from datetime import date
from decimal import Decimal as D

from app.services.pl_quota_allocation import SourceDemand, PermitCandidate


def permit(id, qty, products, unit='吨', refs=frozenset()):
    return PermitCandidate(id, D(qty), unit, date.max, frozenset(products), refs)


def test_shared_capacity_is_counted_once_per_kind_and_unit():
    from app.services.pl_quota_diagnostics import allocation_diagnostics
    sources = [SourceDemand('a', 'a', D('20'), '吨'), SourceDemand('b', 'b', D('10'), '吨')]
    rows = allocation_diagnostics(sources, [permit('p', '25', ['a', 'b'])], [])
    purchase = rows[0]
    assert purchase['demand'] == '30' and purchase['availableUpperBound'] == '25'
    assert purchase['gapLowerBound'] == '5' and purchase['unit'] == '吨'
    assert rows[1]['gapLowerBound'] == '30'


def test_foreign_unit_is_not_summed_or_implicitly_converted():
    from app.services.pl_quota_diagnostics import allocation_diagnostics
    rows = allocation_diagnostics([SourceDemand('a', 'a', D('30'), '吨')], [permit('p', '1000', ['a'], '千克')], [])
    assert rows[0]['availableUpperBound'] is None and rows[0]['gapLowerBound'] is None
    assert '人工' in rows[0]['reason']


def test_sufficient_totals_do_not_claim_joint_feasibility():
    from app.services.pl_quota_diagnostics import allocation_diagnostics
    rows = allocation_diagnostics([SourceDemand('a', 'a', D('30'), '吨')], [permit('p', '40', ['a'])], [permit('t', '40', ['a'])])
    assert rows[0]['gapLowerBound'] == '0'
    assert all('引用' in row['reason'] for row in rows)


def test_out_of_scope_balance_does_not_inflate_available():
    from app.services.pl_quota_diagnostics import allocation_diagnostics
    rows = allocation_diagnostics([SourceDemand('a', 'a', D('30'), '吨')], [permit('p', '100', ['b'])], [])
    assert rows[0]['availableUpperBound'] == '0'