# -*- coding: utf-8 -*-
"""
导入 export_db_snapshot.py 生成的演示快照，并还原静态文件与训练元数据。

用法（空库或需覆盖演示数据时）：
  cd BridgeDiseaseBackend-main
  $env:SQLALCHEMY_DATABASE_URI="mysql+pymysql://root:bridgedisease_root@127.0.0.1:3307/bridge_disease?charset=utf8mb4"
  python scripts/import_db_snapshot.py

可选：仅还原文件不导入 SQL
  python scripts/import_db_snapshot.py --files-only
"""
from __future__ import annotations

import argparse
import os
import shutil
import subprocess
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
SQL_FILE = ROOT / 'sql' / 'seed_snapshot.sql'
SNAPSHOT_STATIC = ROOT / 'seed_assets' / 'snapshot' / 'static'
SNAPSHOT_TRAINING = ROOT / 'seed_assets' / 'snapshot' / 'training_meta'
STATIC_DST = ROOT / 'app' / 'static'
TRAINING_DST = ROOT / 'data' / 'training_meta'

sys.path.insert(0, str(ROOT))
os.environ.setdefault(
    'SQLALCHEMY_DATABASE_URI',
    'mysql+pymysql://root:bridgedisease_root@127.0.0.1:3307/bridge_disease?charset=utf8mb4',
)


def _db_env():
    uri = os.environ['SQLALCHEMY_DATABASE_URI']
    body = uri.split('://', 1)[-1]
    auth, rest = body.split('@', 1)
    user, password = auth.split(':', 1)
    host_port, db_part = rest.split('/', 1)
    database = db_part.split('?', 1)[0]
    host, port = (host_port.split(':', 1) + ['3306'])[:2]
    return host, port, user, password, database


def import_sql() -> None:
    if not SQL_FILE.is_file():
        print(f'缺少 {SQL_FILE}，请先运行 export_db_snapshot.py', file=sys.stderr)
        sys.exit(1)
    host, port, user, password, database = _db_env()
    from app import create_app
    from app.models import db

    app = create_app()
    from sqlalchemy import text

    with app.app_context():
        db.create_all()
        # 清空业务表（保留表结构）
        db.session.execute(text('SET FOREIGN_KEY_CHECKS=0'))
        for table in ('detection', 'operation', 'media', 'model', 'user'):
            db.session.execute(text(f'TRUNCATE TABLE `{table}`'))
        db.session.commit()
        db.session.execute(text('SET FOREIGN_KEY_CHECKS=1'))
        db.session.commit()
        print('[ok] 已清空 user/model/media/detection/operation')

    cmd = [
        'mysql',
        f'--host={host}',
        f'--port={port}',
        f'-u{user}',
        f'-p{password}',
        '--default-character-set=utf8mb4',
        database,
    ]
    try:
        with open(SQL_FILE, 'rb') as f:
            subprocess.run(cmd, stdin=f, check=True)
    except FileNotFoundError:
        docker_cmd = [
            'docker',
            'exec',
            '-i',
            'bridge-disease-mysql',
            'mysql',
            f'-u{user}',
            f'-p{password}',
            '--default-character-set=utf8mb4',
            database,
        ]
        with open(SQL_FILE, 'rb') as f:
            subprocess.run(docker_cmd, stdin=f, check=True)
    print(f'[ok] 已导入 {SQL_FILE}')


def restore_files() -> None:
    if not SNAPSHOT_STATIC.is_dir():
        print(f'缺少 {SNAPSHOT_STATIC}，跳过静态文件还原')
        return
    STATIC_DST.mkdir(parents=True, exist_ok=True)
    for child in SNAPSHOT_STATIC.iterdir():
        dst = STATIC_DST / child.name
        if dst.exists():
            shutil.rmtree(dst)
        shutil.copytree(child, dst)
        n = sum(1 for _ in dst.rglob('*') if _.is_file())
        print(f'[ok] 静态 {child.name} -> {dst} ({n} files)')

    if SNAPSHOT_TRAINING.is_dir():
        TRAINING_DST.mkdir(parents=True, exist_ok=True)
        for f in SNAPSHOT_TRAINING.glob('*.json'):
            shutil.copy2(f, TRAINING_DST / f.name)
        print(f'[ok] training_meta -> {TRAINING_DST}')


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument('--files-only', action='store_true', help='仅还原静态与 training_meta')
    parser.add_argument('--sql-only', action='store_true', help='仅导入 SQL')
    args = parser.parse_args()

    if not args.files_only:
        import_sql()
    if not args.sql_only:
        restore_files()

    print('\n完成。请启动后端并刷新前端（admin / Admin123456）。')
    return 0


if __name__ == '__main__':
    sys.exit(main())