#
# Copyright (c) 2021 Airbyte, Inc., all rights reserved.
#

import time
from abc import ABC
from datetime import datetime
from typing import Any, Iterable, List, Mapping, MutableMapping, Optional, Tuple
from urllib.parse import parse_qsl, urlparse

import requests
from airbyte_cdk.logger import AirbyteLogger
from airbyte_cdk.sources import AbstractSource
from airbyte_cdk.sources.streams import Stream
from airbyte_cdk.sources.streams.http import HttpStream
from airbyte_cdk.sources.streams.http.auth import HttpAuthenticator, TokenAuthenticator


class IntercomStream(HttpStream, ABC):
    url_base = "https://api.intercom.io/"

    # https://developers.intercom.com/intercom-api-reference/reference#rate-limiting
    queries_per_minute = 1000  # 1000 queries per minute == 16.67 req per sec

    primary_key = "id"
    data_fields = ["data"]

    def __init__(
        self,
        authenticator: HttpAuthenticator,
        start_date: str = None,
        **kwargs,
    ):
        self.start_date = start_date

        super().__init__(authenticator=authenticator)

    def next_page_token(self, response: requests.Response) -> Optional[Mapping[str, Any]]:
        """
        Abstract method of HttpStream - should be overwritten.
        Returning None means there are no more pages to read in response.
        """

        next_page = response.json().get("pages", {}).get("next")

        if next_page:
            return dict(parse_qsl(urlparse(next_page).query))

    def request_params(self, next_page_token: Mapping[str, Any] = None, **kwargs) -> MutableMapping[str, Any]:
        params = {}
        if next_page_token:
            params.update(**next_page_token)
        return params

    def request_headers(self, **kwargs) -> Mapping[str, Any]:
        return {"Accept": "application/json"}

    def read_records(self, *args, **kwargs) -> Iterable[Mapping[str, Any]]:
        try:
            yield from super().read_records(*args, **kwargs)
        except requests.exceptions.HTTPError as e:
            error_message = e.response.text
            if error_message:
                self.logger.error(f"Stream {self.name}: {e.response.status_code} " f"{e.response.reason} - {error_message}")
            raise e

    def get_data(self, response: requests.Response) -> List:
        data = response.json()

        for data_field in self.data_fields:
            if data and isinstance(data, dict):
                data = data.get(data_field, [])

        if isinstance(data, list):
            data = data
        elif isinstance(data, dict):
            data = [data]

        return data

    def parse_response(self, response: requests.Response, stream_state: Mapping[str, Any], **kwargs) -> Iterable[Mapping]:
        data = self.get_data(response)

        for record in data:
            yield record

        # This is probably overkill because the request itself likely took more
        # than the rate limit, but keep it just to be safe.
        time.sleep(60.0 / self.queries_per_minute)


class IncrementalIntercomStream(IntercomStream, ABC):
    cursor_field = "updated_at"

    def filter_by_state(self, stream_state: Mapping[str, Any] = None, record: Mapping[str, Any] = None) -> Iterable:
        """
        Endpoint does not provide query filtering params, but they provide us
        updated_at field in most cases, so we used that as incremental filtering
        during the slicing.
        """

        if not stream_state or record[self.cursor_field] >= stream_state.get(self.cursor_field):
            yield record

    def parse_response(self, response: requests.Response, stream_state: Mapping[str, Any], **kwargs) -> Iterable[Mapping]:
        record = super().parse_response(response, stream_state, **kwargs)

        for record in record:
            yield from self.filter_by_state(stream_state=stream_state, record=record)

    def get_updated_state(self, current_stream_state: MutableMapping[str, Any], latest_record: Mapping[str, Any]) -> Mapping[str, any]:
        """
        This method is called once for each record returned from the API to
        compare the cursor field value in that record with the current state
        we then return an updated state object. If this is the first time we
        run a sync or no state was passed, current_stream_state will be None.
        """

        current_stream_state = current_stream_state or {}

        current_stream_state_date = current_stream_state.get(self.cursor_field, self.start_date)
        latest_record_date = latest_record.get(self.cursor_field, self.start_date)

        return {self.cursor_field: max(current_stream_state_date, latest_record_date)}


class ChildStreamMixin:
    parent_stream_class: Optional[IntercomStream] = None

    def stream_slices(self, sync_mode, **kwargs) -> Iterable[Optional[Mapping[str, any]]]:
        for item in self.parent_stream_class(authenticator=self.authenticator, start_date=self.start_date).read_records(
            sync_mode=sync_mode
        ):
            yield {"id": item["id"]}

        yield from []


class Admins(IntercomStream):
    """Return list of all admins.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-admins
    Endpoint: https://api.intercom.io/admins
    """

    data_fields = ["admins"]

    def path(self, **kwargs) -> str:
        return "admins"


class Companies(IncrementalIntercomStream):
    """Return list of all companies.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#iterating-over-all-companies
    Endpoint: https://api.intercom.io/companies/scroll
    """

    def next_page_token(self, response: requests.Response) -> Optional[Mapping[str, Any]]:
        """For reset scroll needs to iterate pages untill the last.
        Another way need wait 1 min for the scroll to expire to get a new list for companies segments."""

        data = response.json().get("data")

        if data:
            return {"scroll_param": response.json().get("scroll_param")}

    def path(self, **kwargs) -> str:
        return "companies/scroll"


class CompanySegments(ChildStreamMixin, IncrementalIntercomStream):
    """Return list of all company segments.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-attached-segments-1
    Endpoint: https://api.intercom.io/companies/<id>/segments
    """

    parent_stream_class = Companies

    def path(self, stream_slice: Mapping[str, Any] = None, **kwargs) -> str:
        return f"/companies/{stream_slice['id']}/segments"


class Conversations(IncrementalIntercomStream):
    """Return list of all conversations.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-conversations
    Endpoint: https://api.intercom.io/conversations
    """

    data_fields = ["conversations"]

    def path(self, **kwargs) -> str:
        return "conversations"


class ConversationParts(ChildStreamMixin, IncrementalIntercomStream):
    """Return list of all conversation parts.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#retrieve-a-conversation
    Endpoint: https://api.intercom.io/conversations/<id>
    """

    data_fields = ["conversation_parts", "conversation_parts"]
    parent_stream_class = Conversations

    def path(self, stream_slice: Mapping[str, Any] = None, **kwargs) -> str:
        return f"/conversations/{stream_slice['id']}"


class Segments(IncrementalIntercomStream):
    """Return list of all segments.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-segments
    Endpoint: https://api.intercom.io/segments
    """

    data_fields = ["segments"]

    def path(self, **kwargs) -> str:
        return "segments"


class Contacts(IncrementalIntercomStream):
    """Return list of all contacts.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-contacts
    Endpoint: https://api.intercom.io/contacts
    """

    def next_page_token(self, response: requests.Response) -> Optional[Mapping[str, Any]]:
        """
        Abstract method of HttpStream - should be overwritten.
        Returning None means there are no more pages to read in response.
        """

        next_page = response.json().get("pages", {}).get("next")

        if isinstance(next_page, dict):
            return {"starting_after": next_page["starting_after"]}

        if isinstance(next_page, str):
            return super().next_page_token(response)

    def path(self, **kwargs) -> str:
        return "contacts"


class DataAttributes(IntercomStream):
    primary_key = "name"

    def path(self, **kwargs) -> str:
        return "data_attributes"


class CompanyAttributes(DataAttributes):
    """Return list of all data attributes belonging to a workspace for companies.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-data-attributes
    Endpoint: https://api.intercom.io/data_attributes?model=company
    """

    def request_params(self, **kwargs) -> MutableMapping[str, Any]:
        return {"model": "company"}


class ContactAttributes(DataAttributes):
    """Return list of all data attributes belonging to a workspace for contacts.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-data-attributes
    Endpoint: https://api.intercom.io/data_attributes?model=contact
    """

    def request_params(self, **kwargs) -> MutableMapping[str, Any]:
        return {"model": "contact"}


class Tags(IntercomStream):
    """Return list of all tags.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-tags-for-an-app
    Endpoint: https://api.intercom.io/tags
    """

    primary_key = "name"

    def path(self, **kwargs) -> str:
        return "tags"


class Teams(IntercomStream):
    """Return list of all teams.
    API Docs: https://developers.intercom.com/intercom-api-reference/reference#list-teams
    Endpoint: https://api.intercom.io/teams
    """

    primary_key = "name"
    data_fields = ["teams"]

    def path(self, **kwargs) -> str:
        return "teams"


class SourceIntercom(AbstractSource):
    """
    Source Intercom fetch data from messaging platform.
    """

    def check_connection(self, logger, config) -> Tuple[bool, any]:
        authenticator = TokenAuthenticator(token=config["access_token"])
        try:
            url = f"{IntercomStream.url_base}/tags"
            auth_headers = {"Accept": "application/json", **authenticator.get_auth_header()}
            session = requests.get(url, headers=auth_headers)
            session.raise_for_status()
            return True, None
        except requests.exceptions.RequestException as e:
            return False, e

    def streams(self, config: Mapping[str, Any]) -> List[Stream]:
        AirbyteLogger().log("INFO", f"Using start_date: {config['start_date']}")

        config["start_date"] = datetime.strptime(config["start_date"], "%Y-%m-%dT%H:%M:%SZ").timestamp()

        auth = TokenAuthenticator(token=config["access_token"])
        return [
            Admins(authenticator=auth, **config),
            Companies(authenticator=auth, **config),
            CompanySegments(authenticator=auth, **config),
            Conversations(authenticator=auth, **config),
            ConversationParts(authenticator=auth, **config),
            Contacts(authenticator=auth, **config),
            CompanyAttributes(authenticator=auth, **config),
            ContactAttributes(authenticator=auth, **config),
            Segments(authenticator=auth, **config),
            Tags(authenticator=auth, **config),
            Teams(authenticator=auth, **config),
        ]