From 1f9479b943663cf28826d318d5c40641c6a401c2 Mon Sep 17 00:00:00 2001
From: Max Prokhorov <prokhorov.max@outlook.com>
Date: Thu, 27 Aug 2020 01:21:21 +0300
Subject: [PATCH] rpn: rfbridge operators and mqtt fixes (#2302)

- cache received rfbridge codes in the internal list, allow to operate on it via the rpn operators
- add `<N> <proto> <code> rfb_match`, matching when we receive specified protocol + code string at least N times
- add `<proto> <code> <proto> <code> rfb_sequence`, checking if specified protocol + code pairs happen in sequence
- add `<TIME> <N> <proto> <code> rfb_match_wait` - similar to `rfb_match`, but waiting for at least `TIME` (ms) via oneshot runner
- add `<proto> <code> rfb_info`, pushes code's latest timestamp and it's counter on the stack
- add `<proto> <code> rfb_pop`, which removes the specified protocol + code from the internal cache
- fix MQTT skip setting making RPN variables absent on initial connection
- default to no skip when receiving MQTT
(small issue still stands with us having non-clean MQTT session, broker will persist variable subscriptions even after unsubscribe event)
---
 code/espurna/config/general.h |   6 +-
 code/espurna/mqtt.cpp         |  29 +++--
 code/espurna/rpnrules.cpp     | 233 +++++++++++++++++++++++++++++++++-
 3 files changed, 246 insertions(+), 22 deletions(-)

diff --git a/code/espurna/config/general.h b/code/espurna/config/general.h
index fa770f31..e2ce510e 100644
--- a/code/espurna/config/general.h
+++ b/code/espurna/config/general.h
@@ -1098,12 +1098,8 @@
 #endif
 
 
-#ifndef MQTT_SKIP_RETAINED
-#define MQTT_SKIP_RETAINED          1               // Skip retained messages on connection
-#endif
-
 #ifndef MQTT_SKIP_TIME
-#define MQTT_SKIP_TIME              1000            // Skip messages for 1 second anter connection
+#define MQTT_SKIP_TIME              0               // Skip messages for N ms after connection. Disabled by default
 #endif
 
 #ifndef MQTT_USE_JSON
diff --git a/code/espurna/mqtt.cpp b/code/espurna/mqtt.cpp
index d6dadbe7..62e0fdb6 100644
--- a/code/espurna/mqtt.cpp
+++ b/code/espurna/mqtt.cpp
@@ -70,12 +70,13 @@ Updated secure client support by Niek van der Maas < mail at niekvandermaas dot
 #endif // MQTT_LIBRARY == MQTT_ASYNCMQTTCLIENT
 
 
-bool _mqtt_enabled = MQTT_ENABLED;
-bool _mqtt_use_json = false;
-unsigned long _mqtt_reconnect_delay = MQTT_RECONNECT_DELAY_MIN;
 unsigned long _mqtt_last_connection = 0;
 AsyncClientState _mqtt_state = AsyncClientState::Disconnected;
-bool _mqtt_retain_skipped = false;
+bool _mqtt_skip_messages = false;
+unsigned long _mqtt_skip_time = MQTT_SKIP_TIME;
+unsigned long _mqtt_reconnect_delay = MQTT_RECONNECT_DELAY_MIN;
+bool _mqtt_enabled = MQTT_ENABLED;
+bool _mqtt_use_json = false;
 bool _mqtt_retain = MQTT_RETAIN;
 int _mqtt_qos = MQTT_QOS;
 int _mqtt_keepalive = MQTT_KEEPALIVE;
@@ -343,6 +344,9 @@ void _mqttConfigure() {
         _mqttApplyTopic(_mqtt_topic_json, MQTT_TOPIC_JSON);
     }
 
+    // Skip messages in a small window right after the connection
+    _mqtt_skip_time = getSetting("mqttSkipTime", MQTT_SKIP_TIME);
+
     // Custom payload strings
     settingsProcessConfig({
         {_mqtt_payload_online,  "mqttPayloadOnline",  MQTT_STATUS_ONLINE},
@@ -433,6 +437,7 @@ void _mqttInfo() {
             );
         }
     }
+
 }
 
 // -----------------------------------------------------------------------------
@@ -535,7 +540,6 @@ void _mqttOnConnect() {
 
     _mqtt_last_connection = millis();
     _mqtt_state = AsyncClientState::Connected;
-    _mqtt_retain_skipped = false;
 
     DEBUG_MSG_P(PSTR("[MQTT] Connected!\n"));
 
@@ -554,7 +558,6 @@ void _mqttOnDisconnect() {
     // Reset reconnection delay
     _mqtt_last_connection = millis();
     _mqtt_state = AsyncClientState::Disconnected;
-    _mqtt_retain_skipped = false;
 
     DEBUG_MSG_P(PSTR("[MQTT] Disconnected!\n"));
 
@@ -568,14 +571,12 @@ void _mqttOnDisconnect() {
 // Force-skip everything received in a short window right after connecting to avoid syncronization issues.
 
 bool _mqttMaybeSkipRetained(char* topic) {
-    #if MQTT_SKIP_RETAINED
-        if (!_mqtt_retain_skipped && (millis() - _mqtt_last_connection < MQTT_SKIP_TIME)) {
-            DEBUG_MSG_P(PSTR("[MQTT] Received %s - SKIPPED\n"), topic);
-            return true;
-        }
-    #endif
+    if (_mqtt_skip_messages && (millis() - _mqtt_last_connection < _mqtt_skip_time)) {
+        DEBUG_MSG_P(PSTR("[MQTT] Received %s - SKIPPED\n"), topic);
+        return true;
+    }
 
-    _mqtt_retain_skipped = true;
+    _mqtt_skip_messages = false;
     return false;
 }
 
@@ -1006,6 +1007,8 @@ void _mqttConnect() {
 
     _mqtt_state = AsyncClientState::Connecting;
 
+    _mqtt_skip_messages = (_mqtt_skip_time > 0);
+
     #if SECURE_CLIENT != SECURE_CLIENT_NONE
         const bool secure = getSetting("mqttUseSSL", 1 == MQTT_SSL_ENABLED);
     #else
diff --git a/code/espurna/rpnrules.cpp b/code/espurna/rpnrules.cpp
index 0b9d71df..596dc39f 100644
--- a/code/espurna/rpnrules.cpp
+++ b/code/espurna/rpnrules.cpp
@@ -16,10 +16,13 @@ Copyright (C) 2019 by Xose Pérez <xose dot perez at gmail dot com>
 #include "relay.h"
 #include "rpc.h"
 #include "sensor.h"
+#include "rfbridge.h"
 #include "terminal.h"
 #include "ws.h"
 
+#include <list>
 #include <vector>
+
 // -----------------------------------------------------------------------------
 // Custom commands
 // -----------------------------------------------------------------------------
@@ -236,6 +239,214 @@ rpn_error _rpnRelayStatus(rpn_context & ctxt, bool force) {
 
 #endif // RELAY_SUPPORT
 
+#if RFB_SUPPORT
+
+struct rpn_rfbridge_code {
+    unsigned char protocol;
+    String raw;
+    size_t count;
+    decltype(millis()) last;
+};
+
+// TODO: in theory, we could do with forward_list. however, this would require a more complicated removal process,
+//       as we would no longer know the previous element and would need to track 2 elements at a time
+static std::list<rpn_rfbridge_code> _rfb_codes;
+
+static uint32_t _rfb_code_repeat_window;
+static uint32_t _rfb_code_stale_delay;
+
+static uint32_t _rfb_code_match_window;
+
+struct rpn_rfbridge_match {
+    unsigned char protocol;
+    String raw;
+};
+
+rpn_error _rpnRfbSequence(rpn_context& ctxt) {
+    auto raw_second = rpn_stack_pop(ctxt);
+    auto proto_second = rpn_stack_pop(ctxt);
+
+    auto raw_first = rpn_stack_pop(ctxt);
+    auto proto_first = rpn_stack_pop(ctxt);
+
+    // find 2 codes in the same order and save pointers
+    rpn_rfbridge_match match[2] {
+        {static_cast<unsigned char>(proto_first.toUint()), raw_first.toString()},
+        {static_cast<unsigned char>(proto_second.toUint()), raw_second.toString()}
+    };
+    rpn_rfbridge_code* refs[2] {nullptr, nullptr};
+
+    for (auto& recent : _rfb_codes) {
+        if ((refs[0] != nullptr) && (refs[1] != nullptr)) {
+            break;
+        }
+        for (int index = 0; index < 2; ++index) {
+            if ((refs[index] == nullptr)
+             && (match[index].protocol == recent.protocol)
+             && (match[index].raw == recent.raw)) {
+                refs[index] = &recent;
+            }
+        }
+    }
+
+    if ((refs[0] == nullptr) || (refs[1] == nullptr)) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    // purge codes to avoid matching again on the next rules run
+    if ((millis() - refs[0]->last) > (millis() - refs[1]->last)) {
+        _rfb_codes.remove_if([&refs](rpn_rfbridge_code& code) {
+            return (refs[0] == &code) || (refs[1] == &code);
+        });
+        return rpn_operator_error::Ok;
+    }
+
+    return rpn_operator_error::CannotContinue;
+}
+
+decltype(_rfb_codes)::iterator _rpnRfbFindCode(unsigned char protocol, const String& match) {
+    return std::find_if(_rfb_codes.begin(), _rfb_codes.end(), [protocol, &match](const rpn_rfbridge_code& code) {
+        return (code.protocol == protocol) && (code.raw == match);
+    });
+}
+
+rpn_error _rpnRfbPop(rpn_context& ctxt) {
+    auto code = rpn_stack_pop(ctxt);
+    auto proto = rpn_stack_pop(ctxt);
+
+    auto result = _rpnRfbFindCode(proto.toUint(), code.toString());
+    if (result == _rfb_codes.end()) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    _rfb_codes.erase(result);
+    return rpn_operator_error::Ok;
+}
+
+rpn_error _rpnRfbInfo(rpn_context& ctxt) {
+    auto code = rpn_stack_pop(ctxt);
+    auto proto = rpn_stack_pop(ctxt);
+
+    auto result = _rpnRfbFindCode(proto.toUint(), code.toString());
+    if (result == _rfb_codes.end()) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    rpn_stack_push(ctxt, rpn_value(
+        static_cast<rpn_uint>((*result).count)));
+    rpn_stack_push(ctxt, rpn_value(
+        static_cast<rpn_uint>((*result).last)));
+
+    return rpn_operator_error::Ok;
+}
+
+rpn_error _rpnRfbWaitMatch(rpn_context& ctxt) {
+    auto code = rpn_stack_pop(ctxt);
+    auto proto = rpn_stack_pop(ctxt);
+    auto count = rpn_stack_pop(ctxt);
+    auto time = rpn_stack_pop(ctxt);
+
+    auto result = _rpnRfbFindCode(proto.toUint(), code.toString());
+    if (result == _rfb_codes.end()) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    if ((*result).count < count.toUint()) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    // purge code to avoid matching again on the next rules run
+    if (rpn_operator_error::Ok == _rpnRunnerHandler(ctxt, RpnRunner::Policy::OneShot, time.toUint())) {
+        _rfb_codes.erase(result);
+        return rpn_operator_error::Ok;
+    }
+
+    return rpn_operator_error::CannotContinue;
+}
+
+rpn_error _rpnRfbMatcher(rpn_context& ctxt) {
+    auto code = rpn_stack_pop(ctxt);
+    auto proto = rpn_stack_pop(ctxt);
+    auto count = rpn_stack_pop(ctxt);
+
+    auto result = _rpnRfbFindCode(proto.toUint(), code.toString());
+    if (result == _rfb_codes.end()) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    // only process recent codes, ignore when rule is processing outside of this small window
+    if (millis() - (*result).last >= _rfb_code_match_window) {
+        return rpn_operator_error::CannotContinue;
+    }
+
+    // purge code to avoid matching again on the next rules run
+    if ((*result).count == count.toUint()) {
+        _rfb_codes.erase(result);
+        return rpn_operator_error::Ok;
+    }
+
+    return rpn_operator_error::CannotContinue;
+}
+
+void _rpnBrokerRfbridgeCallback(unsigned char protocol, const char* raw_code) {
+
+    // remove really old codes that we have not seen in a while to avoid memory exhaustion
+    auto ts = millis();
+    auto old = std::remove_if(_rfb_codes.begin(), _rfb_codes.end(), [ts](rpn_rfbridge_code& code) {
+        return (ts - code.last) >= _rfb_code_stale_delay;
+    });
+
+    if (old != _rfb_codes.end()) {
+        _rfb_codes.erase(old, _rfb_codes.end());
+    }
+
+    auto result = _rpnRfbFindCode(protocol, raw_code);
+    if (result != _rfb_codes.end()) {
+        // we also need to reset the counter at a certain point to allow next batch of repeats to go through
+        if (millis() - (*result).last >= _rfb_code_repeat_window) {
+            (*result).count = 0;
+        }
+        (*result).last = millis();
+        (*result).count += 1u;
+    } else {
+        _rfb_codes.push_back({protocol, raw_code, 1u, millis()});
+    }
+
+    _rpn_run = true;
+}
+
+void _rpnRfbSetup() {
+    // - Repeat window is an arbitrary time, just about 3-4 more times it takes for
+    //   a code to be sent again when holding a generic remote button
+    //   Code counter is reset to 0 when outside of the window.
+    // - Stale delay allows broker callback to remove really old codes.
+    //   (TODO: can this happen in loop() cb instead?)
+    _rfb_code_repeat_window = getSetting("rfbRepeatWindow", 2000ul);
+    _rfb_code_match_window = getSetting("rfbMatchWindow", 2000ul);
+    _rfb_code_stale_delay = getSetting("rfbStaleDelay", 10000ul);
+
+#if TERMINAL_SUPPORT
+    terminalRegisterCommand(F("RFB.CODES"), [](const terminal::CommandContext& ctx) {
+        for (auto& code : _rfb_codes) {
+            char buffer[128] = {0};
+            snprintf_P(buffer, sizeof(buffer),
+                PSTR("\"%s\" proto=%u count=%u last=%u"),
+                code.protocol,
+                code.raw.c_str(),
+                code.count,
+                code.last
+            );
+            ctx.output.println(buffer);
+        }
+    });
+#endif
+
+    // Main bulk of the processing goes on in here
+    RfbridgeBroker::Register(_rpnBrokerRfbridgeCallback);
+}
+
+#endif // RFB_SUPPORT
+
 void _rpnShowStack(Print& print) {
     print.println(F("Stack:"));
 
@@ -369,6 +580,14 @@ void _rpnInit() {
 
     #endif
 
+    #if RFB_SUPPORT
+        rpn_operator_set(_rpn_ctxt, "rfb_pop", 2, _rpnRfbPop);
+        rpn_operator_set(_rpn_ctxt, "rfb_info", 2, _rpnRfbInfo);
+        rpn_operator_set(_rpn_ctxt, "rfb_sequence", 4, _rpnRfbSequence);
+        rpn_operator_set(_rpn_ctxt, "rfb_match", 3, _rpnRfbMatcher);
+        rpn_operator_set(_rpn_ctxt, "rfb_match_wait", 4, _rpnRfbWaitMatch);
+    #endif
+
     #if MQTT_SUPPORT
         rpn_operator_set(_rpn_ctxt, "mqtt_send", 2, [](rpn_context & ctxt) -> rpn_error {
             rpn_value message;
@@ -384,10 +603,12 @@ void _rpnInit() {
     #endif
 
     // Some debugging. Dump stack contents
-    rpn_operator_set(_rpn_ctxt, "showstack", 0, [](rpn_context & ctxt) -> rpn_error {
-        _rpnShowStack(terminalDefaultStream());
-        return 0;
-    });
+    #if TERMINAL_SUPPORT
+        rpn_operator_set(_rpn_ctxt, "showstack", 0, [](rpn_context & ctxt) -> rpn_error {
+            _rpnShowStack(terminalDefaultStream());
+            return 0;
+        });
+    #endif
 
     // And, simple string logging
     #if DEBUG_SUPPORT
@@ -591,6 +812,10 @@ void rpnSetup() {
 
     StatusBroker::Register(_rpnBrokerStatus);
 
+    #if RFB_SUPPORT
+        _rpnRfbSetup();
+    #endif
+
     #if SENSOR_SUPPORT
         SensorReadBroker::Register(_rpnBrokerCallback);
     #endif