const planningDatabase = require('./planningDatabase');

const TABLE_NAME = 'taobao_detail_plus_data';
const JSON_COLUMNS = [
  'item_imgs_json',
  'skus_json',
  'attribute_json',
  'specs_json',
  'props_json',
  'main_item_info_json',
  'raw_data_json',
  'raw_response_json',
];

function normalizeItemId(value) {
  return String(value || '').trim();
}

function parseJsonColumn(value) {
  if (value === null || value === undefined || value === '') {
    return null;
  }

  if (typeof value !== 'string') {
    return value;
  }

  try {
    return JSON.parse(value);
  } catch (_error) {
    return value;
  }
}

function normalizeRow(row) {
  if (!row) {
    return null;
  }

  const data = { ...row };
  for (const column of JSON_COLUMNS) {
    if (Object.prototype.hasOwnProperty.call(data, column)) {
      data[column] = parseJsonColumn(data[column]);
    }
  }
  return data;
}

function validateItemId(itemId) {
  if (!itemId) {
    return '请提供商品 id';
  }

  if (itemId.length > 64) {
    return '商品 id 长度不能超过 64 个字符';
  }

  if (!/^[0-9A-Za-z_-]+$/.test(itemId)) {
    return '商品 id 只能包含数字、字母、下划线或短横线';
  }

  return '';
}

async function getTaobaoDetailPlusByItemId(rawItemId) {
  const itemId = normalizeItemId(rawItemId);
  const validationError = validateItemId(itemId);
  if (validationError) {
    const error = new Error(validationError);
    error.statusCode = 400;
    throw error;
  }

  const rows = await planningDatabase.query(
    `SELECT *
       FROM ${TABLE_NAME}
      WHERE requested_item_id = ?
         OR item_id = ?
      ORDER BY fetched_at DESC, id DESC
      LIMIT 1`,
    [itemId, itemId]
  );

  return normalizeRow(rows[0]);
}

module.exports = {
  getTaobaoDetailPlusByItemId,
};