From d3ccd8a65dcbcdf8f5d4845bcec78d4636f64303 Mon Sep 17 00:00:00 2001
From: Kjell Winblad <kjellwinblad@gmail.com>
Date: Thu, 13 Apr 2023 15:20:04 +0200
Subject: [PATCH] feat: add date_to_unix_ts/3 function to the rule engine

Fixes:
https://emqx.atlassian.net/browse/EMQX-9245
---
 apps/emqx_rule_engine/src/emqx_rule_funcs.erl  |  9 +++++++++
 .../test/emqx_rule_funcs_SUITE.erl             | 18 ++++++++++++++++++
 changes/ce/feat-10392.en.md                    |  1 +
 3 files changed, 28 insertions(+)
 create mode 100644 changes/ce/feat-10392.en.md

diff --git a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
index b8bfeb84c..7f7662b1b 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
@@ -227,6 +227,7 @@
     now_timestamp/1,
     format_date/3,
     format_date/4,
+    date_to_unix_ts/3,
     date_to_unix_ts/4
 ]).
 
@@ -1085,6 +1086,14 @@ format_date(TimeUnit, Offset, FormatString, TimeEpoch) ->
         )
     ).
 
+date_to_unix_ts(TimeUnit, FormatString, InputString) ->
+    emqx_rule_date:parse_date(
+        time_unit(TimeUnit),
+        "Z",
+        emqx_plugin_libs_rule:str(FormatString),
+        emqx_plugin_libs_rule:str(InputString)
+    ).
+
 date_to_unix_ts(TimeUnit, Offset, FormatString, InputString) ->
     emqx_rule_date:parse_date(
         time_unit(TimeUnit),
diff --git a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
index 94adb3506..2bce5a1b4 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
@@ -1003,6 +1003,24 @@ prop_format_date_fun() ->
                         )
                     ]
             )
+    ),
+    %% When no offset is specified, the offset should be taken from the formatted time string
+    ArgsNoOffset = [<<"second">>, <<"%y-%m-%d-%H:%M:%S%Z">>],
+    ArgsOffset = [<<"second">>, <<"+08:00">>, <<"%y-%m-%d-%H:%M:%S%Z">>],
+    ?FORALL(
+        S,
+        erlang:system_time(second),
+        S ==
+            apply_func(
+                date_to_unix_ts,
+                ArgsNoOffset ++
+                    [
+                        apply_func(
+                            format_date,
+                            ArgsOffset ++ [S]
+                        )
+                    ]
+            )
     ).
 
 %%------------------------------------------------------------------------------
diff --git a/changes/ce/feat-10392.en.md b/changes/ce/feat-10392.en.md
new file mode 100644
index 000000000..04c6c85cc
--- /dev/null
+++ b/changes/ce/feat-10392.en.md
@@ -0,0 +1 @@
+A new function to convert a formatted date to an integer timestamp has been added: date_to_unix_ts/3