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

import argparse
import logging
import os
import sys
import time

import yaml

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


def setup_logging(log_file):
    """Configure logging to both console and file."""
    logger = logging.getLogger()
    logger.setLevel(logging.INFO)

    fmt = logging.Formatter(
        '%(asctime)s [%(levelname)s] %(message)s',
        datefmt='%Y-%m-%d %H:%M:%S'
    )

    # Console handler
    ch = logging.StreamHandler(sys.stdout)
    ch.setLevel(logging.INFO)
    ch.setFormatter(fmt)
    logger.addHandler(ch)

    # File handler
    fh = logging.FileHandler(log_file, encoding='utf-8')
    fh.setLevel(logging.INFO)
    fh.setFormatter(fmt)
    logger.addHandler(fh)

    return logger


def run_once(cfg, logger):
    """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)

    for rel_path, (status, error_msg) in sync_results.items():
        if status == 'error':
            logger.error(f"  同步失败: {rel_path} - {error_msg}")
        elif status in ('copied', 'updated'):
            logger.info(f"  {status}: {rel_path}")
        else:
            logger.debug(f"  跳过: {rel_path}")

    # 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()

    # Setup logging
    log_file = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'watch.log')
    logger = setup_logging(log_file)

    # Load config
    cfg = load_config(args.config)
    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)

    first_run = True

    while True:
        try:
            if first_run:
                logger.info("首次运行，强制同步并迁移所有表...")
                # On first run, force all tables to migrate by marking all files as 'updated'
                excel_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'Excel')
                sync_results = sync_all_files(cfg, excel_dir)

                # Log sync results
                for rel_path, (status, error_msg) in sync_results.items():
                    if status == 'error':
                        logger.error(f"  同步失败: {rel_path} - {error_msg}")
                    else:
                        logger.info(f"  {status}: {rel_path}")

                # Force all tables to migrate on first run
                all_tables = {t['table'] for t in cfg['tables']}

                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']
                        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)
                            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

                first_run = False
            else:
                run_once(cfg, logger)

        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()