ESP32_FSWebServer.ino

/****************************************************************************************************************************
  ESP32_FSWebServer - Example WebServer with SPIFFS backend for esp8266
  For ESP32 boards
  
  ESP_WiFiManager is a library for the ESP8266/ESP32 platform (https://github.com/esp8266/Arduino) to enable easy
  configuration and reconfiguration of WiFi credentials using a Captive Portal.
  
  Modified from Tzapu https://github.com/tzapu/WiFiManager
  and from Ken Taylor https://github.com/kentaylor
  
  Built by Khoi Hoang https://github.com/khoih-prog/ESP_WiFiManager
  Licensed under MIT license
  
  Example modified from https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WebServer/examples/FSBrowser/FSBrowser.ino
  
  Copyright (c) 2015 Hristo Gochkov. All rights reserved.
  This file is part of the ESP8266WebServer library for Arduino environment.
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *****************************************************************************************************************************/
/*****************************************************************************************************************************
   How To Use:
   1) Upload the contents of the data folder with MkSPIFFS Tool ("ESP32 Sketch Data Upload" in Tools menu in Arduino IDE)
   2) or you can upload the contents of a folder if you CD in that folder and run the following command:
      for file in `\ls -A1`; do curl -F "file=@$PWD/$file" esp32-fs-browser.local/edit; done
   3) access the sample web page at http://esp32-fs-browser.local
   4) edit the page by going to http://esp32-fs-browser.local/edit
*****************************************************************************************************************************/

#if !defined(ESP32)
  #error This code is intended to run on the ESP32 platform! Please check your Tools->Board setting.
#elif ( defined(ARDUINO_ESP32S3_DEV) || defined(ARDUINO_ESP32_S3_BOX) || defined(ARDUINO_TINYS3) || \
        defined(ARDUINO_PROS3) || defined(ARDUINO_FEATHERS3) )
  #error ESP32_S3 is not supported yet
#endif

#define ESP_WIFIMANAGER_VERSION_MIN_TARGET      "ESP_WiFiManager v1.12.0"
#define ESP_WIFIMANAGER_VERSION_MIN             1012000

// Use from 0 to 4. Higher number, more debugging messages and memory usage.
#define _WIFIMGR_LOGLEVEL_    1

// To not display stored SSIDs and PWDs on Config Portal, select false. Default is true
// Even the stored Credentials are not display, just leave them all blank to reconnect and reuse the stored Credentials 
//#define DISPLAY_STORED_CREDENTIALS_IN_CP        false

#include <WiFi.h>
#include <WiFiClient.h>
#include <WebServer.h>
#include <ESPmDNS.h>

// From v1.1.0
#include <WiFiMulti.h>
WiFiMulti wifiMulti;
//////

// You only need to format the filesystem once
//#define FORMAT_FILESYSTEM       true
#define FORMAT_FILESYSTEM         false

// LittleFS has higher priority than SPIFFS
#if ( defined(ESP_ARDUINO_VERSION_MAJOR) && (ESP_ARDUINO_VERSION_MAJOR >= 2) )
  #define USE_LITTLEFS    true
  #define USE_SPIFFS      false
#elif defined(ARDUINO_ESP32C3_DEV)
  // For core v1.0.6-, ESP32-C3 only supporting SPIFFS and EEPROM. To use v2.0.0+ for LittleFS
  #define USE_LITTLEFS          false
  #define USE_SPIFFS            true
#endif

#if USE_LITTLEFS
  // Use LittleFS
  #include "FS.h"

  // Check cores/esp32/esp_arduino_version.h and cores/esp32/core_version.h
    //#if ( ESP_ARDUINO_VERSION >= ESP_ARDUINO_VERSION_VAL(2, 0, 0) )  //(ESP_ARDUINO_VERSION_MAJOR >= 2)
    #if ( defined(ESP_ARDUINO_VERSION_MAJOR) && (ESP_ARDUINO_VERSION_MAJOR >= 2) )
      #if (_WIFIMGR_LOGLEVEL_ > 3)
        #warning Using ESP32 Core 1.0.6 or 2.0.0+
      #endif
      
      // The library has been merged into esp32 core from release 1.0.6
      #include <LittleFS.h>       // https://github.com/espressif/arduino-esp32/tree/master/libraries/LittleFS
      
      FS* filesystem =      &LittleFS;
      #define FileFS        LittleFS
      #define FS_Name       "LittleFS"
    #else
      #if (_WIFIMGR_LOGLEVEL_ > 3)
        #warning Using ESP32 Core 1.0.5-. You must install LITTLEFS library
      #endif
      
    // The library has been merged into esp32 core from release 1.0.6
    #include <LITTLEFS.h>       // https://github.com/lorol/LITTLEFS
    
    FS* filesystem =      &LITTLEFS;
    #define FileFS        LITTLEFS
    #define FS_Name       "LittleFS"
  #endif
    
#elif USE_SPIFFS
  #include <SPIFFS.h>
  FS* filesystem =      &SPIFFS;
  #define FileFS        SPIFFS
  #define FS_Name       "SPIFFS"
#else
  // Use FFat
  #include <FFat.h>
  FS* filesystem =      &FFat;
  #define FileFS        FFat
  #define FS_Name       "FFat"
#endif

#define DBG_OUTPUT_PORT Serial

// From v1.1.0
#define MIN_AP_PASSWORD_SIZE    8

#define SSID_MAX_LEN            32
//From v1.0.10, WPA2 passwords can be up to 63 characters long.
#define PASS_MAX_LEN            64

typedef struct
{
  char wifi_ssid[SSID_MAX_LEN];
  char wifi_pw  [PASS_MAX_LEN];
}  WiFi_Credentials;

typedef struct
{
  String wifi_ssid;
  String wifi_pw;
}  WiFi_Credentials_String;

#define NUM_WIFI_CREDENTIALS      2

// Assuming max 491 chars
#define TZNAME_MAX_LEN            50
#define TIMEZONE_MAX_LEN          50

typedef struct
{
  WiFi_Credentials  WiFi_Creds [NUM_WIFI_CREDENTIALS];
  char TZ_Name[TZNAME_MAX_LEN];     // "America/Toronto"
  char TZ[TIMEZONE_MAX_LEN];        // "EST5EDT,M3.2.0,M11.1.0"
  uint16_t checksum;
} WM_Config;

WM_Config         WM_config;

#define  CONFIG_FILENAME              F("/wifi_cred.dat")
//////

// Indicates whether ESP has WiFi credentials saved from previous session, or double reset detected
bool initialConfig = false;

// Use false if you don't like to display Available Pages in Information Page of Config Portal
// Comment out or use true to display Available Pages in Information Page of Config Portal
// Must be placed before #include <ESP_WiFiManager.h>
#define USE_AVAILABLE_PAGES     false

// From v1.0.10 to permit disable/enable StaticIP configuration in Config Portal from sketch. Valid only if DHCP is used.
// You'll loose the feature of dynamically changing from DHCP to static IP, or vice versa
// You have to explicitly specify false to disable the feature.
//#define USE_STATIC_IP_CONFIG_IN_CP          false

// Use false to disable NTP config. Advisable when using Cellphone, Tablet to access Config Portal.
// See Issue 23: On Android phone ConfigPortal is unresponsive (https://github.com/khoih-prog/ESP_WiFiManager/issues/23)
#define USE_ESP_WIFIMANAGER_NTP     true

// Just use enough to save memory. On ESP8266, can cause blank ConfigPortal screen
// if using too much memory
#define USING_AFRICA        false
#define USING_AMERICA       true
#define USING_ANTARCTICA    false
#define USING_ASIA          false
#define USING_ATLANTIC      false
#define USING_AUSTRALIA     false
#define USING_EUROPE        false
#define USING_INDIAN        false
#define USING_PACIFIC       false
#define USING_ETC_GMT       false

// Use true to enable CloudFlare NTP service. System can hang if you don't have Internet access while accessing CloudFlare
// See Issue #21: CloudFlare link in the default portal (https://github.com/khoih-prog/ESP_WiFiManager/issues/21)
#define USE_CLOUDFLARE_NTP          false

// New in v1.0.11
#define USING_CORS_FEATURE          true

////////////////////////////////////////////

// Use USE_DHCP_IP == true for dynamic DHCP IP, false to use static IP which you have to change accordingly to your network
#if (defined(USE_STATIC_IP_CONFIG_IN_CP) && !USE_STATIC_IP_CONFIG_IN_CP)
  // Force DHCP to be true
  #if defined(USE_DHCP_IP)
    #undef USE_DHCP_IP
  #endif
  #define USE_DHCP_IP     true
#else
  // You can select DHCP or Static IP here
  #define USE_DHCP_IP     true
  //#define USE_DHCP_IP     false
#endif

#if ( USE_DHCP_IP )
  // Use DHCP
  
  #if (_WIFIMGR_LOGLEVEL_ > 3)
    #warning Using DHCP IP
  #endif
  
  IPAddress stationIP   = IPAddress(0, 0, 0, 0);
  IPAddress gatewayIP   = IPAddress(192, 168, 2, 1);
  IPAddress netMask     = IPAddress(255, 255, 255, 0);
  
#else
  // Use static IP
  
  #if (_WIFIMGR_LOGLEVEL_ > 3)
    #warning Using static IP
  #endif
  
  #ifdef ESP32
    IPAddress stationIP   = IPAddress(192, 168, 2, 232);
  #else
    IPAddress stationIP   = IPAddress(192, 168, 2, 186);
  #endif
  
  IPAddress gatewayIP   = IPAddress(192, 168, 2, 1);
  IPAddress netMask     = IPAddress(255, 255, 255, 0);
#endif

////////////////////////////////////////////

#define USE_CONFIGURABLE_DNS      true

IPAddress dns1IP      = gatewayIP;
IPAddress dns2IP      = IPAddress(8, 8, 8, 8);

#define USE_CUSTOM_AP_IP          false

// New in v1.4.0
IPAddress APStaticIP  = IPAddress(192, 168, 100, 1);
IPAddress APStaticGW  = IPAddress(192, 168, 100, 1);
IPAddress APStaticSN  = IPAddress(255, 255, 255, 0);

// Must be placed before #include <ESP_WiFiManager.h>, or default port 80 will be used
//#define HTTP_PORT     8080

#include <ESP_WiFiManager.h>              //https://github.com/khoih-prog/ESP_WiFiManager

// Redundant, for v1.8.0 only
//#include <ESP_WiFiManager-Impl.h>         //https://github.com/khoih-prog/ESP_WiFiManager

// SSID and PW for Config Portal
String ssid       = "ESP_" + String(ESP_getChipId(), HEX);
String password;

// SSID and PW for your Router
String Router_SSID;
String Router_Pass;

const char* host = "esp32-fs-browser";

#define HTTP_PORT     80

WebServer server(HTTP_PORT);

//holds the current upload
File fsUploadFile;

// Function Prototypes
uint8_t connectMultiWiFi();

///////////////////////////////////////////
// New in v1.4.0
/******************************************
 * // Defined in ESPAsync_WiFiManager.h
typedef struct
{
  IPAddress _ap_static_ip;
  IPAddress _ap_static_gw;
  IPAddress _ap_static_sn;

}  WiFi_AP_IPConfig;

typedef struct
{
  IPAddress _sta_static_ip;
  IPAddress _sta_static_gw;
  IPAddress _sta_static_sn;
#if USE_CONFIGURABLE_DNS  
  IPAddress _sta_static_dns1;
  IPAddress _sta_static_dns2;
#endif
}  WiFi_STA_IPConfig;
******************************************/

WiFi_AP_IPConfig  WM_AP_IPconfig;
WiFi_STA_IPConfig WM_STA_IPconfig;

void initAPIPConfigStruct(WiFi_AP_IPConfig &in_WM_AP_IPconfig)
{
  in_WM_AP_IPconfig._ap_static_ip   = APStaticIP;
  in_WM_AP_IPconfig._ap_static_gw   = APStaticGW;
  in_WM_AP_IPconfig._ap_static_sn   = APStaticSN;
}

void initSTAIPConfigStruct(WiFi_STA_IPConfig &in_WM_STA_IPconfig)
{
  in_WM_STA_IPconfig._sta_static_ip   = stationIP;
  in_WM_STA_IPconfig._sta_static_gw   = gatewayIP;
  in_WM_STA_IPconfig._sta_static_sn   = netMask;
#if USE_CONFIGURABLE_DNS  
  in_WM_STA_IPconfig._sta_static_dns1 = dns1IP;
  in_WM_STA_IPconfig._sta_static_dns2 = dns2IP;
#endif
}

void displayIPConfigStruct(WiFi_STA_IPConfig in_WM_STA_IPconfig)
{
  LOGERROR3(F("stationIP ="), in_WM_STA_IPconfig._sta_static_ip, F(", gatewayIP ="), in_WM_STA_IPconfig._sta_static_gw);
  LOGERROR1(F("netMask ="), in_WM_STA_IPconfig._sta_static_sn);
#if USE_CONFIGURABLE_DNS
  LOGERROR3(F("dns1IP ="), in_WM_STA_IPconfig._sta_static_dns1, F(", dns2IP ="), in_WM_STA_IPconfig._sta_static_dns2);
#endif
}

void configWiFi(WiFi_STA_IPConfig in_WM_STA_IPconfig)
{
  #if USE_CONFIGURABLE_DNS  
    // Set static IP, Gateway, Subnetmask, DNS1 and DNS2. New in v1.0.5
    WiFi.config(in_WM_STA_IPconfig._sta_static_ip, in_WM_STA_IPconfig._sta_static_gw, in_WM_STA_IPconfig._sta_static_sn, in_WM_STA_IPconfig._sta_static_dns1, in_WM_STA_IPconfig._sta_static_dns2);  
  #else
    // Set static IP, Gateway, Subnetmask, Use auto DNS1 and DNS2.
    WiFi.config(in_WM_STA_IPconfig._sta_static_ip, in_WM_STA_IPconfig._sta_static_gw, in_WM_STA_IPconfig._sta_static_sn);
  #endif 
}

///////////////////////////////////////////

uint8_t connectMultiWiFi()
{
#if ESP32
  // For ESP32, this better be 0 to shorten the connect time.
  // For ESP32-S2/C3, must be > 500
  #if ( USING_ESP32_S2 || USING_ESP32_C3 )
    #define WIFI_MULTI_1ST_CONNECT_WAITING_MS           500L
  #else
    // For ESP32 core v1.0.6, must be >= 500
    #define WIFI_MULTI_1ST_CONNECT_WAITING_MS           800L
  #endif
#else
  // For ESP8266, this better be 2200 to enable connect the 1st time
  #define WIFI_MULTI_1ST_CONNECT_WAITING_MS             2200L
#endif

#define WIFI_MULTI_CONNECT_WAITING_MS                   500L

  uint8_t status;

  //WiFi.mode(WIFI_STA);

  LOGERROR(F("ConnectMultiWiFi with :"));

  if ( (Router_SSID != "") && (Router_Pass != "") )
  {
    LOGERROR3(F("* Flash-stored Router_SSID = "), Router_SSID, F(", Router_Pass = "), Router_Pass );
    LOGERROR3(F("* Add SSID = "), Router_SSID, F(", PW = "), Router_Pass );
    wifiMulti.addAP(Router_SSID.c_str(), Router_Pass.c_str());
  }

  for (uint8_t i = 0; i < NUM_WIFI_CREDENTIALS; i++)
  {
    // Don't permit NULL SSID and password len < MIN_AP_PASSWORD_SIZE (8)
    if ( (String(WM_config.WiFi_Creds[i].wifi_ssid) != "") && (strlen(WM_config.WiFi_Creds[i].wifi_pw) >= MIN_AP_PASSWORD_SIZE) )
    {
      LOGERROR3(F("* Additional SSID = "), WM_config.WiFi_Creds[i].wifi_ssid, F(", PW = "), WM_config.WiFi_Creds[i].wifi_pw );
    }
  }

  LOGERROR(F("Connecting MultiWifi..."));

  //WiFi.mode(WIFI_STA);

#if !USE_DHCP_IP
  // New in v1.4.0
  configWiFi(WM_STA_IPconfig);
  //////
#endif

  int i = 0;
  status = wifiMulti.run();
  delay(WIFI_MULTI_1ST_CONNECT_WAITING_MS);

  while ( ( i++ < 20 ) && ( status != WL_CONNECTED ) )
  {
    status = WiFi.status();

    if ( status == WL_CONNECTED )
      break;
    else
      delay(WIFI_MULTI_CONNECT_WAITING_MS);
  }

  if ( status == WL_CONNECTED )
  {
    LOGERROR1(F("WiFi connected after time: "), i);
    LOGERROR3(F("SSID:"), WiFi.SSID(), F(",RSSI="), WiFi.RSSI());
    LOGERROR3(F("Channel:"), WiFi.channel(), F(",IP address:"), WiFi.localIP() );
  }
  else
  {
    LOGERROR(F("WiFi not connected"));
 
#if ESP8266      
    ESP.reset();
#else
    ESP.restart();
#endif  
  }

  return status;
}

#if USE_ESP_WIFIMANAGER_NTP

void printLocalTime()
{
#if ESP8266
  static time_t now;
  
  now = time(nullptr);
  
  if ( now > 1451602800 )
  {
    Serial.print("Local Date/Time: ");
    Serial.print(ctime(&now));
  }
#else
  struct tm timeinfo;

  getLocalTime( &timeinfo );

  // Valid only if year > 2000. 
  // You can get from timeinfo : tm_year, tm_mon, tm_mday, tm_hour, tm_min, tm_sec
  if (timeinfo.tm_year > 100 )
  {
    Serial.print("Local Date/Time: ");
    Serial.print( asctime( &timeinfo ) );
  }
#endif
}

#endif

void heartBeatPrint()
{
#if USE_ESP_WIFIMANAGER_NTP
  printLocalTime();
#else
  static int num = 1;

  if (WiFi.status() == WL_CONNECTED)
    Serial.print(F("H"));        // H means connected to WiFi
  else
    Serial.print(F("F"));        // F means not connected to WiFi

  if (num == 80)
  {
    Serial.println();
    num = 1;
  }
  else if (num++ % 10 == 0)
  {
    Serial.print(F(" "));
  }
#endif  
}

void check_WiFi()
{
  if ( (WiFi.status() != WL_CONNECTED) )
  {
    Serial.println(F("\nWiFi lost. Call connectMultiWiFi in loop"));
    connectMultiWiFi();
  }
}  

void check_status()
{
  static ulong checkstatus_timeout  = 0;
  static ulong checkwifi_timeout    = 0;

  static ulong current_millis;

#define WIFICHECK_INTERVAL    1000L

#if USE_ESP_WIFIMANAGER_NTP
  #define HEARTBEAT_INTERVAL    60000L
#else
  #define HEARTBEAT_INTERVAL    10000L
#endif

  current_millis = millis();
  
  // Check WiFi every WIFICHECK_INTERVAL (1) seconds.
  if ((current_millis > checkwifi_timeout) || (checkwifi_timeout == 0))
  {
    check_WiFi();
    checkwifi_timeout = current_millis + WIFICHECK_INTERVAL;
  }

  // Print hearbeat every HEARTBEAT_INTERVAL (10) seconds.
  if ((current_millis > checkstatus_timeout) || (checkstatus_timeout == 0))
  {
    heartBeatPrint();
    checkstatus_timeout = current_millis + HEARTBEAT_INTERVAL;
  }
}

//format bytes
String formatBytes(size_t bytes) 
{
  if (bytes < 1024) 
  {
    return String(bytes) + "B";
  } 
  else if (bytes < (1024 * 1024)) 
  {
    return String(bytes / 1024.0) + "KB";
  } 
  else if (bytes < (1024 * 1024 * 1024)) 
  {
    return String(bytes / 1024.0 / 1024.0) + "MB";
  } 
  else 
  {
    return String(bytes / 1024.0 / 1024.0 / 1024.0) + "GB";
  }
}

String getContentType(String filename) 
{
  if (server.hasArg("download")) 
  {
    return "application/octet-stream";
  } 
  else if (filename.endsWith(".htm")) 
  {
    return "text/html";
  } 
  else if (filename.endsWith(".html")) 
  {
    return "text/html";
  } 
  else if (filename.endsWith(".css")) 
  {
    return "text/css";
  } 
  else if (filename.endsWith(".js")) 
  {
    return "application/javascript";
  } 
  else if (filename.endsWith(".png")) 
  {
    return "image/png";
  } 
  else if (filename.endsWith(".gif")) 
  {
    return "image/gif";
  } 
  else if (filename.endsWith(".jpg")) 
  {
    return "image/jpeg";
  } 
  else if (filename.endsWith(".ico")) 
  {
    return "image/x-icon";
  } 
  else if (filename.endsWith(".xml")) 
  {
    return "text/xml";
  } 
  else if (filename.endsWith(".pdf")) 
  {
    return "application/x-pdf";
  } 
  else if (filename.endsWith(".zip")) 
  {
    return "application/x-zip";
  } 
  else if (filename.endsWith(".gz")) 
  {
    return "application/x-gzip";
  }
  return "text/plain";
}

bool handleFileRead(String path) 
{
  Serial.println("handleFileRead: " + path);
  
  if (path.endsWith("/")) 
  {
    path += "index.htm";
  }
  
  String contentType = getContentType(path);
  String pathWithGz = path + ".gz";
  
  if (filesystem->exists(pathWithGz) || filesystem->exists(path)) 
  {
    if (filesystem->exists(pathWithGz)) 
    {
      path += ".gz";
    }
    
    File file = filesystem->open(path, "r");
    server.streamFile(file, contentType);
    file.close();
    return true;
  }
  
  return false;
}

void handleFileUpload() 
{
  if (server.uri() != "/edit") 
  {
    return;
  }
  
  HTTPUpload& upload = server.upload();
  
  if (upload.status == UPLOAD_FILE_START) 
  {
    String filename = upload.filename;
    if (!filename.startsWith("/")) 
    {
      filename = "/" + filename;
    }
    
    Serial.print(F("handleFileUpload Name: ")); Serial.println(filename);
    fsUploadFile = filesystem->open(filename, "w");
    filename.clear();
  } 
  else if (upload.status == UPLOAD_FILE_WRITE) 
  {
    //Serial.print(F("handleFileUpload Data: ")); Serial.println(upload.currentSize);
    if (fsUploadFile) 
    {
      fsUploadFile.write(upload.buf, upload.currentSize);
    }
  } 
  else if (upload.status == UPLOAD_FILE_END) 
  {
    if (fsUploadFile) 
    {
      fsUploadFile.close();
    }
    Serial.print(F("handleFileUpload Size: ")); Serial.println(upload.totalSize);
  }
}

void handleFileDelete() 
{
  if (server.args() == 0) 
  {
    return server.send(500, "text/plain", "BAD ARGS");
  }
  String path = server.arg(0);
  Serial.println("handleFileDelete: " + path);
  
  if (path == "/") 
  {
    return server.send(500, "text/plain", "BAD PATH");
  }
  
  if (!filesystem->exists(path)) 
  {
    return server.send(404, "text/plain", "FileNotFound");
  }
  
  filesystem->remove(path);
  server.send(200, "text/plain", "");
  path.clear();
}

void handleFileCreate() 
{
  if (server.args() == 0) 
  {
    return server.send(500, "text/plain", "BAD ARGS");
  }
  
  String path = server.arg(0);
  Serial.println("handleFileCreate: " + path);
  
  if (path == "/") 
  {
    return server.send(500, "text/plain", "BAD PATH");
  }
  
  if (filesystem->exists(path)) 
  {
    return server.send(500, "text/plain", "FILE EXISTS");
  }
  
  File file = filesystem->open(path, "w");
  
  if (file) 
  {
    file.close();
  } 
  else 
  {
    return server.send(500, "text/plain", "CREATE FAILED");
  }
  server.send(200, "text/plain", "");
  path.clear();
}

void handleFileList() 
{
  if (!server.hasArg("dir")) 
  {
    server.send(500, "text/plain", "BAD ARGS");
    return;
  }

  String path = server.arg("dir");
  Serial.println("handleFileList: " + path);
  
  File root = FileFS.open(path);
  path = String();

  String output = "[";
  
  if (root.isDirectory()) 
  {
    File file = root.openNextFile();
    
    while (file) 
    {
      if (output != "[") 
      {
        output += ',';
      }
      
      output += "{\"type\":\"";
      output += (file.isDirectory()) ? "dir" : "file";
      output += "\",\"name\":\"";
      //output += String(file.name()).substring(1);
      output += String(file.name()).substring(0);
      output += "\"}";
      file = root.openNextFile();
    }
  }
  
  output += "]";

  Serial.println("handleFileList: " + output);

  server.send(200, "text/json", output);
}

int calcChecksum(uint8_t* address, uint16_t sizeToCalc)
{
  uint16_t checkSum = 0;
  
  for (uint16_t index = 0; index < sizeToCalc; index++)
  {
    checkSum += * ( ( (byte*) address ) + index);
  }

  return checkSum;
}

bool loadConfigData()
{
  File file = FileFS.open(CONFIG_FILENAME, "r");
  LOGERROR(F("LoadWiFiCfgFile "));

  memset((void *) &WM_config,       0, sizeof(WM_config));

  // New in v1.4.0
  memset((void *) &WM_STA_IPconfig, 0, sizeof(WM_STA_IPconfig));
  //////

  if (file)
  {
    file.readBytes((char *) &WM_config,   sizeof(WM_config));

    // New in v1.4.0
    file.readBytes((char *) &WM_STA_IPconfig, sizeof(WM_STA_IPconfig));
    //////

    file.close();
    LOGERROR(F("OK"));

    if ( WM_config.checksum != calcChecksum( (uint8_t*) &WM_config, sizeof(WM_config) - sizeof(WM_config.checksum) ) )
    {
      LOGERROR(F("WM_config checksum wrong"));
      
      return false;
    }
    
    // New in v1.4.0
    displayIPConfigStruct(WM_STA_IPconfig);
    //////

    return true;
  }
  else
  {
    LOGERROR(F("failed"));

    return false;
  }
}

void saveConfigData()
{
  File file = FileFS.open(CONFIG_FILENAME, "w");
  LOGERROR(F("SaveWiFiCfgFile "));

  if (file)
  {
    WM_config.checksum = calcChecksum( (uint8_t*) &WM_config, sizeof(WM_config) - sizeof(WM_config.checksum) );
    
    file.write((uint8_t*) &WM_config, sizeof(WM_config));

    displayIPConfigStruct(WM_STA_IPconfig);

    // New in v1.4.0
    file.write((uint8_t*) &WM_STA_IPconfig, sizeof(WM_STA_IPconfig));
    //////

    file.close();
    LOGERROR(F("OK"));
  }
  else
  {
    LOGERROR(F("failed"));
  }
}

void setup()
{
  Serial.begin(115200);
  while (!Serial);

  delay(200);

  Serial.print(F("\nStarting ESP32_FSWebServer using ")); Serial.print(FS_Name);
  Serial.print(F(" on ")); Serial.println(ARDUINO_BOARD);
  Serial.println(ESP_WIFIMANAGER_VERSION);

#if defined(ESP_WIFIMANAGER_VERSION_MIN)
  if (ESP_WIFIMANAGER_VERSION_INT < ESP_WIFIMANAGER_VERSION_MIN)
  {
    Serial.print("Warning. Must use this example on Version later than : ");
    Serial.println(ESP_WIFIMANAGER_VERSION_MIN_TARGET);
  }
#endif
  
  Serial.setDebugOutput(false);

  if (FORMAT_FILESYSTEM) 
    FileFS.format();

  // Format FileFS if not yet
  if (!FileFS.begin(true))
  {
    Serial.println(F("SPIFFS/LittleFS failed! Already tried formatting."));
  
    if (!FileFS.begin())
    {     
      // prevents debug info from the library to hide err message.
      delay(100);
      
#if USE_LITTLEFS
      Serial.println(F("LittleFS failed!. Please use SPIFFS or EEPROM. Stay forever"));
#else
      Serial.println(F("SPIFFS failed!. Please use LittleFS or EEPROM. Stay forever"));
#endif

      while (true)
      {
        delay(1);
      }
    }
  }
  
  File root = FileFS.open("/");
  File file = root.openNextFile();
  while (file) 
  {
    String fileName = file.name();
    size_t fileSize = file.size();
    Serial.printf("FS File: %s, size: %s\n", fileName.c_str(), formatBytes(fileSize).c_str());
    file = root.openNextFile();
  }
  
  Serial.println();

  unsigned long startedAt = millis();

  // New in v1.4.0
  initAPIPConfigStruct(WM_AP_IPconfig);
  initSTAIPConfigStruct(WM_STA_IPconfig);
  //////

  //Local intialization. Once its business is done, there is no need to keep it around
  // Use this to default DHCP hostname to ESP8266-XXXXXX or ESP32-XXXXXX
  //ESP_WiFiManager ESP_wifiManager;
  // Use this to personalize DHCP hostname (RFC952 conformed)
  ESP_WiFiManager ESP_wifiManager("ESP32-FSWebServer");

#if USE_CUSTOM_AP_IP
  //set custom ip for portal
  // New in v1.4.0
  ESP_wifiManager.setAPStaticIPConfig(WM_AP_IPconfig);
  //////
#endif

  ESP_wifiManager.setMinimumSignalQuality(-1);

  // From v1.0.10 only
  // Set config portal channel, default = 1. Use 0 => random channel from 1-13
  ESP_wifiManager.setConfigPortalChannel(0);
  //////
  
#if !USE_DHCP_IP    
    // Set (static IP, Gateway, Subnetmask, DNS1 and DNS2) or (IP, Gateway, Subnetmask). New in v1.0.5
    // New in v1.4.0
    ESP_wifiManager.setSTAStaticIPConfig(WM_STA_IPconfig);
    //////
#endif

  // New from v1.1.1
#if USING_CORS_FEATURE
  ESP_wifiManager.setCORSHeader("Your Access-Control-Allow-Origin");
#endif

  // We can't use WiFi.SSID() in ESP32as it's only valid after connected.
  // SSID and Password stored in ESP32 wifi_ap_record_t and wifi_config_t are also cleared in reboot
  // Have to create a new function to store in EEPROM/SPIFFS for this purpose
  Router_SSID = ESP_wifiManager.WiFi_SSID();
  Router_Pass = ESP_wifiManager.WiFi_Pass();

  //Remove this line if you do not want to see WiFi password printed
  Serial.println("ESP Self-Stored: SSID = " + Router_SSID + ", Pass = " + Router_Pass);

  // SSID to uppercase
  ssid.toUpperCase();
  password = "My" + ssid;

  bool configDataLoaded = loadConfigData();

  if (configDataLoaded)
  {
    #if USE_ESP_WIFIMANAGER_NTP      
    if ( strlen(WM_config.TZ_Name) > 0 )
    {
      LOGERROR3(F("Saving current TZ_Name ="), WM_config.TZ_Name, F(", TZ = "), WM_config.TZ);

  #if ESP8266
      configTime(WM_config.TZ, "pool.ntp.org"); 
  #else
      //configTzTime(WM_config.TZ, "pool.ntp.org" );
      configTzTime(WM_config.TZ, "time.nist.gov", "0.pool.ntp.org", "1.pool.ntp.org");
  #endif  
    }
    else
    {
      Serial.println(F("Current Timezone is not set. Enter Config Portal to set."));
    } 
#endif
  }
  else
  {
    // From v1.1.0, Don't permit NULL password
    if ( (Router_SSID == "") || (Router_Pass == "") )
    {
      Serial.println(F("We haven't got any access point credentials, so get them now"));
  
      initialConfig = true;

      Serial.print(F("Starting configuration portal @ "));
    
#if USE_CUSTOM_AP_IP    
      Serial.print(APStaticIP);
#else
      Serial.print(F("192.168.4.1"));
#endif

#if defined(HTTP_PORT_TO_USE)
    Serial.print(F(":")); Serial.print(HTTP_PORT_TO_USE);
#endif

      Serial.print(F(", SSID = "));
      Serial.print(ssid);
      Serial.print(F(", PWD = "));
      Serial.println(password);

#if DISPLAY_STORED_CREDENTIALS_IN_CP
    // New. Update Credentials, got from loadConfigData(), to display on CP
    ESP_wifiManager.setCredentials(WM_config.WiFi_Creds[0].wifi_ssid, WM_config.WiFi_Creds[0].wifi_pw, 
                                   WM_config.WiFi_Creds[1].wifi_ssid, WM_config.WiFi_Creds[1].wifi_pw);
#endif

      // Starts an access point
      if (!ESP_wifiManager.startConfigPortal((const char *) ssid.c_str(), password.c_str()))
        Serial.println(F("Not connected to WiFi but continuing anyway."));
      else
        Serial.println(F("WiFi connected...yeey :)"));
  
      // Stored  for later usage, from v1.1.0, but clear first
      memset(&WM_config, 0, sizeof(WM_config));
      
      for (uint8_t i = 0; i < NUM_WIFI_CREDENTIALS; i++)
      {
        String tempSSID = ESP_wifiManager.getSSID(i);
        String tempPW   = ESP_wifiManager.getPW(i);
    
        if (strlen(tempSSID.c_str()) < sizeof(WM_config.WiFi_Creds[i].wifi_ssid) - 1)
          strcpy(WM_config.WiFi_Creds[i].wifi_ssid, tempSSID.c_str());
        else
          strncpy(WM_config.WiFi_Creds[i].wifi_ssid, tempSSID.c_str(), sizeof(WM_config.WiFi_Creds[i].wifi_ssid) - 1);
  
        if (strlen(tempPW.c_str()) < sizeof(WM_config.WiFi_Creds[i].wifi_pw) - 1)
          strcpy(WM_config.WiFi_Creds[i].wifi_pw, tempPW.c_str());
        else
          strncpy(WM_config.WiFi_Creds[i].wifi_pw, tempPW.c_str(), sizeof(WM_config.WiFi_Creds[i].wifi_pw) - 1);  
  
        // Don't permit NULL SSID and password len < MIN_AP_PASSWORD_SIZE (8)
        if ( (String(WM_config.WiFi_Creds[i].wifi_ssid) != "") && (strlen(WM_config.WiFi_Creds[i].wifi_pw) >= MIN_AP_PASSWORD_SIZE) )
        {
          LOGERROR3(F("* Add SSID = "), WM_config.WiFi_Creds[i].wifi_ssid, F(", PW = "), WM_config.WiFi_Creds[i].wifi_pw );
          wifiMulti.addAP(WM_config.WiFi_Creds[i].wifi_ssid, WM_config.WiFi_Creds[i].wifi_pw);
        }
      }

#if USE_ESP_WIFIMANAGER_NTP      
    String tempTZ   = ESP_wifiManager.getTimezoneName();

    if (strlen(tempTZ.c_str()) < sizeof(WM_config.TZ_Name) - 1)
      strcpy(WM_config.TZ_Name, tempTZ.c_str());
    else
      strncpy(WM_config.TZ_Name, tempTZ.c_str(), sizeof(WM_config.TZ_Name) - 1);

    const char * TZ_Result = ESP_wifiManager.getTZ(WM_config.TZ_Name);
    
    if (strlen(TZ_Result) < sizeof(WM_config.TZ) - 1)
      strcpy(WM_config.TZ, TZ_Result);
    else
      strncpy(WM_config.TZ, TZ_Result, sizeof(WM_config.TZ_Name) - 1);
         
    if ( strlen(WM_config.TZ_Name) > 0 )
    {
      LOGERROR3(F("Saving current TZ_Name ="), WM_config.TZ_Name, F(", TZ = "), WM_config.TZ);

#if ESP8266
      configTime(WM_config.TZ, "pool.ntp.org"); 
#else
      //configTzTime(WM_config.TZ, "pool.ntp.org" );
      configTzTime(WM_config.TZ, "time.nist.gov", "0.pool.ntp.org", "1.pool.ntp.org");
#endif
    }
    else
    {
      LOGERROR(F("Current Timezone Name is not set. Enter Config Portal to set."));
    }
#endif

      // New in v1.4.0
      ESP_wifiManager.getSTAStaticIPConfig(WM_STA_IPconfig);
      //////
      
      saveConfigData();
    }
    else
    {
      wifiMulti.addAP(Router_SSID.c_str(), Router_Pass.c_str());
    }
  }

  startedAt = millis();

  if (!initialConfig)
  {
    // Load stored data, the addAP ready for MultiWiFi reconnection
    if (!configDataLoaded)
      loadConfigData();

    for (uint8_t i = 0; i < NUM_WIFI_CREDENTIALS; i++)
    {
      // Don't permit NULL SSID and password len < MIN_AP_PASSWORD_SIZE (8)
      if ( (String(WM_config.WiFi_Creds[i].wifi_ssid) != "") && (strlen(WM_config.WiFi_Creds[i].wifi_pw) >= MIN_AP_PASSWORD_SIZE) )
      {
        LOGERROR3(F("* Add SSID = "), WM_config.WiFi_Creds[i].wifi_ssid, F(", PW = "), WM_config.WiFi_Creds[i].wifi_pw );
        wifiMulti.addAP(WM_config.WiFi_Creds[i].wifi_ssid, WM_config.WiFi_Creds[i].wifi_pw);
      }
    }

    if ( WiFi.status() != WL_CONNECTED ) 
    {
      Serial.println(F("ConnectMultiWiFi in setup"));
     
      connectMultiWiFi();
    }
  }

  Serial.print(F("After waiting "));
  Serial.print((float) (millis() - startedAt) / 1000L);
  Serial.print(F(" secs more in setup(), connection result is "));

  if (WiFi.status() == WL_CONNECTED)
  {
    Serial.print(F("connected. Local IP: "));
    Serial.println(WiFi.localIP());
  }
  else
    Serial.println(ESP_wifiManager.getStatus(WiFi.status()));

  //SERVER INIT
  //list directory
  server.on("/list", HTTP_GET, handleFileList);
  
  //load editor
  server.on("/edit", HTTP_GET, []() 
  {
    if (!handleFileRead("/edit.htm")) 
    {
      server.send(404, "text/plain", "FileNotFound");
    }
  });
  
  //create file
  server.on("/edit", HTTP_PUT, handleFileCreate);
  
  //delete file
  server.on("/edit", HTTP_DELETE, handleFileDelete);
  
  //first callback is called after the request has ended with all parsed arguments
  //second callback handles file uploads at that location
  server.on("/edit", HTTP_POST, []() 
  {
    server.send(200, "text/plain", "");
  }, handleFileUpload);

  //called when the url is not defined here
  //use it to load content from SPIFFS
  server.onNotFound([]() 
  {
    if (!handleFileRead(server.uri())) 
    {
      server.send(404, "text/plain", "FileNotFound");
    }
  });

  //get heap status, analog input value and all GPIO statuses in one json call
  server.on("/all", HTTP_GET, []() 
  {
    String json = "{";
    json += "\"heap\":" + String(ESP.getFreeHeap());
    json += ", \"analog\":" + String(analogRead(A0));
    json += ", \"gpio\":" + String((uint32_t)(0));
    json += "}";
    server.send(200, "text/json", json);
    json = String();
  });

  server.begin();
  
  Serial.print(F("HTTP server started @ "));
  Serial.println(WiFi.localIP());

  MDNS.begin(host);
  // Add service to MDNS-SD
  MDNS.addService("http", "tcp", HTTP_PORT);

  Serial.print(F("Open http://"));
  Serial.print(host);
  Serial.println(F(".local/edit to see the file browser"));
}

void loop() 
{ 
  server.handleClient();

  // this is just for checking if we are alive and connected to WiFi
  check_status();
}