From c37e442dd7c9681816fd44fc5ffbb12e7ad9cd0d Mon Sep 17 00:00:00 2001
From: usbharu <i@usbharu.dev>
Date: Wed, 19 Feb 2025 12:33:52 +0900
Subject: [PATCH] =?UTF-8?q?feat:=20WebFinger=E3=82=92=E5=AE=9F=E8=A3=85?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../webfinger/WebFingerApplicationService.kt  | 51 +++++++++++++++++++
 .../wellknown/WebFingerController.kt          | 18 +++++++
 2 files changed, 69 insertions(+)
 create mode 100644 hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/application/webfinger/WebFingerApplicationService.kt
 create mode 100644 hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/interfaces/wellknown/WebFingerController.kt

diff --git a/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/application/webfinger/WebFingerApplicationService.kt b/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/application/webfinger/WebFingerApplicationService.kt
new file mode 100644
index 00000000..3d10f4a1
--- /dev/null
+++ b/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/application/webfinger/WebFingerApplicationService.kt
@@ -0,0 +1,51 @@
+package dev.usbharu.hideout.activitypub.application.webfinger
+
+import dev.usbharu.hideout.activitypub.interfaces.wellknown.Link
+import dev.usbharu.hideout.activitypub.interfaces.wellknown.XRD
+import dev.usbharu.hideout.core.application.shared.AbstractApplicationService
+import dev.usbharu.hideout.core.application.shared.Transaction
+import dev.usbharu.hideout.core.config.ApplicationConfig
+import dev.usbharu.hideout.core.domain.model.actor.ActorRepository
+import dev.usbharu.hideout.core.domain.model.support.domain.apHost
+import dev.usbharu.hideout.core.domain.model.support.principal.Principal
+import org.slf4j.LoggerFactory
+import org.springframework.stereotype.Service
+import java.net.URI
+
+@Service
+class WebFingerApplicationService(
+    transaction: Transaction,
+    private val applicationConfig: ApplicationConfig,
+    private val actorRepository: ActorRepository,
+) : AbstractApplicationService<String, XRD>(transaction, logger) {
+
+
+    override suspend fun internalExecute(resource: String, principal: Principal): XRD {
+        if (resource.startsWith("acct:").not()) {
+            throw IllegalArgumentException("Parameter (resource) is invalid.")
+        }
+        val acct = resource.substringAfter("acct:")
+
+        val host = acct.substringAfter('@', "")
+        if (applicationConfig.url.apHost != host) {
+            throw IllegalArgumentException("Parameter (resource) is invalid.")
+        }
+        val username = acct.substringBefore('@', "")
+        if (username.isEmpty()) {
+            throw IllegalArgumentException("Actor is not found.")
+        }
+
+        val actor = actorRepository.findByNameAndDomain(username, applicationConfig.url.apHost)
+            ?: throw IllegalArgumentException("Actor $username not found.")
+
+        return XRD(
+            listOf(Link("self", null, "application/activity+json", actor.url.toString())),
+            URI.create("acct:${actor.name.name}@${actor.domain.domain}")
+        )
+
+    }
+
+    companion object {
+        private val logger = LoggerFactory.getLogger(WebFingerApplicationService::class.java)
+    }
+}
\ No newline at end of file
diff --git a/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/interfaces/wellknown/WebFingerController.kt b/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/interfaces/wellknown/WebFingerController.kt
new file mode 100644
index 00000000..2af12b52
--- /dev/null
+++ b/hideout/hideout-activitypub/src/main/kotlin/dev/usbharu/hideout/activitypub/interfaces/wellknown/WebFingerController.kt
@@ -0,0 +1,18 @@
+package dev.usbharu.hideout.activitypub.interfaces.wellknown
+
+import dev.usbharu.hideout.activitypub.application.webfinger.WebFingerApplicationService
+import dev.usbharu.hideout.core.domain.model.support.principal.Anonymous
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RequestParam
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@RequestMapping("/.well-known")
+class WebFingerController(
+    private val webFingerApplicationService: WebFingerApplicationService,
+) {
+    @GetMapping("/webfinger", produces = ["application/json"])
+    suspend fun webfinger(@RequestParam(name = "resource", required = true) resource: String): XRD =
+        webFingerApplicationService.execute(resource, Anonymous)
+}
\ No newline at end of file