"""Badge resolution for the printedparts plugin.

Same input contract as the USB plugin (deliberately copied, not imported -
cross-plugin imports break the shopdb.api-only contract):

- all digits            -> an SSO typed or scanned directly
- 0<digits>BZ           -> a physical badge wrapping a PayNo (keyboard-wedge
                           scanners emit this shape)
- anything else         -> unresolvable

Names come from the employees plugin's self-hosted directory, looked up by
SSO. The directory carries no PayNo column, so PayNo badges resolve only when
the wrapped digits are themselves the SSO (true at sites whose badges encode
the SSO); otherwise they fall to the unknown-badge policy.

Policy (Setting printedparts_unknown_badge): 'deny' (default) rejects a badge
with no directory match; 'allow' records the SSO with an empty name.
"""

import re

from shopdb.api import Setting

_PAYNO_BADGE = re.compile(r'^0(\d+)BZ$', re.IGNORECASE)


class BadgeError(ValueError):
    """Raised when a badge cannot be accepted under the site policy."""


def _directory_name(sso):
    """Best-effort display name from the employees plugin directory."""
    try:
        from plugins.employees.models import DirectoryEmployee
        from shopdb.api import db
        if sso and str(sso).isdigit():
            employee = db.session.get(DirectoryEmployee, int(sso))
            if employee:
                return f'{employee.firstname} {employee.lastname}'.strip()
    except Exception:
        pass
    return None


def resolve_badge(badge):
    """Return (sso, name) for a scanned badge, enforcing the site policy.

    Raises BadgeError with a kiosk-displayable message when the badge shape is
    unrecognized or the policy denies an unmatched badge.
    """
    badge = (badge or '').strip()
    if not badge:
        raise BadgeError('Scan or enter a badge')

    if badge.isdigit():
        sso = badge
    else:
        match = _PAYNO_BADGE.match(badge)
        if not match:
            raise BadgeError('Unrecognized badge format')
        sso = match.group(1)

    name = _directory_name(sso)
    if name is None:
        policy = (Setting.get('printedparts_unknown_badge') or 'deny').lower()
        if policy != 'allow':
            raise BadgeError('Badge not recognized - see the parts team')
        return sso, ''
    return sso, name