import xml.etree.ElementTree as ET
from datetime import date
from typing import Dict, List, Tuple, Union

import requests

from domain.abri.models import (
    AbriRequestRejected,
    AmendJobRequest,
    AmendJobResult,
    AppointmentAmended,
    GetTenantDataResult,
    JobLogged,
    LogJobRequest,
    LogJobResult,
    PlaceRef,
    TenancyData,
    Tenant,
)
from domain.abri.phone_selection import PhoneEntry, PhoneKind, select_phone_numbers
from infrastructure.abri.config import AbriConfig
from infrastructure.abri.envelope import serialise_relay_request
from infrastructure.abri.errors import AbriResponseParseError, AbriTransportError

STD_JOB_CODE = "SCSEXT"
CLIENT_CODE = "HSG"
RESOURCE_GROUP = "Surveyors"


def _format_appointment_date(appointment_date: date) -> str:
    return appointment_date.strftime("%d/%m/%Y")


# Wire tags -> the domain's phone kinds; selection policy lives in the domain.
_PHONE_KINDS: Dict[str, PhoneKind] = {"Mobile": "mobile", "Telephone": "telephone"}


def _phone_entries(tenant_element: ET.Element) -> List[PhoneEntry]:
    return [
        PhoneEntry(
            kind=_PHONE_KINDS[child.tag],
            number=child.text or "",
            priority=child.get("priority"),
        )
        for child in tenant_element
        if child.tag in _PHONE_KINDS
    ]


class AbriClient:
    def __init__(self, config: AbriConfig) -> None:
        self._config = config
        self._session = requests.Session()

    def log_job(self, request: LogJobRequest) -> LogJobResult:
        outcome = self._exchange(
            request_type="logjob",
            parameters=[
                ("place_ref", request.place_ref),
                ("std_job_code", STD_JOB_CODE),
                ("client", CLIENT_CODE),
                ("short_description", request.short_description),
                ("long_description", request.long_description),
                ("client_ref", request.client_ref),
                ("appointment_date", _format_appointment_date(request.appointment_date)),
                ("appointment_time", request.appointment_time),
                ("resource", self._config.default_resource),
                ("resource_group", RESOURCE_GROUP),
            ],
        )

        if isinstance(outcome, AbriRequestRejected):
            return outcome

        return self._parse_job_logged(outcome)

    def amend_job(self, request: AmendJobRequest) -> AmendJobResult:
        parameters = [
            ("job_no", request.job_no),
            ("action", "amend"),
            ("appointment_date", _format_appointment_date(request.appointment_date)),
            ("appointment_time", request.appointment_time),
        ]
        if request.resource is not None:
            parameters.append(("resource", request.resource))

        outcome = self._exchange(
            request_type="amendoptiappt",
            parameters=parameters,
        )

        if isinstance(outcome, AbriRequestRejected):
            return outcome

        return self._parse_appointment_amended(outcome)

    def get_tenant_data(self, place_ref: PlaceRef) -> GetTenantDataResult:
        outcome = self._exchange(
            request_type="getSCSTenantData",
            parameters=[("place_ref", place_ref)],
        )

        if isinstance(outcome, AbriRequestRejected):
            return outcome

        return self._parse_tenancy_data(outcome)

    def _exchange(
        self, request_type: str, parameters: List[Tuple[str, str]]
    ) -> Union[ET.Element, AbriRequestRejected]:
        envelope = serialise_relay_request(
            request_type=request_type,
            parameters=parameters,
            username=self._config.username,
            password=self._config.password,
        )

        reply = self._parse_reply(self._post(envelope))

        if self._is_failure_document(reply):
            return self._parse_rejection(reply)

        return reply

    def _post(self, envelope: bytes) -> bytes:
        try:
            response = self._session.post(self._config.endpoint_url, data=envelope)
            response.raise_for_status()
        except requests.RequestException as error:
            raise AbriTransportError(str(error)) from error

        return response.content

    @staticmethod
    def _parse_reply(body: bytes) -> ET.Element:
        try:
            return ET.fromstring(body)
        except ET.ParseError as error:
            raise AbriResponseParseError(str(error)) from error

    @staticmethod
    def _is_failure_document(reply: ET.Element) -> bool:
        return reply.tag == "response"

    @staticmethod
    def _parse_job_logged(root: ET.Element) -> JobLogged:
        job_logged = root.find("Jobs/Job_logged")

        if job_logged is None:
            raise AbriResponseParseError(
                "Job_logged element missing from relay response"
            )

        job_no = job_logged.get("job_no")
        logged_info = job_logged.get("logged_info")

        if job_no is None or logged_info is None:
            raise AbriResponseParseError(
                "Job_logged element missing job_no or logged_info"
            )

        return JobLogged(job_no=job_no, logged_info=logged_info)

    @staticmethod
    def _parse_appointment_amended(root: ET.Element) -> AppointmentAmended:
        amended = root.find("AmendOptiAppt")

        if amended is None:
            raise AbriResponseParseError(
                "AmendOptiAppt element missing from relay response"
            )

        if amended.get("success") != "Y":
            raise AbriResponseParseError(
                "AmendOptiAppt element did not confirm success"
            )

        job_no = amended.get("job_no")
        appointment_date = amended.get("appointment_date")
        appointment_time = amended.get("appointment_time")

        if job_no is None or appointment_date is None or appointment_time is None:
            raise AbriResponseParseError(
                "AmendOptiAppt element missing job_no, appointment_date "
                "or appointment_time"
            )

        return AppointmentAmended(
            job_no=job_no,
            appointment_date=appointment_date,
            appointment_time=appointment_time,
        )

    @staticmethod
    def _parse_tenancy_data(root: ET.Element) -> TenancyData:
        tenancies = root.findall("Tenancy")

        if len(tenancies) != 1:
            raise AbriResponseParseError(
                f"expected exactly one Tenancy element, found {len(tenancies)}"
            )

        tenancy = tenancies[0]
        tenancy_reference = (tenancy.text or "").strip()

        if not tenancy_reference:
            raise AbriResponseParseError("Tenancy element missing its reference")

        return TenancyData(
            tenancy_reference=tenancy_reference,
            tenants=tuple(
                AbriClient._parse_tenant(tenant)
                for tenant in tenancy.findall("Tenant")
            ),
        )

    @staticmethod
    def _parse_tenant(element: ET.Element) -> Tenant:
        # Data minimisation: person_title, main-contact and the per-person
        # reference (the element text) are deliberately not read.
        numbers = select_phone_numbers(_phone_entries(element))
        return Tenant(
            forenames=(element.get("forenames") or "").strip(),
            surname=(element.get("surname") or "").strip(),
            mobile=numbers.mobile,
            telephone=numbers.telephone,
            secondary_number=numbers.secondary,
            vulnerabilities=tuple(
                text
                for vulnerability in element.findall("Vulnerability")
                if (text := (vulnerability.text or "").strip())
            ),
        )

    @staticmethod
    def _parse_rejection(root: ET.Element) -> AbriRequestRejected:
        success = root.findtext("success")
        code = root.findtext("code")
        message = root.findtext("message")

        if success != "false" or code is None or message is None:
            raise AbriResponseParseError("malformed relay failure response")

        return AbriRequestRejected(code=code, message=message)