"""病例检查项：C1 解析归一化、C3 落库校验。"""

from decimal import Decimal, InvalidOperation

from config.exceptions import AppError

EXAM_ITEM_FIELDS = {
    'item_code', 'item_name', 'item_type', 'category',
    'result_text', 'result_structured',
    'is_key', 'is_abnormal', 'score_weight', 'display_order',
}


def normalize_exam_items(raw_items) -> list:
    """归一化检查项列表；按 item_code 去重（保留首次出现）。"""
    if not raw_items:
        return []
    if not isinstance(raw_items, list):
        raise AppError('CASE_VALIDATION_ERROR', 'exam_items 必须为数组', status_code=400)

    seen = set()
    normalized = []
    for i, item in enumerate(raw_items):
        if not isinstance(item, dict):
            raise AppError('CASE_VALIDATION_ERROR', f'exam_items[{i}] 必须为对象', status_code=400)
        code = (item.get('item_code') or '').strip()
        name = (item.get('item_name') or '').strip()
        item_type = (item.get('item_type') or '').strip()
        result_text = (item.get('result_text') or '').strip()
        if not code:
            raise AppError('CASE_VALIDATION_ERROR', f'exam_items[{i}].item_code 必填', status_code=400)
        if not name:
            raise AppError('CASE_VALIDATION_ERROR', f'exam_items[{i}].item_name 必填', status_code=400)
        if not item_type:
            raise AppError('CASE_VALIDATION_ERROR', f'exam_items[{i}].item_type 必填', status_code=400)
        if not result_text:
            raise AppError('CASE_VALIDATION_ERROR', f'exam_items[{i}].result_text 必填', status_code=400)
        if code in seen:
            continue
        seen.add(code)

        try:
            weight = item.get('score_weight', 1)
            weight = Decimal(str(weight))
        except (InvalidOperation, TypeError, ValueError):
            raise AppError(
                'CASE_VALIDATION_ERROR',
                f'exam_items[{i}].score_weight 须为数字',
                status_code=400,
            )
        if weight <= 0:
            raise AppError(
                'CASE_VALIDATION_ERROR',
                f'exam_items[{i}].score_weight 须大于 0',
                status_code=400,
            )

        normalized.append({
            'item_code': code[:64],
            'item_name': name[:128],
            'item_type': item_type[:32],
            'category': (item.get('category') or '')[:64],
            'result_text': result_text,
            'result_structured': item.get('result_structured') if isinstance(
                item.get('result_structured'), dict
            ) else None,
            'is_key': bool(item.get('is_key', False)),
            'is_abnormal': bool(item.get('is_abnormal', False)),
            'score_weight': float(weight),
            'display_order': int(item.get('display_order', len(normalized) + 1)),
        })
    return normalized


def assert_no_duplicate_exam_items(items: list):
    """创建前再次校验同一病例内 item_code 不重复。"""
    codes = [it['item_code'] for it in items]
    if len(codes) != len(set(codes)):
        raise AppError(
            'CASE_EXAM_ITEM_DUPLICATE',
            '同一病例内检查项 item_code 不能重复',
            status_code=400,
        )