import json
import os
from pathlib import Path

from flask import request, Response, make_response, send_file
from flask_restful import Resource
from hub.city_model_structure.city import City
from hub.exports.energy_building_exports_factory import EnergyBuildingsExportsFactory
from hub.version import __version__ as version

from hub_api.config import Config
from hub_api.helpers.session_helper import refresh_session, session


class IdfGenerator(Resource, Config):
  def __init__(self):
    self._tmp_path = (Path(__file__).parent / 'tmp').resolve()
    super().__init__()

  def post(self):
    """
    API call generate the IDF file for the input data
    """
    session_id = request.headers.get('session-id', None)
    token = request.headers.get('token', None)
    application_uuid = request.headers.get('application-uuid', None)
    _session = refresh_session(session_id, token, application_uuid)
    if _session is None:
      return Response(json.dumps({'error': 'unauthorized'}), status=403)
    else:
      token = _session['token']
      application_id = session(session_id)['application_id']
      user_id = session(session_id)['user_id']
    tmp_path = (self._tmp_path / token).resolve()
    try:
      os.mkdir(tmp_path)
    except FileExistsError:
      pass
    payload = request.get_json()
    for key, value in payload.items():
      db_city = self.database.get_city(self.database.building(value, user_id, application_id, key).city_id)
      if version != db_city.hub_release:
        return Response(json.dumps({
          'error': 'The selected building belongs to an old hub release and cannot be loaded.'
        }), status=422)
      idf_file = tmp_path/db_city.name
      city = City.load_compressed(db_city.pickle_path, idf_file)
      EnergyBuildingsExportsFactory('idf', city, tmp_path, target_buildings=[value]).export()
      response = make_response(send_file(idf_file))
      response.headers['token'] = token
      return response