#include "sim5215_umts_shield.h"

Shield::Shield(int onPin, int shieldRX, int shieldTX) : shieldSerial(shieldRX, shieldTX){
  shieldSerial.begin(115200);
  onModulePin = onPin;
  pinMode(onModulePin, OUTPUT);
}

int Shield::init(char pin_number[], char apn[], char user_name[], char password[]) {
  char aux_str[50];
  int answer = -1;
  
  Serial.println("Starting...");

  delay(3000);

  //sets the PIN code
  sprintf(aux_str, "AT+CPIN=%s", pin_number);
  sendATcommand(aux_str, "OK", 2000);

  delay(3000);

  Serial.println("Connecting to the network...");

  while( (sendATcommand("AT+CREG?", "+CREG: 0,1", 500) || sendATcommand("AT+CREG?", "+CREG: 0,5", 500)) == 0 );

  sendATcommand("AT+CMGF=1", "OK", 1000);    // sets the SMS mode to text

  // sets APN, user name and password
  sprintf(aux_str, "AT+CGSOCKCONT=1,\"IP\",\"%s\"", apn);
  answer &= sendATcommand(aux_str, "OK", 2000);

  sprintf(aux_str, "AT+CSOCKAUTH=1,1,\"%s\",\"%s\"", user_name, password);
  answer &= sendATcommand(aux_str, "OK", 2000);
  
  return answer;
}

void Shield::power_on(){
  uint8_t answer=0;
  // checks if the module is started
  answer = sendATcommand("AT", "OK", 2000);
  if (answer == 0) {
    // power on pulse
    digitalWrite(onModulePin,HIGH);
    delay(3000);
    digitalWrite(onModulePin,LOW);
    // waits for an answer from the module
    while(answer == 0) {     
      // Send AT every two seconds and wait for the answer
      answer = sendATcommand("AT", "OK", 2000); 
      Serial.println(answer);   
    }
  }
}

int8_t Shield::sendATcommand(char* ATcommand, char* expected_answer, unsigned int timeout){

  uint8_t x=0,  answer=0;
  char response[100];
  unsigned long previous;

  memset(response, '\0', 100);    // Initialice the string

  delay(100);

  while( shieldSerial.available() > 0) shieldSerial.read();    // Clean the input buffer

  int bytes = shieldSerial.println(ATcommand);    // Send the AT command

  x = 0;
  previous = millis();

  // this loop waits for the answer
  do {
    // if there are data in the UART input buffer, reads it and checks for the answer
    if (shieldSerial.available() != 0){
//      Serial.println("Data in UART");    
      response[x] = shieldSerial.read();
      x++;
      // check if the desired answer is in the response of the module
      if (strstr(response, expected_answer) != NULL)    
      {
        answer = 1;
      }
    }
    // Waits for the answer with time out
  }
  while((answer == 0) && ((millis() - previous) < timeout));    

  return answer;
}  

bool match(char * cible, char * current) {
  int i = 0;
  boolean ok = true;
  while (i<6 && ok) {
    ok = (cible[i] == current[i]);
    i++;
  }
  return ok;
}

void add_c(char * chaine, char c) {
  chaine[0] = chaine[1];
  chaine[1] = chaine[2];
  chaine[2] = chaine[3];
  chaine[3] = chaine[4];
  chaine[4] = chaine[5];
  chaine[5] = c;
}

int8_t Shield::sendPOSTrequest(char url[], int port, char request[], unsigned int timeout) {
  char aux_str[50];
  unsigned long previous;
  int data_size = 0;
  int http_x, http_status, x, answer;
  char data[400];
  previous = millis();
  sprintf(aux_str, "AT+CHTTPACT=\"%s\",%d", url, port);
  answer = sendATcommand(aux_str, "+CHTTPACT: REQUEST", timeout);
  if (answer == 1) {
    // Sends the request
    shieldSerial.println(request);
    // Sends <Ctrl+Z>
    shieldSerial.write(0x1A);
    http_status = 1;
    
    answer = sendATcommand("", "+CHTTPACT: ", timeout);
    if (answer == 0) {
      if (http_status == 1) {
        http_status = 3;
        Serial.println("ERROR : No first +CHTTPACT: ");
      } 
    } else {
      // answer == 1
      Serial.println("+CHTTPACT: received");
      while(shieldSerial.available()==0);
      aux_str[0] = shieldSerial.read();
    
      if ((aux_str[0] == 'D') && (http_status == 1)) {
          while(shieldSerial.available()<4);
          shieldSerial.read();  // A
          shieldSerial.read();  // T
          shieldSerial.read();  // A
          shieldSerial.read();  // ,

          // Reads the packet size
          x=0;
          do {
            while(shieldSerial.available()==0);
            aux_str[x] = shieldSerial.read();
            x++;
          } while((aux_str[x-1] != '\r') && (aux_str[x-1] != '\n'));

          aux_str[x-1] = '\0';
          data_size = atoi(aux_str);
          
        // Now, search for (200 ok)
        char cible[] = "200 ok";
        char current[] = "\0\0\0\0\0\0";
        while ((!match(cible,current)) && (data_size > 0)) {
          while (shieldSerial.available() < 1);
          add_c(current, shieldSerial.read());
          data_size--;
        }
        if (match(cible,current)) {
          Serial.println("Found 200 ok");
          // End of the header found
          http_status = 2;

          // Vidus du buffer
          while (data_size > 0) {
            shieldSerial.read();
            data_size--;
          }
        } else {
          Serial.println("No 200 ok");
          http_status = 3;
        }
      } else {
        Serial.println("No first DATA");
        http_status = 3;
      }
    }   
    

   if (http_status == 2) {
      answer = sendATcommand("", "+CHTTPACT: ", timeout);
      if (answer == 0) {
        http_status = 3;
        Serial.println("ERROR : No second +CHTTPACT: ");
      } else {
        // answer == 1
        Serial.println("+CHTTPACT: received");
        while(shieldSerial.available()==0);
        aux_str[0] = shieldSerial.read();
        Serial.println(aux_str[0]);
        if (aux_str[0] == '0') {
            http_status = 0;
        } else {
          Serial.println("No 0");
          http_status = 3;
        }
      }   
   } 

    previous = millis() - previous;
  } else {
    Serial.println("!Error on CHTTPACT REQUEST!");
    http_status = 3;
  }

  Serial.print(F("http_status= "));
  Serial.println(http_status, DEC);
  return http_status;
}

int8_t Shield::sendTextMessage(char phone_number[], char text[]) {
  char aux_str[50];
  int aux, answer;
  
  sendATcommand("AT+CMGF=1", "OK", 1000);    // sets the SMS mode to text
  
  sprintf(aux_str,"AT+CMGS=\"%s\"", phone_number);
  answer = sendATcommand(aux_str, ">", 2000);    // send the SMS number
  if (answer == 1) {
    shieldSerial.println(text);
    shieldSerial.write(0x1A);
    answer = sendATcommand("", "OK", 20000);
    if (answer == 1) {
      Serial.print("Text message sent.");
    } else {
      Serial.print("Could not send text message.");
    }
  } else {
    Serial.print("Could not send text message");
    Serial.println(answer, DEC);
  }
  return answer;
}