API Response sealed class

APIResponse.kt

//package ...

import java.net.UnknownHostException

sealed class APIResponse<T>(val success: Boolean) {
	class APISuccess<T>(val data: T) : APIResponse<T>(true)
	sealed class APIFail<T>(val message: String) : APIResponse<T>(false) {
		class APIUnsuccessful<T>(val code: Int, message: String) : APIFail<T>(message) {
			constructor(other: APIUnsuccessful<out Any>) : this(other.code, other.message)
		}

		class APINetworkError<T>(message: String, val exception: UnknownHostException) :
				APIFail<T>(message) {
			constructor(exception: UnknownHostException) : this("Network Error", exception)
			constructor(other: APINetworkError<out Any>) : this(other.message, other.exception)
		}

		class APIError<T>(message: String, val exception: Throwable) : APIFail<T>(message) {
			constructor(exception: Throwable) : this("Something went wrong", exception)
			constructor(other: APIError<out Any>) : this(other.message, other.exception)
		}
	}
}

exampleUsage.kt

class ExampleRepo {

	suspend fun getSomeAPIData(): APIResponse<SomeObjectModel> {
		return try {
			val response: Response<SomeObjectModel> = apiService.someAPICall()
			val body = response.body()
			if(response.isSuccessful && body != null) {
				APIResponse.APISuccess(body)
			} else {
				Log.e(this, "Error in someAPIcall, code: ${response.code()}, " +
					"massage: " + "${response.message() ?: response.errorBody()}")
				APIResponse.APIFail.APIUnsuccessful(response.code(), response.message() ?: response.errorBody().toString())
			}
		} catch(e: UnknownHostException) {
			Log.w(this, "Network error in someAPIcall companies", e)
			APIResponse.APIFail.APINetworkError(e)
		} catch(e: Exception) {
			Log.e(this, "Error in someAPIcall companies", e)
			APIResponse.APIFail.APIError(e)
		}
	}
}

class ExampleClass {
	suspend fun foo() {
		when(val response = ExampleRepo.getSomeAPIData()) {
			is APIResponse.APISuccess -> TODO("Do something with response.data")
			is APIResponse.APIFail.APIUnsuccessful -> TODO("API call was not successfull, check response.code & response.message")
			is APIResponse.APIFail.APINetworkError -> TODO("Probably no internet connection...")
			is APIResponse.APIFail.APIError -> TODO("Something else went wrong...")
		}
	}
}