From 446370092d769a9030f7a1019ea6bddf804a055d Mon Sep 17 00:00:00 2001
From: Mike Degatano <michael.degatano@gmail.com>
Date: Tue, 18 Jan 2022 18:13:00 -0500
Subject: [PATCH] Add option for `last_seen`

---
 amr2mqtt/DOCS.md                            |  6 +++++
 amr2mqtt/config.yaml                        |  1 +
 amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py        | 29 ++++++++++++++++++++-
 amr2mqtt/rootfs/amr2mqtt/settings.py        |  4 +++
 amr2mqtt/rootfs/etc/services.d/amr2mqtt/run |  3 +++
 5 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/amr2mqtt/DOCS.md b/amr2mqtt/DOCS.md
index f7ac77a..d429a81 100644
--- a/amr2mqtt/DOCS.md
+++ b/amr2mqtt/DOCS.md
@@ -212,6 +212,12 @@ Client ID to use when connecting to the MQTT broker.
 By default, the topics of all MQTT messages begins with `amr2mqtt/{meter_ID}`.
 If you set this option then the topics will begin with `{mqtt.base_topic}/{meter_id}`.
 
+### Option: `last_seen`
+
+Add `last_seen` field to each message with the current time in the specified format.
+Options are: `ISO_8601`, `ISO_8601_local`, and `epoch`. Disabled if omitted. Useful
+for detecting issues when meter normally reports in on a consistent interval.
+
 ### Option: `home_assistant_discovery_enabled`
 
 Set to `false` to disable the add-on from sending discovery messages for the
diff --git a/amr2mqtt/config.yaml b/amr2mqtt/config.yaml
index cca6071..b44c21a 100644
--- a/amr2mqtt/config.yaml
+++ b/amr2mqtt/config.yaml
@@ -43,3 +43,4 @@ schema:
   log_level: list(trace|debug|info|notice|warning|error|fatal)?
   home_assistant_discovery_enabled: bool?
   home_assistant_discovery_prefix: match(^[^+#]{1,65535}$)?
+  last_seen: list(ISO_8601|ISO_8601_local|epoch)?
diff --git a/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py b/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
index 86c2d0f..76eafd6 100644
--- a/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
+++ b/amr2mqtt/rootfs/amr2mqtt/amr2mqtt.py
@@ -5,7 +5,7 @@
 is a watched one, processes its reading using settings first.
 
 """
-from datetime import timedelta
+from datetime import timedelta, datetime, timezone
 import logging
 import subprocess
 import signal
@@ -13,6 +13,7 @@
 import time
 import json
 import re
+import math
 import paho.mqtt.client as mqtt
 import settings
 from dateutil import parser
@@ -29,6 +30,7 @@
 IDM_CONSUMPTION_FIELD = "LastConsumptionCount"
 NETIDM_CONSUMPTION_FIELD = "LastConsumptionNet"
 SCMPLUS_ID_FIELD = "EndpointID"
+LAST_SEEN_ATTR = "'last_seen': value_json.last_seen"
 ALL_IDM = [
     "Preamble",
     "PacketLength",
@@ -185,6 +187,8 @@ def create_mqtt_client():
 
 def create_interval_sensor(meter_id, meter, device_name, device_id):
     """Create discovery message for interval consumption sensor."""
+    last_seen_attr = f"{LAST_SEEN_ATTR}," if settings.LAST_SEEN_ENABLED else ""
+
     return set_consumption_details(
         payload={
             "enabled_by_default": True,
@@ -196,6 +200,7 @@ def create_interval_sensor(meter_id, meter, device_name, device_id):
                 "{{ {"
                 f"'{INTERVAL_FIELD}': value_json.{INTERVAL_FIELD},"
                 f"'{INTERVAL_START_FIELD}': value_json.{INTERVAL_START_FIELD},"
+                f"{last_seen_attr}"
                 f"'last_reset': value_json.{INTERVAL_START_FIELD}"
                 "} | tojson }}"
             ),
@@ -236,6 +241,11 @@ def create_sensor(attribute, device_name, device_id, enabled=True, category=None
     if category:
         sensor["entity_category"] = category
 
+    if settings.LAST_SEEN_ENABLED:
+        sensor[
+            "json_attributes_template"
+        ] = f"{{{{ {{ {LAST_SEEN_ATTR} }} | tojson }}}}"
+
     return sensor
 
 
@@ -440,6 +450,23 @@ def main_loop():
             else:
                 continue
 
+            # Add last seen if in use
+            if settings.LAST_SEEN_ENABLED:
+                if settings.LAST_SEEN_FORMAT == "ISO_8601":
+                    last_seen = (
+                        datetime.now().replace(microsecond=0).astimezone().isoformat()
+                    )
+                elif settings.LAST_SEEN_FORMAT == "ISO_8601_local":
+                    last_seen = (
+                        datetime.utcnow()
+                        .replace(microsecond=0, tzinfo=timezone.utc)
+                        .isoformat()
+                    )
+                else:
+                    last_seen = math.floor(time.time())
+
+                amr_message["last_seen"] = last_seen
+
             # If in debugging mode, add the protocol to the message
             if settings.WATCHED_PROTOCOLS == "all":
                 amr_message["Protocol"] = msg_type
diff --git a/amr2mqtt/rootfs/amr2mqtt/settings.py b/amr2mqtt/rootfs/amr2mqtt/settings.py
index 2d6edd4..6a8c35c 100644
--- a/amr2mqtt/rootfs/amr2mqtt/settings.py
+++ b/amr2mqtt/rootfs/amr2mqtt/settings.py
@@ -49,6 +49,10 @@ def make_meters_map(meters, meter):
 MQTT_BASE_TOPIC = base_topic if bool(base_topic) else "amr2mqtt"
 MQTT_AVAILABILTY_TOPIC = f"{MQTT_BASE_TOPIC}/bridge/state"
 
+# Using last seen
+LAST_SEEN_FORMAT = os.environ.get("LAST_SEEN")
+LAST_SEEN_ENABLED = LAST_SEEN_FORMAT != "disable"
+
 # Set up logging
 EV_TO_LOG_LEVEL = {
     "DEBUG": logging.DEBUG,
diff --git a/amr2mqtt/rootfs/etc/services.d/amr2mqtt/run b/amr2mqtt/rootfs/etc/services.d/amr2mqtt/run
index e7a0458..91a6740 100644
--- a/amr2mqtt/rootfs/etc/services.d/amr2mqtt/run
+++ b/amr2mqtt/rootfs/etc/services.d/amr2mqtt/run
@@ -52,6 +52,9 @@ elif bashio::config.exists 'home_assistant_discovery_prefix'; then
     export "HA_DISCOVERY_TOPIC=$(bashio::config 'home_assistant_discovery_prefix')"
 fi
 
+# --- OTHER SETTINGS ---
+export "LAST_SEEN=$(bashio::config 'last_seen' 'disable')"
+
 # --- SET LOG LEVEL ---
 case "$(bashio::config 'log_level')" in \
     trace)      ;& \