import hashlib
import hmac
import json
import logging
from typing import Optional

from django.conf import settings
from django.http import HttpResponse
from rest_framework import status
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.views import APIView

from apps.api.permissions import RBACPermission
from apps.auth_token.auth import PluginAuthentication
from apps.base.utils import live_settings
from apps.slack.scenarios.alertgroup_appearance import STEPS_ROUTING as ALERTGROUP_APPEARANCE_ROUTING

# Importing routes from scenarios
from apps.slack.scenarios.declare_incident import STEPS_ROUTING as DECLARE_INCIDENT_ROUTING
from apps.slack.scenarios.distribute_alerts import STEPS_ROUTING as DISTRIBUTION_STEPS_ROUTING
from apps.slack.scenarios.invited_to_channel import STEPS_ROUTING as INVITED_TO_CHANNEL_ROUTING
from apps.slack.scenarios.manual_incident import STEPS_ROUTING as MANUAL_INCIDENT_ROUTING
from apps.slack.scenarios.notified_user_not_in_channel import STEPS_ROUTING as NOTIFIED_USER_NOT_IN_CHANNEL_ROUTING
from apps.slack.scenarios.onboarding import STEPS_ROUTING as ONBOARDING_STEPS_ROUTING
from apps.slack.scenarios.paging import STEPS_ROUTING as DIRECT_PAGE_ROUTING
from apps.slack.scenarios.profile_update import STEPS_ROUTING as PROFILE_UPDATE_ROUTING
from apps.slack.scenarios.resolution_note import STEPS_ROUTING as RESOLUTION_NOTE_ROUTING
from apps.slack.scenarios.scenario_step import (
    EVENT_SUBTYPE_BOT_MESSAGE,
    EVENT_SUBTYPE_FILE_SHARE,
    EVENT_SUBTYPE_MESSAGE_CHANGED,
    EVENT_SUBTYPE_MESSAGE_DELETED,
    EVENT_TYPE_APP_MENTION,
    EVENT_TYPE_MESSAGE,
    EVENT_TYPE_MESSAGE_CHANNEL,
    EVENT_TYPE_SUBTEAM_CREATED,
    EVENT_TYPE_SUBTEAM_MEMBERS_CHANGED,
    EVENT_TYPE_SUBTEAM_UPDATED,
    EVENT_TYPE_USER_CHANGE,
    PAYLOAD_TYPE_BLOCK_ACTIONS,
    PAYLOAD_TYPE_DIALOG_SUBMISSION,
    PAYLOAD_TYPE_EVENT_CALLBACK,
    PAYLOAD_TYPE_INTERACTIVE_MESSAGE,
    PAYLOAD_TYPE_MESSAGE_ACTION,
    PAYLOAD_TYPE_SLASH_COMMAND,
    PAYLOAD_TYPE_VIEW_SUBMISSION,
    ScenarioStep,
)
from apps.slack.scenarios.schedules import STEPS_ROUTING as SCHEDULES_ROUTING
from apps.slack.scenarios.slack_channel import STEPS_ROUTING as CHANNEL_ROUTING
from apps.slack.scenarios.slack_channel_integration import STEPS_ROUTING as SLACK_CHANNEL_INTEGRATION_ROUTING
from apps.slack.scenarios.slack_usergroup import STEPS_ROUTING as SLACK_USERGROUP_UPDATE_ROUTING
from apps.slack.slack_client import SlackClientWithErrorHandling
from apps.slack.slack_client.exceptions import SlackAPIException, SlackAPITokenException
from apps.slack.tasks import clean_slack_integration_leftovers, unpopulate_slack_user_identities
from common.insight_log import ChatOpsEvent, ChatOpsTypePlug, write_chatops_insight_log
from common.oncall_gateway import delete_slack_connector

from .models import SlackMessage, SlackTeamIdentity, SlackUserIdentity

SCENARIOS_ROUTES = []  # Add all other routes here
SCENARIOS_ROUTES.extend(ONBOARDING_STEPS_ROUTING)
SCENARIOS_ROUTES.extend(DISTRIBUTION_STEPS_ROUTING)
SCENARIOS_ROUTES.extend(INVITED_TO_CHANNEL_ROUTING)
SCENARIOS_ROUTES.extend(SCHEDULES_ROUTING)
SCENARIOS_ROUTES.extend(SLACK_CHANNEL_INTEGRATION_ROUTING)
SCENARIOS_ROUTES.extend(ALERTGROUP_APPEARANCE_ROUTING)
SCENARIOS_ROUTES.extend(RESOLUTION_NOTE_ROUTING)
SCENARIOS_ROUTES.extend(SLACK_USERGROUP_UPDATE_ROUTING)
SCENARIOS_ROUTES.extend(CHANNEL_ROUTING)
SCENARIOS_ROUTES.extend(PROFILE_UPDATE_ROUTING)
SCENARIOS_ROUTES.extend(MANUAL_INCIDENT_ROUTING)
SCENARIOS_ROUTES.extend(DIRECT_PAGE_ROUTING)
SCENARIOS_ROUTES.extend(DECLARE_INCIDENT_ROUTING)
SCENARIOS_ROUTES.extend(NOTIFIED_USER_NOT_IN_CHANNEL_ROUTING)

logger = logging.getLogger(__name__)

SELECT_ORGANIZATION_AND_ROUTE_BLOCK_ID = "SELECT_ORGANIZATION_AND_ROUTE"


class StopAnalyticsReporting(APIView):
    def get(self, request):
        response = HttpResponse(
            "Your app installation would not be tracked by analytics from backend, "
            "use browser plugin to disable from a frontend side. "
        )
        response.set_cookie("no_track", True, max_age=10 * 360 * 24 * 60 * 60)
        return response


class InstallLinkRedirectView(APIView):
    def get(self, request, subscription="free", utm="not_specified"):
        return HttpResponse(("Sign up is not allowed"), status=status.HTTP_400_BAD_REQUEST)


class SignupRedirectView(APIView):
    def get(self, request, subscription="free", utm="not_specified"):
        return HttpResponse(("Sign up is not allowed"), status=status.HTTP_400_BAD_REQUEST)


class OAuthSlackView(APIView):
    def get(self, request, format=None, subscription="free", utm="not_specified"):
        return HttpResponse(("Sign up is not allowed"), status=status.HTTP_400_BAD_REQUEST)


class SlackEventApiEndpointView(APIView):
    @staticmethod
    def verify_signature(timestamp, signature, body, secret):
        # https://github.com/slackapi/python-slack-events-api/blob/master/slackeventsapi/server.py#L47

        if hasattr(hmac, "compare_digest"):
            req = str.encode("v0:" + str(timestamp) + ":") + body
            request_hash = "v0=" + hmac.new(str.encode(secret), req, hashlib.sha256).hexdigest()
            return hmac.compare_digest(request_hash, signature)

    def get(self, request, format=None):
        return Response("hello")

    def post(self, request):
        logger.info("Request id: {}".format(request.META.get("HTTP_X_REQUEST_ID")))
        body = request.body

        try:
            slack_signature = request.META["HTTP_X_SLACK_SIGNATURE"]
            slack_request_timestamp = request.META["HTTP_X_SLACK_REQUEST_TIMESTAMP"]
        except KeyError:
            logger.warning("X-Slack-Signature or X-Slack-Request_Timestamp don't exist, This request is not from slack")
            return Response(status=403)

        if not settings.DEBUG:
            if live_settings.SLACK_SIGNING_SECRET is None and settings.SLACK_SIGNING_SECRET_LIVE:
                raise Exception("Please specify SLACK_SIGNING_SECRET or use DEBUG.")

            if not (
                SlackEventApiEndpointView.verify_signature(
                    slack_request_timestamp, slack_signature, body, live_settings.SLACK_SIGNING_SECRET
                )
                or SlackEventApiEndpointView.verify_signature(
                    slack_request_timestamp, slack_signature, body, settings.SLACK_SIGNING_SECRET_LIVE
                )
            ):
                return Response(status=403)

        # Unifying payload
        if "payload" in request.data:
            payload = request.data["payload"]
        else:
            payload = request.data
        if isinstance(payload, str):
            payload = json.JSONDecoder().decode(payload)

        logger.info(
            "team_id: %s channel_id: %s user_id: %s command: %s event: %s",
            payload.get("team_id"),
            payload.get("channel_id"),
            payload.get("user_id"),
            payload.get("command"),
            payload.get("event", {}).get("type"),
        )

        # Checking if it's repeated Slack request
        if "HTTP_X_SLACK_RETRY_NUM" in request.META and int(request.META["HTTP_X_SLACK_RETRY_NUM"]) > 1:
            logger.critical(
                "Slack retries {} time, request data: {}".format(request.META["HTTP_X_SLACK_RETRY_NUM"], request.data)
            )
            payload["amixr_slack_retries"] = request.META["HTTP_X_SLACK_RETRY_NUM"]

        # Initial url verification
        if "type" in payload and payload["type"] == "url_verification":
            logger.critical("URL verification from Slack side. That's suspicious.")
            return Response(payload["challenge"])

        # Linking team
        slack_team_identity = self._get_slack_team_identity_from_payload(payload)

        if not slack_team_identity:
            logger.info("Dropping request because it does not have SlackTeamIdentity.")
            return Response()

        # Means that slack_team_identity unpopulated
        if not slack_team_identity.organizations.exists():
            logger.warning(f"OnCall Team for SlackTeamIdentity is not detected, stop it!")
            # Open pop-up to inform user why OnCall bot doesn't work if any action was triggered
            warning_text = (
                "OnCall is not able to process this action because this Slack workspace was "
                "disconnected from OnCall. Please log in to the OnCall web interface and install "
                "Slack Integration with this workspace again."
            )
            self._open_warning_window_if_needed(payload, slack_team_identity, warning_text)
            return Response(status=200)

        # Todo: the case when team has no keys is unexpected, investigation is required
        if slack_team_identity.access_token is None and slack_team_identity.bot_access_token is None:
            logger.info(f"Team {slack_team_identity.slack_id} has no keys, dropping request.")
            return Response()

        sc = SlackClientWithErrorHandling(slack_team_identity.bot_access_token)

        if slack_team_identity.detected_token_revoked is not None:
            # check if token is still invalid
            try:
                sc.api_call(
                    "auth.test",
                    team=slack_team_identity,
                )
            except SlackAPITokenException:
                logger.info(f"Team {slack_team_identity.slack_id} has revoked token, dropping request.")
                return Response(status=200)

        Step = None
        step_was_found = False

        slack_user_id = None
        user = None
        # Linking user identity
        slack_user_identity = None

        if "event" in payload and payload["event"] is not None:
            if ("user" in payload["event"]) and slack_team_identity and (payload["event"]["user"] is not None):
                if "id" in payload["event"]["user"]:
                    slack_user_id = payload["event"]["user"]["id"]
                elif type(payload["event"]["user"]) is str:
                    slack_user_id = payload["event"]["user"]
                else:
                    raise Exception("Failed Linking user identity")

            elif (
                ("bot_id" in payload["event"])
                and slack_team_identity
                and (
                    payload["event"]["bot_id"] is not None
                    and "channel_type" in payload["event"]
                    and payload["event"]["channel_type"] == EVENT_TYPE_MESSAGE_CHANNEL
                )
            ):
                response = sc.api_call("bots.info", bot=payload["event"]["bot_id"])
                bot_user_id = response.get("bot", {}).get("user_id", "")

                # Don't react on own bot's messages.
                if bot_user_id == slack_team_identity.bot_user_id:
                    return Response(status=200)

            elif "user" in payload["event"].get("message", {}):
                slack_user_id = payload["event"]["message"]["user"]
            # event subtype 'message_deleted'
            elif "user" in payload["event"].get("previous_message", {}):
                slack_user_id = payload["event"]["previous_message"]["user"]

        if "user" in payload:
            slack_user_id = payload["user"]["id"]

        elif "user_id" in payload:
            slack_user_id = payload["user_id"]

        if slack_user_id is not None and slack_user_id != slack_team_identity.bot_user_id:
            slack_user_identity = SlackUserIdentity.objects.filter(
                slack_id=slack_user_id,
                slack_team_identity=slack_team_identity,
            ).first()

        organization = self._get_organization_from_payload(payload, slack_team_identity)
        logger.info("Organization: " + str(organization))
        logger.info("SlackUserIdentity detected: " + str(slack_user_identity))

        if not slack_user_identity:
            if "type" in payload and payload["type"] == PAYLOAD_TYPE_EVENT_CALLBACK:
                if payload["event"]["type"] in [
                    EVENT_TYPE_SUBTEAM_CREATED,
                    EVENT_TYPE_SUBTEAM_UPDATED,
                    EVENT_TYPE_SUBTEAM_MEMBERS_CHANGED,
                ]:
                    logger.info("Slack event without user slack_id.")
                elif payload["event"]["type"] == EVENT_TYPE_USER_CHANGE:
                    logger.info("Event user_change. Dropping request because it does not have SlackUserIdentity.")
                    return Response()
            else:
                logger.info("Dropping request because it does not have SlackUserIdentity.")
                self._open_warning_for_unconnected_user(sc, payload)
                return Response()
        elif organization:
            user = slack_user_identity.get_user(organization)
            if not user:
                # Means that user slack_user_identity is not in any organization, connected to this Slack workspace
                warning_text = "Permission denied. Please connect your Slack account to OnCall."
                # Open pop-up to inform user why OnCall bot doesn't work if any action was triggered
                self._open_warning_window_if_needed(payload, slack_team_identity, warning_text)
                return Response(status=200)
        elif not slack_user_identity.users.exists():
            # Means that slack_user_identity doesn't have any connected user
            # Open pop-up to inform user why OnCall bot doesn't work if any action was triggered
            self._open_warning_for_unconnected_user(sc, payload)
            return Response(status=200)

        # Capture cases when we expect stateful message from user
        if not step_was_found and "type" in payload and payload["type"] == PAYLOAD_TYPE_EVENT_CALLBACK:
            # Message event is from channel
            if (
                payload["event"]["type"] == EVENT_TYPE_MESSAGE
                and payload["event"]["channel_type"] == EVENT_TYPE_MESSAGE_CHANNEL
                and (
                    "subtype" not in payload["event"]
                    or payload["event"]["subtype"] == EVENT_SUBTYPE_BOT_MESSAGE
                    or payload["event"]["subtype"] == EVENT_SUBTYPE_MESSAGE_CHANGED
                    or payload["event"]["subtype"] == EVENT_SUBTYPE_FILE_SHARE
                    or payload["event"]["subtype"] == EVENT_SUBTYPE_MESSAGE_DELETED
                )
            ):
                for route in SCENARIOS_ROUTES:
                    if (
                        "message_channel_type" in route
                        and payload["event"]["channel_type"] == route["message_channel_type"]
                    ):
                        Step = route["step"]
                        logger.info("Routing to {}".format(Step))
                        step = Step(slack_team_identity, organization, user)
                        step.process_scenario(slack_user_identity, slack_team_identity, payload)
                        step_was_found = True
            # We don't do anything on app mention, but we doesn't want to unsubscribe from this event yet.
            if payload["event"]["type"] == EVENT_TYPE_APP_MENTION:
                logger.info(f"Received event of type {EVENT_TYPE_APP_MENTION} from slack. Skipping.")
                return Response(status=200)
        # Routing to Steps based on routing rules
        if not step_was_found:
            for route in SCENARIOS_ROUTES:
                # Slash commands have to "type"
                if "command" in payload and route["payload_type"] == PAYLOAD_TYPE_SLASH_COMMAND:
                    if payload["command"] in route["command_name"]:
                        Step = route["step"]
                        logger.info("Routing to {}".format(Step))
                        step = Step(slack_team_identity, organization, user)
                        step.process_scenario(slack_user_identity, slack_team_identity, payload)
                        step_was_found = True

                if "type" in payload and payload["type"] == route["payload_type"]:
                    if payload["type"] == PAYLOAD_TYPE_EVENT_CALLBACK:
                        if payload["event"]["type"] == route["event_type"]:
                            # event_name is used for stateful
                            if "event_name" not in route:
                                Step = route["step"]
                                logger.info("Routing to {}".format(Step))
                                step = Step(slack_team_identity, organization, user)
                                step.process_scenario(slack_user_identity, slack_team_identity, payload)
                                step_was_found = True

                    if payload["type"] == PAYLOAD_TYPE_INTERACTIVE_MESSAGE:
                        for action in payload["actions"]:
                            if action["type"] == route["action_type"]:
                                # Action name may also contain action arguments.
                                # So only beginning is used for routing.
                                if action["name"].startswith(route["action_name"]):
                                    Step = route["step"]
                                    logger.info("Routing to {}".format(Step))
                                    step = Step(slack_team_identity, organization, user)
                                    result = step.process_scenario(slack_user_identity, slack_team_identity, payload)
                                    if result is not None:
                                        return result
                                    step_was_found = True

                    if payload["type"] == PAYLOAD_TYPE_BLOCK_ACTIONS:
                        for action in payload["actions"]:
                            if action["type"] == route["block_action_type"]:
                                if action["action_id"].startswith(route["block_action_id"]):
                                    Step = route["step"]
                                    logger.info("Routing to {}".format(Step))
                                    step = Step(slack_team_identity, organization, user)
                                    step.process_scenario(slack_user_identity, slack_team_identity, payload)
                                    step_was_found = True

                    if payload["type"] == PAYLOAD_TYPE_DIALOG_SUBMISSION:
                        if payload["callback_id"] == route["dialog_callback_id"]:
                            Step = route["step"]
                            logger.info("Routing to {}".format(Step))
                            step = Step(slack_team_identity, organization, user)
                            result = step.process_scenario(slack_user_identity, slack_team_identity, payload)
                            if result is not None:
                                return result
                            step_was_found = True

                    if payload["type"] == PAYLOAD_TYPE_VIEW_SUBMISSION:
                        if payload["view"]["callback_id"].startswith(route["view_callback_id"]):
                            Step = route["step"]
                            logger.info("Routing to {}".format(Step))
                            step = Step(slack_team_identity, organization, user)
                            result = step.process_scenario(slack_user_identity, slack_team_identity, payload)
                            if result is not None:
                                return result
                            step_was_found = True

                    if payload["type"] == PAYLOAD_TYPE_MESSAGE_ACTION:
                        if payload["callback_id"] in route["message_action_callback_id"]:
                            Step = route["step"]
                            logger.info("Routing to {}".format(Step))
                            step = Step(slack_team_identity, organization, user)
                            step.process_scenario(slack_user_identity, slack_team_identity, payload)
                            step_was_found = True

        if not step_was_found:
            raise Exception("Step is undefined" + str(payload))

        return Response(status=200)

    def _get_slack_team_identity_from_payload(self, payload) -> Optional[SlackTeamIdentity]:
        slack_team_identity = None

        if "team" in payload:
            slack_team_id = payload["team"]["id"]
        elif "team_id" in payload:
            slack_team_id = payload["team_id"]
        else:
            return slack_team_identity

        try:
            slack_team_identity = SlackTeamIdentity.objects.get(slack_id=slack_team_id)
        except SlackTeamIdentity.DoesNotExist as e:
            logger.warning("Team identity not detected, that's dangerous!" + str(e))
        return slack_team_identity

    def _get_organization_from_payload(self, payload, slack_team_identity):
        message_ts = None
        channel_id = None
        organization = None

        # view submission or actions in view
        if "view" in payload:
            organization_id = None
            private_metadata = payload["view"].get("private_metadata")
            # steps with private_metadata in which we know organization before open view
            if private_metadata and "organization_id" in private_metadata:
                organization_id = json.loads(private_metadata).get("organization_id")
            # steps with organization selection in view (e.g. slash commands)
            elif SELECT_ORGANIZATION_AND_ROUTE_BLOCK_ID in payload["view"].get("state", {}).get("values", {}):
                payload_values = payload["view"]["state"]["values"]
                selected_value = payload_values[SELECT_ORGANIZATION_AND_ROUTE_BLOCK_ID][
                    SELECT_ORGANIZATION_AND_ROUTE_BLOCK_ID
                ]["selected_option"]["value"]
                organization_id = int(selected_value.split("-")[0])
            if organization_id:
                organization = slack_team_identity.organizations.get(pk=organization_id)
                return organization
        # buttons and actions
        elif payload.get("type") in [
            PAYLOAD_TYPE_BLOCK_ACTIONS,
            PAYLOAD_TYPE_INTERACTIVE_MESSAGE,
            PAYLOAD_TYPE_MESSAGE_ACTION,
        ]:
            # for cases when we put organization_id into action value (e.g. public suggestion)
            if (
                payload.get("actions")
                and payload["actions"][0].get("value", {})
                and "organization_id" in payload["actions"][0]["value"]
            ):
                organization_id = int(json.loads(payload["actions"][0]["value"])["organization_id"])
                organization = slack_team_identity.organizations.get(pk=organization_id)
                return organization

            channel_id = payload["channel"]["id"]
            if "message" in payload:
                message_ts = payload["message"].get("thread_ts") or payload["message"]["ts"]
            # for interactive message
            elif "message_ts" in payload:
                message_ts = payload["message_ts"]
            else:
                return
        # events
        elif payload.get("type") == PAYLOAD_TYPE_EVENT_CALLBACK:
            if "channel" in payload["event"]:  # events without channel: user_change, events with subteam, etc.
                channel_id = payload["event"]["channel"]

            if "message" in payload["event"]:
                message_ts = payload["event"]["message"].get("thread_ts") or payload["event"]["message"]["ts"]
            elif "thread_ts" in payload["event"]:
                message_ts = payload["event"]["thread_ts"]
            else:
                return

        if not (message_ts and channel_id):
            return

        try:
            slack_message = SlackMessage.objects.get(
                slack_id=message_ts,
                _slack_team_identity=slack_team_identity,
                channel_id=channel_id,
            )
        except SlackMessage.DoesNotExist:
            pass
        else:
            alert_group = slack_message.get_alert_group()
            if alert_group:
                organization = alert_group.channel.organization
                return organization
        return organization

    def _open_warning_window_if_needed(self, payload, slack_team_identity, warning_text) -> None:
        if payload.get("trigger_id") is not None:
            step = ScenarioStep(slack_team_identity)
            try:
                step.open_warning_window(payload, warning_text)
            except SlackAPIException as e:
                logger.info(
                    f"Failed to open pop-up for unpopulated SlackTeamIdentity {slack_team_identity.pk}\n" f"Error: {e}"
                )

    def _open_warning_for_unconnected_user(self, slack_client, payload):
        if payload.get("trigger_id") is None:
            return

        text = (
            "The information in this workspace is read-only. To interact with OnCall alert groups you need to connect a personal account.\n"
            "Please go to *Grafana* -> *OnCall* -> *Users*, "
            "choose *your profile* and click the *connect* button.\n"
            ":rocket: :rocket: :rocket:"
        )

        view = {
            "blocks": (
                {"type": "section", "block_id": "section-identifier", "text": {"type": "mrkdwn", "text": text}},
            ),
            "type": "modal",
            "callback_id": "modal-identifier",
            "title": {
                "type": "plain_text",
                "text": "One more step!",
            },
        }
        slack_client.api_call(
            "views.open",
            trigger_id=payload["trigger_id"],
            view=view,
        )


class ResetSlackView(APIView):

    permission_classes = (IsAuthenticated, RBACPermission)
    authentication_classes = [PluginAuthentication]

    rbac_permissions = {
        "post": [RBACPermission.Permissions.CHATOPS_UPDATE_SETTINGS],
    }

    def post(self, request):
        if settings.SLACK_INTEGRATION_MAINTENANCE_ENABLED:
            response = Response(
                "Grafana OnCall is temporary unable to connect your slack account or install OnCall to your slack workspace",
                status=400,
            )
        else:
            organization = request.auth.organization
            slack_team_identity = organization.slack_team_identity
            if slack_team_identity is not None:
                clean_slack_integration_leftovers.apply_async((organization.pk,))
                if settings.FEATURE_MULTIREGION_ENABLED:
                    delete_slack_connector(str(organization.uuid))
                write_chatops_insight_log(
                    author=request.user,
                    event_name=ChatOpsEvent.WORKSPACE_DISCONNECTED,
                    chatops_type=ChatOpsTypePlug.SLACK.value,
                )
                unpopulate_slack_user_identities(organization.pk, True)
                response = Response(status=200)
            else:
                response = Response(status=400)
        return response