Refactoring `get_months_in_date_range`

diff.patch

diff --git koku/api/test_utils.py koku/api/test_utils.py
index 960f4653..daf3c376 100644
--- koku/api/test_utils.py
+++ koku/api/test_utils.py
@@ -290,12 +290,10 @@ class GetMonthsInDateRangeTest(unittest.TestCase):
         self.early_start_date = datetime.datetime(2022, 4, 3, tzinfo=pytz.UTC)
         self.early_end_date = datetime.datetime(2022, 4, 12, tzinfo=pytz.UTC)
 
-    @patch("api.utils.DateAccessor.today")
     @patch("api.utils.DateHelper.today", new_callable=PropertyMock)
-    def test_get_months_in_date_range__report_with_dates(self, mock_dh_today, mock_date_accessor_today):
+    def test_get_months_in_date_range__report_with_dates(self, mock_dh_today):
         """Test that calling get_months_in_date_range with report only returns list of month tuples"""
 
-        mock_date_accessor_today.return_value = self.start_date
         mock_dh_today.return_value = self.start_date
         expected_start = self.start_date.strftime("%Y-%m-%d")
         expected_end = self.end_date.strftime("%Y-%m-%d")
@@ -311,16 +309,14 @@ class GetMonthsInDateRangeTest(unittest.TestCase):
 
         self.assertEqual(returned_months, expected_months)
 
-    @patch("api.utils.DateAccessor.today")
     @patch("api.utils.DateHelper.today", new_callable=PropertyMock)
-    def test_get_months_in_date_range__report_with_no_dates(self, mock_dh_today, mock_date_accessor_today):
+    def test_get_months_in_date_range__report_with_no_dates(self, mock_dh_today):
         """
         Test that calling get_months_in_date_range
         with a report missing start, end or both dates
         returns list of month tuples.
         """
 
-        mock_date_accessor_today.return_value = self.start_date
         mock_dh_today.return_value = self.start_date
         test_report = {
             "schema": "org1234567",
@@ -334,16 +330,14 @@ class GetMonthsInDateRangeTest(unittest.TestCase):
 
         self.assertEqual(returned_months, expected_months)
 
-    @patch("api.utils.DateAccessor.today")
     @patch("api.utils.DateHelper.today", new_callable=PropertyMock)
-    def test_get_months_in_date_range__report_with_no_dates_year_start(self, mock_dh_today, mock_date_accessor_today):
+    def test_get_months_in_date_range__report_with_no_dates_year_start(self, mock_dh_today):
         """
         Test that calling get_months_in_date_range
         with a report missing start, end or both dates
         returns list of month tuples at the beginning of the year
         """
 
-        mock_date_accessor_today.return_value = self.first_of_year
         mock_dh_today.return_value = self.first_of_year
         test_report = {
             "schema": "org1234567",
@@ -360,16 +354,14 @@ class GetMonthsInDateRangeTest(unittest.TestCase):
 
         self.assertEqual(returned_months, expected_months)
 
-    @patch("api.utils.DateAccessor.today")
     @patch("api.utils.DateHelper.today", new_callable=PropertyMock)
-    def test_get_months_in_date_range__report_with_no_dates_month_start(self, mock_dh_today, mock_date_accessor_today):
+    def test_get_months_in_date_range__report_with_no_dates_month_start(self, mock_dh_today):
         """
         Test that calling get_months_in_date_range
         with a report missing start, end or both dates
         returns list of month tuples during first of a month
         """
 
-        mock_date_accessor_today.return_value = self.first_of_month
         mock_dh_today.return_value = self.first_of_month
         test_report = {
             "schema": "org1234567",
@@ -394,7 +386,7 @@ class GetMonthsInDateRangeTest(unittest.TestCase):
         returns list of month tuples.
         """
 
-        mock_dh_today.return_value.date.return_value = self.start_date
+        mock_dh_today.return_value = self.start_date
         invoice_month = self.start_date.strftime("%Y%m")
         expected_date = self.start_date.strftime("%Y-%m-%d")
         expected_months = [(expected_date, expected_date, invoice_month)]
diff --git koku/api/utils.py koku/api/utils.py
index 542d019d..17c17023 100644
--- koku/api/utils.py
+++ koku/api/utils.py
@@ -21,7 +21,6 @@ from api.user_settings.settings import USER_SETTINGS
 from koku.settings import KOKU_DEFAULT_COST_TYPE
 from koku.settings import KOKU_DEFAULT_CURRENCY
 from masu.config import Config
-from masu.external.date_accessor import DateAccessor
 from reporting.user_settings.models import UserSettings
 
 
@@ -463,10 +462,24 @@ def get_split_date_string(date_str):
     return date_str
 
 
-def get_months_in_date_range(report=None, start=None, end=None, invoice_month=None):
+def get_months_in_date_range(
+    report: dict[str, str] = None, start: str = None, end: str = None, invoice_month: str = None
+) -> list[tuple[str, str]]:
     """returns the month periods in a given date range from report"""
 
     dh = DateHelper()
+    date_format = "%Y-%m-%d"
+    invoice_date_format = "%Y%m"
+
+    # Converting inputs to datetime objects
+    dt_start = datetime.datetime.strptime(start, date_format).replace(tzinfo=pytz.UTC) if start else None
+    dt_end = datetime.datetime.strptime(end, date_format).replace(tzinfo=pytz.UTC) if end else None
+    dt_invoice_month = (
+        datetime.datetime.strptime(invoice_month, invoice_date_format).replace(tzinfo=pytz.UTC)
+        if invoice_month
+        else None
+    )
+
     if report:
         manifest_start = report.get("start")
         manifest_end = report.get("end")
@@ -474,55 +487,62 @@ def get_months_in_date_range(report=None, start=None, end=None, invoice_month=No
 
         if manifest_start and manifest_end:
             LOG.info(f"using start: {manifest_start} and end: {manifest_end} dates from manifest")
-            start_date = manifest_start
-            end_date = manifest_end
+            dt_start = datetime.datetime.strptime(manifest_start, date_format).replace(tzinfo=pytz.UTC)
+            dt_end = datetime.datetime.strptime(manifest_end, date_format).replace(tzinfo=pytz.UTC)
             if manifest_invoice_month:
                 LOG.info(f"using invoice_month: {manifest_invoice_month}")
-                invoice_month = manifest_invoice_month
+                dt_invoice_month = datetime.datetime.strptime(manifest_invoice_month, invoice_date_format).replace(
+                    tzinfo=pytz.UTC
+                )
         else:
             LOG.info("generating start and end dates for manifest")
-            start_date = DateAccessor().today() - datetime.timedelta(days=2)
-            start_date = start_date.strftime("%Y-%m-%d")
-            end_date = DateAccessor().today().strftime("%Y-%m-%d")
-
-    elif invoice_month:
-        if not end:
-            end = dh.today.date().strftime("%Y-%m-%d")
-        return [(start, end, invoice_month)]  # For report_data masu api
-
-    else:
-        start_date = start
-        end_date = end
+            dt_start = dh.today - datetime.timedelta(days=2)
+            dt_end = dh.today
+
+    elif dt_invoice_month:
+        if not dt_end:
+            dt_end = dh.today
+
+        # For report_data masu API
+        return [
+            (
+                dt_start.strftime(date_format),
+                dt_end.strftime(date_format),
+                dt_invoice_month.strftime(invoice_date_format),
+            )
+        ]
 
     # Grabbing ingest delta for initial ingest/summary
-    summary_month = (dh.today + relativedelta(months=-Config.INITIAL_INGEST_NUM_MONTHS)).replace(day=1)
-    start_date = get_split_date_string(start_date)
-    end_date = get_split_date_string(end_date)
-    if datetime.datetime.strptime(start_date, "%Y-%m-%d").replace(tzinfo=pytz.UTC) < summary_month:
-        start_date = summary_month.strftime("%Y-%m-01")
+    summary_month = (dh.today - relativedelta(months=Config.INITIAL_INGEST_NUM_MONTHS)).replace(day=1)
+    if dt_start < summary_month:  # dt_start could be None
+        dt_start = summary_month.replace(day=1)
 
-    if end_date and datetime.datetime.strptime(end_date, "%Y-%m-%d").replace(tzinfo=pytz.UTC) < summary_month:
-        end_date = dh.today.strftime("%Y-%m-%d")
+    if dt_end < summary_month:  # dt_end could be None
+        dt_end = dh.today
 
     if report and report.get("provider_type") in [Provider.PROVIDER_GCP, Provider.PROVIDER_GCP_LOCAL]:
-        return [(start_date, end_date, invoice_month)]
-
-    start_date = ciso8601.parse_datetime(start_date).replace(tzinfo=pytz.UTC)
-    end_date = ciso8601.parse_datetime(end_date).replace(tzinfo=pytz.UTC) if end_date else dh.today
-    months = dh.list_month_tuples(start_date, end_date)
-
-    num_months = len(months)
+        return [
+            (
+                dt_start.strftime(date_format),
+                dt_end.strftime(date_format),
+                dt_invoice_month.strftime(invoice_date_format),
+            )
+        ]
+
+    months = dh.list_month_tuples(dt_start, dt_end)
+    # The order is fragile here. For one item lists, months[0] == months[-1].
     first_month = months[0]
-    months[0] = (start_date, first_month[1])
-
-    last_month = months[num_months - 1]
-    months[num_months - 1] = (last_month[0], end_date)
-
-    # need to format all the datetimes into strings with the format "%Y-%m-%d" for the celery task
-    for i, month in enumerate(months):
-        start, end = month
-        start_date = start.date().strftime("%Y-%m-%d")
-        end_date = end.date().strftime("%Y-%m-%d")
-        months[i] = (start_date, end_date, invoice_month)  # Invoice month is really only for GCP
-
-    return months
+    months[0] = (dt_start, first_month[1])
+
+    last_month = months[-1]
+    months[-1] = (last_month[0], dt_end)
+
+    # Format all the datetimes into strings with the format "%Y-%m-%d" for the celery task
+    return [
+        (
+            start.strftime(date_format),
+            end.strftime(date_format),
+            invoice_month,  # Invoice month is really only for GCP
+        )
+        for start, end in months
+    ]

utils.py

def get_months_in_date_range(
    report: dict[str, str] = None, start: str = None, end: str = None, invoice_month: str = None
) -> list[tuple[str, str]]:
    """returns the month periods in a given date range from report"""

    dh = DateHelper()
    date_format = "%Y-%m-%d"
    invoice_date_format = "%Y%m"

    # Converting inputs to datetime objects
    dt_start = datetime.datetime.strptime(start, date_format).replace(tzinfo=pytz.UTC) if start else None
    dt_end = datetime.datetime.strptime(end, date_format).replace(tzinfo=pytz.UTC) if end else None
    dt_invoice_month = (
        datetime.datetime.strptime(invoice_month, invoice_date_format).replace(tzinfo=pytz.UTC)
        if invoice_month
        else None
    )

    if report:
        manifest_start = report.get("start")
        manifest_end = report.get("end")
        manifest_invoice_month = report.get("invoice_month")

        if manifest_start and manifest_end:
            LOG.info(f"using start: {manifest_start} and end: {manifest_end} dates from manifest")
            dt_start = datetime.datetime.strptime(manifest_start, date_format).replace(tzinfo=pytz.UTC)
            dt_end = datetime.datetime.strptime(manifest_end, date_format).replace(tzinfo=pytz.UTC)
            if manifest_invoice_month:
                LOG.info(f"using invoice_month: {manifest_invoice_month}")
                dt_invoice_month = datetime.datetime.strptime(manifest_invoice_month, invoice_date_format).replace(
                    tzinfo=pytz.UTC
                )
        else:
            LOG.info("generating start and end dates for manifest")
            dt_start = dh.today - datetime.timedelta(days=2)
            dt_end = dh.today

    elif dt_invoice_month:
        if not dt_end:
            dt_end = dh.today

        # For report_data masu API
        return [
            (
                dt_start.strftime(date_format),
                dt_end.strftime(date_format),
                dt_invoice_month.strftime(invoice_date_format),
            )
        ]

    # Grabbing ingest delta for initial ingest/summary
    summary_month = (dh.today - relativedelta(months=Config.INITIAL_INGEST_NUM_MONTHS)).replace(day=1)
    if dt_start < summary_month:  # dt_start could be None
        dt_start = summary_month.replace(day=1)

    if dt_end < summary_month:  # dt_end could be None
        dt_end = dh.today

    if report and report.get("provider_type") in [Provider.PROVIDER_GCP, Provider.PROVIDER_GCP_LOCAL]:
        return [
            (
                dt_start.strftime(date_format),
                dt_end.strftime(date_format),
                dt_invoice_month.strftime(invoice_date_format),
            )
        ]

    months = dh.list_month_tuples(dt_start, dt_end)
    # The order is fragile here. For one item lists, months[0] == months[-1].
    first_month = months[0]
    months[0] = (dt_start, first_month[1])

    last_month = months[-1]
    months[-1] = (last_month[0], dt_end)

    # Format all the datetimes into strings with the format "%Y-%m-%d" for the celery task
    return [
        (
            start.strftime(date_format),
            end.strftime(date_format),
            invoice_month,  # Invoice month is really only for GCP
        )
        for start, end in months
    ]