from __future__ import annotations

import os
import secrets
from dataclasses import dataclass
from pathlib import Path
from urllib.parse import quote_plus


ROOT_DIR = Path(__file__).resolve().parent.parent


@dataclass(slots=True)
class Settings:
    app_name: str = "Spring Check-In Activity Manager"
    timezone: str = os.getenv("APP_TIMEZONE", "Asia/Shanghai")
    session_secret: str = os.getenv("SESSION_SECRET", secrets.token_urlsafe(32))

    admin_username: str = os.getenv("ADMIN", "superadmin")
    admin_password: str = os.getenv("PASSWORD", "change-me-now")

    mysql_user: str = os.getenv("SQL_USER", "avnadmin")
    mysql_password: str = os.getenv("SQL_PASSWORD", "")
    mysql_host: str = os.getenv("SQL_HOST", "mysql-2bace9cd-cacode.i.aivencloud.com")
    mysql_port: int = int(os.getenv("SQL_PORT", "21260"))
    mysql_db: str = os.getenv("SQL_DATABASE", "CAM")
    mysql_ca_file: Path = ROOT_DIR / os.getenv("MYSQL_CA_FILE", "ca.pem")

    db_pool_size: int = int(os.getenv("DB_POOL_SIZE", "12"))
    db_max_overflow: int = int(os.getenv("DB_MAX_OVERFLOW", "24"))
    db_pool_timeout: int = int(os.getenv("DB_POOL_TIMEOUT", "30"))
    db_pool_recycle: int = int(os.getenv("DB_POOL_RECYCLE", "1800"))

    docker_root: Path = ROOT_DIR / os.getenv("DOCKER_ROOT", "docker_data")

    @property
    def upload_root(self) -> Path:
        return self.docker_root / "submissions"

    @property
    def task_media_root(self) -> Path:
        return self.docker_root / "tasks"

    @property
    def database_url(self) -> str:
        if raw_url := os.getenv("DATABASE_URL"):
            return raw_url
        user = quote_plus(self.mysql_user)
        password = quote_plus(self.mysql_password)
        return f"mysql+pymysql://{user}:{password}@{self.mysql_host}:{self.mysql_port}/{self.mysql_db}"

    @property
    def database_connect_args(self) -> dict:
        if self.database_url.startswith("sqlite"):
            return {}
        if self.mysql_ca_file.exists():
            return {"ssl": {"ca": str(self.mysql_ca_file)}}
        return {}

    @property
    def database_engine_kwargs(self) -> dict:
        kwargs = {
            "pool_pre_ping": True,
            "connect_args": self.database_connect_args,
        }
        if not self.database_url.startswith("sqlite"):
            kwargs.update(
                {
                    "pool_size": self.db_pool_size,
                    "max_overflow": self.db_max_overflow,
                    "pool_timeout": self.db_pool_timeout,
                    "pool_recycle": self.db_pool_recycle,
                    "pool_use_lifo": True,
                }
            )
        return kwargs


settings = Settings()