"""同步服务主入口（NSSM 部署）。

用法:
  python -m src.runner                  # 服务循环模式（NSSM）
  python -m src.runner --once           # 单次运行后退出
  python -m src.runner --local X.xlsx   # 用本地文件作源（跳过 169 下载，联调用）
  python -m src.runner --local X.xlsx --dry-run  # 只解析并打印，不写库
"""
import argparse
import logging
import os
import sys
import time
from pathlib import Path

from .config_loader import load_config
from .excel_parser import parse_excel
from .sync_writer import sync_all, _build_insert
from . import source_watcher

logger = logging.getLogger(__name__)


def setup_logging(cfg):
    log_cfg = cfg.get("logging", {})
    level = getattr(logging, log_cfg.get("level", "INFO").upper(), logging.INFO)
    log_dir = Path(log_cfg.get("dir", "logs"))
    log_dir.mkdir(parents=True, exist_ok=True)
    fmt = logging.Formatter("%(asctime)s [%(levelname)s] %(name)s: %(message)s")
    root = logging.getLogger()
    root.setLevel(level)
    fh = logging.FileHandler(log_dir / "sync.log", encoding="utf-8")
    fh.setFormatter(fmt)
    root.addHandler(fh)
    sh = logging.StreamHandler(sys.stdout)
    sh.setFormatter(fmt)
    root.addHandler(sh)


def run_once(cfg, source_path=None, dry_run=False):
    unc = cfg["source"]["unc_path"]
    cache = cfg["source"]["local_cache_dir"]
    meta_path = os.path.join(cache, ".source_meta.json")

    if source_path:
        local_file = source_path
        logger.info("使用本地源: %s", local_file)
    else:
        if not source_watcher.has_changed(unc, meta_path):
            return
        local_file = source_watcher.download(unc, cache)

    records, fields = parse_excel(local_file, cfg.get("field_map", {}))

    if dry_run:
        import_col = cfg.get("auto_fields", {}).get("import_time_field", "导入时间")
        s = cfg["sql_server"]
        sql_tbl = f"{s['schema']}.[{s['table']}]"
        logger.info("[dry-run] 字段数=%d 行数=%d", len(fields), len(records))
        logger.info("[dry-run] SQL INSERT: %s", _build_insert(sql_tbl, fields, import_col))
        for i, r in enumerate(records[:3]):
            logger.info("[dry-run] 样本%d: %s", i + 1, {k: r[k] for k in fields[:6]})
        return

    sync_all(cfg, records, fields)

    # 仅整轮（解析 + 写库）成功后才落基线，
    # 避免把瞬态/损坏源记为“已处理”（曾导致基线被记成 size=0）。
    if not source_path:
        try:
            source_watcher.save_baseline(meta_path, source_watcher.get_source_meta(unc))
        except OSError as e:
            logger.warning("保存基线失败(不影响本次同步): %s", e)


def main():
    parser = argparse.ArgumentParser(description="采购执行情况即时数据 同步服务")
    parser.add_argument("--once", action="store_true", help="单次运行后退出")
    parser.add_argument("--local", metavar="PATH", help="用本地文件作源（跳过 169 下载）")
    parser.add_argument("--dry-run", action="store_true", help="只解析并打印，不写库")
    parser.add_argument("--config", default="config/config.yaml")
    args = parser.parse_args()

    cfg = load_config(args.config)
    setup_logging(cfg)

    if args.local or args.dry_run:
        run_once(cfg, source_path=args.local, dry_run=args.dry_run)
        return
    if args.once:
        run_once(cfg)
        return

    interval = cfg["scan"]["interval_seconds"]
    logger.info("服务循环启动，扫描间隔 %s 秒", interval)
    while True:
        try:
            run_once(cfg)
        except Exception as e:
            logger.exception("同步周期失败: %s", e)
        time.sleep(interval)


if __name__ == "__main__":
    main()