import type ShowFn from "./Show";
import type { Fn1 } from "../../HKT";
import type { ValueOf } from "../../Obj/ValueOf";
import type { Eq, Lazied, Lazied$Get } from "../../helpers";

/**
 * A type class for types that can be converted to a string.
 */
export type Show = Lazied$Get<ShowL>;
/**
 * {@link Lazied} version of {@link Show}.
 */
export type ShowL = Lazied<ShowImpl[keyof ShowImpl][0]>;

/**
 * Type class constraints for type class {@link Show}.
 */
export interface TypeClass$$Show<T> {
  Show: Fn1<T, string>;
}

/**
 * Implementations for type class {@link Show}.
 */
export interface ShowImpl {}

/**
 * Helper type for implementing type class {@link Show}.
 *
 * @example
 * ```typescript
 * import type { Args, Fn2, Show } from "rivo";
 * import type { TypeClass$$Show } from "rivo/typeclass";
 * import type { Show as Show_ } from "rivo/typeclass/Show/Show";
 * //            ^^^^^^^^^^^^^
 * // Use the internal implementation for `Show.Show` for better performance
 *
 * interface MyType<N extends number = number> {
 *   value: N;
 * }
 *
 * declare module "rivo/typeclass/Show" {
 *   interface ShowImpl {
 *     MyType: ImplShowFor<MyType, MyType$$Show>;
 * //  ^^^^^^
 * // Can be any property key
 *   }
 * }
 *
 * interface MyType$$Show extends TypeClass$$Show<MyType> {
 *   Show: MyType$$Show$Show;
 * }
 *
 * interface MyType$$Show$Show extends Fn1<MyType, string> {
 *   def: ([s]: Args<this>) => `MyType<${Show_<(typeof s)["value"]>}>`;
 * }
 *
 * type R = Show.Show<MyType<42>>;
 * //   ^?: "MyType<42>"
 * ```
 */
export type ImplShowFor<T, TypeClass extends TypeClass$$Show<T>> = [T, TypeClass];

/**
 * Get the matching entry of {@link ShowImpl} for `S`.
 * @private
 */
type _Show$GetMatch<S extends Show> = ValueOf<{
  [P in keyof ShowImpl as S extends ShowImpl[P][0] ? P : never]: ShowImpl[P];
}>;

/**
 * Get the constructor of `S` from {@link ShowImpl}.
 */
export type Show$GetConstruct<S extends Show> =
  Eq<S, Show> extends true ? Show
  : _Show$GetMatch<S> extends [infer T, unknown] ? T
  : never;
/**
 * The **unsafe** version of {@link Show$GetConstruct} (i.e. no type checking with `S`).
 */
export type Show$GetConstructW<S> = S extends Show ? Show$GetConstruct<S> : never;

/**
 * Get the type class of `S` from {@link ShowImpl}.
 */
export type Show$GetTypeClass<S extends Show> =
  _Show$GetMatch<S> extends [unknown, infer TypeClass extends TypeClass$$Show<any>] ? TypeClass
  : never;
/**
 * The **unsafe** version of {@link Show$GetTypeClass} (i.e. no type checking with `S`).
 */
export type Show$GetTypeClassW<S> = S extends Show ? Show$GetTypeClass<S> : never;

/***********
 * Methods *
 ***********/
/**
 * Methods for `Show`.
 */
export namespace Show {
  /**
   * [Fn] Convert a `Show` instance to a string.
   *
   * Sig: `(s: Show) => string`
   */
  export type Show = ShowFn;
}