src/main/kotlin/roomescape/common/log/ApiLogMessageConverter.kt

@@ -0,0 +1,81 @@
+package roomescape.common.log
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import jakarta.servlet.http.HttpServletRequest
+import org.slf4j.MDC
+
+enum class LogType {
+    INCOMING_HTTP_REQUEST,
+    CONTROLLER_INVOKED,
+    CONTROLLER_SUCCESS,
+    AUTHENTICATION_FAILURE,
+    APPLICATION_FAILURE,
+    UNHANDLED_EXCEPTION
+}
+
+class ApiLogMessageConverter(
+    private val objectMapper: ObjectMapper
+) {
+    fun convertToHttpRequestMessage(
+        request: HttpServletRequest
+    ): String {
+        val payload: MutableMap<String, Any> = commonRequestPayload(LogType.INCOMING_HTTP_REQUEST, request)
+
+        request.queryString?.let { payload["query_params"] = it }
+        payload["client_ip"] = request.remoteAddr
+        payload["user_agent"] = request.getHeader("User-Agent")
+
+        return objectMapper.writeValueAsString(payload)
+    }
+
+    fun convertToControllerInvokedMessage(
+        request: HttpServletRequest,
+        controllerPayload: Map<String, Any>,
+    ): String {
+        val payload: MutableMap<String, Any> = commonRequestPayload(LogType.CONTROLLER_INVOKED, request)
+        val memberId: Long? = MDC.get("member_id")?.toLong()
+        if (memberId != null) payload["member_id"] = memberId else payload["member_id"] = "NONE"
+
+        payload.putAll(controllerPayload)
+
+        return objectMapper.writeValueAsString(payload)
+    }
+
+    fun convertToResponseMessage(request: ConvertResponseMessageRequest): String {
+        val payload: MutableMap<String, Any> = mutableMapOf()
+        payload["type"] = request.type
+        payload["status_code"] = request.httpStatus
+
+        MDC.get("member_id")?.toLongOrNull()
+            ?.let { payload["member_id"] = it }
+            ?: run { payload["member_id"] = "NONE" }
+
+        request.startTime?.let { payload["start_time"] = it }
+        request.body?.let { payload["response_body"] = it }
+        request.exception?.let {
+            payload["exception"] = mapOf(
+                "class" to it.javaClass.simpleName,
+                "message" to it.message
+            )
+        }
+
+        return objectMapper.writeValueAsString(payload)
+    }
+
+    private fun commonRequestPayload(
+        logType: LogType,
+        request: HttpServletRequest
+    ): MutableMap<String, Any> = mutableMapOf(
+        "type" to logType,
+        "method" to request.method,
+        "uri" to request.requestURI
+    )
+}
+
+data class ConvertResponseMessageRequest(
+    val type: LogType,
+    val httpStatus: Int = 200,
+    val startTime: Long? = null,
+    val body: Any? = null,
+    val exception: Exception? = null
+)