import os
import secrets
from dataclasses import dataclass
from typing import Optional


@dataclass
class BotConfig:
    token: str
    skip_pending: bool
    timeout: int
    polling_timeout: int
    num_threads: int
    parse_mode: str

    @classmethod
    def from_env(cls):
        return cls(os.getenv("BOT_TOKEN"),
                   bool(int(os.getenv("BOT_SKIP_PENDING", True))),
                   int(os.getenv("BOT_TIMEOUT", 20)),
                   int(os.getenv("BOT_POLLING_TIMEOUT", 20)),
                   int(os.getenv("BOT_NUM_THREADS", 2)),
                   os.getenv("BOT_PARSE_MODE", "html"))


@dataclass
class WebhookConfig:
    domain: Optional[str]
    url_path: str
    max_connections: int
    drop_pending_updates: bool

    # secret token
    use_secret_token: bool
    secret_token: Optional[str]

    # self-signed certificate
    cert_path: Optional[str]

    def __post_init__(self):
        if self.use_secret_token and not self.secret_token:
            self.secret_token = secrets.token_hex()

    @property
    def url(self):
        return f"https://{self.domain}{self.url_path}"

    @classmethod
    def from_env(cls):
        return cls(os.getenv("WEBHOOK_DOMAIN"),
                   os.getenv("WEBHOOK_URL_PATH", "/"),
                   int(os.getenv("WEBHOOK_MAX_CONNECTIONS", 40)),
                   bool(int(os.getenv("WEBHOOK_DROP_PENDING", True))),
                   bool(int(os.getenv("WEBHOOK_USE_SECRET_TOKEN", True))),
                   os.getenv("WEBHOOK_SECRET_TOKEN"),
                   os.getenv("WEBHOOK_CERT_PATH"))


@dataclass
class I18NConfig:
    path: str
    lang: str
    fallback_lang: str

    @classmethod
    def from_env(cls):
        return cls(os.getenv("I18N_PATH", "i18n.yaml"),
                   os.getenv("I18N_LANG", "en"),
                   os.getenv("I18N_FALLBACK_LANG", "en"))


@dataclass
class StateStorageConfig:
    type: str
    redis_host: Optional[str]
    redis_port: int
    redis_db: int
    redis_pass: Optional[str]

    @classmethod
    def from_env(cls):
        return cls(os.getenv("SS_TYPE", "memory"),
                   os.getenv("SS_REDIS_HOST"),
                   int(os.getenv("SS_REDIS_PORT", 6379)),
                   int(os.getenv("SS_REDIS_DB", 0)),
                   os.getenv("SS_REDIS_PASS"))


@dataclass
class DatabaseConfig:
    url: str
    pool_recycle: int
    pool_pre_ping: bool

    @classmethod
    def from_env(cls):
        return cls(os.getenv("DB_URL", "sqlite:///bot.db"),
                   int(os.getenv("DB_POOL_RECYCLE", 3600)),
                   bool(int(os.getenv("DB_POOL_PRE_PING", True))))


@dataclass
class Config:
    bot: BotConfig
    i18n: I18NConfig
    states: StateStorageConfig
    database: DatabaseConfig
    webhook: WebhookConfig

    use_webhook: bool
    log_level: str
    owner_id: int

    @classmethod
    def from_env(cls):
        return cls(
            bot=BotConfig.from_env(),
            i18n=I18NConfig.from_env(),
            states=StateStorageConfig.from_env(),
            database=DatabaseConfig.from_env(),
            webhook=WebhookConfig.from_env(),
            use_webhook=bool(int(os.getenv("USE_WEBHOOK", False))),
            log_level=os.getenv("LOG_LEVEL", "INFO"),
            owner_id=int(os.getenv("OWNER_ID", 1)),
        )


def load_config() -> Config:
    return Config.from_env()