import time
import os
import sys
import pyodbc
import config
import db_utils
import logging
from logging.handlers import TimedRotatingFileHandler

# ================= 日志系统配置 =================
def setup_logger():
    log_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'log')
    if not os.path.exists(log_dir):
        os.makedirs(log_dir)

    logger = logging.getLogger("SyncService")
    logger.setLevel(logging.INFO)
    logger.handlers = []

    log_file_path = os.path.join(log_dir, 'sync_service.log')
    file_handler = TimedRotatingFileHandler(
        log_file_path, when='midnight', interval=1, backupCount=30, encoding='utf-8'
    )
    file_handler.suffix = "%Y-%m-%d"
    file_fmt = logging.Formatter('%(asctime)s - [%(levelname)s] - %(message)s')
    file_handler.setFormatter(file_fmt)

    console_handler = logging.StreamHandler(sys.stdout)
    console_fmt = logging.Formatter('%(asctime)s - %(message)s', datefmt='%H:%M:%S')
    console_handler.setFormatter(console_fmt)

    logger.addHandler(file_handler)
    logger.addHandler(console_handler)
    return logger

logger = setup_logger()

# ================= 主逻辑 =================

def process_sync_task():
    """
    逻辑重构：
    遍历 config.SYNC_MAPPING 中的每一个文件 -> 去日志表查询该文件下特定表的未同步记录。
    """
    sql_conn = db_utils.get_sql_conn()
    sql_cursor = sql_conn.cursor()
    sql_cursor.fast_executemany = True # 高性能开关
    
    # 标记是否有工作被处理（用于控制轮询休眠时间）
    work_done = False
    
    cols = config.LOG_TABLE_CONFIG
    log_full_name = db_utils.fmt_table(cols['schema'], cols['table_name'])

    try:
        # === 核心循环：以配置文件为驱动 ===
        for clean_path, tables_map in config.SYNC_MAPPING.items():
            
            # 1. 准备查询条件
            # 获取该文件下所有需要同步的表名列表
            target_tables = list(tables_map.keys())
            if not target_tables:
                continue

            # 构造 TableAddress 的精确匹配条件
            # VBA 逻辑：网络路径带 ";DATABASE=", 本地路径带 "LOCAL:"
            # 我们直接构造这两个字符串，让 SQL Server 做精确匹配，效率极高
            # 注意：将路径转为 Windows 标准反斜杠
            win_path = os.path.normpath(clean_path) 
            addr_candidates = [
                f";DATABASE={win_path}", # 情况1
                f"LOCAL={win_path}",      # 情况2 (注意 VBA 代码里可能是 LOCAL: 或 LOCAL=，请核对)
                f"LOCAL:{win_path}",      # 情况3
                win_path                  # 情况4 (兼容没有前缀的情况)
            ]
            
            # 2. 构造动态 SQL 查询
            # WHERE Synced=0 AND Address IN (...) AND TableName IN (...)
            placeholders_addr = ','.join(['?'] * len(addr_candidates))
            placeholders_tbl = ','.join(['?'] * len(target_tables))
            
            query_log = f"""
            SELECT TOP 1000 
                {cols['col_log_id']}, 
                {cols['col_table_name']}, 
                {cols['col_record_id']}
            FROM {log_full_name} 
            WHERE {cols['col_synced']} = 0 
              AND TableType = 'LINKED_ACCESS'
              AND {cols['col_address']} IN ({placeholders_addr})
              AND {cols['col_table_name']} IN ({placeholders_tbl})
            ORDER BY {cols['col_log_id']} ASC
            """
            
            # 参数列表：先放地址，再放表名
            params = addr_candidates + target_tables
            
            sql_cursor.execute(query_log, params)
            logs = sql_cursor.fetchall()
            
            if not logs:
                continue # 这个文件没有需要同步的记录，检查下一个文件

            work_done = True # 标记有工作
            logger.info(f"📂 文件 {os.path.basename(clean_path)} 发现 {len(logs)} 条变更...")

            # 3. 本地分组 (按表名)
            # 结构: table_tasks[TableName] = { ids: {}, log_ids: [] }
            table_tasks = {}
            for row in logs:
                log_id, acc_table, record_id = row
                if acc_table not in table_tasks:
                    table_tasks[acc_table] = {'record_ids': set(), 'log_ids': []}
                table_tasks[acc_table]['record_ids'].add(record_id)
                table_tasks[acc_table]['log_ids'].append(log_id)

            # 4. 执行同步 (连接一次 Access，处理多张表)
            if not os.path.exists(clean_path):
                logger.error(f"无法访问文件: {clean_path}")
                continue

            try:
                acc_conn = db_utils.get_access_conn(clean_path)
                acc_cursor = acc_conn.cursor()
            except Exception as conn_err:
                logger.error(f"连接 Access 失败: {conn_err}")
                continue

            for acc_table, data in table_tasks.items():
                record_ids = list(data['record_ids'])
                log_ids = data['log_ids']
                
                # 读取目标配置
                target_conf = tables_map[acc_table]
                target_schema = target_conf['target_schema']
                target_table = target_conf['target_table']
                pk_col = target_conf['pk_col']
                target_full_name = db_utils.fmt_table(target_schema, target_table)

                try:
                    # --- A. Access 查新数据 ---
                    ids_placeholders = ','.join(['?'] * len(record_ids))
                    acc_sql = f"SELECT * FROM [{acc_table}] WHERE [{pk_col}] IN ({ids_placeholders})"
                    acc_cursor.execute(acc_sql, record_ids)
                    new_rows = acc_cursor.fetchall()
                    acc_cols = [col[0] for col in acc_cursor.description]

                    # --- B. SQL Server 删旧插新 (事务) ---
                    # 1. 删除
                    del_sql = f"DELETE FROM {target_full_name} WHERE [{pk_col}] IN ({ids_placeholders})"
                    sql_cursor.execute(del_sql, record_ids)

                    # 2. 插入
                    if new_rows:
                        insert_sql = db_utils.generate_insert_sql(target_schema, target_table, acc_cols)
                        try: sql_cursor.execute(f"SET IDENTITY_INSERT {target_full_name} ON")
                        except: pass
                        
                        sql_cursor.executemany(insert_sql, new_rows)
                        
                        try: sql_cursor.execute(f"SET IDENTITY_INSERT {target_full_name} OFF")
                        except: pass

                    # 3. 标记日志 Synced = 1
                    log_placeholders = ','.join(['?'] * len(log_ids))
                    update_log_sql = f"""
                    UPDATE {log_full_name} 
                    SET {cols['col_synced']} = 1 
                    WHERE {cols['col_log_id']} IN ({log_placeholders})
                    """
                    sql_cursor.execute(update_log_sql, log_ids)

                    sql_conn.commit()
                    logger.info(f"  -> {target_table} 同步成功: {len(record_ids)} 条")

                except Exception as tbl_err:
                    logger.error(f"  -> 处理表 {acc_table} 异常: {tbl_err}")
                    sql_conn.rollback()

            acc_conn.close() # 关闭 Access 连接

        return work_done

    except Exception as e:
        logger.critical(f"全局严重异常: {e}")
        return False
    finally:
        try: sql_conn.close()
        except: pass

if __name__ == "__main__":
    logger.info("=== 增量同步服务启动 (配置驱动模式) ===")
    logger.info("正在按 config.SYNC_MAPPING 轮询...")
    
    while True:
        try:
            has_work = process_sync_task()
            # 如果有工作，说明可能还有积压，休息短一点(0.1s)
            # 如果没工作，休息标准间隔(5s)
            time.sleep(0.1 if has_work else config.POLL_INTERVAL)
        except KeyboardInterrupt:
            logger.info("服务停止")
            break
        except Exception as e:
            logger.critical(f"主循环崩溃: {e}")
            time.sleep(5)