import urllib

from flask import current_app
from notifications_utils.s3 import S3ObjectNotFound, s3download as utils_s3download
from sqlalchemy.orm.exc import NoResultFound

from app import create_random_identifier
from app.config import QueueNames
from app.dao.notifications_dao import _update_notification_status
from app.dao.service_email_reply_to_dao import dao_get_reply_to_by_id
from app.dao.service_sms_sender_dao import dao_get_service_sms_senders_by_id
from app.notifications.validators import (
    check_service_has_permission,
    check_service_over_daily_message_limit,
    validate_and_format_recipient,
    validate_template,
    validate_address)
from app.notifications.process_notifications import (
    persist_notification,
    send_notification_to_queue
)
from app.models import (
    KEY_TYPE_NORMAL,
    PRIORITY,
    SMS_TYPE,
    EMAIL_TYPE,
    LETTER_TYPE,
    NOTIFICATION_DELIVERED,
)
from app.dao.services_dao import dao_fetch_service_by_id
from app.dao.templates_dao import dao_get_template_by_id_and_service_id, get_precompiled_letter_template
from app.dao.users_dao import get_user_by_id
from app.letters.utils import (
    get_billable_units_for_letter_page_count,
    get_letter_pdf_filename,
    get_page_count,
    move_uploaded_pdf_to_letters_bucket,
)
from app.v2.errors import BadRequestError


def validate_created_by(service, created_by_id):
    user = get_user_by_id(created_by_id)
    if service not in user.services:
        message = 'Can’t create notification - {} is not part of the "{}" service'.format(
            user.name,
            service.name
        )
        raise BadRequestError(message=message)


def create_one_off_reference(template_type):
    if template_type == LETTER_TYPE:
        return create_random_identifier()
    return None


def send_one_off_notification(service_id, post_data):
    service = dao_fetch_service_by_id(service_id)
    template = dao_get_template_by_id_and_service_id(
        template_id=post_data['template_id'],
        service_id=service_id
    )

    personalisation = post_data.get('personalisation', None)

    validate_template(template.id, personalisation, service, template.template_type)

    check_service_over_daily_message_limit(KEY_TYPE_NORMAL, service)

    validate_and_format_recipient(
        send_to=post_data['to'],
        key_type=KEY_TYPE_NORMAL,
        service=service,
        notification_type=template.template_type,
        allow_guest_list_recipients=False,
    )
    postage = None
    if template.template_type == LETTER_TYPE:
        # Validate address and set postage to europe|rest-of-world if international letter,
        # otherwise persist_notification with use template postage
        postage = validate_address(service, personalisation)
        if not postage:
            postage = template.postage
    validate_created_by(service, post_data['created_by'])

    sender_id = post_data.get('sender_id', None)
    reply_to = get_reply_to_text(
        notification_type=template.template_type,
        sender_id=sender_id,
        service=service,
        template=template
    )
    notification = persist_notification(
        template_id=template.id,
        template_version=template.version,
        recipient=post_data['to'],
        service=service,
        personalisation=personalisation,
        notification_type=template.template_type,
        api_key_id=None,
        key_type=KEY_TYPE_NORMAL,
        created_by_id=post_data['created_by'],
        reply_to_text=reply_to,
        reference=create_one_off_reference(template.template_type),
        postage=postage
    )

    queue_name = QueueNames.PRIORITY if template.process_type == PRIORITY else None

    if template.template_type == LETTER_TYPE and service.research_mode:
        _update_notification_status(
            notification,
            NOTIFICATION_DELIVERED,
        )
    else:
        send_notification_to_queue(
            notification=notification,
            research_mode=service.research_mode,
            queue=queue_name,
        )

    return {'id': str(notification.id)}


def get_reply_to_text(notification_type, sender_id, service, template):
    reply_to = None
    if sender_id:
        try:
            if notification_type == EMAIL_TYPE:
                message = 'Reply to email address not found'
                reply_to = dao_get_reply_to_by_id(service.id, sender_id).email_address
            elif notification_type == SMS_TYPE:
                message = 'SMS sender not found'
                reply_to = dao_get_service_sms_senders_by_id(service.id, sender_id).get_reply_to_text()
        except NoResultFound:
            raise BadRequestError(message=message)
    else:
        reply_to = template.get_reply_to_text()
    return reply_to


def send_pdf_letter_notification(service_id, post_data):
    service = dao_fetch_service_by_id(service_id)

    check_service_has_permission(LETTER_TYPE, [
        p.permission for p in service.permissions
    ])
    check_service_over_daily_message_limit(KEY_TYPE_NORMAL, service)
    validate_created_by(service, post_data['created_by'])
    validate_and_format_recipient(
        send_to=post_data['recipient_address'],
        key_type=KEY_TYPE_NORMAL,
        service=service,
        notification_type=LETTER_TYPE,
        allow_guest_list_recipients=False,
    )

    template = get_precompiled_letter_template(service.id)
    file_location = 'service-{}/{}.pdf'.format(service.id, post_data['file_id'])

    try:
        letter = utils_s3download(current_app.config['TRANSIENT_UPLOADED_LETTERS'], file_location)
    except S3ObjectNotFound as e:
        current_app.logger.exception('Letter {}.pdf not in transient {} bucket'.format(
            post_data['file_id'], current_app.config['TRANSIENT_UPLOADED_LETTERS'])
        )
        raise e

    # Getting the page count won't raise an error since admin has already checked the PDF is valid
    page_count = get_page_count(letter.read())
    billable_units = get_billable_units_for_letter_page_count(page_count)

    personalisation = {
        'address_line_1': post_data['filename']
    }

    notification = persist_notification(
        notification_id=post_data['file_id'],
        template_id=template.id,
        template_version=template.version,
        recipient=urllib.parse.unquote(post_data['recipient_address']),
        service=service,
        personalisation=personalisation,
        notification_type=LETTER_TYPE,
        api_key_id=None,
        key_type=KEY_TYPE_NORMAL,
        reference=create_one_off_reference(LETTER_TYPE),
        client_reference=post_data['filename'],
        created_by_id=post_data['created_by'],
        billable_units=billable_units,
        postage=post_data['postage'] or template.postage,
    )

    upload_filename = get_letter_pdf_filename(
        reference=notification.reference,
        crown=notification.service.crown,
        sending_date=notification.created_at,
        ignore_folder=False,
        postage=notification.postage
    )

    move_uploaded_pdf_to_letters_bucket(file_location, upload_filename)

    return {'id': str(notification.id)}