"""
.. module: lemur.plugins.lemur_email.plugin
    :platform: Unix
    :copyright: (c) 2015 by Netflix Inc., see AUTHORS for more
    :license: Apache, see LICENSE for more details.

.. moduleauthor:: Kevin Glisson <kglisson@netflix.com>
"""
import boto3
from flask import current_app
from flask_mail import Message

from lemur.extensions import smtp_mail
from lemur.exceptions import InvalidConfiguration

from lemur.plugins.bases import ExpirationNotificationPlugin
from lemur.plugins import lemur_email as email

from lemur.plugins.lemur_email.templates.config import env


def render_html(template_name, message):
    """
    Renders the html for our email notification.

    :param template_name:
    :param message:
    :return:
    """
    template = env.get_template('{}.html'.format(template_name))
    return template.render(dict(message=message, hostname=current_app.config.get('LEMUR_HOSTNAME')))


def send_via_smtp(subject, body, targets):
    """
    Attempts to deliver email notification via SES service.

    :param subject:
    :param body:
    :param targets:
    :return:
    """
    msg = Message(subject, recipients=targets, sender=current_app.config.get("LEMUR_EMAIL"))
    msg.body = ""  # kinda a weird api for sending html emails
    msg.html = body
    smtp_mail.send(msg)


def send_via_ses(subject, body, targets):
    """
    Attempts to deliver email notification via SMTP.
    :param subject:
    :param body:
    :param targets:
    :return:
    """
    client = boto3.client('ses')
    client.send_email(
        Source=current_app.config.get('LEMUR_EMAIL'),
        Destination={
            'ToAddresses': targets
        },
        Message={
            'Subject': {
                'Data': subject,
                'Charset': 'string'
            },
            'Body': {
                'Html': {
                    'Data': body,
                    'Charset': 'string'
                }
            }
        }
    )


class EmailNotificationPlugin(ExpirationNotificationPlugin):
    title = 'Email'
    slug = 'email-notification'
    description = 'Sends expiration email notifications'
    version = email.VERSION

    author = 'Kevin Glisson'
    author_url = 'https://github.com/netflix/lemur'

    additional_options = [
        {
            'name': 'recipients',
            'type': 'str',
            'required': True,
            'validation': '^([\w+-.%]+@[\w-.]+\.[A-Za-z]{2,4},?)+$',
            'helpMessage': 'Comma delimited list of email addresses',
        },
    ]

    def __init__(self, *args, **kwargs):
        """Initialize the plugin with the appropriate details."""
        sender = current_app.config.get('LEMUR_EMAIL_SENDER', 'ses').lower()

        if sender not in ['ses', 'smtp']:
            raise InvalidConfiguration('Email sender type {0} is not recognized.')

    @staticmethod
    def send(notification_type, message, targets, options, **kwargs):

        subject = 'Lemur: {0} Notification'.format(notification_type.capitalize())

        data = {'options': options, 'certificates': message}
        body = render_html(notification_type, data)

        s_type = current_app.config.get("LEMUR_EMAIL_SENDER", 'ses').lower()

        if s_type == 'ses':
            send_via_ses(subject, body, targets)

        elif s_type == 'smtp':
            send_via_smtp(subject, body, targets)