Model/backend/SearchEpc.py

import os
import time
from epc_api.client import EpcClient
from utils.logger import setup_logger
from typing import List

logger = setup_logger()


class SearchEpc:
    """
    Given address information about a home, this class is responsible for retrieving the EPC data associated
    to the property.

    For a home, we might have address lines 1, 2, 3 and 4, as well as a postcode.

    Often, simply searching the EPC database with address line 1 and postcode will be enough to find
    the property, but there are some cases where this is not true and we might need to utilise other
    combinations about the home to find the property
    """

    MAX_RETRIES = 5

    SUCCESS = {
        "status": 200,
        "message": "success",
        "error": None
    }

    NODATA = {
        "status": 201,
        "message": "No data",
        "error": None
    }

    def __init__(
        self,
        address1: str,
        postcode: str,
        address2: str = None,
        address3: str = None,
        address4: str = None,
        max_retries: int = None
    ):
        """
        Address lines 1 and postcode are mandatory fields. The other address lines are optional
        but can be used to find the epc for the home, if address1 and postcode are insufficient
        :param address1: string, propery's address line 1
        :param postcode: string, propery's postcode
        :param address2: string, optional, propery's address line 2
        :param address3: string, optional, propery's address line 3
        :param address4: string, optional, propery's address line 4
        """

        self.address1 = address1
        self.postcode = postcode
        self.address2 = address2
        self.address3 = address3
        self.address4 = address4

        self.max_retries = max_retries if max_retries is not None else self.MAX_RETRIES

        self.client = EpcClient(auth_token=os.getenv("EPC_AUTH_TOKEN"))

        self.data = None

    def search(self):
        # Get the EPC data with retries

        for retry in range(self.max_retries):
            try:
                response = self.client.domestic.search(
                    params={"address": self.address1, "postcode": self.postcode}
                )

                if response:
                    self.data = response
                    return self.SUCCESS

                if retry > 0:
                    print("Failed previous attempt but retry successful")
                # If we got nothing, final try
                if not response:
                    # TODO: Make a call to OS uprn service and get the address' uprn, just in case there is an
                    #       issue with how we are searching the api

                    return {
                        "status": 204,
                        "message": "no data",
                        "error": None
                    }

                return {
                    "status": 200,
                    "message": "success",
                    "error": None
                }

            except Exception as e:
                if retry < self.max_retries - 1:
                    # If not the last retry, wait for 3 seconds before retrying
                    time.sleep(3)
                else:
                    # If it's the last retry, we continue
                    return {
                        "status": 500,
                        "message": "Could not retrieve EPC data",
                        "error": str(e)
                    }

    def retrieve(self, property_type=None):

        """
        Given a successful search, this method will format the data and return it
        :return:
        """

        if self.data is None:
            raise ValueError("data is missing, run search first")

        rows = self.data["rows"]

        # We perform some checks on the rows
        # Firstly, we should only have 1 urpn so if we have multiple, we'll need to filter down the
        # property further
        uprns = {r["uprn"] for r in rows}

        if len(uprns) != 1:
            logger.error("Multiple EPCs found - we should use an alternate method of searching - TODO")
            if property_type is not None:
                # We can do a filter on the property type
                rows_filtered = [r for r in rows if r["property-type"] == property_type]
                if rows_filtered:
                    rows = rows_filtered

        # We now check for a full sap epc:
        full_sap_epc = [r for r in rows if r["transaction-type"] == "new dwelling"]
        full_sap_epc = full_sap_epc[0] if full_sap_epc else {}

        # Finally, we identify the newest epc and the rest, and then return
        newest_epc, older_epcs = self.filter_newest_epc(list_of_epcs=rows)

        return newest_epc, older_epcs, full_sap_epc

    @staticmethod
    def filter_newest_epc(list_of_epcs: List):
        newest_response = [
            r for r in list_of_epcs if
            r["lodgement-datetime"] == max([x["lodgement-datetime"] for x in list_of_epcs])
        ]

        if not newest_response:
            return {}, []

        if len(newest_response) != 1:
            raise Exception("More than one result found for this address - investigate me")

        older_epcs = [epc for epc in list_of_epcs if epc["lmk-key"] != newest_response[0]["lmk-key"]]

        return newest_response[0], older_epcs