From d079c112c8071c2a2d4fcf1db047bba8d23d99f0 Mon Sep 17 00:00:00 2001
From: Md Nazrul Islam <connect2nazrul@gmail.com>
Date: Mon, 16 Nov 2020 21:43:43 +0100
Subject: [PATCH] :sparkles: More helper functions (``get_local_timezone``,
 ``timestamp_utc``, ``timestamp_utc``) are created. * ``initial_bundle_data``
 method is now available in Base Elasticsearch engine class, * fixes: Default
 bundle initial data was constructed ``meta.lastUpdated`` value with utc now
 time but without timezone offset

---
 HISTORY.rst                        | 11 ++++++-
 setup.py                           |  2 +-
 src/fhirpath/engine/es/__init__.py |  9 +++++-
 src/fhirpath/utils.py              | 47 ++++++++++++++++++++++++++----
 4 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index ab37f09..a2c7673 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -5,8 +5,17 @@ History
 0.10.3 (unreleased)
 -------------------
 
-- Nothing changed yet.
+Improvements
+
+- More helper functions (``get_local_timezone``, ``timestamp_utc``, ``timestamp_utc``) are created.
+
+- ``initial_bundle_data`` method is now available in Base Elasticsearch engine class,
+  meaning that it is possible construct Bundle initial data into the derived class, so more flexibility.
+
+Bugfixes
 
+- Default bundle initial data was constructed ``meta.lastUpdated`` value with utc now time but without timezone offset, so
+  during json serialization, timezone info was missed as a result reverse construct of Bundle complains validation error.
 
 0.10.2 (2020-11-06)
 -------------------
diff --git a/setup.py b/setup.py
index 72494b4..601a39b 100644
--- a/setup.py
+++ b/setup.py
@@ -51,7 +51,7 @@ def run(self):
     "zope.interface>=5.1.2",
     "multidict",
     "fhirspec>=0.2.5",
-    "fhir.resources>=6.0.0b9,<7.0",
+    "fhir.resources>=6.0.0b10,<7.0",
     "yarl",
     "isodate",
 ]
diff --git a/src/fhirpath/engine/es/__init__.py b/src/fhirpath/engine/es/__init__.py
index 8861032..2f14c5a 100644
--- a/src/fhirpath/engine/es/__init__.py
+++ b/src/fhirpath/engine/es/__init__.py
@@ -47,6 +47,10 @@ def navigate_indexed_path(source, path_):
 
 
 class ElasticsearchEngineBase(Engine):
+    def initial_bundle_data(self):
+        """Can be overridden in sub class"""
+        return BundleWrapper.init_data()
+
     def extract_hits(self, source_filters, hits, container, doc_type="_doc"):
         """ """
         for res in hits:
@@ -92,7 +96,10 @@ def wrapped_with_bundle(self, result, includes=None, as_json=False):
         url = self.current_url()
         if includes is None:
             includes = list()
-        wrapper = BundleWrapper(self, result, includes, url, "searchset")
+        init_data = self.initial_bundle_data()
+        wrapper = BundleWrapper(
+            self, result, includes, url, "searchset", init_data=init_data
+        )
         return wrapper(as_json=as_json)
 
     def generate_mappings(
diff --git a/src/fhirpath/utils.py b/src/fhirpath/utils.py
index 454b107..75a5144 100644
--- a/src/fhirpath/utils.py
+++ b/src/fhirpath/utils.py
@@ -6,6 +6,7 @@
 import pkgutil
 import re
 import sys
+import time
 import uuid
 from importlib import import_module
 from inspect import signature
@@ -50,6 +51,8 @@
 
 __author__ = "Md Nazrul Islam <email2nazrul@gmail.com>"
 
+LOCAL_TIMEZONE: Optional[datetime.timezone] = None
+
 
 def _reraise(tp, value, tb=None):
     if value is None:
@@ -529,15 +532,21 @@ class BundleWrapper:
     """ """
 
     def __init__(
-        self, engine, result, includes: List, url: URL, bundle_type="searchset"
+        self,
+        engine,
+        result,
+        includes: List,
+        url: URL,
+        bundle_type="searchset",
+        init_data: Dict[str, Any] = None,
     ):
         """ """
         self.fhir_version = engine.fhir_release
         self.bundle_model = lookup_fhir_class("Bundle", fhir_release=self.fhir_version)
-        self.data: Dict[str, Any] = dict()
-        self.data["id"] = str(uuid.uuid4())
-
-        self.data["meta"] = {"lastUpdated": datetime.datetime.utcnow()}
+        if init_data:
+            self.data = init_data
+        else:
+            self.data = BundleWrapper.init_data()
 
         self.data["type"] = bundle_type
         # our pagination is based main query result.
@@ -553,6 +562,12 @@ def __init__(
 
         self.attach_links(url, len(result.body))
 
+    @staticmethod
+    def init_data() -> Dict[str, Any]:
+        """Initialized Bundle data"""
+        data = {"id": str(uuid.uuid4()), "meta": {"lastUpdated": timestamp_utc()}}
+        return data
+
     def attach_entry(self, result, mode="match"):
         """ """
         if "entry" not in self.data:
@@ -653,3 +668,25 @@ def __call__(self, as_json=False):
     def json(self):
         """ """
         return self.__call__().json()
+
+
+def get_local_timezone() -> datetime.timezone:
+    if LOCAL_TIMEZONE is not None:
+        return LOCAL_TIMEZONE
+
+    is_dst = time.daylight and time.localtime().tm_isdst > 0
+    seconds = -(time.altzone if is_dst else time.timezone)
+    tz = datetime.timezone(datetime.timedelta(seconds=seconds))
+    return tz
+
+
+def timestamp_utc() -> datetime.datetime:
+    """UTC datetime with timezone offset"""
+    dt_now = datetime.datetime.utcnow()
+    dt_now.replace(tzinfo=datetime.timezone.utc)
+    return dt_now
+
+
+def timestamp_local() -> datetime.datetime:
+    """Timezone aware datetime with local timezone offset"""
+    return datetime.datetime.now(tz=get_local_timezone())