Massive code cleanup

- Avoid fighting import cycles using a factory function
- Collapse useless subpackages into simple modules
- Move flask plugins / infrastructure in own module
- Refactor how blueprints are used to localize information about
  URL routing to app factory

snikket_web/admin.py

@@ -0,0 +1,127 @@
+import typing
+
+from datetime import datetime
+
+import quart.flask_patch
+
+import wtforms
+import wtforms.fields.html5
+
+from quart import (Blueprint, render_template, redirect, url_for)
+import flask_wtf
+
+from flask_babel import lazy_gettext as _l
+
+from .infra import client
+
+bp = Blueprint("admin", __name__, url_prefix="/admin")
+
+
+@bp.route("/")
+@client.require_admin_session()
+async def index() -> str:
+    user_info = await client.get_user_info()
+    return await render_template("admin_home.html", user_info=user_info)
+
+
+@bp.route("/users")
+@client.require_admin_session()
+async def users() -> str:
+    user_info = await client.get_user_info()
+    users = sorted(
+        await client.list_users(),
+        key=lambda x: x.localpart
+    )
+    return await render_template(
+        "admin_users.html",
+        users=users,
+        user_info=user_info,
+    )
+
+
+class DeleteUserForm(flask_wtf.FlaskForm):  # type:ignore
+    action_delete = wtforms.SubmitField(
+        _l("Delete user permanently")
+    )
+
+
+@bp.route("/user/<localpart>/delete", methods=["GET", "POST"])
+@client.require_admin_session()
+async def delete_user(localpart: str) -> typing.Union[str, quart.Response]:
+    user_info = await client.get_user_info()
+    target_user_info = await client.get_user_by_localpart(localpart)
+    form = DeleteUserForm()
+    if form.validate_on_submit():
+        if form.action_delete.data:
+            await client.delete_user_by_localpart(localpart)
+        return redirect(url_for(".users"))
+
+    return await render_template(
+        "admin_delete_user.html",
+        target_user=target_user_info,
+        user_info=user_info,
+        form=form,
+    )
+
+
+class InvitesListForm(flask_wtf.FlaskForm):  # type:ignore
+    action_revoke = wtforms.StringField()
+
+    action_create_invite = wtforms.SubmitField(
+        _l("New invitation link")
+    )
+
+
+@bp.route("/invitations", methods=["GET", "POST"])
+@client.require_admin_session()
+async def invitations() -> typing.Union[str, quart.Response]:
+    user_info = await client.get_user_info()
+    invites = sorted(
+        await client.list_invites(),
+        key=lambda x: x.created_at
+    )
+
+    form = InvitesListForm()
+    if form.validate_on_submit():
+        if form.action_revoke.data:
+            await client.delete_invite(form.action_revoke.data)
+        if form.action_create_invite.data:
+            info = await client.create_invite()
+            return redirect(url_for(".edit_invite", id_=info.id_))
+        return redirect(url_for(".invitations"))
+
+    return await render_template(
+        "admin_invites.html",
+        user_info=user_info,
+        invites=invites,
+        now=datetime.utcnow(),
+        form=form,
+    )
+
+
+class InviteForm(flask_wtf.FlaskForm):  # type:ignore
+    action_revoke = wtforms.SubmitField(
+        _l("Revoke")
+    )
+
+
+@bp.route("/invitation/<id_>", methods=["GET", "POST"])
+@client.require_admin_session()
+async def edit_invite(id_: str) -> typing.Union[str, quart.Response]:
+    user_info = await client.get_user_info()
+    invite_info = await client.get_invite_by_id(id_)
+
+    form = InviteForm()
+    if form.validate_on_submit():
+        if form.action_revoke.data:
+            await client.delete_invite(id_)
+            return redirect(url_for(".invitations"))
+        return redirect(url_for(".edit_invite", id_=id_))
+
+    return await render_template(
+        "admin_edit_invite.html",
+        user_info=user_info,
+        invite=invite_info,
+        now=datetime.utcnow(),
+        form=form,
+    )