implementing non blocking download functions in ota interface

Author: andreagilardoni

libraries/OTAUpdate/src/OTAUpdate.cpp

@@ -87,6 +87,49 @@ int OTAUpdate::download(const char* url, const char* file_path) {
   return ret;
 }
 
+int OTAUpdate::startDownload(const char* url) {
+  string res = "";
+  int ret = -1;
+  if ( url != nullptr && strlen(url) > 0) {
+    modem.timeout(EXTENDED_MODEM_TIMEOUT);
+    if(modem.write(string(PROMPT(_OTA_DOWNLOAD_START)), res, "%s%s\r\n", CMD_WRITE(_OTA_DOWNLOAD_START), url)) {
+      ret = atoi(res.c_str());
+    } else {
+      ret = static_cast<int>(Error::Modem);
+    }
+  } else {
+    ret = static_cast<int>(Error::Library);
+  }
+  modem.timeout(MODEM_TIMEOUT);
+  return ret;
+}
+
+int OTAUpdate::startDownload(const char* url, const char* file_path) {
+  string res = "";
+  int ret = -1;
+
+  if ( url != nullptr && strlen(url) > 0 && file_path != nullptr && strlen(file_path) >0) {
+    modem.timeout(EXTENDED_MODEM_TIMEOUT);
+    if(modem.write(string(PROMPT(_OTA_DOWNLOAD_START)), res, "%s%s,%s\r\n", CMD_WRITE(_OTA_DOWNLOAD_START), url, file_path)) {
+      ret = atoi(res.c_str());
+    } else {
+      ret = static_cast<int>(Error::Modem);
+    }
+  } else {
+    ret = static_cast<int>(Error::Library);
+  }
+  modem.timeout(MODEM_TIMEOUT);
+  return ret;
+}
+
+int OTAUpdate::downloadProgress() {
+  string res = "";
+  if (modem.write(string(PROMPT(_OTA_DOWNLOAD_PROGRESS)), res, "%s", CMD(_OTA_DOWNLOAD_PROGRESS))) {
+    return atoi(res.c_str());
+  }
+  return static_cast<int>(Error::Modem);
+}
+
 int OTAUpdate::verify() {
   string res = "";
   if (modem.write(string(PROMPT(_OTA_VERIFY)), res, "%s", CMD(_OTA_VERIFY))) {

libraries/OTAUpdate/src/OTAUpdate.h

@@ -42,6 +42,12 @@ class OTAUpdate {
   int begin(const char* file_path);
   int download(const char* url);
   int download(const char* url, const char* file_path);
+
+  int startDownload(const char* url);
+  int startDownload(const char* url, const char* file_path);
+
+  int downloadProgress();
+
   int verify();
   int update();
   int update(const char* file_path);