"""Select adjustments from saved effects, never from a checkbox alone."""
from .fundamentacao import number

REDUCERS = {
    'redutor88I': ('Art. 88, inciso I', 'Art. 88, inciso I — total'),
    'redutor6061': ('Art. 60 e 61', 'Art. 60 e 61 — aplicado'),
    'redutorTopografia': ('Topografia', 'Topografia — total'),
    'redutorAgua': ('Inundação e ação da água', 'Inundação — aplicado'),
    'redutor88II': ('Art. 88, inciso II', 'Redução total do imóvel'),
}


def saved_result(row):
    return (row.get('evolutivo') or {}).get('resultadoComposicao') or {}


def saved_step(row, code):
    return next((s for s in saved_result(row).get('memoria') or []
                 if isinstance(s, dict) and s.get('codigo') == code), {})


def step_has_effect(step):
    # The applied factor takes precedence over a selected/reference percentage.
    factor = number(step.get('fator'))
    if factor is not None:
        return factor != 1
    rate = number(step.get('percentualReducao'))
    return rate != 0 if rate is not None else True  # Unknown is not zero.


def visible_memory(row):
    return [s for s in saved_result(row).get('memoria') or [] if isinstance(s, dict)
            and (s.get('codigo') not in ('redutores_terreno', 'redutores_imovel') or step_has_effect(s))]


def reducer_rate(row, key):
    values = saved_result(row)
    if key in values:
        return number(values[key])
    if key == 'redutor88II' and 'redutorImovel' in values:
        return number(values['redutorImovel'])
    code = 'redutores_imovel' if key == 'redutor88II' else 'redutores_terreno'
    for component in saved_step(row, code).get('componentes') or []:
        if isinstance(component,dict) and component.get('rotulo') == REDUCERS[key][0]:
            return number(component.get('reducao'))
    return None


def applied_reducers(row, territorial):
    code = 'redutores_terreno' if territorial else 'redutores_imovel'
    step = saved_step(row, code)
    # Explicitly neutral execution wins over selected components, including caps.
    if step and not step_has_effect(step):
        return []
    keys = list(REDUCERS)[:4] if territorial else ['redutor88II']
    items = [(key, REDUCERS[key][0], reducer_rate(row, key)) for key in keys
             if reducer_rate(row, key) is not None and reducer_rate(row, key) > 0]
    if items:
        return items
    aggregate_key = 'redutorTerreno' if territorial else 'redutorImovel'
    rate = number(saved_result(row).get(aggregate_key))
    if rate is None and step:
        factor = number(step.get('fator'))
        rate = 1-factor if factor is not None else number(step.get('percentualReducao'))
    if rate is not None and rate <= 0:
        return []
    if (rate is not None and rate > 0) or (step and step_has_effect(step)):
        return [(aggregate_key, 'Redução territorial registrada' if territorial else 'Redução do imóvel registrada', rate)]
    return []