from __future__ import annotations

import os
import re
from dataclasses import dataclass
from pathlib import Path


def _env(key: str, default: str = "") -> str:
    return (os.environ.get(key) or default).strip()


def _env_int(key: str, default: int) -> int:
    raw = _env(key)
    try:
        return int(raw) if raw else default
    except ValueError:
        return default


def _env_bool(key: str, default: bool) -> bool:
    raw = _env(key).lower()
    if not raw:
        return default
    return raw in {"1", "true", "yes", "y", "on"}


@dataclass
class RelayConfig:
    watch_dir: Path
    state_file: Path
    poll_interval: int
    report_globs: list[str]
    alert_re: re.Pattern | None
    log_file: Path
    device_id: str
    login_token: str
    target_chat: int
    hello: bool
    max_lines_per_cycle: int

    @classmethod
    def load(cls) -> "RelayConfig":
        watch_dir = Path(_env("WATCH_DIR") or "/watch")
        state_dir = Path(_env("STATE_DIR") or "/data")
        state_dir.mkdir(parents=True, exist_ok=True)
        alert_raw = _env("ALERT_RE", r"(?i)(⚠|Сбой по расписанию|отчёт неполный|FATAL)")
        try:
            alert_re = re.compile(alert_raw) if alert_raw else None
        except re.error as err:
            raise RuntimeError(f"Некорректный ALERT_RE: {err}") from err
        return cls(
            watch_dir=watch_dir,
            state_file=state_dir / "state.json",
            poll_interval=max(5, _env_int("POLL_INTERVAL", 10)),
            report_globs=[g.strip() for g in _env("REPORT_GLOBS", "otchet_*.pdf").split(",") if g.strip()],
            alert_re=alert_re,
            log_file=Path(_env("RELAY_LOG") or (watch_dir / "report_shot.log")),
            device_id=_env("MAX_DEVICE_ID"),
            login_token=_env("MAX_LOGIN_TOKEN"),
            target_chat=_env_int("MAX_TARGET_CHAT", 0),
            hello=_env_bool("RELAY_HELLO", True),
            max_lines_per_cycle=_env_int("MAX_LINES_PER_CYCLE", 5),
        )