text: import connexion
  from swagger_server.models.asset import Asset
  from swagger_server.models.asset_details import AssetDetails
  from swagger_server.models.error_model import ErrorModel
  from datetime import date, datetime
  from typing import List, Dict
  from six import iteritems
  from ..util import deserialize_date, deserialize_datetime
  
  from flask import json
  import string
  import random
  import re
  import cuckoofilter
  from collections import defaultdict
  
  
  class AssetStore(object):
  
      def __init__(self):
          self.data = {}
          self.tags = defaultdict(set)
  
      def insert(self, asset):
          self.data[asset.name] = asset
          self.tags[asset.type].add(asset.name)
          self.tags[asset._class].add(asset.name)
  
  
  datastore = AssetStore()
  CF = cuckoofilter.CuckooFilter(capacity=500000, fingerprint_size=2)
  PATTERN = re.compile("[A-Za-z0-9][\w-]{3,63}")
  
  
  def add_asset(asset):
      """
      add_asset
      Creates a new asset.  Duplicates are not allowed
      :param asset: Asset to add
      :type asset: dict | bytes
      :param X_User: User key
      :type X_User: str
  
      :rtype: Asset
      """
  
      if not isAuthorized(connexion.request.headers['X-User']):
          return "User not authorized to post data", 401
  
      if connexion.request.is_json:
          asset = Asset.from_dict(connexion.request.get_json())
  
      if asset.name == "_random":
          asset.name = genRandName()
  
      if not PATTERN.match(asset.name):
          return "Given asset name `{}` is invalid.".format(asset.name), 422
  
      if CF.contains(asset.name):
          return "An asset already exists with the name " + asset.name, 409
  
      if not isValidClass(asset.type, asset._class.lower()):
          return "Invalid asset class for given asset type", 422
  
      if asset.details:
          details = asset.details
          for detail in details:
              isvalidDetail(asset, detail)
  
      CF.insert(asset.name)
  
      datastore.insert(asset)
  
      return json.jsonify(asset)
  
  
  def find_asset_by_name(name):
      """
      find_asset_by_name
      Returns an asset based on a its name
      :param name: name of asset to fetch
      :type name: str
  
      :rtype: Asset
  
      """
      if not CF.contains(name):
          return "The asset `{}` does not exist".format(name), 400
      return json.jsonify(datastore.data[name])
  
  
  def find_assets(tags=None):
      """
      find_assets
      Returns all assets from the system
      :param tags: tags to filter by, asset_type and/or asset_code
      :type tags: List[str]
  
      :rtype: List[Asset]
      """
      if not tags:
          return json.jsonify(list(datastore.data.values()))
  
      tags = tags.lower()
      if tags not in {"satellite", "dove", "rapideye", "antenna", "dish", "yagi"}:
          return "Invalid tag " + tags, 422
  
      return json.jsonify([datastore.data[k] for k in datastore.tags[tags]])
  
  
  def update_asset_by_name(name, assetDetails):
      """
      update_asset_by_name
      Updates the asset details by name.
      :param name: name of asset to update
      :type name: str
      :param assetDetails: Asset to add
      :type assetDetails: list | bytes`
      :param X_User: User key
      :type X_User: str
  
      :rtype: Asset
      """
      if not isAuthorized(connexion.request.headers['X-User']):
          return "User not authorized to perform this operation", 500
  
      if not CF.contains(name):
          return "The asset `{}` does not exist.".format(name), 400
  
      if connexion.request.is_json:
          assetDetails = [AssetDetails.from_dict(d)
                          for d in connexion.request.get_json()]
  
      asset = datastore.data[name]
  
      for detail in assetDetails:
          isvalidDetail(asset, detail)
  
      return json.jsonify(asset)
  
  
  def isAuthorized(user):
      "Checks the X-User Header validity "
      if not user or not user.isalpha() or user.lower() != "admin":
          return False
      return True
  
  
  def isValidClass(assetType, assetClass):
      "Checks the validity of the given AssetClass for the AssetType"
      if assetType == "satellite":
          if assetClass not in {"dove", "rapideye"}:
              return False
      else:
          if assetClass not in {"dish", "yagi"}:
              return False
      return True
  
  
  def isvalidDetail(asset, detail):
      if not asset.details or type(asset.details) != type(dict()):
          asset.details = {}
      key, value = detail.type, detail.value
      if asset._class == "dish":
          if key == "diameter" and isFloat(value):
              asset.details[key] = float(value)
              return True
          elif key == "radome" and value in {"true", "false"}:
              asset.details[key] = value
              return True
      elif asset._class == "yagi":
          if key == "gain" and isFloat(value):
              asset.details[key] = float(value)
              return True
      return False
  
  def genRandName():
      "generates a psuedorandom string for the name"
      res = random.choice(string.ascii_letters + string.digits) + "".join(random.choice(string.ascii_letters \
              + string.digits +"_-") for _ in range(random.randint(3,63)))
      if CF.contains(res):
          res = genRandName()
      return res
  
  
  
  def isFloat(n):
      try:
          float(n)
          return True
      except:
          return False
  