Add django command to bill for Trotec use

apiserver/apiserver/api/emails/usage_bill.txt

@@ -0,0 +1,21 @@
+Hi [name],
+
+Please find attached a summary of your [device] usage in [month]. You used
+[overage] minutes over your free allotment, which at $0.50/min comes to $[bill].
+You can pay this on the portal's Paymaster page under the consumables section,
+or send an e-Transfer to info@protospace.ca, or hand a director cash.
+
+INVOICE
+Device:  [device]
+Month:   [month]
+Usage:   [minutes] min
+Overage: [overage] min
+----------------------
+Bill:    $[bill]
+
+If you want to reply to this email, please click "reply-all" since the Spaceport
+inbox does not exist.
+
+If you've already paid, ignore this email.
+
+Spaceport

apiserver/apiserver/api/management/commands/bill_trotec.py

@@ -0,0 +1,101 @@
+from django.core.management.base import BaseCommand, CommandError
+from django.contrib.auth.models import User
+from django.db.models import Max, F, Count, Q, Sum
+from django.utils.timezone import now
+from django.core.cache import cache
+from django.db import transaction
+from dateutil import relativedelta
+import math
+
+from apiserver import secrets, settings
+from apiserver.api import models, utils, utils_email
+
+import time
+
+class Command(BaseCommand):
+    help = 'Bill Trotec laser usage for last month. Wise to run this on the 2nd of each month to prevent any timezone issues.'
+
+    FREE_MINUTES = 60 * 6
+    DEVICE = 'TROTECS300'
+    DEVICE_NAME = 'Trotec'
+    DOLLARS_PER_MINUTE = 0.50
+
+    def bill_trotec(self):
+        count = 0
+
+        now = utils.now_alberta_tz()
+        current_month_start = now.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
+        previous_month_start = current_month_start - relativedelta.relativedelta(months=1)
+
+        self.stdout.write('Billing from {} to {}...'.format(
+            previous_month_start,
+            current_month_start,
+        ))
+
+        usages = models.Usage.objects.order_by('id').filter(should_bill=True)
+        month_trotec_usages = usages.filter(
+            started_at__gte=previous_month_start,
+            started_at__lt=current_month_start,
+            device=self.DEVICE,
+        )
+
+        month_trotec_user_ids = month_trotec_usages.values_list('user', flat=True).distinct()
+        month_trotec_users = User.objects.filter(id__in=month_trotec_user_ids)
+
+        self.stdout.write('Found {} usages by {} users.'.format(
+            month_trotec_usages.count(),
+            month_trotec_users.count(),
+        ))
+
+        for user in month_trotec_users:
+            if not user:
+                continue
+
+            self.stdout.write('Billing {}:'.format(user.username))
+
+            users_usages = month_trotec_usages.filter(
+                user=user,
+            )
+
+            total_seconds = users_usages.aggregate(Sum('num_seconds'))['num_seconds__sum'] or 0
+            total_minutes = math.ceil(total_seconds / 60.0)
+            billable_minutes = total_minutes - self.FREE_MINUTES
+
+            self.stdout.write('    Total seconds: {}'.format(total_seconds))
+            self.stdout.write('    Total minutes: {}'.format(total_minutes))
+            self.stdout.write('    Billable minutes: {}'.format(billable_minutes))
+
+            if billable_minutes <= 0:
+                self.stdout.write('    Skipping, used free time.')
+                continue
+
+            bill = billable_minutes * self.DOLLARS_PER_MINUTE
+            bill_str = format(bill, '.2f')
+
+            self.stdout.write('    Total bill: ${}'.format(bill_str))
+
+            utils_email.send_usage_bill_email(
+                user,
+                self.DEVICE_NAME,
+                previous_month_start.strftime('%B'),
+                total_minutes,
+                billable_minutes,
+                bill_str,
+            )
+
+            self.stdout.write('    Sent usage bill email.')
+
+            count += 1
+
+        return count
+
+    def handle(self, *args, **options):
+        self.stdout.write('{} - Billing Trotec'.format(str(now())))
+        start = time.time()
+
+        count = self.bill_trotec()
+        self.stdout.write('Billed {} members'.format(count))
+
+        self.stdout.write('Completed billing in {} s'.format(
+            str(time.time() - start)[:4]
+        ))

apiserver/apiserver/api/utils_email.py

@@ -97,3 +97,34 @@ def send_interest_email(interest):
         time.sleep(0.5)  # simulate slowly sending emails when logging to console
 
     logger.info('Sent interest email:\n' + email_text)
+
+def send_usage_bill_email(user, device, month, minutes, overage, bill):
+    def replace_fields(text):
+        return text.replace(
+            '[name]', user.member.preferred_name,
+        ).replace(
+            '[device]', device,
+        ).replace(
+            '[month]', month,
+        ).replace(
+            '[minutes]', str(minutes),
+        ).replace(
+            '[overage]', str(overage),
+        ).replace(
+            '[bill]', bill,
+        )
+
+    with open(EMAIL_DIR + 'usage_bill.txt', 'r') as f:
+        email_text = replace_fields(f.read())
+
+    send_mail(
+        subject='{} {} Usage Bill'.format(month, device),
+        message=email_text,
+        from_email=None,  # defaults to DEFAULT_FROM_EMAIL
+        recipient_list=[user.email, 'directors@protospace.ca', 'protospace@tannercollin.com'],
+    )
+
+    if not settings.EMAIL_HOST:
+        time.sleep(0.5)  # simulate slowly sending emails when logging to console
+
+    logger.info('Sent usage bill email:\n' + email_text)