Thingspeak: tweak SecureClient connection (#2144)

- continue #2140 , use the correct implementation for http requests not confuse code readers with our parsing
- fix data sender data duplication, run build test
- add note that this is actually really RAM heavy, some connection failures are not easily distinguishable from any code errors and are simply OOM.

also
- fix arduinoota prototype error when building without it (... ino2cpp, again)
- add comment about 160mhz into the platformio.ini

code/espurna/config/general.h

@@ -1420,6 +1420,9 @@
 // so you should compile it with WEB_SUPPORT to 0.
 // When THINGSPEAK_USE_ASYNC is 1, requires EspAsyncTCP to be built with ASYNC_TCP_SSL_ENABLED=1 and ESP8266 Arduino Core >= 2.4.0.
 // When THINGSPEAK_USE_ASYNC is 0, requires Arduino Core >= 2.6.0 and SECURE_CLIENT_BEARSSL
+//
+// WARNING: Thingspeak servers do not support MFLN right now, connection requires at least 30KB of free RAM.
+//          Also see MQTT comments above.
 
 #ifndef THINGSPEAK_USE_SSL
 #define THINGSPEAK_USE_SSL          0               // Use secure connection

code/espurna/ota.h

@@ -7,10 +7,10 @@ OTA MODULE
 #pragma once
 
 #include <Updater.h>
+#include <ArduinoOTA.h>
 
 #if OTA_ARDUINOOTA_SUPPORT
 
-#include <ArduinoOTA.h>
 void arduinoOtaSetup();
 
 #endif // OTA_ARDUINOOTA_SUPPORT == 1

code/espurna/thingspeak.h

@@ -12,6 +12,8 @@ Copyright (C) 2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #if THINGSPEAK_USE_ASYNC
 #include <ESPAsyncTCP.h>
+#else
+#include <ESP8266HTTPClient.h>
 #endif
 
 constexpr const size_t tspkDataBufferSize = 256;

code/espurna/thinkspeak.ino

@@ -205,13 +205,7 @@ void _tspkInitClient(const String& _url) {
                     unsigned int code = (p) ? atoi(&p[4]) : 0;
                     DEBUG_MSG_P(PSTR("[THINGSPEAK] Response value: %u\n"), code);
 
-                    if ((0 == code) && _tspk_tries) {
-                        _tspk_flush = true;
-                        DEBUG_MSG_P(PSTR("[THINGSPEAK] Re-enqueuing %u more time(s)\n"), _tspk_tries);
-                    } else {
-                        _tspkClearQueue();
-                    }
-
+                    _tspkRetry(code);
                     client->close(true);
 
                     _tspk_client_state = tspk_state_t::NONE;
@@ -293,45 +287,29 @@ SecureClientConfig _tspk_sc_config {
 
 #endif // THINGSPEAK_USE_SSL && SECURE_CLIENT_BEARSSL
 
-void _tspkPost(WiFiClient* client, const URL& url) {
-
-    if (!client->connect(url.host.c_str(), url.port)) {
-        DEBUG_MSG_P(PSTR("[THINGSPEAK] Connection failed\n"));
-        return;
-    }
+void _tspkPost(WiFiClient& client, const URL& url, bool https) {
 
-    DEBUG_MSG_P(PSTR("[THINGSPEAK] Connected to %s:%u\n"), url.host.c_str(), url.port);
     DEBUG_MSG_P(PSTR("[THINGSPEAK] POST %s?%s\n"), url.path.c_str(), _tspk_data.c_str());
 
-    char headers[strlen_P(THINGSPEAK_REQUEST_TEMPLATE) + url.path.length() + url.host.length() + 1];
-    snprintf_P(headers, sizeof(headers),
-        THINGSPEAK_REQUEST_TEMPLATE,
-        url.path.c_str(),
-        url.host.c_str(),
-        _tspk_data.length()
-    );
-
-    client->print(headers);
-    client->print(_tspk_data);
-
-    nice_delay(100);
+    HTTPClient http;
+    http.begin(client, url.host, url.port, url.path, https);
 
-    const auto response = client->readString();
-    int pos = response.indexOf("\r\n\r\n");
+    http.addHeader("User-agent", "ESPurna");
+    http.addHeader("Content-Type", "application/x-www-form-urlencoded");
 
-    unsigned int code = (pos > 0) ? response.substring(pos + 4).toInt() : 0;
-    DEBUG_MSG_P(PSTR("[THINGSPEAK] Response value: %u\n"), code);
+    const auto http_code = http.POST(_tspk_data);
+    int value = 0;
 
-    client->stop();
-
-    _tspk_last_flush = millis();
-    if ((0 == code) && _tspk_tries) {
-        _tspk_flush = true;
-        DEBUG_MSG_P(PSTR("[THINGSPEAK] Re-enqueuing %u more time(s)\n"), _tspk_tries);
+    if (http_code == 200) {
+        value = http.getString().toInt();
+        DEBUG_MSG_P(PSTR("[THINGSPEAK] Response value: %u\n"), value);
     } else {
-        _tspkClearQueue();
+        DEBUG_MSG_P(PSTR("[THINGSPEAK] Response HTTP code: %d\n"), http_code);
     }
 
+    _tspkRetry(value);
+    _tspk_data = "";
+
 }
 
 void _tspkPost(const String& address) {
@@ -351,14 +329,14 @@ void _tspkPost(const String& address) {
                 return;
             }
 
-            _tspkPost(&client->get(), url);
+            _tspkPost(client->get(), url, true);
             return;
         }
     #endif
 
     if (url.protocol == "http") {
         auto client = std::make_unique<WiFiClient>();
-        _tspkPost(client.get(), url);
+        _tspkPost(*client.get(), url, false);
         return;
     }        
 
@@ -385,6 +363,15 @@ void _tspkClearQueue() {
     }
 }
 
+void _tspkRetry(int code) {
+    if ((0 == code) && _tspk_tries) {
+        _tspk_flush = true;
+        DEBUG_MSG_P(PSTR("[THINGSPEAK] Re-enqueuing %u more time(s)\n"), _tspk_tries);
+    } else {
+        _tspkClearQueue();
+    }
+}
+
 void _tspkFlush() {
 
     if (!_tspk_flush) return;

code/platformio.ini

@@ -61,6 +61,9 @@ debug_flags = -DDEBUG_ESP_CORE -DDEBUG_ESP_SSL -DDEBUG_ESP_WIFI -DDEBUG_ESP_HTTP
 #    -DPIO_FRAMEWORK_ARDUINO_LWIP2_LOW_MEMORY       = v2 Lower Memory
 #    -DPIO_FRAMEWORK_ARDUINO_LWIP2_HIGHER_BANDWIDTH = v2 Higher Bandwidth
 #
+# BearSSL performance:
+#  When building with -DSECURE_CLIENT=SECURE_CLIENT_BEARSSL, please add `board_build.f_cpu = 160000000` to the environment configuration
+#
 # BearSSL ciphers:
 #   When building on core >= 2.5, you can add the build flag -DBEARSSL_SSL_BASIC in order to build BearSSL with a limited set of ciphers:
 #     TLS_RSA_WITH_AES_128_CBC_SHA256 / AES128-SHA256
@@ -285,6 +288,7 @@ src_build_flags =
 [env:nodemcu-lolin-secure-client]
 platform = ${common.platform_latest}
 board = ${common.board_4m}
+board_build.f_cpu = 160000000
 build_flags =
 	${common.build_flags_4m1m}
 	-DDEBUG_FAUXMO=Serial