add default error

- add error setting in application.yml
- update tailwind.css
- add error.html
- add information.html
- update UserAttribute with GuestUser
- add ErrorAttributes
- add GuestUser

src/main/kotlin/ltd/hlaeja/controller/advice/ErrorAttributes.kt

@@ -0,0 +1,29 @@
+package ltd.hlaeja.controller.advice
+
+import kotlinx.coroutines.runBlocking
+import ltd.hlaeja.security.RemoteAuthentication
+import ltd.hlaeja.security.user.GuestUser
+import org.springframework.boot.web.error.ErrorAttributeOptions
+import org.springframework.boot.web.reactive.error.DefaultErrorAttributes
+import org.springframework.security.core.context.SecurityContextImpl
+import org.springframework.stereotype.Component
+import org.springframework.web.reactive.function.server.ServerRequest
+import org.springframework.web.reactive.function.server.awaitSession
+
+@Component
+class ErrorAttributes : DefaultErrorAttributes(), GuestUser {
+
+    override fun getErrorAttributes(
+        serverRequest: ServerRequest,
+        errorAttributeOptions: ErrorAttributeOptions,
+    ): MutableMap<String, Any> =
+        super.getErrorAttributes(serverRequest, errorAttributeOptions)
+            .also { attribute ->
+                attribute["remoteUser"] = runBlocking {
+                    serverRequest.awaitSession()
+                        .attributes["SPRING_SECURITY_CONTEXT"]
+                        ?.let { context -> (context as SecurityContextImpl).authentication }
+                        ?: guestUser()
+                } as RemoteAuthentication
+            }
+}

src/main/kotlin/ltd/hlaeja/controller/advice/UserAttribute.kt

@@ -1,29 +1,24 @@
 package ltd.hlaeja.controller.advice
 
-import java.util.UUID
 import kotlinx.coroutines.reactive.awaitFirstOrNull
 import ltd.hlaeja.security.RemoteAuthentication
-import ltd.hlaeja.security.RemoteUserDetail
+import ltd.hlaeja.security.user.GuestUser
 import org.springframework.security.core.context.ReactiveSecurityContextHolder
 import org.springframework.ui.Model
 import org.springframework.web.bind.annotation.ControllerAdvice
 import org.springframework.web.bind.annotation.ModelAttribute
 
 @ControllerAdvice
-class UserAttribute {
+class UserAttribute : GuestUser {
 
     @ModelAttribute
     suspend fun remoteUser(model: Model) {
-        val remoteAuthentication: RemoteAuthentication = ReactiveSecurityContextHolder.getContext()
-            .awaitFirstOrNull()
-            ?.let { it.authentication as RemoteAuthentication }
-            ?: RemoteAuthentication(
-                RemoteUserDetail(
-                    UUID.fromString("00000000-0000-0000-0000-000000000000"),
-                    "n/a",
-                ),
-                mutableListOf(),
-            )
-        model.addAttribute("remoteUser", remoteAuthentication)
+        model.addAttribute(
+            "remoteUser",
+            ReactiveSecurityContextHolder.getContext()
+                .awaitFirstOrNull()
+                ?.let { it.authentication as RemoteAuthentication }
+                ?: guestUser(),
+        )
     }
 }

src/main/kotlin/ltd/hlaeja/security/user/GuestUser.kt

@@ -0,0 +1,16 @@
+package ltd.hlaeja.security.user
+
+import java.util.UUID
+import ltd.hlaeja.security.RemoteAuthentication
+import ltd.hlaeja.security.RemoteUserDetail
+
+interface GuestUser {
+
+    fun guestUser(): RemoteAuthentication = RemoteAuthentication(
+        RemoteUserDetail(
+            UUID.fromString("00000000-0000-0000-0000-000000000000"),
+            "n/a",
+        ),
+        mutableListOf(),
+    )
+}