synapse/synapse/push/mailer.py

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from twisted.internet import defer
from twisted.mail.smtp import sendmail

import email.utils
import email.mime.multipart
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

from synapse.util.async import concurrently_execute
from synapse.util.presentable_names import (
    calculate_room_name, name_from_member_event, descriptor_from_member_events
)
from synapse.types import UserID
from synapse.api.errors import StoreError
from synapse.api.constants import EventTypes
from synapse.visibility import filter_events_for_client

import jinja2
import bleach

import time
import urllib

import logging
logger = logging.getLogger(__name__)


MESSAGE_FROM_PERSON_IN_ROOM = "You have a message on %(app)s from %(person)s " \
                              "in the %(room)s room..."
MESSAGE_FROM_PERSON = "You have a message on %(app)s from %(person)s..."
MESSAGES_FROM_PERSON = "You have messages on %(app)s from %(person)s..."
MESSAGES_IN_ROOM = "You have messages on %(app)s in the %(room)s room..."
MESSAGES_IN_ROOM_AND_OTHERS = \
    "You have messages on %(app)s in the %(room)s room and others..."
MESSAGES_FROM_PERSON_AND_OTHERS = \
    "You have messages on %(app)s from %(person)s and others..."
INVITE_FROM_PERSON_TO_ROOM = "%(person)s has invited you to join the " \
                             "%(room)s room on %(app)s..."
INVITE_FROM_PERSON = "%(person)s has invited you to chat on %(app)s..."

CONTEXT_BEFORE = 1
CONTEXT_AFTER = 1

# From https://github.com/matrix-org/matrix-react-sdk/blob/master/src/HtmlUtils.js
ALLOWED_TAGS = [
    'font',  # custom to matrix for IRC-style font coloring
    'del',  # for markdown
    # deliberately no h1/h2 to stop people shouting.
    'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
    'nl', 'li', 'b', 'i', 'u', 'strong', 'em', 'strike', 'code', 'hr', 'br', 'div',
    'table', 'thead', 'caption', 'tbody', 'tr', 'th', 'td', 'pre'
]
ALLOWED_ATTRS = {
    # custom ones first:
    "font": ["color"],  # custom to matrix
    "a": ["href", "name", "target"],  # remote target: custom to matrix
    # We don't currently allow img itself by default, but this
    # would make sense if we did
    "img": ["src"],
}
# When bleach release a version with this option, we can specify schemes
# ALLOWED_SCHEMES = ["http", "https", "ftp", "mailto"]


class Mailer(object):
    def __init__(self, hs, app_name):
        self.hs = hs
        self.store = self.hs.get_datastore()
        self.auth_handler = self.hs.get_auth_handler()
        self.state_handler = self.hs.get_state_handler()
        loader = jinja2.FileSystemLoader(self.hs.config.email_template_dir)
        self.app_name = app_name
        logger.info("Created Mailer for app_name %s" % app_name)
        env = jinja2.Environment(loader=loader)
        env.filters["format_ts"] = format_ts_filter
        env.filters["mxc_to_http"] = self.mxc_to_http_filter
        self.notif_template_html = env.get_template(
            self.hs.config.email_notif_template_html
        )
        self.notif_template_text = env.get_template(
            self.hs.config.email_notif_template_text
        )

    @defer.inlineCallbacks
    def send_notification_mail(self, app_id, user_id, email_address,
                               push_actions, reason):
        try:
            from_string = self.hs.config.email_notif_from % {
                "app": self.app_name
            }
        except TypeError:
            from_string = self.hs.config.email_notif_from

        raw_from = email.utils.parseaddr(from_string)[1]
        raw_to = email.utils.parseaddr(email_address)[1]

        if raw_to == '':
            raise RuntimeError("Invalid 'to' address")

        rooms_in_order = deduped_ordered_list(
            [pa['room_id'] for pa in push_actions]
        )

        notif_events = yield self.store.get_events(
            [pa['event_id'] for pa in push_actions]
        )

        notifs_by_room = {}
        for pa in push_actions:
            notifs_by_room.setdefault(pa["room_id"], []).append(pa)

        # collect the current state for all the rooms in which we have
        # notifications
        state_by_room = {}

        try:
            user_display_name = yield self.store.get_profile_displayname(
                UserID.from_string(user_id).localpart
            )
            if user_display_name is None:
                user_display_name = user_id
        except StoreError:
            user_display_name = user_id

        @defer.inlineCallbacks
        def _fetch_room_state(room_id):
            room_state = yield self.state_handler.get_current_state(room_id)
            state_by_room[room_id] = room_state

        # Run at most 3 of these at once: sync does 10 at a time but email
        # notifs are much less realtime than sync so we can afford to wait a bit.
        yield concurrently_execute(_fetch_room_state, rooms_in_order, 3)

        # actually sort our so-called rooms_in_order list, most recent room first
        rooms_in_order.sort(
            key=lambda r: -(notifs_by_room[r][-1]['received_ts'] or 0)
        )

        rooms = []

        for r in rooms_in_order:
            roomvars = yield self.get_room_vars(
                r, user_id, notifs_by_room[r], notif_events, state_by_room[r]
            )
            rooms.append(roomvars)

        reason['room_name'] = calculate_room_name(
            state_by_room[reason['room_id']], user_id, fallback_to_members=True
        )

        summary_text = self.make_summary_text(
            notifs_by_room, state_by_room, notif_events, user_id, reason
        )

        template_vars = {
            "user_display_name": user_display_name,
            "unsubscribe_link": self.make_unsubscribe_link(
                user_id, app_id, email_address
            ),
            "summary_text": summary_text,
            "app_name": self.app_name,
            "rooms": rooms,
            "reason": reason,
        }

        html_text = self.notif_template_html.render(**template_vars)
        html_part = MIMEText(html_text, "html", "utf8")

        plain_text = self.notif_template_text.render(**template_vars)
        text_part = MIMEText(plain_text, "plain", "utf8")

        multipart_msg = MIMEMultipart('alternative')
        multipart_msg['Subject'] = "[%s] %s" % (self.app_name, summary_text)
        multipart_msg['From'] = from_string
        multipart_msg['To'] = email_address
        multipart_msg['Date'] = email.utils.formatdate()
        multipart_msg['Message-ID'] = email.utils.make_msgid()
        multipart_msg.attach(text_part)
        multipart_msg.attach(html_part)

        logger.info("Sending email push notification to %s" % email_address)
        # logger.debug(html_text)

        yield sendmail(
            self.hs.config.email_smtp_host,
            raw_from, raw_to, multipart_msg.as_string(),
            port=self.hs.config.email_smtp_port
        )

    @defer.inlineCallbacks
    def get_room_vars(self, room_id, user_id, notifs, notif_events, room_state):
        my_member_event = room_state[("m.room.member", user_id)]
        is_invite = my_member_event.content["membership"] == "invite"

        room_vars = {
            "title": calculate_room_name(room_state, user_id),
            "hash": string_ordinal_total(room_id),  # See sender avatar hash
            "notifs": [],
            "invite": is_invite,
            "link": self.make_room_link(room_id),
        }

        if not is_invite:
            for n in notifs:
                notifvars = yield self.get_notif_vars(
                    n, user_id, notif_events[n['event_id']], room_state
                )

                # merge overlapping notifs together.
                # relies on the notifs being in chronological order.
                merge = False
                if room_vars['notifs'] and 'messages' in room_vars['notifs'][-1]:
                    prev_messages = room_vars['notifs'][-1]['messages']
                    for message in notifvars['messages']:
                        pm = filter(lambda pm: pm['id'] == message['id'], prev_messages)
                        if pm:
                            if not message["is_historical"]:
                                pm[0]["is_historical"] = False
                            merge = True
                        elif merge:
                            # we're merging, so append any remaining messages
                            # in this notif to the previous one
                            prev_messages.append(message)

                if not merge:
                    room_vars['notifs'].append(notifvars)

        defer.returnValue(room_vars)

    @defer.inlineCallbacks
    def get_notif_vars(self, notif, user_id, notif_event, room_state):
        results = yield self.store.get_events_around(
            notif['room_id'], notif['event_id'],
            before_limit=CONTEXT_BEFORE, after_limit=CONTEXT_AFTER
        )

        ret = {
            "link": self.make_notif_link(notif),
            "ts": notif['received_ts'],
            "messages": [],
        }

        the_events = yield filter_events_for_client(
            self.store, user_id, results["events_before"]
        )
        the_events.append(notif_event)

        for event in the_events:
            messagevars = self.get_message_vars(notif, event, room_state)
            if messagevars is not None:
                ret['messages'].append(messagevars)

        defer.returnValue(ret)

    def get_message_vars(self, notif, event, room_state):
        if event.type != EventTypes.Message:
            return None

        sender_state_event = room_state[("m.room.member", event.sender)]
        sender_name = name_from_member_event(sender_state_event)
        sender_avatar_url = None
        if "avatar_url" in sender_state_event.content:
            sender_avatar_url = sender_state_event.content["avatar_url"]

        # 'hash' for deterministically picking default images: use
        # sender_hash % the number of default images to choose from
        sender_hash = string_ordinal_total(event.sender)

        ret = {
            "msgtype": event.content["msgtype"],
            "is_historical": event.event_id != notif['event_id'],
            "id": event.event_id,
            "ts": event.origin_server_ts,
            "sender_name": sender_name,
            "sender_avatar_url": sender_avatar_url,
            "sender_hash": sender_hash,
        }

        if event.content["msgtype"] == "m.text":
            self.add_text_message_vars(ret, event)
        elif event.content["msgtype"] == "m.image":
            self.add_image_message_vars(ret, event)

        if "body" in event.content:
            ret["body_text_plain"] = event.content["body"]

        return ret

    def add_text_message_vars(self, messagevars, event):
        if "format" in event.content:
            msgformat = event.content["format"]
        else:
            msgformat = None
        messagevars["format"] = msgformat

        if msgformat == "org.matrix.custom.html":
            messagevars["body_text_html"] = safe_markup(event.content["formatted_body"])
        else:
            messagevars["body_text_html"] = safe_text(event.content["body"])

        return messagevars

    def add_image_message_vars(self, messagevars, event):
        messagevars["image_url"] = event.content["url"]

        return messagevars

    def make_summary_text(self, notifs_by_room, state_by_room,
                          notif_events, user_id, reason):
        if len(notifs_by_room) == 1:
            # Only one room has new stuff
            room_id = notifs_by_room.keys()[0]

            # If the room has some kind of name, use it, but we don't
            # want the generated-from-names one here otherwise we'll
            # end up with, "new message from Bob in the Bob room"
            room_name = calculate_room_name(
                state_by_room[room_id], user_id, fallback_to_members=False
            )

            my_member_event = state_by_room[room_id][("m.room.member", user_id)]
            if my_member_event.content["membership"] == "invite":
                inviter_member_event = state_by_room[room_id][
                    ("m.room.member", my_member_event.sender)
                ]
                inviter_name = name_from_member_event(inviter_member_event)

                if room_name is None:
                    return INVITE_FROM_PERSON % {
                        "person": inviter_name,
                        "app": self.app_name
                    }
                else:
                    return INVITE_FROM_PERSON_TO_ROOM % {
                        "person": inviter_name,
                        "room": room_name,
                        "app": self.app_name,
                    }

            sender_name = None
            if len(notifs_by_room[room_id]) == 1:
                # There is just the one notification, so give some detail
                event = notif_events[notifs_by_room[room_id][0]["event_id"]]
                if ("m.room.member", event.sender) in state_by_room[room_id]:
                    state_event = state_by_room[room_id][("m.room.member", event.sender)]
                    sender_name = name_from_member_event(state_event)

                if sender_name is not None and room_name is not None:
                    return MESSAGE_FROM_PERSON_IN_ROOM % {
                        "person": sender_name,
                        "room": room_name,
                        "app": self.app_name,
                    }
                elif sender_name is not None:
                    return MESSAGE_FROM_PERSON % {
                        "person": sender_name,
                        "app": self.app_name,
                    }
            else:
                # There's more than one notification for this room, so just
                # say there are several
                if room_name is not None:
                    return MESSAGES_IN_ROOM % {
                        "room": room_name,
                        "app": self.app_name,
                    }
                else:
                    # If the room doesn't have a name, say who the messages
                    # are from explicitly to avoid, "messages in the Bob room"
                    sender_ids = list(set([
                        notif_events[n['event_id']].sender
                        for n in notifs_by_room[room_id]
                    ]))

                    return MESSAGES_FROM_PERSON % {
                        "person": descriptor_from_member_events([
                            state_by_room[room_id][("m.room.member", s)]
                            for s in sender_ids
                        ]),
                        "app": self.app_name,
                    }
        else:
            # Stuff's happened in multiple different rooms

            # ...but we still refer to the 'reason' room which triggered the mail
            if reason['room_name'] is not None:
                return MESSAGES_IN_ROOM_AND_OTHERS % {
                    "room": reason['room_name'],
                    "app": self.app_name,
                }
            else:
                # If the reason room doesn't have a name, say who the messages
                # are from explicitly to avoid, "messages in the Bob room"
                sender_ids = list(set([
                    notif_events[n['event_id']].sender
                    for n in notifs_by_room[reason['room_id']]
                ]))

                return MESSAGES_FROM_PERSON_AND_OTHERS % {
                    "person": descriptor_from_member_events([
                        state_by_room[reason['room_id']][("m.room.member", s)]
                        for s in sender_ids
                    ]),
                    "app": self.app_name,
                }

    def make_room_link(self, room_id):
        # need /beta for Universal Links to work on iOS
        if self.app_name == "Vector":
            return "https://vector.im/beta/#/room/%s" % (room_id,)
        else:
            return "https://matrix.to/#/%s" % (room_id,)

    def make_notif_link(self, notif):
        # need /beta for Universal Links to work on iOS
        if self.app_name == "Vector":
            return "https://vector.im/beta/#/room/%s/%s" % (
                notif['room_id'], notif['event_id']
            )
        else:
            return "https://matrix.to/#/%s/%s" % (
                notif['room_id'], notif['event_id']
            )

    def make_unsubscribe_link(self, user_id, app_id, email_address):
        params = {
            "access_token": self.auth_handler.generate_delete_pusher_token(user_id),
            "app_id": app_id,
            "pushkey": email_address,
        }

        # XXX: make r0 once API is stable
        return "%s_matrix/client/unstable/pushers/remove?%s" % (
            self.hs.config.public_baseurl,
            urllib.urlencode(params),
        )

    def mxc_to_http_filter(self, value, width, height, resize_method="crop"):
        if value[0:6] != "mxc://":
            return ""

        serverAndMediaId = value[6:]
        fragment = None
        if '#' in serverAndMediaId:
            (serverAndMediaId, fragment) = serverAndMediaId.split('#', 1)
            fragment = "#" + fragment

        params = {
            "width": width,
            "height": height,
            "method": resize_method,
        }
        return "%s_matrix/media/v1/thumbnail/%s?%s%s" % (
            self.hs.config.public_baseurl,
            serverAndMediaId,
            urllib.urlencode(params),
            fragment or "",
        )


def safe_markup(raw_html):
    return jinja2.Markup(bleach.linkify(bleach.clean(
        raw_html, tags=ALLOWED_TAGS, attributes=ALLOWED_ATTRS,
        # bleach master has this, but it isn't released yet
        # protocols=ALLOWED_SCHEMES,
        strip=True
    )))


def safe_text(raw_text):
    """
    Process text: treat it as HTML but escape any tags (ie. just escape the
    HTML) then linkify it.
    """
    return jinja2.Markup(bleach.linkify(bleach.clean(
        raw_text, tags=[], attributes={},
        strip=False
    )))


def deduped_ordered_list(l):
    seen = set()
    ret = []
    for item in l:
        if item not in seen:
            seen.add(item)
            ret.append(item)
    return ret


def string_ordinal_total(s):
    tot = 0
    for c in s:
        tot += ord(c)
    return tot


def format_ts_filter(value, format):
    return time.strftime(format, time.localtime(value / 1000))