from datetime import (
    datetime,
    timedelta
)

from flask import current_app
from sqlalchemy.exc import SQLAlchemyError

from app.aws import s3
from app import notify_celery
from app import performance_platform_client
from app.dao.invited_user_dao import delete_invitations_created_more_than_two_days_ago
from app.dao.jobs_dao import dao_set_scheduled_jobs_to_pending, dao_get_jobs_older_than_limited_by
from app.dao.notifications_dao import (
    delete_notifications_created_more_than_a_week_ago,
    dao_timeout_notifications,
    is_delivery_slow_for_provider
)
from app.dao.provider_details_dao import (
    get_current_provider,
    dao_toggle_sms_provider
)
from app.dao.users_dao import delete_codes_older_created_more_than_a_day_ago
from app.statsd_decorators import statsd
from app.celery.tasks import process_job


@notify_celery.task(name="remove_csv_files")
@statsd(namespace="tasks")
def remove_csv_files():
    jobs = dao_get_jobs_older_than_limited_by()
    for job in jobs:
        s3.remove_job_from_s3(job.service_id, job.id)
        current_app.logger.info("Job ID {} has been removed from s3.".format(job.id))


@notify_celery.task(name="run-scheduled-jobs")
@statsd(namespace="tasks")
def run_scheduled_jobs():
    try:
        for job in dao_set_scheduled_jobs_to_pending():
            process_job.apply_async([str(job.id)], queue="process-job")
            current_app.logger.info("Job ID {} added to process job queue".format(job.id))
    except SQLAlchemyError as e:
        current_app.logger.exception("Failed to run scheduled jobs")
        raise


@notify_celery.task(name="delete-verify-codes")
@statsd(namespace="tasks")
def delete_verify_codes():
    try:
        start = datetime.utcnow()
        deleted = delete_codes_older_created_more_than_a_day_ago()
        current_app.logger.info(
            "Delete job started {} finished {} deleted {} verify codes".format(start, datetime.utcnow(), deleted)
        )
    except SQLAlchemyError as e:
        current_app.logger.exception("Failed to delete verify codes")
        raise


@notify_celery.task(name="delete-successful-notifications")
@statsd(namespace="tasks")
def delete_successful_notifications():
    try:
        start = datetime.utcnow()
        deleted = delete_notifications_created_more_than_a_week_ago('delivered')
        current_app.logger.info(
            "Delete job started {} finished {} deleted {} successful notifications".format(
                start,
                datetime.utcnow(),
                deleted
            )
        )
    except SQLAlchemyError as e:
        current_app.logger.exception("Failed to delete successful notifications")
        raise


@notify_celery.task(name="delete-failed-notifications")
@statsd(namespace="tasks")
def delete_failed_notifications():
    try:
        start = datetime.utcnow()
        deleted = delete_notifications_created_more_than_a_week_ago('failed')
        deleted += delete_notifications_created_more_than_a_week_ago('technical-failure')
        deleted += delete_notifications_created_more_than_a_week_ago('temporary-failure')
        deleted += delete_notifications_created_more_than_a_week_ago('permanent-failure')
        current_app.logger.info(
            "Delete job started {} finished {} deleted {} failed notifications".format(
                start,
                datetime.utcnow(),
                deleted
            )
        )
    except SQLAlchemyError as e:
        current_app.logger.exception("Failed to delete failed notifications")
        raise


@notify_celery.task(name="delete-invitations")
@statsd(namespace="tasks")
def delete_invitations():
    try:
        start = datetime.utcnow()
        deleted = delete_invitations_created_more_than_two_days_ago()
        current_app.logger.info(
            "Delete job started {} finished {} deleted {} invitations".format(start, datetime.utcnow(), deleted)
        )
    except SQLAlchemyError as e:
        current_app.logger.exception("Failed to delete invitations")
        raise


@notify_celery.task(name='timeout-sending-notifications')
@statsd(namespace="tasks")
def timeout_notifications():
    updated = dao_timeout_notifications(current_app.config.get('SENDING_NOTIFICATIONS_TIMEOUT_PERIOD'))
    if updated:
        current_app.logger.info(
            "Timeout period reached for {} notifications, status has been updated.".format(updated))


@notify_celery.task(name='send-daily-performance-platform-stats')
@statsd(namespace="tasks")
def send_daily_performance_platform_stats():
    if performance_platform_client.active:
        count_dict = performance_platform_client.get_total_sent_notifications_yesterday()
        email_sent_count = count_dict.get('email').get('count')
        sms_sent_count = count_dict.get('sms').get('count')
        start_date = count_dict.get('start_date')

        current_app.logger.info(
            "Attempting to update performance platform for date {} with email count {} and sms count {}"
            .format(start_date, email_sent_count, sms_sent_count)
        )

        performance_platform_client.send_performance_stats(
            start_date,
            'sms',
            sms_sent_count,
            'day'
        )

        performance_platform_client.send_performance_stats(
            start_date,
            'email',
            email_sent_count,
            'day'
        )


@notify_celery.task(name='switch-current-sms-provider-on-slow-delivery')
@statsd(namespace="tasks")
def switch_current_sms_provider_on_slow_delivery():
    """
    Switch providers if there are at least two slow delivery notifications (more than four minutes)
    in the last ten minutes. Search from the time we last switched to the current provider.
    """
    functional_test_provider_service_id = current_app.config.get('FUNCTIONAL_TEST_PROVIDER_SERVICE_ID')
    functional_test_provider_template_id = current_app.config.get('FUNCTIONAL_TEST_PROVIDER_SMS_TEMPLATE_ID')

    if functional_test_provider_service_id and functional_test_provider_template_id:
        current_provider = get_current_provider('sms')
        slow_delivery_notifications = is_delivery_slow_for_provider(
            provider=current_provider.identifier,
            threshold=2,
            sent_at=max(datetime.utcnow() - timedelta(minutes=10), current_provider.updated_at),
            delivery_time=timedelta(minutes=4),
            service_id=functional_test_provider_service_id,
            template_id=functional_test_provider_template_id
        )

        if slow_delivery_notifications:
            current_app.logger.warning(
                'Slow delivery notifications detected for provider {}'.format(
                    current_provider.identifier
                )
            )

            dao_toggle_sms_provider(current_provider.identifier)