admin can manage newsletter and test sending it (#1177)

* admin can manage newsletter and test sending it

* add comments

* comment

* doc

* not userID not specified, send the newsletter to current user

* automatically match textarea height to content when editing newsletter

* increase text height and limit img size to 100% in email template

* admin can send newsletter to a specific address

app/admin_model.py

@@ -25,7 +25,9 @@ from app.models import (
     Phase,
     ProviderComplaint,
     Alias,
+    Newsletter,
 )
+from app.newsletter_utils import send_newsletter_to_user, send_newsletter_to_address
 
 
 class SLModelView(sqla.ModelView):
@@ -469,3 +471,83 @@ class ProviderComplaintAdmin(SLModelView):
                 )
             },
         )
+
+
+def _newsletter_plain_text_formatter(view, context, model: Newsletter, name):
+    # to display newsletter plain_text with linebreaks in the list view
+    return Markup(model.plain_text.replace("\n", "<br>"))
+
+
+def _newsletter_html_formatter(view, context, model: Newsletter, name):
+    # to display newsletter html with linebreaks in the list view
+    return Markup(model.html.replace("\n", "<br>"))
+
+
+class NewsletterAdmin(SLModelView):
+    list_template = "admin/model/newsletter-list.html"
+    edit_template = "admin/model/newsletter-edit.html"
+    edit_modal = False
+
+    can_edit = True
+    can_create = True
+
+    column_formatters = {
+        "plain_text": _newsletter_plain_text_formatter,
+        "html": _newsletter_html_formatter,
+    }
+
+    @action(
+        "send_newsletter_to_user",
+        "Send this newsletter to myself or the specified userID",
+    )
+    def send_newsletter_to_user(self, newsletter_ids):
+        user_id = request.form["user_id"]
+        if user_id:
+            user = User.get(user_id)
+            if not user:
+                flash(f"No such user with ID {user_id}", "error")
+                return
+        else:
+            flash("use the current user", "info")
+            user = current_user
+
+        for newsletter_id in newsletter_ids:
+            newsletter = Newsletter.get(newsletter_id)
+            sent, error_msg = send_newsletter_to_user(newsletter, user)
+            if sent:
+                flash(f"{newsletter} sent to {user}", "success")
+            else:
+                flash(error_msg, "error")
+
+    @action(
+        "send_newsletter_to_address",
+        "Send this newsletter to a specific address",
+    )
+    def send_newsletter_to_address(self, newsletter_ids):
+        to_address = request.form["to_address"]
+        if not to_address:
+            flash("to_address missing", "error")
+            return
+
+        for newsletter_id in newsletter_ids:
+            newsletter = Newsletter.get(newsletter_id)
+            # use the current_user for rendering email
+            sent, error_msg = send_newsletter_to_address(
+                newsletter, current_user, to_address
+            )
+            if sent:
+                flash(
+                    f"{newsletter} sent to {to_address} with {current_user} context",
+                    "success",
+                )
+            else:
+                flash(error_msg, "error")
+
+
+class NewsletterUserAdmin(SLModelView):
+    column_searchable_list = ["id"]
+    column_filters = ["id", "user.email", "newsletter.subject"]
+    column_exclude_list = ["created_at", "updated_at", "id"]
+
+    can_edit = False
+    can_create = False

app/models.py

@@ -3256,3 +3256,29 @@ class PartnerSubscription(Base, ModelMixin):
 
 
 # endregion
+
+
+class Newsletter(Base, ModelMixin):
+    __tablename__ = "newsletter"
+    subject = sa.Column(sa.String(), nullable=False, unique=True, index=True)
+
+    html = sa.Column(sa.Text)
+    plain_text = sa.Column(sa.Text)
+
+    def __repr__(self):
+        return f"<Newsletter {self.id} {self.subject}>"
+
+
+class NewsletterUser(Base, ModelMixin):
+    """This model keeps track of what newsletter is sent to what user"""
+
+    __tablename__ = "newsletter_user"
+    user_id = sa.Column(sa.ForeignKey(User.id, ondelete="cascade"), nullable=True)
+    newsletter_id = sa.Column(
+        sa.ForeignKey(Newsletter.id, ondelete="cascade"), nullable=True
+    )
+    # not use created_at here as it should only used for auditting purpose
+    sent_at = sa.Column(ArrowType, default=arrow.utcnow, nullable=False)
+
+    user = orm.relationship(User)
+    newsletter = orm.relationship(Newsletter)

app/newsletter_utils.py

@@ -0,0 +1,68 @@
+import os
+
+from jinja2 import Environment, FileSystemLoader
+
+from app.config import ROOT_DIR, URL
+from app.email_utils import send_email
+from app.log import LOG
+from app.models import NewsletterUser
+
+
+def send_newsletter_to_user(newsletter, user) -> (bool, str):
+    """Return whether the newsletter is sent successfully and the error if not"""
+    try:
+        templates_dir = os.path.join(ROOT_DIR, "templates", "emails")
+        env = Environment(loader=FileSystemLoader(templates_dir))
+        html_template = env.from_string(newsletter.html)
+        text_template = env.from_string(newsletter.plain_text)
+
+        to_email, unsubscribe_link, via_email = user.get_communication_email()
+        if not to_email:
+            return False, f"{user} not subscribed to newsletter"
+
+        send_email(
+            to_email,
+            newsletter.subject,
+            text_template.render(
+                user=user,
+                URL=URL,
+            ),
+            html_template.render(
+                user=user,
+                URL=URL,
+            ),
+        )
+
+        NewsletterUser.create(newsletter_id=newsletter.id, user_id=user.id, commit=True)
+        return True, ""
+    except Exception as err:
+        LOG.w(f"cannot send {newsletter} to {user}", exc_info=True)
+        return False, str(err)
+
+
+def send_newsletter_to_address(newsletter, user, to_address) -> (bool, str):
+    """Return whether the newsletter is sent successfully and the error if not"""
+    try:
+        templates_dir = os.path.join(ROOT_DIR, "templates", "emails")
+        env = Environment(loader=FileSystemLoader(templates_dir))
+        html_template = env.from_string(newsletter.html)
+        text_template = env.from_string(newsletter.plain_text)
+
+        send_email(
+            to_address,
+            newsletter.subject,
+            text_template.render(
+                user=user,
+                URL=URL,
+            ),
+            html_template.render(
+                user=user,
+                URL=URL,
+            ),
+        )
+
+        NewsletterUser.create(newsletter_id=newsletter.id, user_id=user.id, commit=True)
+        return True, ""
+    except Exception as err:
+        LOG.w(f"cannot send {newsletter} to {user}", exc_info=True)
+        return False, str(err)

migrations/versions/2022_072119_c66f2c5b6cb1_.py

@@ -0,0 +1,51 @@
+"""empty message
+
+Revision ID: c66f2c5b6cb1
+Revises: 89081a00fc7d
+Create Date: 2022-07-21 19:06:38.330239
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'c66f2c5b6cb1'
+down_revision = '89081a00fc7d'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('newsletter',
+    sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
+    sa.Column('created_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=False),
+    sa.Column('updated_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=True),
+    sa.Column('subject', sa.String(), nullable=False),
+    sa.Column('html', sa.Text(), nullable=True),
+    sa.Column('plain_text', sa.Text(), nullable=True),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_newsletter_subject'), 'newsletter', ['subject'], unique=True)
+    op.create_table('newsletter_user',
+    sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
+    sa.Column('created_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=False),
+    sa.Column('updated_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=True),
+    sa.Column('newsletter_id', sa.Integer(), nullable=True),
+    sa.Column('sent_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=False),
+    sa.ForeignKeyConstraint(['newsletter_id'], ['newsletter.id'], ondelete='cascade'),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='cascade'),
+    sa.PrimaryKeyConstraint('id')
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('newsletter_user')
+    op.drop_index(op.f('ix_newsletter_subject'), table_name='newsletter')
+    op.drop_table('newsletter')
+    # ### end Alembic commands ###

server.py

@@ -40,6 +40,8 @@ from app.admin_model import (
     CustomDomainAdmin,
     AdminAuditLogAdmin,
     ProviderComplaintAdmin,
+    NewsletterAdmin,
+    NewsletterUserAdmin,
 )
 from app.api.base import api_bp
 from app.auth.base import auth_bp
@@ -97,6 +99,8 @@ from app.models import (
     Coupon,
     AdminAuditLog,
     ProviderComplaint,
+    Newsletter,
+    NewsletterUser,
 )
 from app.monitor.base import monitor_bp
 from app.oauth.base import oauth_bp
@@ -745,6 +749,8 @@ def init_admin(app):
     admin.add_view(CustomDomainAdmin(CustomDomain, Session))
     admin.add_view(AdminAuditLogAdmin(AdminAuditLog, Session))
     admin.add_view(ProviderComplaintAdmin(ProviderComplaint, Session))
+    admin.add_view(NewsletterAdmin(Newsletter, Session))
+    admin.add_view(NewsletterUserAdmin(NewsletterUser, Session))
 
 
 def register_custom_commands(app):

templates/admin/model/newsletter-edit.html

@@ -0,0 +1,25 @@
+{#
+Automatically increase textarea height to match content to facilitate editing
+#}
+{% extends 'admin/model/edit.html' %}
+
+{% block head %}
+
+  {{ super() }}
+  <style>
+  body{
+      max-width: 80%;
+      margin: auto;
+  }
+  </style>
+{% endblock %}
+{% block tail %}
+
+  {{ super() }}
+  <script type="application/javascript">
+    $('textarea').each(function (index) {
+      this.style.height = "";
+      this.style.height = this.scrollHeight + "px";
+    });
+  </script>
+{% endblock %}

templates/admin/model/newsletter-list.html

@@ -0,0 +1,30 @@
+{#
+Add custom input form so admin can enter a user id to send a newsletter to
+Based on https://github.com/flask-admin/flask-admin/issues/974#issuecomment-168215285
+#}
+{% extends 'admin/model/list.html' %}
+
+{% block model_menu_bar_before_filters %}
+
+  <br>
+  <li id="here" class="form-row">
+    <input name="user_id"
+           class="form-control"
+           placeholder="User ID"
+           aria-describedby="userID"/>
+    <input name="to_address"
+           class="form-control"
+           placeholder="Specify an address to receive the newsletter for testing"
+           aria-describedby="Email address"/>
+  </li>
+{% endblock %}
+{% block tail %}
+
+  {{ super() }}
+  <script type="application/javascript">
+        $("input[name='user_id']").appendTo($("#action_form"))
+        $("input[name='to_address']").appendTo($("#action_form"))
+        $("#action_form").appendTo($("#here"))
+        $("#action_form").attr("style", "")
+  </script>
+{% endblock %}

templates/emails/base.html

@@ -1,4 +1,4 @@
-{% from "_emailhelpers.html" import render_text, text, render_button, raw_url, grey_section %}
+{% from "_emailhelpers.html" import render_text, text, render_button, raw_url, grey_section, section %}
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" lang="en">
   <head>
@@ -12,6 +12,11 @@
       height: 100%;
       margin: 0;
       -webkit-text-size-adjust: none;
+        line-height: 1.6;
+    }
+
+    img {
+        max-width: 100%;
     }
 
     a {