/*
 * Copyright 2020 HM Revenue & Customs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package uk.gov.hmrc.nisp.utils

import play.api.libs.json.{JsError, JsSuccess, Reads}

object EitherReads {
  implicit def eitherReads[A, B](implicit A: Reads[A], B: Reads[B]): Reads[Either[A, B]] =
    Reads[Either[A, B]] { json =>
      A.reads(json) match {
        case JsSuccess(value, path) => JsSuccess(Left(value), path)
        case JsError(e1) => B.reads(json) match {
          case JsSuccess(value, path) => JsSuccess(Right(value), path)
          case JsError(e2) => JsError(JsError.merge(e1, e2))
        }
      }
    }
}