import os
from datetime import date, timedelta
from typing import Union

from dotenv import load_dotenv

load_dotenv(override=False)

DEFAULT_REDMINE_VERIFY = "/etc/ssl/certs/ca-certificates.crt"
FALSE_VALUES = {"0", "false", "no", "off"}
TRUE_VALUES = {"1", "true", "yes", "on"}


class Config:
    _cli_url: str | None = None
    _cli_api_key: str | None = None

    @classmethod
    def load_config(cls, path: str) -> None:
        """Загружает переменные из указанного .env-файла с override."""
        load_dotenv(path, override=True)

    @classmethod
    def set_redmine_url(cls, url: str) -> None:
        cls._cli_url = url.strip().rstrip("/") if url else None

    @classmethod
    def set_redmine_api_key(cls, key: str) -> None:
        cls._cli_api_key = key.strip() if key else None

    @classmethod
    def get_redmine_url(cls) -> str:
        if cls._cli_url is not None:
            return cls._cli_url
        return os.getenv("REDMINE_URL", "").strip().rstrip("/")

    @classmethod
    def get_redmine_api_key(cls) -> str:
        if cls._cli_api_key is not None:
            return cls._cli_api_key
        return os.getenv("REDMINE_API_KEY", "").strip()

    @classmethod
    def get_redmine_user(cls) -> str:
        return os.getenv("REDMINE_USER", "").strip()

    @classmethod
    def get_redmine_password(cls) -> str:
        return os.getenv("REDMINE_PASSWORD", "").strip()

    @classmethod
    def get_redmine_verify(cls) -> Union[bool, str]:
        value = os.getenv("REDMINE_VERIFY", "").strip()
        if not value:
            return DEFAULT_REDMINE_VERIFY

        normalized = value.lower()
        if normalized in FALSE_VALUES:
            return False
        if normalized in TRUE_VALUES:
            return True
        return value

    @classmethod
    def get_author(cls, cli_author: str = "") -> str:
        """Возвращает автора: из CLI если задан, иначе из .env, иначе — заглушку."""
        if cli_author:
            return cli_author
        return os.getenv("REDMINE_AUTHOR", "").strip()

    @classmethod
    def get_default_date_range(cls) -> str:
        default_from_date = os.getenv("DEFAULT_FROM_DATE", "").strip()
        default_to_date = os.getenv("DEFAULT_TO_DATE", "").strip()
        if default_from_date and default_to_date:
            return f"{default_from_date}--{default_to_date}"

        # fallback: текущий месяц
        today = date.today()
        start = today.replace(day=1)
        # последний день месяца: берём первое число следующего месяца и вычитаем день
        if today.month == 12:
            next_month = today.replace(year=today.year + 1, month=1, day=1)
        else:
            next_month = today.replace(month=today.month + 1, day=1)
        end = next_month - timedelta(days=1)
        return f"{start.isoformat()}--{end.isoformat()}"

    @classmethod
    def validate(cls) -> None:
        if not cls.get_redmine_url():
            raise ValueError("REDMINE_URL is required (set via env or .env)")
        if cls.get_redmine_api_key():
            return
        if not (cls.get_redmine_user() and cls.get_redmine_password()):
            raise ValueError(
                "REDMINE_API_KEY is required, or set both REDMINE_USER and REDMINE_PASSWORD"
            )