"""Shared validation for sampling confirmation edits and imports."""
from datetime import date, datetime, timedelta

REASONS = ('价格高', '质感差', '资质不全', '同质化严重')
SAMPLE_STATUSES = ('未付款', '付款中', '样品到货中', '样品已到货', '不授权', '厂家无货', '停产', '其他')
# Keep existing imported values editable without silently changing historical records.
LEGACY_SAMPLE_STATUSES = ('不做', '产品停产', '厂家无现货', '已到货', '待寄出')
TEXT_LIMITS = {
    'sample_status': 50, 'oa_approval_no': 100, 'express_tracking_no': 100,
    'remark': 65535, 'product_code': 100, 'final_product_name': 300,
    'platform': 200, 'sample_confirmed': 50, 'sample_confirmation_reason': 65535,
    'barcode': 100, 'product_unit_price': 1000,
}
EDITABLE = frozenset((*TEXT_LIMITS, 'product_unit_price', 'arrival_date'))


def validate_confirmation_values(data):
    values = {}
    for key in EDITABLE & data.keys():
        raw = data[key]
        value = str(raw).strip() if raw is not None else ''
        if key == 'arrival_date':
            try:
                values[key] = date.fromisoformat(value) if value else None
            except ValueError:
                raise ValueError('到样日期格式错误，请填写YYYY-MM-DD')
        else:
            size = len(value.encode('utf-8')) if TEXT_LIMITS[key] == 65535 else len(value)
            if size > TEXT_LIMITS[key]:
                raise ValueError('字段内容过长')
            if key == 'sample_confirmed' and value not in ('', '做', '不做'):
                raise ValueError('样品确认请选择做或不做')
            if key == 'sample_status' and value not in ('', *SAMPLE_STATUSES, *LEGACY_SAMPLE_STATUSES):
                raise ValueError('请选择有效的样品状态')
            if key == 'sample_confirmation_reason' and value:
                if value == '其他' or value.startswith('其他：'):
                    other = str(data.get('other_reason') or '').strip() if value == '其他' else value[3:].strip()
                    if not other:
                        raise ValueError('选择其他时，请填写具体原因')
                    if any(reason in other for reason in REASONS):
                        raise ValueError('其他原因不能包含价格高、质感差、资质不全、同质化严重')
                    value = '其他：' + other
                    if len(value.encode('utf-8')) > 65535:
                        raise ValueError('其他原因内容过长')
                elif value not in (*REASONS, '无'):
                    raise ValueError('请选择有效的样品确认原因')
            values[key] = value
    if str(data.get('sample_confirmed') or '').strip() == '做' and not str(
            data.get('sample_confirmation_reason') or '').strip():
        values['sample_confirmation_reason'] = '无'
    return values


def confirmation_reminder_state(arrival_date, sample_confirmed, as_of=None):
    """Return the derived 10-day confirmation reminder state without sending messages."""
    if not arrival_date:
        return {'due_date': None, 'pending': False}
    if isinstance(arrival_date, str):
        try:
            arrival_date = date.fromisoformat(arrival_date[:10])
        except ValueError:
            return {'due_date': None, 'pending': False}
    if isinstance(arrival_date, datetime):
        arrival_date = arrival_date.date()
    due_date = arrival_date + timedelta(days=10)
    today = as_of or date.today()
    pending = not str(sample_confirmed or '').strip() and today >= due_date
    return {'due_date': due_date.isoformat(), 'pending': pending}