/*
   L'ESP32-CAM prend une photo et l'enregistre sur Google Drive.

   Basé sur le sketch de Guillermo Sampallo:
   https://github.com/gsampallo/esp32cam-gdrive

   Plus d'informations:

   https://electroniqueamateur.blogspot.com/2020/05/enregistrement-sur-google-drive-des.html
   
*/

#include "esp_camera.h"
#include <WiFi.h>
#include <WiFiClientSecure.h>

const char* ssid     = "**********";   // nom du réseau Wifi
const char* password = "**********";   // mot de passe du réseau Wifi
// à remplacer par l'url de votre Google Apps Script:
String urlScript = "/macros/s/*******************/exec";

const int delaiImage = 60000; // nombre de millisecondes entre 2 enregistrements succesifs
const int delaiReponse = 30000; // nombre de millisecondes max d'attente pour la réponse de Google

const char* host = "script.google.com";
String nomFichier = "filename=ESP32-CAM.jpg";
String mimeType = "&mimetype=image/jpeg";
String monImage = "&data=";

void setup()
{
  Serial.begin(115200);
  delay(10);

  WiFi.mode(WIFI_STA);

  Serial.println("");
  Serial.print("Connexion a ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }

  Serial.println("");
  Serial.println("Adresse IP: ");
  Serial.println(WiFi.localIP());

  Serial.println("");

  camera_config_t config;
  config.ledc_channel = LEDC_CHANNEL_0;
  config.ledc_timer = LEDC_TIMER_0;
  config.pin_d0 = 5;
  config.pin_d1 = 18;
  config.pin_d2 = 19;
  config.pin_d3 = 21;
  config.pin_d4 = 36;
  config.pin_d5 = 39;
  config.pin_d6 = 34;
  config.pin_d7 = 35;
  config.pin_xclk = 0;
  config.pin_pclk = 22;
  config.pin_vsync = 25;
  config.pin_href = 23;
  config.pin_sscb_sda = 26;
  config.pin_sscb_scl = 27;
  config.pin_pwdn = 32;
  config.pin_reset = -1;
  config.xclk_freq_hz = 20000000;
  config.pixel_format = PIXFORMAT_JPEG;
  config.frame_size = FRAMESIZE_VGA;  // UXGA|SXGA|XGA|SVGA|VGA|CIF|QVGA|HQVGA|QQVGA
  config.jpeg_quality = 10;
  config.fb_count = 1;

  esp_err_t err = esp_camera_init(&config);
  if (err != ESP_OK) {
    Serial.printf("Echec de l'initialisation 0x%x", err);
    delay(1000);
    ESP.restart();
  }
}

void loop() {
  enregistreImage();
  delay(delaiImage);
}

void enregistreImage() {
  Serial.println("Connexion a " + String(host));

  WiFiClientSecure client;

  if (client.connect(host, 443)) {
    Serial.println("Connection reussie");

    camera_fb_t * fb = NULL;
    fb = esp_camera_fb_get();
    if (!fb) {
      Serial.println("Echec de la prise de photo ");
      delay(1000);
      ESP.restart();
      return;
    }

    char *input = (char *)fb->buf;
    char output[base64_enc_len(3)];
    String imageFile = "";
    for (int i = 0; i < fb->len; i++) {
      base64_encode(output, (input++), 3);
      if (i % 3 == 0) imageFile += urlencode(String(output));
    }
    String Data = nomFichier + mimeType + monImage;

    esp_camera_fb_return(fb);

    Serial.println("Image envoyee a Google Drive.");

    client.println("POST " + urlScript + " HTTP/1.1");
    client.println("Host: " + String(host));
    client.println("Content-Length: " + String(Data.length() + imageFile.length()));
    client.println("Content-Type: application/x-www-form-urlencoded");
    client.println();
    client.print(Data);
    int Index;
    for (Index = 0; Index < imageFile.length(); Index = Index + 1000) {
      client.print(imageFile.substring(Index, Index + 1000));
    }

    Serial.println("Attente de la reponse.");
    long int StartTime = millis();
    while (!client.available()) {
      Serial.print(".");
      delay(100);
      if ((StartTime + waitingTime) < millis()) {
        Serial.println();
        Serial.println("Pas de reponse.");
        break;
      }
    }
    Serial.println();
    while (client.available()) {
      Serial.print(char(client.read()));
    }
  } else {
    Serial.println("Echec de la connexion a " + String(host) + ".");
  }
  client.stop();
}

/************** Encodage de l'url *******************************/

// urlencode sert à remplacer les caractères indésirables
// dans une url (par exemple, remplacer un espace par %20`)

//https://github.com/zenmanenergy/ESP8266-Arduino-Examples/
String urlencode(String str)
{
  String encodedString = "";
  char c;
  char code0;
  char code1;
  char code2;
  for (int i = 0; i < str.length(); i++) {
    c = str.charAt(i);
    if (c == ' ') {
      encodedString += '+';
    } else if (isalnum(c)) {
      encodedString += c;
    } else {
      code1 = (c & 0xf) + '0';
      if ((c & 0xf) > 9) {
        code1 = (c & 0xf) - 10 + 'A';
      }
      c = (c >> 4) & 0xf;
      code0 = c + '0';
      if (c > 9) {
        code0 = c - 10 + 'A';
      }
      code2 = '\0';
      encodedString += '%';
      encodedString += code0;
      encodedString += code1;
    }
    yield();
  }
  return encodedString;
}


// *************** Encodage de l'image en base64 *************************
//Copyright (c) 2013 Adam Rudd.
//https://github.com/adamvr/arduino-base64

const char PROGMEM b64_alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                    "abcdefghijklmnopqrstuvwxyz"
                                    "0123456789+/";

int base64_encode(char *output, char *input, int inputLen) {
  int i = 0, j = 0;
  int encLen = 0;
  unsigned char a3[3];
  unsigned char a4[4];

  while (inputLen--) {
    a3[i++] = *(input++);
    if (i == 3) {
      a3_to_a4(a4, a3);

      for (i = 0; i < 4; i++) {
        output[encLen++] = pgm_read_byte(&b64_alphabet[a4[i]]);
      }
      i = 0;
    }
  }

  if (i) {
    for (j = i; j < 3; j++) {
      a3[j] = '\0';
    }

    a3_to_a4(a4, a3);

    for (j = 0; j < i + 1; j++) {
      output[encLen++] = pgm_read_byte(&b64_alphabet[a4[j]]);
    }

    while ((i++ < 3)) {
      output[encLen++] = '=';
    }
  }
  output[encLen] = '\0';
  return encLen;
}

int base64_enc_len(int plainLen) {
  int n = plainLen;
  return (n + 2 - ((n + 2) % 3)) / 3 * 4;
}

inline void a3_to_a4(unsigned char * a4, unsigned char * a3) {
  a4[0] = (a3[0] & 0xfc) >> 2;
  a4[1] = ((a3[0] & 0x03) << 4) + ((a3[1] & 0xf0) >> 4);
  a4[2] = ((a3[1] & 0x0f) << 2) + ((a3[2] & 0xc0) >> 6);
  a4[3] = (a3[2] & 0x3f);
}