Invitation email

[Ironicbay]

I've written quite a lot of comments to highlight the issues I'm facing, mostly :

• I'm unsure about the place I've put the modifications in, if it should be inside the class or outside
• The email HTML text is huge and I'm not sure where it should be, clearly it's not ideal right now
• I don't know what email address will be used to send it, and I don't know how to secure its password while keeping the process automated

[codecov]

Codecov Report

Merging #1177 into master will increase coverage by 0.27%.
The diff coverage is 45.65%.

@@            Coverage Diff             @@
##           master    #1177      +/-   ##
==========================================
+ Coverage   80.21%   80.49%   +0.27%     
==========================================
  Files         283      284       +1     
  Lines       24082    25195    +1113     
==========================================
+ Hits        19318    20281     +963     
- Misses       4764     4914     +150     

Impacted Files	Coverage Δ
parsec/backend/invite.py	84.59% <30.18%> (-10.56%)	⬇️
parsec/backend/cli/run.py	70.80% <45.00%> (-0.63%)	⬇️
parsec/backend/client_context.py	94.52% <66.66%> (-2.50%)	⬇️
parsec/backend/config.py	93.54% <100.00%> (+1.39%)	⬆️
parsec/backend/memory/factory.py	100.00% <100.00%> (ø)
parsec/backend/postgresql/factory.py	100.00% <100.00%> (ø)
...c/backend/postgresql/realm_queries/update_roles.py	94.59% <0.00%> (-1.16%)	⬇️
parsec/core/gui/trio_thread.py	90.55% <0.00%> (-1.12%)	⬇️
parsec/core/fs/workspacefs/entry_transactions.py	96.47% <0.00%> (-0.59%)	⬇️
parsec/core/gui/files_widget.py	74.86% <0.00%> (-0.54%)	⬇️
... and 67 more

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[c4ffein]

LGTM

[touilleMan]

This seems too fragile (for instance why do we skip body[2] ? ^^).
If we want to change the place invite_link is we have to change this part, the body list (for each language) and the html formating too... If we consider the body as a list of paragraph, we just have to move the {invite_link} part in the body (well still for each language).

And the formatting becomes trivial:

body = MAIL_TEXT[lang]['body']

text_body = '\n'.join(body).format(sender_name=sender_name, parsec_url=parsec_url, invite_link=invite_link)

html_body = '<br>'.join(body).format(sender_name=sender_name, parsec_url=parsec_url, invite_link=invite_link)
html_template = importlib_resources.read_text(parsec.backend.mail, "invite_mail.tmpl.html")
html = html_template.format(body=html_body, preheader=MAIL_TEXT[lang]['preheader'], ...)

[touilleMan]

It seems you can add LANGUAGE headers to email messages

RFC1766 §4.1 seems to present an example of multi-language message (https://tools.ietf.org/html/rfc1766):

    Content-Type: multipart/alternative; differences=Content-Language;
              boundary="limit"
    Content-Language: en, fr, de

    --limit
    Content-Language: fr

    Le renard brun et agile saute par dessus le chien paresseux
    --limit
    Content-Language: de
    Content-Type: text/plain; charset=iso-8859-1
    Content-Transfer-encoding: quoted-printable

    Der schnelle braune Fuchs h=FCpft =FCber den faulen Hund
    --limit
    Content-Language: en

    The quick brown fox jumps over the lazy dog
    --limit--

see also https://tools.ietf.org/html/rfc2231.html

Have you tried this kind of stuff in your email ?

[touilleMan]

I've made a couple of tests for multilingual mails

import smtplib, ssl
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

sender_email = "no-reply@parsec.cloud"
# receiver_email = "yyy@gmail.com"
receiver_email = "xxx@gmail.com"
password = "xxxxxxxxxxxxx"

message = MIMEMultipart("alternative")
message["Subject"] = "Bonjour 2"
message["From"] = sender_email
message["To"] = receiver_email

# Create the plain-text and HTML version of your message
text_fr = """\
Salut,
Comment ça va ?
Real Python has many great tutorials:
www.realpython.com"""

html_fr = """\
<html>
  <body>
    <p>Salut,<br>
       Comment ça va ?<br>
       <a href="http://www.realpython.com">Real Python</a> 
       has many great tutorials.
    </p>
  </body>
</html>
"""

text_en = """\
Hi,
How are you?
Real Python has many great tutorials:
www.realpython.com"""

html_en = """\
<html>
  <body>
    <p>Hi,<br>
       How are you?<br>
       <a href="http://www.realpython.com">Real Python</a> 
       has many great tutorials.
    </p>
  </body>
</html>
"""

# Turn these into plain/html MIMEText objects
part_text_fr = MIMEText(text_fr, "plain")
part_html_fr = MIMEText(html_fr, "html")
part_text_en = MIMEText(text_en, "plain")
part_html_en = MIMEText(html_en, "html")

part_text_fr.add_header("Content-Language", "fr-FR")
part_html_fr.add_header("Content-Language", "fr-FR")
part_text_en.add_header("Content-Language", "en-US")
part_html_en.add_header("Content-Language", "en-US")

# Add HTML/plain-text parts to MIMEMultipart message
# The email client will try to render the last part first
message.attach(part_text_en)
message.attach(part_html_en)
message.attach(part_text_fr)
message.attach(part_html_fr)

# Create secure connection with server and send email
context = ssl.create_default_context()
with smtplib.SMTP("mail.gandi.net", 587) as server:
    tls_ready = server.starttls(context=context)
    if tls_ready[0] != 220:
        print("TLS error:", tls_ready)
    server.login(sender_email, password)
    server.sendmail(
        sender_email, receiver_email, message.as_string()
    )

which create this kind of email body:

[...]
Content-Type: multipart/alternative; boundary="===============2245090318428771878=="
MIME-Version: 1.0
Subject: Bonjour 1
From: no-reply@parsec.cloud
To: xxx@gmail.com

--===============2245090318428771878==
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Language: fr

U2FsdXQsCkNvbW1lbnQgw6dhIHZhID8KUmVhbCBQeXRob24gaGFzIG1hbnkgZ3JlYXQgdHV0b3Jp
YWxzOgp3d3cucmVhbHB5dGhvbi5jb20=
--===============2245090318428771878==
Content-Type: text/html; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Language: fr

PGh0bWw+CiAgPGJvZHk+CiAgICA8cD5TYWx1dCw8YnI+CiAgICAgICBDb21tZW50IMOnYSB2YSA/
PGJyPgogICAgICAgPGEgaHJlZj0iaHR0cDovL3d3dy5yZWFscHl0aG9uLmNvbSI+UmVhbCBQeXRo
b248L2E+IAogICAgICAgaGFzIG1hbnkgZ3JlYXQgdHV0b3JpYWxzLgogICAgPC9wPgogIDwvYm9k
eT4KPC9odG1sPgo=
--===============2245090318428771878==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Language: en

Hi,
How are you?
Real Python has many great tutorials:
www.realpython.com
--===============2245090318428771878==
Content-Type: text/html; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Language: en

<html>
  <body>
    <p>Hi,<br>
       How are you?<br>
       <a href="http://www.realpython.com">Real Python</a> 
       has many great tutorials.
    </p>
  </body>
</html>

--===============2245090318428771878==--

However this doesn't seems to be handled correctly with mail clients (I've tried with gmail, the last html part is always used no matter it content-language type and the language of the gmail client) :'-(

[Ironicbay]

Mail preview

[touilleMan]

lgtm