From 867a51a1cd65fb38ae47f7b4190c867201a65a60 Mon Sep 17 00:00:00 2001
From: forge-bot <bot@forge.local>
Date: Sat, 18 Jul 2026 11:05:31 +0000
Subject: [PATCH] =?UTF-8?q?[=EB=A7=A4=EC=9E=85]=20mg=5Frecv=5Fsvc=20?=
 =?UTF-8?q?=E2=86=92=20=EC=A0=84=EB=AC=B8=EC=88=98=EC=8B=A0=20@Service=20(?=
 =?UTF-8?q?ACM-MG-004)?=
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---
 .../acquiring/codec/MessageCodec.java         | 105 ++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 boot/modules/acquiring/src/main/java/com/klaro/acquirecore/acquiring/codec/MessageCodec.java

diff --git a/boot/modules/acquiring/src/main/java/com/klaro/acquirecore/acquiring/codec/MessageCodec.java b/boot/modules/acquiring/src/main/java/com/klaro/acquirecore/acquiring/codec/MessageCodec.java
new file mode 100644
index 0000000..1b9f1f4
--- /dev/null
+++ b/boot/modules/acquiring/src/main/java/com/klaro/acquirecore/acquiring/codec/MessageCodec.java
@@ -0,0 +1,105 @@
+package com.klaro.acquirecore.acquiring.codec;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+/**
+ * 전문 언팩/팩 커덱 (codec)
+ * 바이너리 전문 파싱 및 조립 담당
+ */
+@Component
+public class MessageCodec {
+
+    private static final Logger log = LoggerFactory.getLogger(MessageCodec.class);
+
+    // 전문 헤더 길이
+    private static final int HEADER_LENGTH = 20;
+    // 전문 트레일러 길이
+    private static final int TRAILER_LENGTH = 4;
+
+    /**
+     * 원시 전문 언팩
+     * @param rawMessage 원시 바이트 배열
+     * @return 파싱된 전문 객체
+     */
+    public ParsedMessage unpack(byte[] rawMessage) {
+        log.debug("전문 언팩 시작 - 길이: {}", rawMessage.length);
+
+        if (rawMessage == null || rawMessage.length < HEADER_LENGTH + TRAILER_LENGTH) {
+            throw new IllegalArgumentException("전문 길이 오류");
+        }
+
+        ParsedMessage parsed = new ParsedMessage();
+
+        // 헤더 파싱
+        parsed.setMessageType(decodeString(rawMessage, 0, 4));
+        parsed.setTxId(decodeString(rawMessage, 4, 12));
+        parsed.setTxCode(decodeString(rawMessage, 16, 4));
+
+        // 바디 파싱 (가변 길이)
+        int bodyLength = rawMessage.length - HEADER_LENGTH - TRAILER_LENGTH;
+        if (bodyLength > 0) {
+            parsed.setMerchantId(decodeString(rawMessage, HEADER_LENGTH, 15));
+            parsed.setCardNumber(decodeString(rawMessage, HEADER_LENGTH + 15, 20));
+            parsed.setAmount(decodeString(rawMessage, HEADER_LENGTH + 35, 12));
+            parsed.setApprovalCode(decodeString(rawMessage, HEADER_LENGTH + 47, 10));
+        }
+
+        // 트레일러 검증
+        byte[] trailer = new byte[TRAILER_LENGTH];
+        System.arraycopy(rawMessage, rawMessage.length - TRAILER_LENGTH, trailer, 0, TRAILER_LENGTH);
+        parsed.setTrailer(new String(trailer));
+
+        log.debug("전문 언팩 완료 - TX_ID: {}, TX_CODE: {}", parsed.getTxId(), parsed.getTxCode());
+        return parsed;
+    }
+
+    /**
+     * 전문 팩 (응답 전문 생성)
+     * @param parsed 파싱된 전문
+     * @return 원시 바이트 배열
+     */
+    public byte[] pack(ParsedMessage parsed) {
+        log.debug("전문 팩 시작 - TX_ID: {}", parsed.getTxId());
+
+        StringBuilder sb = new StringBuilder();
+        sb.append(padRight(parsed.getMessageType(), 4));
+        sb.append(padRight(parsed.getTxId(), 12));
+        sb.append(padRight(parsed.getTxCode(), 4));
+        sb.append(padRight(parsed.getMerchantId(), 15));
+        sb.append(padRight(parsed.getCardNumber(), 20));
+        sb.append(padRight(parsed.getAmount(), 12));
+        sb.append(padRight(parsed.getApprovalCode(), 10));
+        sb.append("ETX");
+
+        return sb.toString().getBytes();
+    }
+
+    /**
+     * 바이트 배열에서 문자열 추출
+     */
+    private String decodeString(byte[] data, int offset, int length) {
+        if (offset + length > data.length) {
+            return "";
+        }
+        byte[] sub = new byte[length];
+        System.arraycopy(data, offset, sub, 0, length);
+        return new String(sub).trim();
+    }
+
+    /**
+     * 문자열을 지정 길이만큼 패딩
+     */
+    private String padRight(String value, int length) {
+        if (value == null) value = "";
+        if (value.length() >= length) {
+            return value.substring(0, length);
+        }
+        StringBuilder sb = new StringBuilder(value);
+        while (sb.length() < length) {
+            sb.append(' ');
+        }
+        return sb.toString();
+    }
+}