/****************************************************************************************************************************
  AsyncHTTPRequest_ESP_WiFiManager.ino - Dead simple AsyncHTTPRequest for ESP8266, ESP32 and currently STM32 with built-in LAN8742A Ethernet
  
  For ESP8266, ESP32 and STM32 with built-in LAN8742A Ethernet (Nucleo-144, DISCOVERY, etc)
  
  AsyncHTTPRequest_Generic is a library for the ESP8266, ESP32 and currently STM32 run built-in Ethernet WebServer
  
  Based on and modified from asyncHTTPrequest Library (https://github.com/boblemaire/asyncHTTPrequest)
  
  Built by Khoi Hoang https://github.com/khoih-prog/AsyncHTTPRequest_Generic
  Licensed under MIT license
  
  Copyright (C) <2018>  <Bob Lemaire, IoTaWatt, Inc.>
  This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License 
  as published bythe Free Software Foundation, either version 3 of the License, or (at your option) any later version.
  This program 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 General Public License for more details.
  You should have received a copy of the GNU General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.  
 
  Version: 1.0.0
  
  Version Modified By   Date      Comments
  ------- -----------  ---------- -----------
  1.0.0    K Hoang     14/09/2020 Initial coding to add support to STM32 using built-in Ethernet (Nucleo-144, DISCOVERY, etc).
 *****************************************************************************************************************************/
//************************************************************************************************************
//
// There are scores of ways to use AsyncHTTPRequest.  The important thing to keep in mind is that
// it is asynchronous and just like in JavaScript, everything is event driven.  You will have some
// reason to initiate an asynchronous HTTP request in your program, but then sending the request
// headers and payload, gathering the response headers and any payload, and processing
// of that response, can (and probably should) all be done asynchronously.
//
// In this example, a Ticker function is setup to fire every 300 seconds to initiate a request.
// Everything is handled in AsyncHTTPRequest without blocking.
// The callback onReadyStateChange is made progressively and like most JS scripts, we look for
// readyState == 4 (complete) here.  At that time the response is retrieved and printed.
//
// Note that there is no code in loop().  A code entered into loop would run oblivious to
// the ongoing HTTP requests.  The Ticker could be removed and periodic calls to sendRequest()
// could be made in loop(), resulting in the same asynchronous handling.
//
// For demo purposes, debug is turned on for handling of the first request.  These are the
// events that are being handled in AsyncHTTPRequest.  They all begin with Debug(nnn) where
// nnn is the elapsed time in milliseconds since the transaction was started.
//
//*************************************************************************************************************

#if !( defined(ESP8266) ||  defined(ESP32) )
  #error This code is intended to run on the ESP8266 or ESP32 platform! Please check your Tools->Board setting.
#endif

// Level from 0-4
#define ASYNC_HTTP_DEBUG_PORT     Serial
#define _ASYNC_HTTP_LOGLEVEL_     1    

// 300s = 5 minutes to not flooding
#define HTTP_REQUEST_INTERVAL     300

//Ported to ESP32
#ifdef ESP32
  #include <esp_wifi.h>
  #include <WiFi.h>
  #include <WiFiClient.h>

  // From v1.1.1
  #include <WiFiMulti.h>
  WiFiMulti wifiMulti;

  #define USE_SPIFFS      true

  #if 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 ESP_getChipId()   ((uint32_t)ESP.getEfuseMac())

  #define LED_BUILTIN       2
  #define LED_ON            HIGH
  #define LED_OFF           LOW

#else

  #include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino
  //needed for library
  #include <DNSServer.h>

  // From v1.1.1
  #include <ESP8266WiFiMulti.h>
  ESP8266WiFiMulti wifiMulti;

  #define USE_LITTLEFS      true
  
  #if USE_LITTLEFS
    #include <LittleFS.h>
    FS* filesystem =      &LittleFS;
    #define FileFS        LittleFS
    #define FS_Name       "LittleFS"
  #else
    FS* filesystem =      &SPIFFS;
    #define FileFS        SPIFFS
    #define FS_Name       "SPIFFS"
  #endif
  //////
  
  #define ESP_getChipId()   (ESP.getChipId())
  
  #define LED_ON      LOW
  #define LED_OFF     HIGH
#endif

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

// From v1.1.1
// You only need to format the filesystem once
//#define FORMAT_FILESYSTEM       true
#define FORMAT_FILESYSTEM         false

#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

typedef struct
{
  WiFi_Credentials  WiFi_Creds [NUM_WIFI_CREDENTIALS];
} 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     true

// 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     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 || ( defined(USE_STATIC_IP_CONFIG_IN_CP) && !USE_STATIC_IP_CONFIG_IN_CP ) )
  // Use DHCP
  #warning Using DHCP IP
  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
  #warning Using static IP
  
  #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);

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

#define HTTP_PORT           80

AsyncWebServer webServer(HTTP_PORT);
DNSServer dnsServer;

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

AsyncHTTPRequest request;
Ticker ticker;

void heartBeatPrint(void)
{
  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(" "));
  }
}

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

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

  static ulong current_millis;

#define WIFICHECK_INTERVAL    1000L
#define HEARTBEAT_INTERVAL    10000L

  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;
  }
}

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

  if (file)
  {
    file.readBytes((char *) &WM_config, sizeof(WM_config));
    file.close();
    LOGERROR(F("OK"));
  }
  else
  {
    LOGERROR(F("failed"));
  }
}
    
void saveConfigData(void)
{
  File file = FileFS.open(CONFIG_FILENAME, "w");
  LOGERROR(F("SaveWiFiCfgFile "));

  if (file)
  {
    file.write((uint8_t*) &WM_config, sizeof(WM_config));
    file.close();
    LOGERROR(F("OK"));
  }
  else
  {
    LOGERROR(F("failed"));
  }
}

uint8_t connectMultiWiFi(void)
{
#if ESP32
  // For ESP32, this better be 0 to shorten the connect time
  #define WIFI_MULTI_1ST_CONNECT_WAITING_MS       0
#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           100L
  
  uint8_t status;

  LOGERROR(F("ConnectMultiWiFi with :"));
  
  if ( (Router_SSID != "") && (Router_Pass != "") )
  {
    LOGERROR3(F("* Flash-stored Router_SSID = "), Router_SSID, F(", Router_Pass = "), Router_Pass );
  }

  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    
  #if USE_CONFIGURABLE_DNS  
    // Set static IP, Gateway, Subnetmask, DNS1 and DNS2. New in v1.0.5
    WiFi.config(stationIP, gatewayIP, netMask, dns1IP, dns2IP);  
  #else
    // Set static IP, Gateway, Subnetmask, Use auto DNS1 and DNS2.
    WiFi.config(stationIP, gatewayIP, netMask);
  #endif 
#endif

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

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

    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"));

  return status;
}

void sendRequest() 
{
  if (request.readyState() == readyStateUnsent || request.readyState() == readyStateDone)
  {
    //request.open("GET", "http://worldtimeapi.org/api/timezone/Europe/London.txt");
    request.open("GET", "http://worldtimeapi.org/api/timezone/America/Toronto.txt");
    request.send();
  }
}

void requestCB(void* optParm, AsyncHTTPRequest* request, int readyState) 
{
  if (readyState == readyStateDone) 
  {
    Serial.println("\n**************************************");
    Serial.println(request->responseText());
    Serial.println("**************************************");
    
    request->setDebug(false);
  }
}

void setup()
{
  // put your setup code here, to run once:
  Serial.begin(115200);
  while (!Serial);
  
  Serial.print("\nStarting AsyncHTTPRequest_ESP_WiFiManager using " + String(FS_Name));
  Serial.println(" on " + String(ARDUINO_BOARD));

  if (FORMAT_FILESYSTEM) 
    FileFS.format();

  // Format FileFS if not yet
#ifdef ESP32
  if (!FileFS.begin(true))
#else
  if (!FileFS.begin())
#endif  
  {
    Serial.print(FS_Name);
    Serial.println(F(" failed! AutoFormatting."));
    
#ifdef ESP8266
    FileFS.format();
#endif
  }

  unsigned long startedAt = millis();

  //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
  //ESPAsync_WiFiManager ESPAsync_wifiManager(&webServer, &dnsServer);
  // Use this to personalize DHCP hostname (RFC952 conformed)
  ESPAsync_WiFiManager ESPAsync_wifiManager(&webServer, &dnsServer, "AutoConnectAP");

  ESPAsync_wifiManager.setDebugOutput(true);

  //reset settings - for testing
  //ESPAsync_wifiManager.resetSettings();

  //set custom ip for portal
  ESPAsync_wifiManager.setAPStaticIPConfig(IPAddress(192, 168, 100, 1), IPAddress(192, 168, 100, 1), IPAddress(255, 255, 255, 0));

  ESPAsync_wifiManager.setMinimumSignalQuality(-1);

  // From v1.0.10 only
  // Set config portal channel, default = 1. Use 0 => random channel from 1-13
  ESPAsync_wifiManager.setConfigPortalChannel(0);
  //////
  
#if !USE_DHCP_IP    
  #if USE_CONFIGURABLE_DNS  
    // Set static IP, Gateway, Subnetmask, DNS1 and DNS2. New in v1.0.5
    ESPAsync_wifiManager.setSTAStaticIPConfig(stationIP, gatewayIP, netMask, dns1IP, dns2IP);  
  #else
    // Set static IP, Gateway, Subnetmask, Use auto DNS1 and DNS2.
    ESPAsync_wifiManager.setSTAStaticIPConfig(stationIP, gatewayIP, netMask);
  #endif 
#endif

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

  // We can't use WiFi.SSID() in ESP32 as 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 = ESPAsync_wifiManager.WiFi_SSID();
  Router_Pass = ESPAsync_wifiManager.WiFi_Pass();

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

  if (Router_SSID != "")
  {
    ESPAsync_wifiManager.setConfigPortalTimeout(120); //If no access point name has been previously entered disable timeout.
    Serial.println("Got stored Credentials. Timeout 120s");
  }
  else
  {
    Serial.println("No stored Credentials. No timeout");
  }

  String chipID = String(ESP_getChipId(), HEX);
  chipID.toUpperCase();

  // SSID and PW for Config Portal
  String AP_SSID = "ESP_" + chipID + "_AutoConnectAP";
  String AP_PASS = "MyESP_" + chipID;

  // From v1.1.0, Don't permit NULL password
  if ( (Router_SSID == "") || (Router_Pass == "") )
  {
    Serial.println("We haven't got any access point credentials, so get them now");

    initialConfig = true;

    // Starts an access point
    //if (!ESPAsync_wifiManager.startConfigPortal((const char *) ssid.c_str(), password))
    if ( !ESPAsync_wifiManager.startConfigPortal(AP_SSID.c_str(), AP_PASS.c_str()) )
      Serial.println("Not connected to WiFi but continuing anyway.");
    else
      Serial.println("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 = ESPAsync_wifiManager.getSSID(i);
      String tempPW   = ESPAsync_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);
      }
    }

    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
    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("ConnectMultiWiFi in setup");
     
      connectMultiWiFi();
    }
  }

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

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

  request.setDebug(false);
  
  request.onReadyStateChange(requestCB);
  ticker.attach(HTTP_REQUEST_INTERVAL, sendRequest);

  // Send first request now
  sendRequest();
}

void loop()
{ 
  // put your main code here, to run repeatedly
  check_status();
}