import datetime as dt
from dataclasses import dataclass

import pytz

from db.sf_connector import SnowflakeConnector


__all__ = ["Timestamp", "TimestampError"]


class TimestampError(Exception):
    pass


@dataclass(frozen=True)
class Timestamp:
    _value: dt.datetime

    @classmethod
    def from_sf(cls) -> "Timestamp":
        try:
            with SnowflakeConnector() as sf:
                sf_dt = sf.execute_query("SELECT CURRENT_TIMESTAMP(0) as TIMESTAMP;")
        except Exception as e:
            raise TimestampError("Something went wrong while acquiring timestamp") from e
        return cls(sf_dt[0]["TIMESTAMP"])

    @classmethod
    def from_string(cls, timestamp: str) -> "Timestamp":
        try:
            datetime = dt.datetime.fromtimestamp(int(timestamp), tz=pytz.utc)
        except (ValueError, OSError) as e:
            raise TimestampError(f"'{timestamp}' is invalid timestamp") from e

        return cls(datetime)

    def __str__(self) -> str:
        return str(self.to_int())

    def to_int(self) -> int:
        return int(self._value.timestamp())

    def to_datetime(self) -> dt.datetime:
        return self._value

    def to_date(self):
        return self._value.date()