import dataclasses
from pathlib import Path


@dataclasses.dataclass
class TrackingNumberEntry:
    number: str
    name: str

    def __post_init__(self):
        assert ' ' not in self.number
        assert '\t' not in self.number
        assert '\n' not in self.number
        assert '\t' not in self.name
        assert '\n' not in self.name


FILEPATH = Path('./output/entries_db.txt')


def get_tracking_numbers() -> list[TrackingNumberEntry]:
    try:
        with open(FILEPATH) as f:
            lines = f.read().split('\n')
    except FileNotFoundError:
        lines = ''

    lines = [line.split(' ') for line in lines if len(line) > 0]
    return [TrackingNumberEntry(line[0], ' '.join(line[1:])) for line in lines]


def add_tracking_number(tracking_number: TrackingNumberEntry) -> None:
    FILEPATH.parent.mkdir(exist_ok=True,parents=True)
    with open(FILEPATH, 'a') as f:
        f.write(tracking_number.number)
        f.write(' ')
        f.write(tracking_number.name)
        f.write('\n')