From a1a37bcbee10263a4237ec96fe144c512a845c40 Mon Sep 17 00:00:00 2001
From: Chris <mononym@users.noreply.github.com>
Date: Fri, 25 Mar 2022 17:39:41 +0100
Subject: [PATCH] feat: Add mongo_date function to support saving timestamp as
 MongoDB Date object

---
 .../src/emqx_rule_engine.app.src              |  2 +-
 .../src/emqx_rule_engine.appup.src            |  8 +++++--
 apps/emqx_rule_engine/src/emqx_rule_funcs.erl | 21 +++++++++++++++++++
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.app.src b/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
index cd57630b4..f0d73e581 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.app.src
@@ -1,6 +1,6 @@
 {application, emqx_rule_engine,
  [{description, "EMQ X Rule Engine"},
-  {vsn, "4.3.8"}, % strict semver, bump manually!
+  {vsn, "4.3.9"}, % strict semver, bump manually!
   {modules, []},
   {registered, [emqx_rule_engine_sup, emqx_rule_registry]},
   {applications, [kernel,stdlib,rulesql,getopt]},
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
index 0ed0fee3a..ab2cdd80b 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
@@ -1,7 +1,9 @@
 %% -*- mode: erlang -*-
 %% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
-  [{"4.3.7",
+  [{"4.3.8",
+    [{load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]}]},
+   {"4.3.7",
     [{load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
@@ -78,7 +80,9 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
-  [{"4.3.7",
+  [{"4.3.8",
+    [{load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]}]},
+   {"4.3.7",
     [{load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
diff --git a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
index a9897437e..ae5552159 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
@@ -197,6 +197,9 @@
         , rfc3339_to_unix_ts/2
         , now_timestamp/0
         , now_timestamp/1
+        , mongo_date/0
+        , mongo_date/1
+        , mongo_date/2
         ]).
 
 %% Proc Dict Func
@@ -900,6 +903,24 @@ time_unit(<<"millisecond">>) -> millisecond;
 time_unit(<<"microsecond">>) -> microsecond;
 time_unit(<<"nanosecond">>) -> nanosecond.
 
+mongo_date() ->
+    erlang:timestamp().
+
+mongo_date(MillisecondsTimestamp) ->
+    convert_timestamp(MillisecondsTimestamp).
+
+mongo_date(Timestamp, Unit) ->
+    InsertedTimeUnit = time_unit(Unit),
+    ScaledEpoch = erlang:convert_time_unit(Timestamp, InsertedTimeUnit, millisecond),
+    convert_timestamp(ScaledEpoch).
+
+convert_timestamp(MillisecondsTimestamp) ->
+    MicroTimestamp = MillisecondsTimestamp * 1000,
+    MegaSecs = MicroTimestamp div 1000_000_000_000,
+    Secs = MicroTimestamp div 1000_000 - MegaSecs*1000_000,
+    MicroSecs = MicroTimestamp rem 1000_000,
+    {MegaSecs, Secs, MicroSecs}.
+
 %% @doc This is for sql funcs that should be handled in the specific modules.
 %% Here the emqx_rule_funcs module acts as a proxy, forwarding
 %% the function handling to the worker module.