#!/usr/bin/env python3
"""
创建项目所需 MySQL 数据库（liaotian_db）。
从环境变量 DATABASE_URL 或下方默认值读取连接信息，连接后执行 CREATE DATABASE。
用法:
  cd backend && python scripts/create_database.py
  或指定: export DATABASE_URL='mysql+pymysql://user:pass@host:port/liaotian_db?charset=utf8mb4'
  python scripts/create_database.py
"""
import os
import re
import sys

# 与 app/config.py 中默认一致，不导入 app 以免依赖 Flask 等
DEFAULT_DATABASE_URL = (
    "mysql+pymysql://root:!Rjb12191@"
    "gz-cynosdbmysql-grp-d26pzce5.sql.tencentcdb.com:24936/"
    "liaotian_db?charset=utf8mb4"
)


def parse_database_url(url):
    """从 DATABASE_URL 解析 host, port, user, password, database。"""
    # mysql+pymysql://user:password@host:port/database?query
    m = re.match(
        r"mysql\+pymysql://([^:]+):([^@]+)@([^/:]+):(\d+)/([^?]+)",
        url.strip(),
    )
    if not m:
        raise ValueError("DATABASE_URL 格式应为: mysql+pymysql://user:pass@host:port/dbname?charset=utf8mb4")
    user, password, host, port, database = m.groups()
    import urllib.parse
    password = urllib.parse.unquote(password)
    return {
        "host": host,
        "port": int(port),
        "user": user,
        "password": password,
        "database": database.strip("/"),
    }


def main():
    url = os.getenv("DATABASE_URL", DEFAULT_DATABASE_URL)
    try:
        params = parse_database_url(url)
    except Exception as e:
        print("解析 DATABASE_URL 失败:", e)
        sys.exit(1)

    db_name = params["database"]
    print(f"连接 {params['host']}:{params['port']} (用户 {params['user']})，创建数据库: {db_name}")

    try:
        import pymysql
    except ImportError:
        print("请先安装: pip install pymysql")
        sys.exit(1)

    # 连接时不指定 database，才能执行 CREATE DATABASE
    conn = pymysql.connect(
        host=params["host"],
        port=params["port"],
        user=params["user"],
        password=params["password"],
        charset="utf8mb4",
    )
    try:
        with conn.cursor() as cur:
            cur.execute(
                "CREATE DATABASE IF NOT EXISTS `%s` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci"
                % db_name
            )
        conn.commit()
        print(f"数据库 {db_name} 已存在或已创建成功。")
    except Exception as e:
        print("创建失败:", e)
        sys.exit(1)
    finally:
        conn.close()


if __name__ == "__main__":
    main()