import re
import uuid

from datetime import date, timedelta
from decimal import Decimal
from io import BytesIO
from typing import Optional

from fastapi import APIRouter
from sqlalchemy.orm import Session

from ..models.master import DbSetting
from ..models.voucher import DbImage


router = APIRouter()


def get_lock_info(db: Session) -> (Optional[date], Optional[date]):
    start: Optional[date]
    finish: Optional[date]
    data = db.query(DbSetting).filter(DbSetting.name == "Lock Info").first()
    if data is None:
        return None, None

    data = data.data
    if not data["Start"]["Locked"]:
        start = None
    elif data["Start"]["Rolling"]:
        start: date = date.today() - timedelta(days=data["Start"]["Days"])
    else:
        start = data["Start"]["Date"].date()

    if not data["Finish"]["Locked"]:
        finish = None
    elif data["Finish"]["Rolling"]:
        finish = date.today() + timedelta(days=data["Finish"]["Days"])
    else:
        finish = data["Finish"]["Date"].date()
    return start, finish


def to_uuid(value):
    p = re.compile(
        "^[A-Fa-f0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}$"
    )
    return uuid.UUID(value) if p.match(value) else None


def to_decimal(value, default=0):
    import re

    _parser = re.compile(
        r"""        # A numeric string consists of:
        (?P<sign>[-+])?              # an optional sign, followed by either...
        (
            (?=\d|\.\d)              # ...a number (with at least one digit)
            (?P<int>\d*)             # having a (possibly empty) integer part
            (\.(?P<frac>\d*))?       # followed by an optional fractional part
        |
            (?P<signal>s)?           # ...an (optionally signaling)
            NaN                      # NaN
            (?P<diag>\d*)            # with (possibly empty) diagnostic info.
        )
        \Z
    """,
        re.VERBOSE | re.IGNORECASE,
    ).match
    return Decimal(value) if _parser(value.strip()) is not None else default