from datetime import datetime
from monotonic import monotonic
from urllib.parse import urljoin

from flask import current_app
from notifications_utils.recipients import (
    validate_and_format_phone_number
)
from notifications_utils.template import Template, get_sms_fragment_count
from notifications_utils.renderers import HTMLEmail, PlainTextEmail, SMSMessage

from app import notify_celery, statsd_client, clients, create_uuid
from app.clients.email import EmailClientException
from app.clients.sms import SmsClientException
from app.dao.notifications_dao import (
    update_provider_stats,
    get_notification_by_id,
    dao_update_notification,
    update_notification_status_by_id
)
from app.dao.provider_details_dao import get_provider_details_by_notification_type
from app.dao.services_dao import dao_fetch_service_by_id
from app.celery.research_mode_tasks import send_sms_response, send_email_response
from app.dao.templates_dao import dao_get_template_by_id

from app.models import SMS_TYPE, EMAIL_TYPE, KEY_TYPE_TEST, BRANDING_ORG
from app.statsd_decorators import statsd


def retry_iteration_to_delay(retry=0):
    """
    Given current retry calculate some delay before retrying
    0: 10 seconds
    1: 60 seconds (1 minutes)
    2: 300 seconds (5 minutes)
    3: 3600 seconds (60 minutes)
    4: 14400 seconds (4 hours)
    :param retry (zero indexed):
    :return length to retry in seconds, default 10 seconds
    """

    delays = {
        0: 10,
        1: 60,
        2: 300,
        3: 3600,
        4: 14400
    }

    return delays.get(retry, 10)


@notify_celery.task(bind=True, name="send-sms-to-provider", max_retries=5, default_retry_delay=5)
@statsd(namespace="tasks")
def send_sms_to_provider(self, service_id, notification_id):
    service = dao_fetch_service_by_id(service_id)
    provider = provider_to_use(SMS_TYPE, notification_id)
    notification = get_notification_by_id(notification_id)
    if notification.status == 'created':
        template_model = dao_get_template_by_id(notification.template_id, notification.template_version)
        template = Template(
            template_model.__dict__,
            values={} if not notification.personalisation else notification.personalisation,
            renderer=SMSMessage(prefix=service.name)
        )
        try:
            if service.research_mode or notification.key_type == KEY_TYPE_TEST:
                send_sms_response.apply_async(
                    (provider.get_name(), str(notification_id), notification.to), queue='research-mode'
                )
                notification.billable_units = 0
            else:
                provider.send_sms(
                    to=validate_and_format_phone_number(notification.to),
                    content=template.replaced,
                    reference=str(notification_id),
                    sender=service.sms_sender
                )
                notification.billable_units = get_sms_fragment_count(template.replaced_content_count)

                update_provider_stats(
                    notification_id,
                    SMS_TYPE,
                    provider.get_name(),
                    billable_units=notification.billable_units
                )

            notification.sent_at = datetime.utcnow()
            notification.sent_by = provider.get_name()
            notification.status = 'sending'
            dao_update_notification(notification)
        except SmsClientException as e:
            try:
                current_app.logger.error(
                    "RETRY: SMS notification {} failed".format(notification_id)
                )
                current_app.logger.exception(e)
                self.retry(queue="retry", countdown=retry_iteration_to_delay(self.request.retries))
            except self.MaxRetriesExceededError:
                current_app.logger.error(
                    "RETRY FAILED: task send_sms_to_provider failed for notification {}".format(notification.id),
                    e
                )
                update_notification_status_by_id(notification.id, 'technical-failure', 'failure')

        current_app.logger.info(
            "SMS {} sent to provider at {}".format(notification_id, notification.sent_at)
        )
        delta_milliseconds = (datetime.utcnow() - notification.created_at).total_seconds() * 1000
        statsd_client.timing("sms.total-time", delta_milliseconds)


def provider_to_use(notification_type, notification_id):
    active_providers_in_order = [
        provider for provider in get_provider_details_by_notification_type(notification_type) if provider.active
        ]

    if not active_providers_in_order:
        current_app.logger.error(
            "{} {} failed as no active providers".format(notification_type, notification_id)
        )
        raise Exception("No active {} providers".format(notification_type))

    return clients.get_client_by_name_and_type(active_providers_in_order[0].identifier, notification_type)


@notify_celery.task(bind=True, name="send-email-to-provider", max_retries=5, default_retry_delay=5)
@statsd(namespace="tasks")
def send_email_to_provider(self, service_id, notification_id):
    service = dao_fetch_service_by_id(service_id)
    provider = provider_to_use(EMAIL_TYPE, notification_id)
    notification = get_notification_by_id(notification_id)
    if notification.status == 'created':
        try:
            template_dict = dao_get_template_by_id(notification.template_id, notification.template_version).__dict__

            html_email = Template(
                template_dict,
                values=notification.personalisation,
                renderer=get_html_email_renderer(service)
            )

            plain_text_email = Template(
                template_dict,
                values=notification.personalisation,
                renderer=PlainTextEmail()
            )

            if service.research_mode or notification.key_type == KEY_TYPE_TEST:
                reference = str(create_uuid())
                send_email_response.apply_async(
                    (provider.get_name(), reference, notification.to), queue='research-mode'
                )
            else:
                from_address = '"{}" <{}@{}>'.format(service.name, service.email_from,
                                                     current_app.config['NOTIFY_EMAIL_DOMAIN'])
                reference = provider.send_email(
                    from_address,
                    notification.to,
                    plain_text_email.replaced_subject,
                    body=plain_text_email.replaced,
                    html_body=html_email.replaced,
                    reply_to_address=service.reply_to_email_address,
                )

                update_provider_stats(
                    notification_id,
                    EMAIL_TYPE,
                    provider.get_name(),
                    billable_units=1
                )
            notification.reference = reference
            notification.sent_at = datetime.utcnow()
            notification.sent_by = provider.get_name(),
            notification.status = 'sending'
            dao_update_notification(notification)
        except EmailClientException as e:
            try:
                current_app.logger.error(
                    "RETRY: Email notification {} failed".format(notification_id)
                )
                current_app.logger.exception(e)
                self.retry(queue="retry", countdown=retry_iteration_to_delay(self.request.retries))
            except self.MaxRetriesExceededError:
                current_app.logger.error(
                    "RETRY FAILED: task send_email_to_provider failed for notification {}".format(notification.id),
                    e
                )
                update_notification_status_by_id(notification.id, 'technical-failure', 'failure')

        current_app.logger.info(
            "Email {} sent to provider at {}".format(notification_id, notification.sent_at)
        )
        delta_milliseconds = (datetime.utcnow() - notification.created_at).total_seconds() * 1000
        statsd_client.timing("email.total-time", delta_milliseconds)


def get_html_email_renderer(service):
    govuk_banner = service.branding != BRANDING_ORG
    if service.organisation:
        logo = '{}{}{}'.format(
            current_app.config['ADMIN_BASE_URL'],
            current_app.config['BRANDING_PATH'],
            service.organisation.logo
        )
        branding = {
            'brand_colour': service.organisation.colour,
            'brand_logo': logo,
            'brand_name': service.organisation.name,
        }
    else:
        branding = {}

    return HTMLEmail(govuk_banner=govuk_banner, **branding)