refactor: Replace spray json with zio-json for FileMetadataSipiResponse

webapi/src/main/scala/org/knora/webapi/store/iiif/api/SipiService.scala

@@ -5,10 +5,9 @@
 
 package org.knora.webapi.store.iiif.api
 
-import org.apache.pekko.http.scaladsl.marshallers.sprayjson.SprayJsonSupport
-import spray.json.DefaultJsonProtocol
-import spray.json.RootJsonFormat
 import zio.*
+import zio.json.DeriveJsonDecoder
+import zio.json.JsonDecoder
 import zio.macros.accessible
 import zio.nio.file.Path
 
@@ -43,18 +42,23 @@
     throw SipiException(s"Sipi returned an empty originalFilename")
   }
 
   if (originalMimeType.contains("")) {
     throw SipiException(s"Sipi returned an empty originalMimeType")
   }
 }
 
-object FileMetadataSipiResponse extends SprayJsonSupport with DefaultJsonProtocol {
-  implicit val sipiKnoraJsonResponseFormat: RootJsonFormat[FileMetadataSipiResponse] = jsonFormat8(
-    FileMetadataSipiResponse.apply
-  )
+object FileMetadataSipiResponse {
+  // Because Sipi returns JSON Numbers which are whole numbers but not a valid Scala Int, e.g. `width: 1920.0`, we need to
+  // use a custom decoder for Int. See also https://github.com/zio/zio-json/issues/1049#issuecomment-1814108354
+  implicit val anyWholeNumber: JsonDecoder[Int] = JsonDecoder[Double].mapOrFail { d =>
+    val i = d.toInt
+    if (d == i.toDouble) { Right(i) }
+    else { Left("32-bit int expected") }
+  }
+  implicit val decoder: JsonDecoder[FileMetadataSipiResponse] = DeriveJsonDecoder.gen[FileMetadataSipiResponse]
 }
 
 @accessible
 trait SipiService {
 
   /**

webapi/src/main/scala/org/knora/webapi/store/iiif/impl/SipiServiceLive.scala

@@ -23,6 +23,7 @@
 import org.apache.http.util.EntityUtils
 import spray.json.*
 import zio.*
+import zio.json.DecoderOps
 import zio.nio.file.Path
 
 import java.net.URI
@@ -72,8 +73,12 @@
    * @return a [[FileMetadataSipiResponse]] containing the requested metadata.
    */
   override def getFileMetadata(filePath: String): Task[FileMetadataSipiResponse] =
     doSipiRequest(new HttpGet(sipiConfig.internalBaseUrl + filePath + "/knora.json"))
-      .mapAttempt(_.parseJson.convertTo[FileMetadataSipiResponse])
+      .flatMap(bodyStr =>
+        ZIO
+          .fromEither(bodyStr.fromJson[FileMetadataSipiResponse])
+          .mapError(e => SipiException(s"Invalid response from Sipi: $e, $bodyStr"))
+      )
 
   /**
    * Asks Sipi to move a file from temporary storage to permanent storage.
@@ -390,6 +395,6 @@
         config     <- ZIO.serviceWith[AppConfig](_.sipi)
         jwtService <- ZIO.service[JwtService]
         httpClient <- ZIO.acquireRelease(acquire(config))(release)
       } yield SipiServiceLive(config, jwtService, httpClient)
     }
 }