feat: とりあえずacceptを返すように

src/main/kotlin/dev/usbharu/hideout/ap/Follow.kt

@@ -1,13 +1,13 @@
 package dev.usbharu.hideout.ap
 
 open class Follow : Object{
-    public var `object`:Object? = null
+    public var `object`:String? = null
     public var actor:String? = null
     protected constructor() : super()
     constructor(
         type: List<String> = emptyList(),
         name: String,
-        `object`: Object?,
+        `object`: String?,
         actor: String?
     ) : super(add(type,"Follow"), name) {
         this.`object` = `object`

src/main/kotlin/dev/usbharu/hideout/ap/Person.kt

@@ -4,7 +4,7 @@ open class Person : Object {
     private var id:String? = null
     var preferredUsername:String? = null
     var summary:String? = null
-    private var inbox:String? = null
+    var inbox:String? = null
     private var outbox:String? = null
     private var url:String? = null
     private var icon:Image? = null

src/main/kotlin/dev/usbharu/hideout/routing/userActivityPubRouting.kt

@@ -1,6 +1,10 @@
 package dev.usbharu.hideout.routing
 
+import com.fasterxml.jackson.module.kotlin.readValue
+import dev.usbharu.hideout.ap.Follow
+import dev.usbharu.hideout.config.Config
 import dev.usbharu.hideout.service.ActivityPubService
+import dev.usbharu.hideout.service.ActivityPubUserService
 import dev.usbharu.hideout.util.HttpUtil
 import io.ktor.http.*
 import io.ktor.server.application.*
@@ -8,7 +12,7 @@ import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
 
-fun Application.userActivityPubRouting(activityPubService: ActivityPubService) {
+fun Application.userActivityPubRouting(activityPubService: ActivityPubService, activityPubUserService: ActivityPubUserService) {
     routing {
         route("/users/{name}") {
             route("/inbox") {
@@ -21,7 +25,17 @@ fun Application.userActivityPubRouting(activityPubService: ActivityPubService) {
                     }
                     val bodyText = call.receiveText()
                     println(bodyText)
-                    activityPubService.switchApType(bodyText)
+                    when (activityPubService.switchApType(bodyText)) {
+                        ActivityPubService.ActivityType.Follow -> {
+                            val readValue = Config.configData.objectMapper.readValue<Follow>(bodyText)
+                            activityPubUserService.receiveFollow(readValue)
+
+                        }
+
+                        ActivityPubService.ActivityType.Undo -> {
+                            TODO()
+                        }
+                    }
 
                 }
             }

src/main/kotlin/dev/usbharu/hideout/service/ActivityPubUserService.kt

@@ -1,8 +1,6 @@
 package dev.usbharu.hideout.service
 
-import dev.usbharu.hideout.ap.Image
+import dev.usbharu.hideout.ap.*
-import dev.usbharu.hideout.ap.Key
-import dev.usbharu.hideout.ap.Person
 import dev.usbharu.hideout.config.Config
 import io.ktor.client.*
 import io.ktor.client.call.*
@@ -11,9 +9,10 @@ import io.ktor.client.request.*
 import io.ktor.http.*
 
 class ActivityPubUserService(
-    private val httpClient:HttpClient,
+        private val httpClient: HttpClient,
         private val userService: UserService,
-    private val userAuthService: IUserAuthService
+        private val userAuthService: IUserAuthService,
+        private val webFingerService: WebFingerService
 ) {
     suspend fun generateUserModel(name: String): Person {
         val userEntity = userService.findByName(name)
@@ -44,7 +43,7 @@ class ActivityPubUserService(
         )
     }
 
-    suspend fun fetchUserModel(url:String):Person? {
+    suspend fun fetchUserModel(url: String): Person? {
         return try {
             httpClient.get(url).body<Person>()
         } catch (e: ResponseException) {
@@ -55,7 +54,16 @@ class ActivityPubUserService(
         }
     }
 
-    suspend fun receiveFollow(){
+    suspend fun receiveFollow(follow: Follow) {
-
+        val actor = follow.actor ?: throw IllegalArgumentException("actor is null")
+        val person = fetchUserModel(actor) ?: throw IllegalArgumentException("actor is not found")
+        val inboxUrl = person.inbox ?: throw IllegalArgumentException("inbox is not found")
+        httpClient.post(inboxUrl) {
+            setBody(Accept(
+                    name = "Follow",
+                    `object` = follow,
+                    actor = follow.`object`.orEmpty()
+            ))
+        }
     }
 }