# -*- coding: utf-8 -*-
"""
주문 관리 DB (SQLite)
- 다중 도매상 지원 (지오영, 수인, 백제 등)
- 주문 상태 추적
- 품목별 결과 관리
- 자동화 ERP 확장 대비
"""

import sqlite3
import os
from datetime import datetime
from typing import Optional, List, Dict
import json

# DB 경로
DB_PATH = os.path.join(os.path.dirname(__file__), 'db', 'orders.db')


def get_connection():
    """DB 연결"""
    os.makedirs(os.path.dirname(DB_PATH), exist_ok=True)
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    return conn


def init_db():
    """DB 초기화 - 테이블 생성"""
    conn = get_connection()
    cursor = conn.cursor()
    
    # ─────────────────────────────────────────────
    # 도매상 마스터
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS wholesalers (
            id TEXT PRIMARY KEY,              -- 'geoyoung', 'sooin', 'baekje'
            name TEXT NOT NULL,               -- '지오영', '수인', '백제'
            api_type TEXT,                    -- 'playwright', 'api', 'manual'
            base_url TEXT,
            is_active INTEGER DEFAULT 1,
            config_json TEXT,                 -- 로그인 정보 등 (암호화 권장)
            created_at TEXT DEFAULT CURRENT_TIMESTAMP
        )
    ''')
    
    # 기본 도매상 등록
    cursor.execute('''
        INSERT OR IGNORE INTO wholesalers (id, name, api_type, base_url)
        VALUES 
            ('geoyoung', '지오영', 'playwright', 'https://gwn.geoweb.kr'),
            ('sooin', '수인', 'manual', NULL),
            ('baekje', '백제', 'manual', NULL)
    ''')
    
    # ─────────────────────────────────────────────
    # 주문 헤더
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS orders (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            order_no TEXT UNIQUE,             -- 주문번호 (ORD-20260306-001)
            wholesaler_id TEXT NOT NULL,      -- 도매상 ID
            
            -- 주문 정보
            order_date TEXT NOT NULL,         -- 주문일 (YYYY-MM-DD)
            order_time TEXT,                  -- 주문시간 (HH:MM:SS)
            order_type TEXT DEFAULT 'manual', -- 'manual', 'auto', 'scheduled'
            order_session TEXT,               -- 'morning', 'afternoon', 'evening'
            
            -- 상태
            status TEXT DEFAULT 'draft',      -- draft, pending, submitted, partial, completed, failed, cancelled
            
            -- 집계
            total_items INTEGER DEFAULT 0,
            total_qty INTEGER DEFAULT 0,
            success_items INTEGER DEFAULT 0,
            failed_items INTEGER DEFAULT 0,
            
            -- 참조
            parent_order_id INTEGER,          -- 재주문 시 원주문 참조
            reference_period TEXT,            -- 사용량 조회 기간 (2026-03-01~2026-03-06)
            
            -- 메타
            note TEXT,
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
            submitted_at TEXT,                -- 실제 제출 시간
            completed_at TEXT,
            
            FOREIGN KEY (wholesaler_id) REFERENCES wholesalers(id),
            FOREIGN KEY (parent_order_id) REFERENCES orders(id)
        )
    ''')
    
    # ─────────────────────────────────────────────
    # 주문 품목 상세
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS order_items (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            order_id INTEGER NOT NULL,
            
            -- 약품 정보
            drug_code TEXT NOT NULL,          -- PIT3000 약품코드
            kd_code TEXT,                     -- 보험코드 (지오영 검색용)
            internal_code TEXT,               -- 🔧 도매상 내부 코드 (장바구니 직접 추가용!)
            product_name TEXT NOT NULL,
            manufacturer TEXT,
            
            -- 규격/수량
            specification TEXT,               -- '30T', '300T', '500T'
            unit_qty INTEGER,                 -- 규격당 수량 (30, 300, 500)
            order_qty INTEGER NOT NULL,       -- 주문 수량 (단위 개수)
            total_dose INTEGER,               -- 총 정제수 (order_qty * unit_qty)
            
            -- 주문 근거
            usage_qty INTEGER,                -- 사용량 (조회 기간)
            current_stock INTEGER,            -- 주문 시점 재고
            
            -- 가격 (선택)
            unit_price INTEGER,
            total_price INTEGER,
            
            -- 상태
            status TEXT DEFAULT 'pending',    -- pending, submitted, success, failed, cancelled
            
            -- 결과
            result_code TEXT,                 -- 'OK', 'OUT_OF_STOCK', 'NOT_FOUND', 'ERROR'
            result_message TEXT,
            wholesaler_order_no TEXT,         -- 도매상 측 주문번호
            
            -- 메타
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
            
            FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE
        )
    ''')
    
    # ─────────────────────────────────────────────
    # 주문 로그 (상태 변경 이력)
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS order_logs (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            order_id INTEGER NOT NULL,
            order_item_id INTEGER,            -- NULL이면 주문 전체 로그
            
            action TEXT NOT NULL,             -- 'created', 'submitted', 'success', 'failed', 'cancelled'
            old_status TEXT,
            new_status TEXT,
            
            message TEXT,
            detail_json TEXT,                 -- API 응답 등 상세 정보
            
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            
            FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE,
            FOREIGN KEY (order_item_id) REFERENCES order_items(id) ON DELETE CASCADE
        )
    ''')
    
    # ─────────────────────────────────────────────
    # 주문 컨텍스트 (AI 학습용 스냅샷)
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS order_context (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            order_item_id INTEGER NOT NULL,
            
            -- 약품 정보
            drug_code TEXT NOT NULL,
            product_name TEXT,
            
            -- 주문 시점 재고
            stock_at_order INTEGER,           -- 주문 시점 현재고
            
            -- 사용량 분석
            usage_1d INTEGER,                 -- 최근 1일 사용량
            usage_7d INTEGER,                 -- 최근 7일 사용량
            usage_30d INTEGER,                -- 최근 30일 사용량
            avg_daily_usage REAL,             -- 일평균 사용량 (30일 기준)
            
            -- 주문 패턴
            ordered_spec TEXT,                -- 주문한 규격 (30T, 300T)
            ordered_qty INTEGER,              -- 주문 수량 (단위 개수)
            ordered_dose INTEGER,             -- 주문 총 정제수
            
            -- 규격 선택 이유 (AI 분석용)
            available_specs TEXT,             -- 가능한 규격들 JSON ["30T", "300T"]
            spec_stocks TEXT,                 -- 규격별 도매상 재고 JSON {"30T": 50, "300T": 0}
            selection_reason TEXT,            -- 'stock_available', 'best_fit', 'only_option', 'user_choice'
            
            -- 예측 vs 실제 (나중에 업데이트)
            days_until_stockout REAL,         -- 주문 시점 예상 재고 소진일
            actual_reorder_days INTEGER,      -- 실제 재주문까지 일수 (나중에 업데이트)
            
            -- 메타
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            
            FOREIGN KEY (order_item_id) REFERENCES order_items(id) ON DELETE CASCADE
        )
    ''')
    
    # ─────────────────────────────────────────────
    # 일별 사용량 추적 (시계열 데이터)
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS daily_usage (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            drug_code TEXT NOT NULL,
            usage_date TEXT NOT NULL,         -- YYYY-MM-DD
            
            -- 처방 데이터
            rx_count INTEGER DEFAULT 0,       -- 처방 건수
            rx_qty INTEGER DEFAULT 0,         -- 처방 수량 (정제수)
            
            -- POS 데이터 (일반약)
            pos_count INTEGER DEFAULT 0,
            pos_qty INTEGER DEFAULT 0,
            
            -- 집계
            total_qty INTEGER DEFAULT 0,
            
            -- 재고 스냅샷
            stock_start INTEGER,              -- 시작 재고
            stock_end INTEGER,                -- 종료 재고
            
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            
            UNIQUE(drug_code, usage_date)
        )
    ''')
    
    # ─────────────────────────────────────────────
    # AI 분석 결과/패턴
    # ─────────────────────────────────────────────
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS order_patterns (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            drug_code TEXT NOT NULL,
            
            -- 분석 기간
            analysis_date TEXT NOT NULL,
            analysis_period_days INTEGER,
            
            -- 사용 패턴
            avg_daily_usage REAL,
            usage_stddev REAL,                -- 사용량 표준편차 (변동성)
            peak_usage INTEGER,               -- 최대 사용량
            
            -- 주문 패턴
            typical_order_spec TEXT,          -- 주로 주문하는 규격
            typical_order_qty INTEGER,        -- 주로 주문하는 수량
            order_frequency_days REAL,        -- 평균 주문 주기 (일)
            
            -- AI 추천
            recommended_spec TEXT,            -- 추천 규격
            recommended_qty INTEGER,          -- 추천 수량
            recommended_reorder_point INTEGER,-- 추천 재주문점 (재고가 이 이하면 주문)
            confidence_score REAL,            -- 추천 신뢰도 (0-1)
            
            -- 모델 정보
            model_version TEXT,
            
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            
            UNIQUE(drug_code, analysis_date)
        )
    ''')
    
    # ─────────────────────────────────────────────
    # 인덱스
    # ─────────────────────────────────────────────
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_orders_date ON orders(order_date)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_orders_status ON orders(status)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_orders_wholesaler ON orders(wholesaler_id)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_order_items_drug ON order_items(drug_code)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_order_items_status ON order_items(status)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_order_context_drug ON order_context(drug_code)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_daily_usage_drug ON daily_usage(drug_code)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_daily_usage_date ON daily_usage(usage_date)')
    cursor.execute('CREATE INDEX IF NOT EXISTS idx_order_patterns_drug ON order_patterns(drug_code)')
    
    conn.commit()
    conn.close()
    
    return True


def generate_order_no(wholesaler_id: str) -> str:
    """주문번호 생성 (ORD-GEO-20260306-001)"""
    prefix_map = {
        'geoyoung': 'GEO',
        'sooin': 'SOO',
        'baekje': 'BAK'
    }
    prefix = prefix_map.get(wholesaler_id, 'ORD')
    date_str = datetime.now().strftime('%Y%m%d')
    
    conn = get_connection()
    cursor = conn.cursor()
    
    # 오늘 해당 도매상 주문 수 카운트
    cursor.execute('''
        SELECT COUNT(*) FROM orders 
        WHERE wholesaler_id = ? AND order_date = ?
    ''', (wholesaler_id, datetime.now().strftime('%Y-%m-%d')))
    
    count = cursor.fetchone()[0] + 1
    conn.close()
    
    return f"ORD-{prefix}-{date_str}-{count:03d}"


def create_order(wholesaler_id: str, items: List[Dict], 
                 order_type: str = 'manual', 
                 order_session: str = None,
                 reference_period: str = None,
                 note: str = None) -> Dict:
    """
    주문 생성 (draft 상태)
    
    items: [
        {
            'drug_code': '670400830',
            'kd_code': '670400830',
            'product_name': '레바미피드정 30T',
            'manufacturer': '휴온스',
            'specification': '30T',
            'unit_qty': 30,
            'order_qty': 10,
            'usage_qty': 280,
            'current_stock': 50
        }
    ]
    """
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        order_no = generate_order_no(wholesaler_id)
        now = datetime.now()
        
        # 주문 헤더 생성
        cursor.execute('''
            INSERT INTO orders (
                order_no, wholesaler_id, order_date, order_time,
                order_type, order_session, reference_period, note,
                total_items, total_qty, status
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'draft')
        ''', (
            order_no,
            wholesaler_id,
            now.strftime('%Y-%m-%d'),
            now.strftime('%H:%M:%S'),
            order_type,
            order_session,
            reference_period,
            note,
            len(items),
            sum(item.get('order_qty', 0) for item in items)
        ))
        
        order_id = cursor.lastrowid
        
        # 주문 품목 생성
        for item in items:
            unit_qty = item.get('unit_qty', 1)
            order_qty = item.get('order_qty', 0)
            
            cursor.execute('''
                INSERT INTO order_items (
                    order_id, drug_code, kd_code, internal_code, product_name, manufacturer,
                    specification, unit_qty, order_qty, total_dose,
                    usage_qty, current_stock, status
                ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'pending')
            ''', (
                order_id,
                item.get('drug_code'),
                item.get('kd_code'),
                item.get('internal_code'),  # 🔧 도매상 내부 코드 저장!
                item.get('product_name'),
                item.get('manufacturer'),
                item.get('specification'),
                unit_qty,
                order_qty,
                order_qty * unit_qty,
                item.get('usage_qty'),
                item.get('current_stock')
            ))
        
        # 로그
        cursor.execute('''
            INSERT INTO order_logs (order_id, action, new_status, message)
            VALUES (?, 'created', 'draft', ?)
        ''', (order_id, f'{len(items)}개 품목 주문 생성'))
        
        conn.commit()
        
        return {
            'success': True,
            'order_id': order_id,
            'order_no': order_no,
            'total_items': len(items)
        }
        
    except Exception as e:
        conn.rollback()
        return {'success': False, 'error': str(e)}
    finally:
        conn.close()


def get_order(order_id: int) -> Optional[Dict]:
    """주문 조회 (품목 포함)"""
    conn = get_connection()
    cursor = conn.cursor()
    
    cursor.execute('SELECT * FROM orders WHERE id = ?', (order_id,))
    order = cursor.fetchone()
    
    if not order:
        conn.close()
        return None
    
    cursor.execute('SELECT * FROM order_items WHERE order_id = ?', (order_id,))
    items = cursor.fetchall()
    
    conn.close()
    
    return {
        **dict(order),
        'items': [dict(item) for item in items]
    }


def update_order_status(order_id: int, status: str, message: str = None) -> bool:
    """주문 상태 업데이트"""
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        # 현재 상태 조회
        cursor.execute('SELECT status FROM orders WHERE id = ?', (order_id,))
        row = cursor.fetchone()
        if not row:
            return False
        
        old_status = row['status']
        
        # 상태 업데이트
        now = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        
        update_fields = ['status = ?', 'updated_at = ?']
        params = [status, now]
        
        if status == 'submitted':
            update_fields.append('submitted_at = ?')
            params.append(now)
        elif status in ('completed', 'failed'):
            update_fields.append('completed_at = ?')
            params.append(now)
        
        params.append(order_id)
        
        cursor.execute(f'''
            UPDATE orders SET {', '.join(update_fields)} WHERE id = ?
        ''', params)
        
        # 로그
        cursor.execute('''
            INSERT INTO order_logs (order_id, action, old_status, new_status, message)
            VALUES (?, ?, ?, ?, ?)
        ''', (order_id, status, old_status, status, message))
        
        conn.commit()
        return True
        
    except Exception as e:
        conn.rollback()
        return False
    finally:
        conn.close()


def update_item_result(item_id: int, status: str, result_code: str = None, 
                       result_message: str = None, wholesaler_order_no: str = None) -> bool:
    """품목 결과 업데이트"""
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        cursor.execute('''
            UPDATE order_items SET
                status = ?,
                result_code = ?,
                result_message = ?,
                wholesaler_order_no = ?,
                updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
        ''', (status, result_code, result_message, wholesaler_order_no, item_id))
        
        # 주문 집계 업데이트
        cursor.execute('SELECT order_id FROM order_items WHERE id = ?', (item_id,))
        order_id = cursor.fetchone()['order_id']
        
        cursor.execute('''
            UPDATE orders SET
                success_items = (SELECT COUNT(*) FROM order_items WHERE order_id = ? AND status = 'success'),
                failed_items = (SELECT COUNT(*) FROM order_items WHERE order_id = ? AND status = 'failed'),
                updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
        ''', (order_id, order_id, order_id))
        
        conn.commit()
        return True
        
    except Exception as e:
        conn.rollback()
        return False
    finally:
        conn.close()


def get_order_history(wholesaler_id: str = None, 
                      start_date: str = None, 
                      end_date: str = None,
                      status: str = None,
                      limit: int = 50) -> List[Dict]:
    """주문 이력 조회"""
    conn = get_connection()
    cursor = conn.cursor()
    
    query = 'SELECT * FROM orders WHERE 1=1'
    params = []
    
    if wholesaler_id:
        query += ' AND wholesaler_id = ?'
        params.append(wholesaler_id)
    
    if start_date:
        query += ' AND order_date >= ?'
        params.append(start_date)
    
    if end_date:
        query += ' AND order_date <= ?'
        params.append(end_date)
    
    if status:
        query += ' AND status = ?'
        params.append(status)
    
    query += ' ORDER BY created_at DESC LIMIT ?'
    params.append(limit)
    
    cursor.execute(query, params)
    orders = [dict(row) for row in cursor.fetchall()]
    
    conn.close()
    return orders


# ─────────────────────────────────────────────
# AI 학습용 함수들
# ─────────────────────────────────────────────

def save_order_context(order_item_id: int, context: Dict) -> bool:
    """
    주문 시점 컨텍스트 저장 (AI 학습용)
    
    context: {
        'drug_code': '670400830',
        'product_name': '레바미피드정',
        'stock_at_order': 50,
        'usage_1d': 30,
        'usage_7d': 180,
        'usage_30d': 800,
        'ordered_spec': '30T',
        'ordered_qty': 10,
        'available_specs': ['30T', '300T'],
        'spec_stocks': {'30T': 50, '300T': 0},
        'selection_reason': 'stock_available'
    }
    """
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        # 일평균 사용량 계산
        usage_30d = context.get('usage_30d', 0)
        avg_daily = usage_30d / 30.0 if usage_30d else 0
        
        # 재고 소진 예상일 계산
        stock = context.get('stock_at_order', 0)
        days_until_stockout = stock / avg_daily if avg_daily > 0 else None
        
        # 주문 총 정제수
        ordered_qty = context.get('ordered_qty', 0)
        spec = context.get('ordered_spec', '')
        unit_qty = int(''.join(filter(str.isdigit, spec))) if spec else 1
        ordered_dose = ordered_qty * unit_qty
        
        cursor.execute('''
            INSERT INTO order_context (
                order_item_id, drug_code, product_name,
                stock_at_order, usage_1d, usage_7d, usage_30d, avg_daily_usage,
                ordered_spec, ordered_qty, ordered_dose,
                available_specs, spec_stocks, selection_reason,
                days_until_stockout
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        ''', (
            order_item_id,
            context.get('drug_code'),
            context.get('product_name'),
            context.get('stock_at_order'),
            context.get('usage_1d'),
            context.get('usage_7d'),
            context.get('usage_30d'),
            avg_daily,
            context.get('ordered_spec'),
            ordered_qty,
            ordered_dose,
            json.dumps(context.get('available_specs', []), ensure_ascii=False),
            json.dumps(context.get('spec_stocks', {}), ensure_ascii=False),
            context.get('selection_reason'),
            days_until_stockout
        ))
        
        conn.commit()
        return True
        
    except Exception as e:
        conn.rollback()
        return False
    finally:
        conn.close()


def update_daily_usage(drug_code: str, usage_date: str, 
                       rx_count: int = 0, rx_qty: int = 0,
                       pos_count: int = 0, pos_qty: int = 0,
                       stock_end: int = None) -> bool:
    """일별 사용량 업데이트 (UPSERT)"""
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        total_qty = rx_qty + pos_qty
        
        cursor.execute('''
            INSERT INTO daily_usage (
                drug_code, usage_date, rx_count, rx_qty, pos_count, pos_qty, 
                total_qty, stock_end
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
            ON CONFLICT(drug_code, usage_date) DO UPDATE SET
                rx_count = rx_count + excluded.rx_count,
                rx_qty = rx_qty + excluded.rx_qty,
                pos_count = pos_count + excluded.pos_count,
                pos_qty = pos_qty + excluded.pos_qty,
                total_qty = total_qty + excluded.total_qty,
                stock_end = COALESCE(excluded.stock_end, stock_end)
        ''', (drug_code, usage_date, rx_count, rx_qty, pos_count, pos_qty, 
              total_qty, stock_end))
        
        conn.commit()
        return True
        
    except Exception as e:
        conn.rollback()
        return False
    finally:
        conn.close()


def get_usage_stats(drug_code: str, days: int = 30) -> Dict:
    """약품 사용량 통계 조회 (AI 분석용)"""
    conn = get_connection()
    cursor = conn.cursor()
    
    from datetime import datetime, timedelta
    end_date = datetime.now().strftime('%Y-%m-%d')
    start_date = (datetime.now() - timedelta(days=days)).strftime('%Y-%m-%d')
    
    cursor.execute('''
        SELECT 
            COUNT(*) as days_with_data,
            SUM(total_qty) as total_usage,
            AVG(total_qty) as avg_daily,
            MAX(total_qty) as max_daily,
            MIN(total_qty) as min_daily
        FROM daily_usage
        WHERE drug_code = ? AND usage_date BETWEEN ? AND ?
    ''', (drug_code, start_date, end_date))
    
    row = cursor.fetchone()
    conn.close()
    
    if row and row['total_usage']:
        return {
            'drug_code': drug_code,
            'period_days': days,
            'days_with_data': row['days_with_data'],
            'total_usage': row['total_usage'],
            'avg_daily': round(row['avg_daily'], 2) if row['avg_daily'] else 0,
            'max_daily': row['max_daily'],
            'min_daily': row['min_daily']
        }
    
    return {
        'drug_code': drug_code,
        'period_days': days,
        'days_with_data': 0,
        'total_usage': 0,
        'avg_daily': 0,
        'max_daily': 0,
        'min_daily': 0
    }


def get_order_pattern(drug_code: str) -> Optional[Dict]:
    """약품 주문 패턴 조회"""
    conn = get_connection()
    cursor = conn.cursor()
    
    # 최근 주문 이력 분석
    cursor.execute('''
        SELECT 
            oi.specification,
            oi.order_qty,
            oi.total_dose,
            o.order_date
        FROM order_items oi
        JOIN orders o ON oi.order_id = o.id
        WHERE oi.drug_code = ? AND oi.status = 'success'
        ORDER BY o.order_date DESC
        LIMIT 10
    ''', (drug_code,))
    
    orders = [dict(row) for row in cursor.fetchall()]
    
    if not orders:
        conn.close()
        return None
    
    # 가장 많이 사용된 규격
    spec_counts = {}
    for o in orders:
        spec = o['specification']
        spec_counts[spec] = spec_counts.get(spec, 0) + 1
    
    typical_spec = max(spec_counts, key=spec_counts.get)
    
    # 평균 주문 수량
    typical_qty = sum(o['order_qty'] for o in orders) // len(orders)
    
    # 주문 주기 계산
    if len(orders) >= 2:
        dates = [datetime.strptime(o['order_date'], '%Y-%m-%d') for o in orders]
        intervals = [(dates[i] - dates[i+1]).days for i in range(len(dates)-1)]
        avg_interval = sum(intervals) / len(intervals) if intervals else 0
    else:
        avg_interval = 0
    
    conn.close()
    
    return {
        'drug_code': drug_code,
        'order_count': len(orders),
        'typical_spec': typical_spec,
        'typical_qty': typical_qty,
        'avg_order_interval_days': round(avg_interval, 1),
        'recent_orders': orders[:5]
    }


def get_ai_training_data(limit: int = 1000) -> List[Dict]:
    """AI 학습용 데이터 추출"""
    conn = get_connection()
    cursor = conn.cursor()
    
    cursor.execute('''
        SELECT 
            oc.*,
            oi.status as order_status,
            oi.result_code,
            o.order_date,
            o.wholesaler_id
        FROM order_context oc
        JOIN order_items oi ON oc.order_item_id = oi.id
        JOIN orders o ON oi.order_id = o.id
        ORDER BY oc.created_at DESC
        LIMIT ?
    ''', (limit,))
    
    data = []
    for row in cursor.fetchall():
        item = dict(row)
        # JSON 필드 파싱
        if item.get('available_specs'):
            item['available_specs'] = json.loads(item['available_specs'])
        if item.get('spec_stocks'):
            item['spec_stocks'] = json.loads(item['spec_stocks'])
        data.append(item)
    
    conn.close()
    return data


def save_ai_pattern(drug_code: str, pattern: Dict) -> bool:
    """AI 분석 결과 저장"""
    conn = get_connection()
    cursor = conn.cursor()
    
    try:
        today = datetime.now().strftime('%Y-%m-%d')
        
        cursor.execute('''
            INSERT INTO order_patterns (
                drug_code, analysis_date, analysis_period_days,
                avg_daily_usage, usage_stddev, peak_usage,
                typical_order_spec, typical_order_qty, order_frequency_days,
                recommended_spec, recommended_qty, recommended_reorder_point,
                confidence_score, model_version
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            ON CONFLICT(drug_code, analysis_date) DO UPDATE SET
                avg_daily_usage = excluded.avg_daily_usage,
                recommended_spec = excluded.recommended_spec,
                recommended_qty = excluded.recommended_qty,
                confidence_score = excluded.confidence_score
        ''', (
            drug_code,
            today,
            pattern.get('period_days', 30),
            pattern.get('avg_daily_usage'),
            pattern.get('usage_stddev'),
            pattern.get('peak_usage'),
            pattern.get('typical_order_spec'),
            pattern.get('typical_order_qty'),
            pattern.get('order_frequency_days'),
            pattern.get('recommended_spec'),
            pattern.get('recommended_qty'),
            pattern.get('recommended_reorder_point'),
            pattern.get('confidence_score'),
            pattern.get('model_version', 'v1')
        ))
        
        conn.commit()
        return True
        
    except Exception as e:
        conn.rollback()
        return False
    finally:
        conn.close()


# 초기화 실행
init_db()