#include <WiFi.h>
#include <WebServer.h>
#include <SPIFFS.h>
#include <WebSocketsServer.h>
#include <cbuf.h>

unsigned char incomingByte,length_data,checksum_recv,checksum_calc = 0,id,length_value,value; // variável
unsigned char bufferpayload[64];
int pos=0,j=0,k=0;

typedef enum {WaitingStartByte,Framelength,Payload,CheckSum,Value} state_machine_t;
state_machine_t data_state_s;

WebServer server;
char* ssid = "AP";
char* password = "";

// hold uploaded file
File fsUploadFile;

// websockets server for handling messages sent by the client
WebSocketsServer webSocket = WebSocketsServer(81);

void setup()
{
  // Format the file system in case it hasn't been done before
  SPIFFS.begin(true);
  // Start access point
  WiFi.softAP(ssid, password);

  Serial.begin(115200);
  // Print our IP address
  Serial.println();
  Serial.println("AP running");
  Serial.print("My IP address: ");
  Serial.println(WiFi.softAPIP());

  server.on("/",handleIndexFile);

  // handle JavaScript files
  server.on("/smoothie.js",handleJS1File);
  server.on("/smoothie-functions.js",handleJS2File);
  server.on("/websocket.js",handleJS3File);
  server.on("/ui.js",handleJS4File);

  // handle CSS files
  server.on("/pure-min.css",handleCSS1file);
  server.on("/side-menu.css",handleCSS2file);

  // list available files
  server.on("/list", HTTP_GET, handleFileList);
  // handle file upload
  server.on("/upload", HTTP_POST, [](){
    server.send(200, "text/plain", "{\"success\":1}");
  }, handleFileUpload);


  server.begin();
  webSocket.begin();
}

void loop()
{

 webSocket.loop();
 server.handleClient();
 //data_SM();

}

// Update file handling functions for the ESP32
void handleFileUpload() {
  HTTPUpload& upload = server.upload();
  if (upload.status == UPLOAD_FILE_START) {
    String filename = upload.filename;
    if (!filename.startsWith("/")) {
      filename = "/" + filename;
    }
    Serial.print("handleFileUpload Name: "); Serial.println(filename);
    fsUploadFile = SPIFFS.open(filename, "w");
    filename = String();
  } else if (upload.status == UPLOAD_FILE_WRITE) {
    //Serial.print("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("handleFileUpload Size: "); Serial.println(upload.totalSize);
  }
}

void handleIndexFile()
{
  File file = SPIFFS.open("/index.html","r");
  server.streamFile(file, "text/html");
  file.close();
}

//Handle JavaScript files
void handleJS1File()
{
  File js = SPIFFS.open("/smoothie.js","r");
  server.streamFile(js, "text/javascript");
  js.close();
}
void handleJS2File()
{
  File js = SPIFFS.open("/smoothie-functions.js","r");
  server.streamFile(js, "text/javascript");
  js.close();
}
void handleJS3File()
{
  File js = SPIFFS.open("/websocket.js","r");
  server.streamFile(js, "text/javascript");
  js.close();
}
void handleJS4File()
{
  File js = SPIFFS.open("/ui.js","r");
  server.streamFile(js, "text/javascript");
  js.close();
}

void handleCSS1file()
{
  File css = SPIFFS.open("/pure-min.css","r");
  server.streamFile(css, "text/css");
  css.close();
}
void handleCSS2file()
{
  File css = SPIFFS.open("/side-menu.css","r");
  server.streamFile(css, "text/css");
  css.close();
}
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 = SPIFFS.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 += "\"}";
          file = root.openNextFile();
      }
  }
  output += "]";
  server.send(200, "text/json", output);
}

bool exists(String path){
  bool yes = false;
  File file = SPIFFS.open(path, "r");
  if(!file.isDirectory()){
    yes = true;
  }
  file.close();
  return yes;
}

void data_SM(void){

  switch(data_state_s){

    case WaitingStartByte:
      checksum_calc = 0;

      if (Serial.available() > 0) {
        incomingByte == Serial.read();
        if(incomingByte = 170){
          data_state_s = Framelength;
        }
      }
      break;

    case Framelength:
      if (Serial.available() > 0) {
        length_data = Serial.read();
        data_state_s = Payload;
      }

      break;

    case Payload:

      if (Serial.available() > 0) {

         bufferpayload[pos] = Serial.read();  //reads payload to buffer

         checksum_calc += bufferpayload[pos]; //calculate checksum

        if(pos == (length_data-1)){
          pos=0;
          data_state_s = CheckSum;
        }
        else{
          pos++;
          data_state_s = Payload;
        }
      }


      break;

    case CheckSum:
        if (Serial.available() > 0) {
          checksum_recv = Serial.read();

        }


        if(checksum_recv == checksum_calc){   //payload correto
          handlepayload();
          data_state_s = WaitingStartByte;
        }

        else{
          Serial.print("recebido:");
          Serial.println(checksum_recv);
          Serial.print("recebido:");
          Serial.println(checksum_calc);
          Serial.println("checksum não correto");
          data_state_s = WaitingStartByte;
        }

      break;

    default:

      break;
  }
}

void handlepayload(void){

String output = "{";
int i = 0;

  while(i<length_data){                //Percorre o buffer todo
    value = 0;
    id = bufferpayload[i];
    output += "\"";
    output += id;
    output += "\":";

    i++;
    length_value = bufferpayload[i];
    i++;
    k=i;

    while(k<(i+length_value)){
      value += bufferpayload[k];
      k++;
    }

    output += "\"";
    output += value;
    output += "\"";
    i=k;

      if(i != length_data){
      output += ",";
      }
  }
    output += "}";

    webSocket.broadcastTXT(output);
    Serial.println(output);
}