import typing

from django.conf import settings
from django.core.cache import cache
from django.db.models import Count, Q

from apps.alerts.constants import AlertGroupState
from apps.metrics_exporter.constants import (
    METRICS_ORGANIZATIONS_IDS,
    METRICS_ORGANIZATIONS_IDS_CACHE_TIMEOUT,
    NO_SERVICE_VALUE,
    SERVICE_LABEL,
    AlertGroupsResponseTimeMetricsDict,
    AlertGroupsTotalMetricsDict,
    RecalculateOrgMetricsDict,
    UserWasNotifiedOfAlertGroupsMetricsDict,
)
from apps.metrics_exporter.helpers import (
    get_default_states_dict,
    get_metric_alert_groups_response_time_key,
    get_metric_alert_groups_total_key,
    get_metric_calculation_started_key,
    get_metric_user_was_notified_of_alert_groups_key,
    get_metrics_cache_timer_key,
    get_metrics_recalculation_timeout,
    get_organization_ids,
    get_organization_ids_from_db,
    get_response_time_period,
    is_allowed_to_start_metrics_calculation,
    metrics_update_user_cache,
)
from apps.metrics_exporter.metrics_cache_manager import MetricsCacheManager
from common.custom_celery_tasks import shared_dedicated_queue_retry_task
from common.database import get_random_readonly_database_key_if_present_otherwise_default


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else None
)
def save_organizations_ids_in_cache():
    organizations_ids = get_organization_ids_from_db()
    cache.set(organizations_ids, METRICS_ORGANIZATIONS_IDS, METRICS_ORGANIZATIONS_IDS_CACHE_TIMEOUT)


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else None
)
def start_calculate_and_cache_metrics(metrics_to_recalculate: list[RecalculateOrgMetricsDict]):
    """Start calculation metrics for each object in metrics_to_recalculate"""
    for counter, recalculation_data in enumerate(metrics_to_recalculate):
        if not is_allowed_to_start_metrics_calculation(**recalculation_data):
            continue
        # start immediately if recalculation starting has been forced
        countdown = 0 if recalculation_data.get("force") else counter
        calculate_and_cache_metrics.apply_async(kwargs=recalculation_data, countdown=countdown)
        calculate_and_cache_user_was_notified_metric.apply_async(
            (recalculation_data["organization_id"],), countdown=countdown
        )


@shared_dedicated_queue_retry_task(autoretry_for=(Exception,), retry_backoff=True, max_retries=0)
def start_recalculation_for_new_metric(metric_name):
    TEN_MINUTES = 600
    calculation_started_key = get_metric_calculation_started_key(metric_name)
    is_calculation_started = cache.get(calculation_started_key)
    if is_calculation_started:
        return
    cache.set(calculation_started_key, True, timeout=TEN_MINUTES)
    org_ids = set(get_organization_ids())
    countdown = 0
    for counter, organization_id in enumerate(org_ids):
        if counter % 10 == 0:
            countdown += 1
        calculate_and_cache_user_was_notified_metric.apply_async((organization_id,), countdown=countdown)


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else None
)
def calculate_and_cache_metrics(organization_id, force=False):
    """
    Calculate integrations metrics for organization.
    """
    from apps.alerts.models import AlertGroup, AlertReceiveChannel
    from apps.user_management.models import Organization

    ONE_HOUR = 3600
    TWO_HOURS = 7200

    organization = Organization.objects.filter(pk=organization_id).first()
    if not organization:
        return

    integrations = (
        AlertReceiveChannel.objects.using(get_random_readonly_database_key_if_present_otherwise_default())
        .filter(~Q(integration=AlertReceiveChannel.INTEGRATION_MAINTENANCE) & Q(organization_id=organization_id))
        .select_related("team")
    )

    response_time_period = get_response_time_period()

    instance_slug = organization.stack_slug
    instance_id = organization.stack_id
    instance_org_id = organization.org_id

    metric_alert_group_total: typing.Dict[int, AlertGroupsTotalMetricsDict] = {}
    metric_alert_group_response_time: typing.Dict[int, AlertGroupsResponseTimeMetricsDict] = {}

    states = {
        AlertGroupState.FIRING.value: AlertGroup.get_new_state_filter(),
        AlertGroupState.SILENCED.value: AlertGroup.get_silenced_state_filter(),
        AlertGroupState.ACKNOWLEDGED.value: AlertGroup.get_acknowledged_state_filter(),
        AlertGroupState.RESOLVED.value: AlertGroup.get_resolved_state_filter(),
    }

    for integration in integrations:
        metric_alert_group_total_data = {
            "integration_name": integration.emojized_verbal_name,
            "team_name": integration.team_name,
            "team_id": integration.team_id_or_no_team,
            "org_id": instance_org_id,
            "slug": instance_slug,
            "id": instance_id,
            "services": {
                NO_SERVICE_VALUE: get_default_states_dict(),
            },
        }
        # calculate states
        for state, alert_group_filter in states.items():
            # count alert groups with `service_name` label group by label value
            alert_group_count_by_service = (
                integration.alert_groups.filter(
                    alert_group_filter,
                    labels__organization=organization,
                    labels__key_name=SERVICE_LABEL,
                )
                .values("labels__value_name")
                .annotate(count=Count("id"))
            )

            for value in alert_group_count_by_service:
                metric_alert_group_total_data["services"].setdefault(
                    value["labels__value_name"],
                    get_default_states_dict(),
                )[state] += value["count"]
            # count alert groups without `service_name` label
            alert_groups_count_without_service = integration.alert_groups.filter(
                alert_group_filter,
                ~Q(labels__key_name=SERVICE_LABEL),
            ).count()
            metric_alert_group_total_data["services"][NO_SERVICE_VALUE][state] += alert_groups_count_without_service
        metric_alert_group_total[integration.id] = metric_alert_group_total_data

        # calculate response time metric
        metric_response_time_data = {
            "integration_name": integration.emojized_verbal_name,
            "team_name": integration.team_name,
            "team_id": integration.team_id_or_no_team,
            "org_id": instance_org_id,
            "slug": instance_slug,
            "id": instance_id,
            "services": {NO_SERVICE_VALUE: []},
        }

        # filter response time by services
        response_time_by_service = integration.alert_groups.filter(
            started_at__gte=response_time_period,
            response_time__isnull=False,
            labels__organization=organization,
            labels__key_name=SERVICE_LABEL,
        ).values_list("id", "labels__value_name", "response_time")
        for _, service_name, response_time in response_time_by_service:
            metric_response_time_data["services"].setdefault(service_name, [])
            metric_response_time_data["services"][service_name].append(response_time.total_seconds())

        no_service_response_time = (
            integration.alert_groups.filter(
                started_at__gte=response_time_period,
                response_time__isnull=False,
            )
            .exclude(id__in=[i[0] for i in response_time_by_service])
            .values_list("response_time", flat=True)
        )

        no_service_response_time_seconds = [
            int(response_time.total_seconds()) for response_time in no_service_response_time
        ]
        metric_response_time_data["services"][NO_SERVICE_VALUE] = no_service_response_time_seconds

        metric_alert_group_response_time[integration.id] = metric_response_time_data

    metric_alert_groups_total_key = get_metric_alert_groups_total_key(organization_id)
    metric_alert_groups_response_time_key = get_metric_alert_groups_response_time_key(organization_id)

    recalculate_timeout = get_metrics_recalculation_timeout()
    metrics_cache_timeout = recalculate_timeout + TWO_HOURS
    cache.set(metric_alert_groups_total_key, metric_alert_group_total, timeout=metrics_cache_timeout)
    cache.set(metric_alert_groups_response_time_key, metric_alert_group_response_time, timeout=metrics_cache_timeout)
    if force:
        metrics_cache_timer_key = get_metrics_cache_timer_key(organization_id)
        metrics_cache_timer = cache.get(metrics_cache_timer_key)
        metrics_cache_timer["forced_started"] = False
        cache.set(metrics_cache_timer_key, metrics_cache_timer, timeout=recalculate_timeout - ONE_HOUR)


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else None
)
def calculate_and_cache_user_was_notified_metric(organization_id):
    """
    Calculate metric "user_was_notified_of_alert_groups" for organization.
    """
    from apps.base.models import UserNotificationPolicyLogRecord
    from apps.user_management.models import Organization, User

    TWO_HOURS = 7200

    organization = Organization.objects.filter(pk=organization_id).first()
    if not organization:
        return

    users = (
        User.objects.using(get_random_readonly_database_key_if_present_otherwise_default())
        .filter(organization_id=organization_id)
        .annotate(num_logs=Count("personal_log_records"))
        .filter(num_logs__gte=1)
    )

    instance_slug = organization.stack_slug
    instance_id = organization.stack_id
    instance_org_id = organization.org_id

    metric_user_was_notified: typing.Dict[int, UserWasNotifiedOfAlertGroupsMetricsDict] = {}

    for user in users:
        counter = (
            user.personal_log_records.filter(type=UserNotificationPolicyLogRecord.TYPE_PERSONAL_NOTIFICATION_TRIGGERED)
            .values("alert_group")
            .distinct()
            .count()
        )

        if counter == 0:  # means that user has no successful notifications
            continue

        metric_user_was_notified[user.id] = {
            "user_username": user.username,
            "org_id": instance_org_id,
            "slug": instance_slug,
            "id": instance_id,
            "counter": counter,
        }

    metric_user_was_notified_key = get_metric_user_was_notified_of_alert_groups_key(organization_id)

    recalculate_timeout = get_metrics_recalculation_timeout()
    metrics_cache_timeout = recalculate_timeout + TWO_HOURS
    cache.set(metric_user_was_notified_key, metric_user_was_notified, timeout=metrics_cache_timeout)


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else 10
)
def update_metrics_for_alert_group(alert_group_id, organization_id, previous_state, new_state):
    from apps.alerts.models import AlertGroup

    alert_group = AlertGroup.objects.get(pk=alert_group_id)
    updated_response_time = alert_group.response_time
    if previous_state != AlertGroupState.FIRING or alert_group.restarted_at:
        # only consider response time from the first action
        updated_response_time = None
    service_label = alert_group.labels.filter(key_name=SERVICE_LABEL).first()
    service_name = service_label.value_name if service_label else NO_SERVICE_VALUE
    MetricsCacheManager.metrics_update_cache_for_alert_group(
        integration_id=alert_group.channel_id,
        organization_id=organization_id,
        old_state=previous_state,
        new_state=new_state,
        response_time=updated_response_time,
        started_at=alert_group.started_at,
        service_name=service_name,
    )


@shared_dedicated_queue_retry_task(
    autoretry_for=(Exception,), retry_backoff=True, max_retries=1 if settings.DEBUG else 10
)
def update_metrics_for_user(user_id, counter=1):
    from apps.user_management.models import User

    user = User.objects.get(id=user_id)
    metrics_update_user_cache(user, counter)