"""
Watch daemon - periodically syncs LAN Excel files and migrates changed tables to SQL Server.
"""

import argparse
import logging
import os
import time

from logger import setup_logger
from migrate import load_config, get_connection, create_schema, migrate_table
from sync import sync_all_files, determine_tables_to_migrate

logger = logging.getLogger('app')


def run_once(cfg):
    """Execute one sync + migrate cycle."""
    excel_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'Excel')

    # 1. Sync files from LAN
    logger.info("开始同步 LAN 文件...")
    sync_results = sync_all_files(cfg, excel_dir)

    # 2. Determine which tables need migration
    tables_to_migrate = determine_tables_to_migrate(cfg, sync_results)

    if not tables_to_migrate:
        logger.info("无文件变更，跳过迁移")
        return

    logger.info(f"需要迁移的表: {', '.join(sorted(tables_to_migrate))}")

    # 3. Open DB connection and migrate each changed table
    conn = None
    try:
        conn = get_connection(cfg)
        cursor = conn.cursor()
        create_schema(cursor, cfg['schema'])

        for table_cfg in cfg['tables']:
            table_name = table_cfg['table']
            if table_name not in tables_to_migrate:
                continue

            try:
                rows = migrate_table(cursor, table_cfg, cfg, use_truncate=True)
                logger.info(f"迁移完成: {table_name} ({rows:,} 行)")
            except Exception as e:
                logger.error(f"迁移失败: {table_name} - {e}", exc_info=True)
                # Rollback any uncommitted transaction for this table
                try:
                    conn.rollback()
                except Exception:
                    pass

        cursor.close()
    except Exception as e:
        logger.error(f"数据库连接失败: {e}", exc_info=True)
    finally:
        if conn:
            try:
                conn.close()
            except Exception:
                pass


def main():
    parser = argparse.ArgumentParser(description='Excel to SQL Server Watch Daemon')
    parser.add_argument('--config', default=None, help='配置文件路径 (默认: config.yaml)')
    parser.add_argument('--once', action='store_true', help='执行一次后退出')
    parser.add_argument('--interval', type=int, default=None,
                        help='覆盖配置文件中的 check_interval_minutes')
    args = parser.parse_args()

    # Load config
    cfg = load_config(args.config)

    # Setup logging
    log_cfg = cfg.get('logging', {})
    setup_logger(
        'app',
        log_dir=log_cfg.get('log_dir'),
        level=log_cfg.get('level', 'INFO'),
        max_keep_days=log_cfg.get('max_keep_days', 30),
    )

    interval = args.interval or cfg.get('check_interval_minutes', 30)

    logger.info("=" * 50)
    logger.info("Watch daemon 启动")
    logger.info(f"  同步间隔: {interval} 分钟")
    logger.info("=" * 50)

    while True:
        try:
            run_once(cfg)
        except Exception as e:
            logger.error(f"运行周期异常: {e}", exc_info=True)

        if args.once:
            logger.info("--once 模式，退出")
            break

        logger.info(f"下次检查: {interval} 分钟后")
        time.sleep(interval * 60)


if __name__ == '__main__':
    main()