: 8,
  mentionable: 9,
  number: 10,
  attachment: 11,
} as const;
type OptionType = keyof typeof OPTION_TYPES;

export interface Option<T, Req extends boolean> {
  type: OptionType;
  description: string;
  required: Req;
  autocomplete?: (
    interaction: AutocompleteInteraction,
    value: T,
  ) => Promise<ApplicationCommandOptionChoiceData[]> | ApplicationCommandOptionChoiceData[];
  __type?: T;
}

export type InferOptions<O> = {
  [K in keyof O]: O[K] extends Option<infer Type, infer Required>
    ? Required extends true
      ? Type
      : Type | undefined
    : never;
};

export type AutocompleteFn<T> = (
  interaction: AutocompleteInteraction,
  value: T,
) => Promise<ApplicationCommandOptionChoiceData[]> | ApplicationCommandOptionChoiceData[];

const createOption = <T>(type: OptionType) => {
  return ((description: string, config?: any): Option<T, any> => ({
    type,
    description,
    required: config?.required ?? false,
    autocomplete: config?.autocomplete,
  })) as {
    (
      description: string,
      config: { required: true; autocomplete?: AutocompleteFn<T> },
    ): Option<T, true>;
    (
      description: string,
      config?: { required?: false; autocomplete?: AutocompleteFn<T> },
    ): Option<T, false>;
  };
};

export const option = {
  string: createOption<string>("string"),
  integer: createOption<number>("integer"),
  number: createOption<number>("number"),
  boolean: createOption<boolean>("boolean"),
  user: createOption<User>("user"),
  channel: createOption<GuildBasedChannel>("channel"),
  role: createOption<Role>("role"),
  mentionable: createOption<User | Role | any>("mentionable"),
  attachment: createOption<Attachment>("attachment"),
};