fixup! fixup! [WIP] Improving parse function in modem class

Author: andreagilardoni

libraries/WiFiS3/src/Modem.cpp

@@ -162,14 +162,16 @@ ModemClass::ParseResult ModemClass::buf_read(const string &prompt, string &data_
    unsigned int result_parse = 0;
    bool restart = false;
 
+   // I expect the answer to be in this form: "ERROR<CR><LF>" "OK<CR><LF>"
+   // if prompt == DO_NOT_CHECK_CMD
+   const bool check_prompt = (prompt != DO_NOT_CHECK_CMD);
 
    if(_serial_debug  && _debug_level >= 1) {
       _serial_debug->print("RAW: ");
    }
 
    unsigned long start_time = millis();
-   while(state != at_parse_state_t::Completed &&
-         state != at_parse_state_t::ParseError) {
+   while(state != at_parse_state_t::Completed) {
 
       if(millis() - start_time > _timeout) {
          res = Timeout;
@@ -212,16 +214,23 @@ ModemClass::ParseResult ModemClass::buf_read(const string &prompt, string &data_
             */
 
          if(c == '+') {
+            // the answer doesn't match the expected form, we need to restart
+            restart = !check_prompt;
+
             commandName += c; // prompt includes also '+'
             state = at_parse_state_t::Cmd;
-         } else if(c == RESULT_OK[result_parse]) { // FIXME this should also account for following characters
+         } else if(c == RESULT_OK[result_parse]) { // FIXME this should also account for following character
+            // the answer doesn't match the expected form, we need to restart
+            restart = check_prompt;
+
             state = at_parse_state_t::Ok;
             result_parse++;
          } else if(c == RESULT_ERROR[result_parse]) { // FIXME this should also account for following characters
+            // the answer doesn't match the expected form, we need to restart
+            restart = check_prompt;
+
             state = at_parse_state_t::Error;
             result_parse++;
-         } else {
-            data_res = "";
          }
          // if we uncomment this we can force strict response matching
          // else {
@@ -238,7 +247,7 @@ ModemClass::ParseResult ModemClass::buf_read(const string &prompt, string &data_
          if(c == ':' || c == '=') {
             commandName += c; // prompt includes also ':'
 
-            if (prompt != DO_NOT_CHECK_CMD && commandName != prompt) {
+            if (check_prompt && commandName != prompt) {
                // the response we got is not the one we were expecting, parse the wrong response till the end
                // and start the parse of the next response
                restart = true;
@@ -333,13 +342,7 @@ ModemClass::ParseResult ModemClass::buf_read(const string &prompt, string &data_
 
          if(result_parse == strlen(RESULT_OK)) {
             res = Ok;
-
-            if(restart) {
-               state = at_parse_state_t::Begin;
-               restart = false;
-            } else {
-               state = at_parse_state_t::Completed;
-            }
+            state = at_parse_state_t::Completed;
          }
          break;
       case at_parse_state_t::Error:
@@ -353,27 +356,23 @@ ModemClass::ParseResult ModemClass::buf_read(const string &prompt, string &data_
 
          if(result_parse == strlen(RESULT_ERROR)) {
             res = Error;
-
-            if(restart) {
-               state = at_parse_state_t::Begin;
-               restart = false;
-            } else {
-               state = at_parse_state_t::Completed;
-            }
+            state = at_parse_state_t::Completed;
          }
          break;
       case at_parse_state_t::ParseError:
          res = ParseError;
-         if(restart) {
-            state = at_parse_state_t::Begin;
-            restart = false;
-         } else {
-            state = at_parse_state_t::Completed;
-         }
+         // if we get a parseError, we go back from the beginning and try again to parse, unitl the timeout expires
+         state = at_parse_state_t::Begin;
+         restart = false;
          break;
       case at_parse_state_t::Completed:
          break;
       }
+
+      if(restart && state == at_parse_state_t::Completed) {
+         state = at_parse_state_t::Begin;
+         restart = false;
+      }
    }
 
    if(_serial_debug  && _debug_level >= 3) {