import logging
from collections.abc import Mapping

from django.conf import settings
from django.db.models import Q

from unifi_access import AccessClient
from unifi_access.schemas import AccessPolicy, DoorResource, UserStatus
from unifi_access.schemas import User as AccessUser

from cmsmanage.django_q2_helper import q_task_group
from doorcontrol.models import (
    AbstractScheduleRule,
    ActiveEventInstructorRule,
    AttributeScheduleRule,
    Door,
    FlagScheduleRule,
    Schedule,
)
from membershipworks.models import Member

logger = logging.getLogger(__name__)


def update_user_groups(
    unifi_access: AccessClient,
    access_users_by_employee_number: Mapping[str, AccessUser],
) -> None:
    groups = unifi_access.fetch_all_user_groups()
    top_group = next(g for g in groups if g.up_id == "")
    rule_groups = {g.name: g for g in groups if g.up_id == top_group.id}

    access_policies_by_name = {
        p.name: p for p in unifi_access.fetch_all_access_policies()
    }
    schedules_by_name = {s.name: s for s in unifi_access.fetch_all_schedules()}
    doors_by_name = {d.name: d for d in unifi_access.fetch_all_doors()}

    def sync_access_policy(schedule: Schedule, door: Door) -> AccessPolicy:
        access_policy_name = f"{rule.schedule.name} | {door.name}"
        expected_access_policy = {
            "name": access_policy_name,
            "resources": (
                [DoorResource(id=doors_by_name[door.name].id)]
                if door.name in doors_by_name
                else []
            ),
            "schedule_id": schedules_by_name[schedule.name].id,
        }
        if access_policy := access_policies_by_name.get(access_policy_name):
            changes = {
                k: v
                for k, v in expected_access_policy.items()
                if getattr(access_policy, k) != v
            }
            if changes:
                logger.debug(
                    " - updating access policy %s: %s", access_policy_name, changes
                )
                access_policy = unifi_access.update_access_policy(
                    access_policy.id, **changes
                )
                access_policies_by_name[access_policy_name] = access_policy

        else:
            logger.debug(
                " - creating access policy %s: %s",
                access_policy_name,
                expected_access_policy,
            )
            access_policy = unifi_access.create_access_policy(**expected_access_policy)
            access_policies_by_name[access_policy_name] = access_policy

        return access_policy

    def update_groups_for_rule(rule: AbstractScheduleRule) -> None:
        assert rule.name
        logger.info("Syncing user group '%s'", rule.name)
        rule_group = rule_groups.get(rule.name)
        if not rule_group:
            logger.debug(" - creating top level group for rule")
            rule_group = unifi_access.create_user_group(rule.name)
            # might be None if it already existed, but we already checked for that earlier
            assert rule_group

        door_groups = {g.name: g for g in groups if g.up_id == rule_group.id}
        for door in rule.doors.all():
            door_rule_group = door_groups.get(door.name)
            if not door_rule_group:
                logger.debug(" - creating child group for door %s", door.name)
                door_rule_group = unifi_access.create_user_group(
                    door.name, up_id=rule_group.id
                )
                # might be None if it already existed, but we already checked for that earlier
                assert door_rule_group

            access_policy = sync_access_policy(rule.schedule, door)
            unifi_access.assign_access_policy_to_user_group(
                door_rule_group.id, [access_policy.id]
            )

            expected_group_members = (
                rule.get_matching_members()
                .with_is_active()
                .filter(
                    Q(**{door.access_field: True})
                    & (
                        Q(is_active=True)
                        | Member.objects.has_flag("folder", "Misc. Access")
                    )
                )
            )
            # all members should exist in Access by this point
            expected_group_member_ids = [
                access_users_by_employee_number[member.uid].id
                for member in expected_group_members
            ]
            if expected_group_member_ids:
                unifi_access.assign_user_to_user_group(
                    door_rule_group.id, expected_group_member_ids
                )

    for rule in FlagScheduleRule.objects.all():
        update_groups_for_rule(rule)
    for rule in AttributeScheduleRule.objects.all():
        update_groups_for_rule(rule)
    # TODO: this could probably be done better by creating temporary
    # schedules for active events
    for rule in ActiveEventInstructorRule.objects.all():
        update_groups_for_rule(rule)


def sync_members(access_client: AccessClient):
    access_users_by_employee_number = {
        user.employee_number: user
        for user in access_client.fetch_all_users__unpaged()
        if user.employee_number
    }

    for member in Member.objects.with_is_active().all():
        logger.info("Syncing member %s", member)
        expected_user = {
            "first_name": member.first_name,
            "last_name": member.last_name,
            # TODO: omitted to avoid spamming members for now
            # "user_email": member.email,
            "employee_number": member.uid,
        }

        if access_user := access_users_by_employee_number.get(member.uid):
            expected_user["status"] = (
                UserStatus.ACTIVE if member.is_active else UserStatus.DEACTIVATED
            )
            changes = {
                k: v for k, v in expected_user.items() if getattr(access_user, k) != v
            }
            if changes:
                logger.debug(" - updating, changes: %s", changes)
                access_client.update_user(
                    **changes,
                    user_id=access_user.id,
                )

        else:
            logger.debug(" - creating user: %s", expected_user)
            access_client.register_user(**expected_user)

    update_user_groups(access_client, access_users_by_employee_number)


@q_task_group("Update UniFi Access Data")
def update_access():
    access_client = AccessClient(
        host=settings.UNIFI_ACCESS_HOST,
        api_token=settings.UNIFI_ACCESS_API_TOKEN,
        # TODO: fix SSL cert
        verify=False,
    )

    sync_members(access_client)