show filesize on user downloads page

- add column to user download page to display filesize
- adds a filter to display file sizes
- don't download the user downloads page from notifications ;)

bookwyrm/templates/notifications/items/user_export.html

@@ -11,5 +11,5 @@
 
 {% block description %}
     {% url 'prefs-user-export'  as url %}
-    {% blocktrans %}Your <a download href="{{ url }}">user export</a> is ready.{% endblocktrans %}
+    {% blocktrans %}Your <a href="{{ url }}">user export</a> is ready.{% endblocktrans %}
 {% endblock %}

bookwyrm/templates/preferences/export-user.html

@@ -1,5 +1,6 @@
 {% extends 'preferences/layout.html' %}
 {% load i18n %}
+{% load utilities %}
 
 {% block title %}{% trans "User Export" %}{% endblock %}
 
@@ -40,9 +41,12 @@
                 <th>
                     {% trans "Date" %}
                 </th>
-                <th colspan="2">
+                <th>
                     {% trans "Status" %}
                 </th>
+                <th colspan="2">
+                    {% trans "Size" %}
+                </th>
             </tr>
             {% if not jobs %}
             <tr>
@@ -76,6 +80,9 @@
                         {% endif %}
                     </span>
                 </td>
+                <td>
+                    <span>{{ job.export_data|get_file_size }}</span>
+                </td>
                 <td>
                     {% if job.complete and not job.status == "stopped" and not job.status == "failed" %}
                     <p>

bookwyrm/templatetags/utilities.py

@@ -125,3 +125,20 @@ def id_to_username(user_id):
         value = f"{name}@{domain}"
 
     return value
+
+
+@register.filter(name="get_file_size")
+def get_file_size(file):
+    """display the size of a file in human readable terms"""
+
+    try:
+        raw_size = os.stat(file.path).st_size
+        if raw_size < 1024:
+            return f"{raw_size} bytes"
+        if raw_size < 1024**2:
+            return f"{raw_size/1024:.2f} KB"
+        if raw_size < 1024**3:
+            return f"{raw_size/1024**2:.2f} MB"
+        return f"{raw_size/1024**3:.2f} GB"
+    except Exception:  # pylint: disable=broad-except
+        return ""