changedetection.io/changedetectionio/notification.py

import apprise
from jinja2 import Environment, BaseLoader
from apprise import NotifyFormat
import json

valid_tokens = {
    'base_url': '',
    'watch_url': '',
    'watch_uuid': '',
    'watch_title': '',
    'watch_tag': '',
    'diff': '',
    'diff_added': '',
    'diff_removed': '',
    'diff_full': '',
    'diff_url': '',
    'preview_url': '',
    'current_snapshot': ''
}

default_notification_format_for_watch = 'System default'
default_notification_format = 'Text'
default_notification_body = '{{watch_url}} had a change.\n---\n{{diff}}\n---\n'
default_notification_title = 'ChangeDetection.io Notification - {{watch_url}}'

valid_notification_formats = {
    'Text': NotifyFormat.TEXT,
    'Markdown': NotifyFormat.MARKDOWN,
    'HTML': NotifyFormat.HTML,
    # Used only for editing a watch (not for global)
    default_notification_format_for_watch: default_notification_format_for_watch
}

# include the decorator
from apprise.decorators import notify

@notify(on="delete")
@notify(on="deletes")
@notify(on="get")
@notify(on="gets")
@notify(on="post")
@notify(on="posts")
@notify(on="put")
@notify(on="puts")
def apprise_custom_api_call_wrapper(body, title, notify_type, *args, **kwargs):
    import requests
    url = kwargs['meta'].get('url')

    if url.startswith('post'):
        r = requests.post
    elif url.startswith('get'):
        r = requests.get
    elif url.startswith('put'):
        r = requests.put
    elif url.startswith('delete'):
        r = requests.delete

    url = url.replace('post://', 'http://')
    url = url.replace('posts://', 'https://')
    url = url.replace('put://', 'http://')
    url = url.replace('puts://', 'https://')
    url = url.replace('get://', 'http://')
    url = url.replace('gets://', 'https://')
    url = url.replace('put://', 'http://')
    url = url.replace('puts://', 'https://')
    url = url.replace('delete://', 'http://')
    url = url.replace('deletes://', 'https://')

    # Try to auto-guess if it's JSON
    headers = {}
    try:
        json.loads(body)
        headers = {'Content-Type': 'application/json; charset=utf-8'}
    except ValueError as e:
        pass


    r(url, headers=headers, data=body)


def process_notification(n_object, datastore):

    # Insert variables into the notification content
    notification_parameters = create_notification_parameters(n_object, datastore)

    # Get the notification body from datastore
    jinja2_env = Environment(loader=BaseLoader)
    n_body = jinja2_env.from_string(n_object.get('notification_body', default_notification_body)).render(**notification_parameters)
    n_title = jinja2_env.from_string(n_object.get('notification_title', default_notification_title)).render(**notification_parameters)
    n_format = valid_notification_formats.get(
        n_object['notification_format'],
        valid_notification_formats[default_notification_format],
    )
    
    # https://github.com/caronc/apprise/wiki/Development_LogCapture
    # Anything higher than or equal to WARNING (which covers things like Connection errors)
    # raise it as an exception
    apobjs=[]
    sent_objs=[]
    from .apprise_asset import asset
    for url in n_object['notification_urls']:
        url = jinja2_env.from_string(url).render(**notification_parameters)
        apobj = apprise.Apprise(debug=True, asset=asset)
        url = url.strip()
        if len(url):
            print(">> Process Notification: AppRise notifying {}".format(url))
            with apprise.LogCapture(level=apprise.logging.DEBUG) as logs:
                # Re 323 - Limit discord length to their 2000 char limit total or it wont send.
                # Because different notifications may require different pre-processing, run each sequentially :(
                # 2000 bytes minus -
                #     200 bytes for the overhead of the _entire_ json payload, 200 bytes for {tts, wait, content} etc headers
                #     Length of URL - Incase they specify a longer custom avatar_url

                # So if no avatar_url is specified, add one so it can be correctly calculated into the total payload
                k = '?' if not '?' in url else '&'
                if not 'avatar_url' in url \
                        and not url.startswith('mail') \
                        and not url.startswith('post') \
                        and not url.startswith('get') \
                        and not url.startswith('delete') \
                        and not url.startswith('put'):
                    url += k + 'avatar_url=https://raw.githubusercontent.com/dgtlmoon/changedetection.io/master/changedetectionio/static/images/avatar-256x256.png'

                if url.startswith('tgram://'):
                    # Telegram only supports a limit subset of HTML, remove the '<br/>' we place in.
                    # re https://github.com/dgtlmoon/changedetection.io/issues/555
                    # @todo re-use an existing library we have already imported to strip all non-allowed tags
                    n_body = n_body.replace('<br/>', '\n')
                    n_body = n_body.replace('</br>', '\n')
                    # real limit is 4096, but minus some for extra metadata
                    payload_max_size = 3600
                    body_limit = max(0, payload_max_size - len(n_title))
                    n_title = n_title[0:payload_max_size]
                    n_body = n_body[0:body_limit]

                elif url.startswith('discord://') or url.startswith('https://discordapp.com/api/webhooks') or url.startswith('https://discord.com/api'):
                    # real limit is 2000, but minus some for extra metadata
                    payload_max_size = 1700
                    body_limit = max(0, payload_max_size - len(n_title))
                    n_title = n_title[0:payload_max_size]
                    n_body = n_body[0:body_limit]

                elif url.startswith('mailto'):
                    # Apprise will default to HTML, so we need to override it
                    # So that whats' generated in n_body is in line with what is going to be sent.
                    # https://github.com/caronc/apprise/issues/633#issuecomment-1191449321
                    if not 'format=' in url and (n_format == 'text' or n_format == 'markdown'):
                        prefix = '?' if not '?' in url else '&'
                        url = "{}{}format={}".format(url, prefix, n_format)

                apobj.add(url)

                apobj.notify(
                    title=n_title,
                    body=n_body,
                    body_format=n_format,
                    # False is not an option for AppRise, must be type None
                    attach=n_object.get('screenshot', None)
                )

                apobj.clear()

                # Incase it needs to exist in memory for a while after to process(?)
                apobjs.append(apobj)

                # Returns empty string if nothing found, multi-line string otherwise
                log_value = logs.getvalue()
                if log_value and 'WARNING' in log_value or 'ERROR' in log_value:
                    raise Exception(log_value)
                
                sent_objs.append({'title': n_title,
                                  'body': n_body,
                                  'url' : url,
                                  'body_format': n_format})

    # Return what was sent for better logging - after the for loop
    return sent_objs


# Notification title + body content parameters get created here.
def create_notification_parameters(n_object, datastore):
    from copy import deepcopy

    # in the case we send a test notification from the main settings, there is no UUID.
    uuid = n_object['uuid'] if 'uuid' in n_object else ''

    if uuid != '':
        watch_title = datastore.data['watching'][uuid]['title']
        watch_tag = datastore.data['watching'][uuid]['tag']
    else:
        watch_title = 'Change Detection'
        watch_tag = ''

    # Create URLs to customise the notification with
    base_url = datastore.data['settings']['application']['base_url']

    watch_url = n_object['watch_url']

    # Re #148 - Some people have just {{ base_url }} in the body or title, but this may break some notification services
    #           like 'Join', so it's always best to atleast set something obvious so that they are not broken.
    if base_url == '':
        base_url = "<base-url-env-var-not-set>"

    diff_url = "{}/diff/{}".format(base_url, uuid)
    preview_url = "{}/preview/{}".format(base_url, uuid)

    # Not sure deepcopy is needed here, but why not
    tokens = deepcopy(valid_tokens)

    # Valid_tokens also used as a field validator
    tokens.update(
        {
            'base_url': base_url if base_url is not None else '',
            'watch_url': watch_url,
            'watch_uuid': uuid,
            'watch_title': watch_title if watch_title is not None else '',
            'watch_tag': watch_tag if watch_tag is not None else '',
            'diff_url': diff_url,
            'diff': n_object.get('diff', ''),  # Null default in the case we use a test
            'diff_added': n_object.get('diff_added', ''),  # Null default in the case we use a test
            'diff_removed': n_object.get('diff_removed', ''),  # Null default in the case we use a test
            'diff_full': n_object.get('diff_full', ''),  # Null default in the case we use a test
            'preview_url': preview_url,
            'current_snapshot': n_object['current_snapshot'] if 'current_snapshot' in n_object else ''
        })

    return tokens