migrate data from service table to annual billing

migrations/versions/0136_migrate_sms_allowance_data.py

@@ -0,0 +1,49 @@
+"""
+
+Revision ID: 013_migrate_sms_allowance_data.py
+Revises: 0135_stats_template_usage.py
+Create Date: 2017-11-10 21:42:59.715203
+
+"""
+from datetime import datetime
+from alembic import op
+import uuid
+from app.dao.date_util import get_current_financial_year_start_year
+
+
+revision = '0136_migrate_sms_allowance_data'
+down_revision = '0135_stats_template_usage'
+
+
+def upgrade():
+    current_year = get_current_financial_year_start_year()
+    default_limit = 250000
+
+    # Step 1: update the column free_sms_fragment_limit in service table if it is empty
+    update_service_table = """
+        UPDATE services SET free_sms_fragment_limit = {} where free_sms_fragment_limit is null
+    """.format(default_limit)
+
+    op.execute(update_service_table)
+
+    # Step 2: insert at least one row for every service in current year if none exist for that service
+    insert_row_if_not_exist = """
+        INSERT INTO annual_billing 
+        (id, service_id, financial_year_start, free_sms_fragment_limit, created_at, updated_at) 
+         SELECT uuid_in(md5(random()::text || now()::text)::cstring), id, {}, {}, '{}', '{}' 
+         FROM services WHERE id NOT IN 
+        (select service_id from annual_billing)
+    """.format(current_year, default_limit, datetime.utcnow(), datetime.utcnow())
+    op.execute(insert_row_if_not_exist)
+
+    # Step 3: copy the free_sms_fragment_limit data from the services table across to annual_billing table.
+    update_sms_allowance = """
+        UPDATE annual_billing SET free_sms_fragment_limit = services.free_sms_fragment_limit
+        FROM services
+        WHERE annual_billing.service_id = services.id
+    """
+    op.execute(update_sms_allowance)
+
+
+def downgrade():
+    print('There is no action for downgrading to the previous version.')