import { type Effect } from "effect/Effect"

export namespace EffectGenUtils {
  export type Success<EG> = EG extends Effect<infer A, infer _E, infer _R> ? A
    // there could be a case where the generator function does not yield anything, so we need to handle that
    : EG extends (..._: infer _3) => Generator<never, infer A, infer _2> ? A
    // generators yield Effect values
    : EG extends (..._: infer _3) => Generator<Effect<any, infer _E, infer _R>, infer A, infer _2> ? A
    : never

  export type Error<EG> = EG extends Effect<infer _A, infer E, infer _R> ? E
    // there could be a case where the generator function does not yield anything, so we need to handle that
    : EG extends (..._: infer _3) => Generator<never, infer _A, infer _2> ? never
    // generators yield Effect values
    : EG extends (..._: infer _3) => Generator<Effect<any, infer E, infer _R>, infer _A, infer _2> ? E
    : never

  export type Context<EG> = EG extends Effect<infer _A, infer _E, infer R> ? R
    // there could be a case where the generator function does not yield anything, so we need to handle that
    : EG extends (..._: infer _3) => Generator<never, infer _A, infer _2> ? never
    // generators yield Effect values
    : EG extends (..._: infer _3) => Generator<Effect<any, infer _E, infer R>, infer _A, infer _2> ? R
    : never
}