from collections import namedtuple

from pyramid.events import BeforeRender, subscriber
from pyramid.renderers import render
from pyramid_mailer.message import Message

SerializableFlashMessage = namedtuple(
    "SerializableFlashMessage", ["text", "more"]
)


class Ordr3Event:
    def __init__(self):
        self.request = None


class FlashMessage(Ordr3Event):
    def __init__(self, channel, text, more):
        super().__init__()
        self.channel = channel
        self.text = text
        self.more = more

    @classmethod
    def info(cls, text, more=""):
        return cls("info", text, more)

    @classmethod
    def warning(cls, text, more=""):
        return cls("warning", text, more)

    @classmethod
    def error(cls, text, more=""):
        return cls("error", text, more)


class EmailNotification(Ordr3Event):
    """ base class for user notifications """

    subject = None
    template = None

    def __init__(self, user, data=None):
        super().__init__()
        self.user = user
        self.data = data


class AccountActivationEmail(EmailNotification):
    """ user notification for account activation """

    subject = "[ordr] Your account was activated"
    template = "ordr3:templates/emails/activation.jinja2"


class OrderStatusChangeEmail(EmailNotification):
    """ user notification for order status change """

    subject = "[ordr] Order Status Change"
    template = "ordr3:templates/emails/status_change.jinja2"


class PasswordResetEmail(EmailNotification):
    """ user notification for password reset link """

    subject = "[ordr] Password Reset"
    template = "ordr3:templates/emails/password_reset.jinja2"


@subscriber(FlashMessage)
def handle_flash_message_event(event):
    if event.request is None:
        return
    session = event.request.session
    message = SerializableFlashMessage(event.text, event.more)
    print(message)
    session.flash(message, event.channel, allow_duplicate=False)


@subscriber(EmailNotification)
def notify_user(event):
    """ notify a user about an event """
    body = render(
        event.template, {"user": event.user, "data": event.data}, event.request
    )
    message = Message(
        subject=event.subject,
        sender=event.request.registry.settings["mail.default_sender"],
        recipients=[event.user.email],
        body=body,
    )
    event.request.mailer.send(message)


@subscriber(BeforeRender)
def add_global(event):
    request = event["request"]
    if not request.is_xhr:
        event.rendering_val["new_user_badge"] = request.repo.count_new_users()


def emit(request, event):
    event.request = request
    request.registry.notify(event)


def includeme(config):
    """initializing Events sytem for the Pyramid app

    Activate this setup using ``config.include('ordr2.events')``.
    """
    config.add_request_method(emit, "emit")