feat: PMR 이전 처방 비교 기능

- /pmr/api/patient/<cus_code>/history: 환자 이전 처방 이력 API
- 하단에 이전 처방 영역 + < > 네비게이션
- 현재 처방과 이전 처방 한눈에 비교 가능

backend/pmr_api.py

@@ -518,3 +518,113 @@ def create_label_image(patient_name, med_name, add_info='', dosage=0, frequency=
     draw_centered("청 춘 약 국", pharmacy_y, info_font)
     
     return image
+
+
+# ─────────────────────────────────────────────────────────────
+# API: 환자 이전 처방 이력
+# ─────────────────────────────────────────────────────────────
+@pmr_bp.route('/api/patient/<cus_code>/history', methods=['GET'])
+def get_patient_history(cus_code):
+    """
+    환자 이전 처방 이력 조회
+    
+    Args:
+        cus_code: 환자 고유코드 (CusCode)
+        
+    Query Params:
+        - limit: 최대 조회 건수 (기본 10, 최대 50)
+        - exclude: 제외할 처방번호 (현재 처방)
+    """
+    try:
+        limit = min(int(request.args.get('limit', 10)), 50)
+        exclude_serial = request.args.get('exclude', '')
+        
+        conn = get_mssql_connection('PM_PRES')
+        cursor = conn.cursor()
+        
+        # 이전 처방 목록 조회
+        query = """
+            SELECT TOP (?)
+                m.PreSerial,
+                m.PassDay,
+                m.PresTime,
+                m.Paname,
+                m.InsName,
+                m.Drname,
+                m.PRICE_P,
+                (SELECT COUNT(*) FROM PS_sub_pharm WHERE PreSerial = m.PreSerial) as drug_count
+            FROM PS_MAIN m
+            WHERE m.CusCode = ?
+        """
+        params = [limit, cus_code]
+        
+        if exclude_serial:
+            query += " AND m.PreSerial != ?"
+            params.append(exclude_serial)
+        
+        query += " ORDER BY m.PassDay DESC, m.PresTime DESC"
+        
+        cursor.execute(query, params)
+        
+        history = []
+        for row in cursor.fetchall():
+            pre_serial = row.PreSerial
+            
+            # 해당 처방의 약품 목록 조회
+            cursor.execute("""
+                SELECT 
+                    s.DrugCode,
+                    s.Days,
+                    s.QUAN,
+                    s.QUAN_TIME,
+                    g.GoodsName,
+                    m.PRINT_TYPE
+                FROM PS_sub_pharm s
+                LEFT JOIN PM_DRUG.dbo.CD_GOODS g ON s.DrugCode = g.DrugCode
+                LEFT JOIN PM_DRUG.dbo.CD_MC m ON s.DrugCode = m.DRUGCODE
+                WHERE s.PreSerial = ?
+                ORDER BY s.SUB_SERIAL
+            """, (pre_serial,))
+            
+            medications = []
+            for med_row in cursor.fetchall():
+                medications.append({
+                    'medication_code': med_row.DrugCode or '',
+                    'med_name': med_row.GoodsName or med_row.DrugCode or '',
+                    'add_info': med_row.PRINT_TYPE or '',
+                    'dosage': float(med_row.QUAN) if med_row.QUAN else 0,
+                    'frequency': med_row.QUAN_TIME or 0,
+                    'duration': med_row.Days or 0
+                })
+            
+            # 날짜 포맷
+            pass_day = row.PassDay
+            if pass_day and len(pass_day) == 8:
+                date_formatted = f"{pass_day[:4]}-{pass_day[4:6]}-{pass_day[6:8]}"
+            else:
+                date_formatted = pass_day or ''
+            
+            history.append({
+                'prescription_id': pre_serial,
+                'date': date_formatted,
+                'time': row.PresTime or '',
+                'patient_name': row.Paname or '',
+                'hospital': row.InsName or '',
+                'doctor': row.Drname or '',
+                'copayment': int(row.PRICE_P or 0),
+                'medication_count': row.drug_count or 0,
+                'medications': medications
+            })
+        
+        conn.close()
+        
+        return jsonify({
+            'success': True,
+            'cus_code': cus_code,
+            'count': len(history),
+            'history': history
+        })
+        
+    except Exception as e:
+        logging.error(f"환자 이전 처방 조회 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500