complete preparations for files uploading via posts

services/posts/common/src/commonMain/kotlin/dev/inmo/postssystem/services/posts/common/BinaryContentSerializer.kt

@@ -0,0 +1,58 @@
+package dev.inmo.postssystem.services.posts.common
+
+import dev.inmo.micro_utils.common.FileName
+import dev.inmo.micro_utils.mime_types.MimeType
+import dev.inmo.micro_utils.mime_types.MimeTypeSerializer
+import dev.inmo.postssystem.features.common.common.SimpleInputProvider
+import dev.inmo.postssystem.features.content.common.BinaryContent
+import kotlinx.serialization.*
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlin.reflect.KClass
+
+@Serializer(BinaryContent::class)
+class BinaryContentSerializer<T: SimpleInputProvider>(
+    private val kClass: KClass<T>,
+    private val serializer: KSerializer<T>
+) : KSerializer<BinaryContent> {
+    @OptIn(InternalSerializationApi::class, ExperimentalSerializationApi::class)
+    override val descriptor: SerialDescriptor = buildSerialDescriptor(
+        "BinaryContent",
+        SerialKind.CONTEXTUAL
+    ) {
+        element("filename", FileName.serializer().descriptor)
+        element("mimetype", MimeTypeSerializer.descriptor)
+        element("data", serializer.descriptor)
+    }
+
+    override fun deserialize(decoder: Decoder): BinaryContent {
+        return decoder.decodeStructure(descriptor) {
+            var fileName: FileName? = null
+            var mimeType: MimeType? = null
+            var data: T? = null
+            while (true) {
+                when (val index = decodeElementIndex(descriptor)) {
+                    0 -> fileName = decodeSerializableElement(descriptor, 0, FileName.serializer())
+                    1 -> mimeType = decodeSerializableElement(descriptor, 1, MimeTypeSerializer)
+                    2 -> data = decodeSerializableElement(descriptor, 2, serializer)
+                    CompositeDecoder.DECODE_DONE -> break
+                    else -> error("Unexpected index: $index")
+                }
+            }
+            BinaryContent(
+                fileName ?: error("Filename must be presented, but was absent"),
+                mimeType ?: error("Mimetype must be presented, but was absent"),
+                data ?: error("Data must be presented, but was absent")
+            )
+        }
+    }
+
+    override fun serialize(encoder: Encoder, value: BinaryContent) {
+        require(kClass.isInstance(value.inputProvider)) { "${value.inputProvider} do not inherit $kClass" }
+        encoder.encodeStructure(descriptor) {
+            encodeSerializableElement(descriptor, 0, FileName.serializer(), value.filename)
+            encodeSerializableElement(descriptor, 1, MimeTypeSerializer, value.mimeType)
+            encodeSerializableElement(descriptor, 2, serializer, value.inputProvider as T)
+        }
+    }
+}

services/posts/common/src/commonMain/kotlin/dev/inmo/postssystem/services/posts/common/Constants.kt

@@ -2,8 +2,7 @@ package dev.inmo.postssystem.services.posts.common
 
 import kotlinx.serialization.SerialFormat
 import kotlinx.serialization.cbor.Cbor
-import kotlinx.serialization.modules.SerializersModule
-import kotlinx.serialization.modules.SerializersModuleBuilder
+import kotlinx.serialization.modules.*
 
 const val postsRootPath = "posts"
 const val postsCreateTempPathPart = "temp"
@@ -13,8 +12,10 @@ const val postsPostIdParameter = "postId"
 fun SerialFormat.createWithSerializerModuleExtension(
     configurator: SerializersModuleBuilder.() -> Unit
 ) = Cbor {
-    serializersModule = SerializersModule {
-        include(this@createWithSerializerModuleExtension.serializersModule)
-        configurator()
-    }
+    serializersModule = this@createWithSerializerModuleExtension.serializersModule.overwriteWith(
+        SerializersModule {
+            include(this@createWithSerializerModuleExtension.serializersModule)
+            configurator()
+        }
+    )
 }