fix(stock-analytics): 동시 요청 시 DB 연결 충돌 해결

- daily-trend, stock-level API에서 각 요청마다 새로운 pyodbc 연결 사용
- SQLAlchemy 세션 공유로 인한 'concurrent operations' 에러 해결
- 연결 종료 처리 추가 (정상/에러 모두)

backend/app.py

@@ -9690,6 +9690,342 @@ def api_drug_usage_prescriptions(drug_code):
         return jsonify({'success': False, 'error': str(e)}), 500
 
 
+# ═══════════════════════════════════════════════════════════════════════════
+# 재고 시계열 분석 API
+# ═══════════════════════════════════════════════════════════════════════════
+
+@app.route('/admin/stock-analytics')
+def admin_stock_analytics():
+    """재고 시계열 분석 페이지"""
+    return render_template('admin_stock_analytics.html')
+
+
+@app.route('/api/stock-analytics/daily-trend')
+def api_stock_daily_trend():
+    """
+    일별 입출고 추이 API
+    GET /api/stock-analytics/daily-trend?start_date=2026-01-01&end_date=2026-03-13&drug_code=A123456789
+    """
+    conn = None
+    try:
+        start_date = request.args.get('start_date', '')
+        end_date = request.args.get('end_date', '')
+        drug_code = request.args.get('drug_code', '').strip()
+        
+        # 날짜 형식 변환 (YYYY-MM-DD -> YYYYMMDD)
+        start_date_fmt = start_date.replace('-', '') if start_date else (datetime.now() - timedelta(days=30)).strftime('%Y%m%d')
+        end_date_fmt = end_date.replace('-', '') if end_date else datetime.now().strftime('%Y%m%d')
+        
+        # 새로운 pyodbc 연결 (동시 요청 충돌 방지)
+        import pyodbc
+        conn_str = (
+            'DRIVER={ODBC Driver 17 for SQL Server};'
+            'SERVER=192.168.0.4\\PM2014;'
+            'DATABASE=PM_DRUG;'
+            'UID=sa;'
+            'PWD=tmddls214!%(;'
+            'TrustServerCertificate=yes'
+        )
+        conn = pyodbc.connect(conn_str, timeout=10)
+        cursor = conn.cursor()
+        
+        # 특정 약품 또는 전체 일별 입출고 집계
+        if drug_code:
+            # 특정 약품
+            cursor.execute("""
+                SELECT 
+                    IM_DT_appl as date,
+                    SUM(ISNULL(IM_QT_sale_credit, 0)) as inbound,
+                    SUM(ISNULL(IM_QT_sale_debit, 0)) as outbound
+                FROM IM_date_total
+                WHERE IM_DT_appl >= ?
+                  AND IM_DT_appl <= ?
+                  AND DrugCode = ?
+                GROUP BY IM_DT_appl
+                ORDER BY IM_DT_appl
+            """, (start_date_fmt, end_date_fmt, drug_code))
+        else:
+            # 전체 합계
+            cursor.execute("""
+                SELECT 
+                    IM_DT_appl as date,
+                    SUM(ISNULL(IM_QT_sale_credit, 0)) as inbound,
+                    SUM(ISNULL(IM_QT_sale_debit, 0)) as outbound
+                FROM IM_date_total
+                WHERE IM_DT_appl >= ?
+                  AND IM_DT_appl <= ?
+                GROUP BY IM_DT_appl
+                ORDER BY IM_DT_appl
+            """, (start_date_fmt, end_date_fmt))
+        
+        rows = cursor.fetchall()
+        
+        items = []
+        total_inbound = 0
+        total_outbound = 0
+        
+        for row in rows:
+            date_str = str(row.date) if row.date else ''
+            # YYYYMMDD -> YYYY-MM-DD
+            formatted_date = f"{date_str[:4]}-{date_str[4:6]}-{date_str[6:8]}" if len(date_str) == 8 else date_str
+            
+            inbound = int(row.inbound or 0)
+            outbound = int(row.outbound or 0)
+            
+            items.append({
+                'date': formatted_date,
+                'inbound': inbound,
+                'outbound': outbound
+            })
+            
+            total_inbound += inbound
+            total_outbound += outbound
+        
+        conn.close()
+        
+        return jsonify({
+            'success': True,
+            'drug_code': drug_code if drug_code else 'ALL',
+            'items': items,
+            'stats': {
+                'total_inbound': total_inbound,
+                'total_outbound': total_outbound,
+                'net_change': total_inbound - total_outbound,
+                'data_count': len(items)
+            }
+        })
+        
+    except Exception as e:
+        if conn:
+            conn.close()
+        logging.error(f"daily-trend API 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+
+@app.route('/api/stock-analytics/top-usage')
+def api_stock_top_usage():
+    """
+    기간별 사용량 TOP N API
+    GET /api/stock-analytics/top-usage?start_date=2026-01-01&end_date=2026-03-13&limit=10
+    """
+    try:
+        start_date = request.args.get('start_date', '')
+        end_date = request.args.get('end_date', '')
+        limit = int(request.args.get('limit', '10'))
+        
+        # 날짜 형식 변환
+        start_date_fmt = start_date.replace('-', '') if start_date else (datetime.now() - timedelta(days=30)).strftime('%Y%m%d')
+        end_date_fmt = end_date.replace('-', '') if end_date else datetime.now().strftime('%Y%m%d')
+        
+        drug_session = db_manager.get_session('PM_DRUG')
+        
+        # 출고량 기준 TOP N
+        query = text("""
+            SELECT TOP(:limit)
+                D.DrugCode as drug_code,
+                G.GoodsName as product_name,
+                G.SplName as supplier,
+                SUM(ISNULL(D.IM_QT_sale_debit, 0)) as total_outbound,
+                SUM(ISNULL(D.IM_QT_sale_credit, 0)) as total_inbound,
+                ISNULL(IT.IM_QT_sale_debit, 0) as current_stock
+            FROM IM_date_total D
+            LEFT JOIN CD_GOODS G ON D.DrugCode = G.DrugCode
+            LEFT JOIN IM_total IT ON D.DrugCode = IT.DrugCode
+            WHERE D.IM_DT_appl >= :start_date
+              AND D.IM_DT_appl <= :end_date
+            GROUP BY D.DrugCode, G.GoodsName, G.SplName, IT.IM_QT_sale_debit
+            ORDER BY SUM(ISNULL(D.IM_QT_sale_debit, 0)) DESC
+        """)
+        
+        rows = drug_session.execute(query, {
+            'start_date': start_date_fmt,
+            'end_date': end_date_fmt,
+            'limit': limit
+        }).fetchall()
+        
+        items = []
+        for row in rows:
+            items.append({
+                'drug_code': row.drug_code or '',
+                'product_name': row.product_name or '알 수 없음',
+                'supplier': row.supplier or '',
+                'total_outbound': int(row.total_outbound or 0),
+                'total_inbound': int(row.total_inbound or 0),
+                'current_stock': int(row.current_stock or 0)
+            })
+        
+        return jsonify({
+            'success': True,
+            'items': items,
+            'limit': limit
+        })
+        
+    except Exception as e:
+        logging.error(f"top-usage API 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+
+@app.route('/api/stock-analytics/stock-level')
+def api_stock_level():
+    """
+    특정 약품 재고 변화 (누적) API
+    GET /api/stock-analytics/stock-level?drug_code=A123456789&start_date=2026-01-01&end_date=2026-03-13
+    """
+    conn = None
+    try:
+        drug_code = request.args.get('drug_code', '').strip()
+        start_date = request.args.get('start_date', '')
+        end_date = request.args.get('end_date', '')
+        
+        if not drug_code:
+            return jsonify({'success': False, 'error': 'drug_code 파라미터 필요'}), 400
+        
+        # 날짜 형식 변환
+        start_date_fmt = start_date.replace('-', '') if start_date else (datetime.now() - timedelta(days=30)).strftime('%Y%m%d')
+        end_date_fmt = end_date.replace('-', '') if end_date else datetime.now().strftime('%Y%m%d')
+        
+        # 새로운 pyodbc 연결 (동시 요청 충돌 방지)
+        import pyodbc
+        conn_str = (
+            'DRIVER={ODBC Driver 17 for SQL Server};'
+            'SERVER=192.168.0.4\\PM2014;'
+            'DATABASE=PM_DRUG;'
+            'UID=sa;'
+            'PWD=tmddls214!%(;'
+            'TrustServerCertificate=yes'
+        )
+        conn = pyodbc.connect(conn_str, timeout=10)
+        cursor = conn.cursor()
+        
+        # 현재 재고
+        cursor.execute("""
+            SELECT 
+                IT.IM_QT_sale_debit as current_stock,
+                G.GoodsName as product_name,
+                G.SplName as supplier
+            FROM IM_total IT
+            LEFT JOIN CD_GOODS G ON IT.DrugCode = G.DrugCode
+            WHERE IT.DrugCode = ?
+        """, (drug_code,))
+        
+        stock_row = cursor.fetchone()
+        current_stock = int(stock_row.current_stock or 0) if stock_row else 0
+        product_name = stock_row.product_name if stock_row else drug_code
+        supplier = stock_row.supplier if stock_row else ''
+        
+        # 일별 입출고 데이터 (역순으로 누적 계산)
+        cursor.execute("""
+            SELECT 
+                IM_DT_appl as date,
+                SUM(ISNULL(IM_QT_sale_credit, 0)) as inbound,
+                SUM(ISNULL(IM_QT_sale_debit, 0)) as outbound
+            FROM IM_date_total
+            WHERE DrugCode = ?
+              AND IM_DT_appl >= ?
+              AND IM_DT_appl <= ?
+            GROUP BY IM_DT_appl
+            ORDER BY IM_DT_appl DESC
+        """, (drug_code, start_date_fmt, end_date_fmt))
+        
+        rows = cursor.fetchall()
+        
+        # 역순으로 누적 재고 계산 (현재 → 과거)
+        items = []
+        running_stock = current_stock
+        
+        for row in rows:
+            date_str = str(row.date) if row.date else ''
+            formatted_date = f"{date_str[:4]}-{date_str[4:6]}-{date_str[6:8]}" if len(date_str) == 8 else date_str
+            
+            inbound = int(row.inbound or 0)
+            outbound = int(row.outbound or 0)
+            
+            items.append({
+                'date': formatted_date,
+                'stock': running_stock,
+                'inbound': inbound,
+                'outbound': outbound
+            })
+            
+            # 과거로 갈수록: 재고 = 재고 - 입고 + 출고
+            running_stock = running_stock - inbound + outbound
+        
+        # 시간순 정렬 (과거 → 현재)
+        items.reverse()
+        
+        conn.close()
+        
+        return jsonify({
+            'success': True,
+            'drug_code': drug_code,
+            'product_name': product_name,
+            'supplier': supplier,
+            'current_stock': current_stock,
+            'items': items
+        })
+        
+    except Exception as e:
+        if conn:
+            conn.close()
+        logging.error(f"stock-level API 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+
+@app.route('/api/stock-analytics/search-drugs')
+def api_search_drugs():
+    """
+    약품 검색 API (재고 분석용)
+    GET /api/stock-analytics/search-drugs?q=타이레놀&limit=20
+    """
+    try:
+        query = request.args.get('q', '').strip()
+        limit = int(request.args.get('limit', '20'))
+        
+        if not query or len(query) < 2:
+            return jsonify({'success': True, 'items': []})
+        
+        drug_session = db_manager.get_session('PM_DRUG')
+        
+        search_query = text("""
+            SELECT TOP(:limit)
+                G.DrugCode as drug_code,
+                G.GoodsName as product_name,
+                G.SplName as supplier,
+                ISNULL(IT.IM_QT_sale_debit, 0) as current_stock
+            FROM CD_GOODS G
+            LEFT JOIN IM_total IT ON G.DrugCode = IT.DrugCode
+            WHERE G.GoodsName LIKE :keyword
+               OR G.DrugCode LIKE :keyword
+            ORDER BY 
+                CASE WHEN G.GoodsName LIKE :exact_keyword THEN 0 ELSE 1 END,
+                IT.IM_QT_sale_debit DESC
+        """)
+        
+        rows = drug_session.execute(search_query, {
+            'keyword': f'%{query}%',
+            'exact_keyword': f'{query}%',
+            'limit': limit
+        }).fetchall()
+        
+        items = []
+        for row in rows:
+            items.append({
+                'drug_code': row.drug_code or '',
+                'product_name': row.product_name or '',
+                'supplier': row.supplier or '',
+                'current_stock': int(row.current_stock or 0)
+            })
+        
+        return jsonify({
+            'success': True,
+            'items': items
+        })
+        
+    except Exception as e:
+        logging.error(f"search-drugs API 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+
 if __name__ == '__main__':
     import os