chg: [crawler stats] add previous month stats by domain type

bin/packages/Date.py

@@ -263,3 +263,9 @@ def sanitise_daterange(date_from, date_to, separator='', date_type='str'):
         date_from = date_to
         date_to = res
     return date_from, date_to
+
+def get_previous_month_date():
+    now = datetime.date.today()
+    first = now.replace(day=1)
+    last_month = first - datetime.timedelta(days=1)
+    return last_month.strftime("%Y%m%d")

var/www/blueprints/crawler_splash.py

@@ -316,6 +316,17 @@ def crawlers_last_domains_month_json():
     stats = crawlers.get_crawlers_stats_by_month(domain_type)
     return jsonify(stats)
 
+@crawler_splash.route('/crawlers/last/domains/month/previous/json')
+@login_required
+@login_read_only
+def crawlers_last_domains_previous_month_json():
+    domain_type = request.args.get('type')
+    if domain_type not in crawlers.get_crawler_all_types():
+        return jsonify({'error': 'Invalid domain type'}), 400
+    date = Date.get_previous_month_date()
+    stats = crawlers.get_crawlers_stats_by_month(domain_type, date=date)
+    return jsonify(stats)
+
 @crawler_splash.route('/crawlers/last/domains/status/month/json')
 @login_required
 @login_read_only

var/www/templates/crawler/crawler_splash/last_crawled.html

@@ -95,6 +95,10 @@ <h3>Month Stats:</h3>
                 <div id="barchart_type_month"></div>
                 <div class="text-center" id="pie_chart_month"></div>
 
+                <h3>Previous Month Stats:</h3>
+                <div id="barchart_type_month"></div>
+                <div class="text-center" id="barchart_type_previous_month"></div>
+
 			</div>
 
 		</div>
@@ -156,6 +160,13 @@ <h3>Month Stats:</h3>
         }
     );
 
+    $.getJSON("{{ url_for('crawler_splash.crawlers_last_domains_previous_month_json') }}?type={{type}}",
+        function (data) {
+                let div_width = $("#barchart_type_previous_month").width();
+                barchart_stack("barchart_type_previous_month", data, {"width": div_width});
+        }
+    );
+
 });
 
 function toggle_sidebar(){