sensor_commands.cpp

#include "sensor_commands.h"

namespace sensor_commands {
  const uint8_t MAX_CALLBACKS = 20;
  const uint8_t MAX_COMMAND_SIZE = 30;

  uint8_t callbacks_count = 0;
// A callback contains both a function and a pointer to arbitrary data
// that will be passed as argument to the function.
  struct Callback {
    Callback(const char *s = 0, void (*f)(void*) = 0, void *d = 0) :
        name(s), function(f), data(d) {
    }
    const char *name;
    void (*function)(void*);
    void *data;
  };

  Callback callbacks[MAX_CALLBACKS];

  void defineCallback(const char *n, void (*f)(void*), void *d) {
    if (callbacks_count < MAX_CALLBACKS) {
      callbacks[callbacks_count] = Callback(n, f, d);
      callbacks_count++;
    } else {
      Serial.println(F("Too many callbacks have been defined."));
    }
  }

  bool startsWith(const char *a, const char *b) {
    return !strncmp(a, b, strlen(b));
  }

  bool parseCommand(const char *command, char *function_name, long &parameter) {
    char split_command[MAX_COMMAND_SIZE];
    strlcpy(split_command, command, MAX_COMMAND_SIZE);
    Serial.print(F("Received : '"));
    Serial.print(command);
    Serial.println("'");
    char *arg;
    char *part1;
    part1 = strtok(split_command, " ");
    if (!part1) {
      // Empty string
      return 1;
    }
    strlcpy(function_name, part1, MAX_COMMAND_SIZE);
    arg = strtok(NULL, " ");
    if (arg) {
      char *end;
      parameter = strtol(arg, &end, 10);
      if (*end) {
        // Second argument isn't a number
        parameter = -9999;
      }
    } else {
      parameter = -9999;
    }
    return 0;
  }

  void listAvailableCallbacks() {
    Serial.println("DEBUG - Available commands :");
    for (uint8_t i = 0; i < callbacks_count; i++) {
      Serial.print("  ");
      Serial.println(callbacks[i].name);
    }
  }

  void run(const char *command) {
    char function_name[MAX_COMMAND_SIZE];
    long parameter;
    if (parseCommand(command, function_name, parameter)) {
      listAvailableCallbacks();
      return;
    }
    Serial.print("Command : '");
    Serial.print(function_name);
    Serial.print("'. Parameter : ");
    Serial.println(parameter);

    // Test all the callbacks.
    for (uint8_t i = 0; i < callbacks_count; i++) {
      if (!strcmp(function_name, callbacks[i].name)) {
        Serial.print("Function found!!!");
        Serial.print("Trying '");
        Serial.print(callbacks[i].name);
        Serial.println("'");
        callbacks[i].function(callbacks[i].data);
        return;
      }
    }
    listAvailableCallbacks();
  }
}