#include <WiFi.h>             
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

#include "utf8coder.hpp"
#include "ddr2unicode.h"
#include "unicode2ddr.h"

// hardware specific includes
#include <Adafruit_NeoPixel.h>
//#include "esp32wroom_board.h" 
#include "M5StampS3_board.h" // in the EFS26 connector
#include "neopixel.hpp"

#define CHATAI 1
#define KOBOLD 2
#define OPENAI 3
#define HOST CHATAI
#include "aimodelconfig.h"
#include "credentials.h"
#define PC_BAUD 115200

class ErikaSchreibmaschine
{
  private:
  int _txPin, _rxPin, _rtsPin, _baud;
  bool _wait = false;

  #ifdef SWSERIAL
  EspSoftwareSerial::UART serconn;
  #else
  #define serconn HWSERIAL  
  #endif
  size_t num_spalten;
  size_t spalte;

  public: 
  ErikaSchreibmaschine(int rxPin, int txPin, int rtsPin, int baud)
   #ifdef SWSERIAL
   :spalte(0), num_spalten(75), serconn(_rxPin, _txPin) // RX, TX
   #else
   :spalte(0), num_spalten(75) // end of line "beep" here
   #endif
  {
    _rtsPin=rtsPin;
    _txPin=txPin;
    _rxPin=rxPin;
    _baud=baud;
  }

  bool Init()
  {
    pinMode(_rtsPin, INPUT_PULLUP);
    #ifdef SWSERIAL
    serconn.begin(_baud, SWSERIAL_8N1, _rxPin, _txPin, false);
    #else
    serconn.begin(_baud);
    #endif
    
    //serconn.setTimeout(0);
    //serconn.begin(_baud);
    //return ClearBuf();
    return true;
  }

  bool ClearBuf()
  {
    // alles weglesen - puffer leeren
    bool r =false;
    while (serconn.read() > 0) 
      r=true;
    if(r)
    {  
      Serial.println("Tastaturpuffer geleert.");
    }
    return r;
  }

  bool CharAvailable()
  {
    return serconn.available();
  }

  char16_t ReadC()
  {
     if(CharAvailable())
     {
      int znummer = serconn.read();
      Serial.print(znummer,16);
      char zeichen = ddr2uni[znummer];
      Serial.print(zeichen,16);
      return zeichen;
     }
     return 0;
  }

// Liest eine ganze Zeile bis \n und liefert das als utf-8 kodierten string
  String ReadLine()
  {
    String eingabestring;
    std::vector<char16_t> uniZeichenfolge;
    while(true)
    {
      if(CharAvailable())
      {
        int ddrZeichen = serconn.read();
        // breaker for while loop
        if(ddrZeichen == 119) // newline
        {
          break;
        }

        switch (ddrZeichen)
        {
          case 114:  // Backtab 
            { 
              if(uniZeichenfolge.size() > 0) //this does not work as expected
              {
                uniZeichenfolge.pop_back();
              }
            break; 
            }                          
          case 117: { break; }                           // Einzug ignorieren
          case 118: { break; }                           // Papier zurück ignorieren
          case 119: { break; }                           // Newline hier ignorieren
          case 121: { break; }                           // Tab ignorieren
          default: 
          {                                   // Druckbare Zeichen anhängen 
            if (ddrZeichen > 127) {} // nothing - kann nicht sein  // it can be ;-) it can be a command code!
            else // gutes Zeichen auf der Erikatastatur
            {
              char16_t uniZeichen = ddr2uni[ddrZeichen]; // a bit dangerous before where it was (8 bit in for 7 bits lookup)
              uniZeichenfolge.push_back(uniZeichen);
            }
            break;
          }
        };
      }
      else
      {
        // däumchen drehen
        delay(100);
      }
    }

    // Tastatur in unicode eingaben sind im vector
    // codepoints in utf-8 bytefolge verwandeln.
    for (size_t i = 0; i < uniZeichenfolge.size(); i++)
    {
        std::vector<uint8_t> utfbytes = numberToUtf8(uniZeichenfolge[i]);
        String s(utfbytes.data(), utfbytes.size());
        eingabestring.concat(s);     
    }
    return eingabestring;  
  }

  /*void WriteC(char zeichen) //char16_t
  {
    Serial.printf("WriteC: %c\n", zeichen);
    if(zeichen=='@')
    {
      serconn.write((char)uni2ddr['O']);
      serconn.write(114); // Backtab
      serconn.write((char)uni2ddr['a']);
      spalte++;
      return;
    }
    else {
      if (zeichen < 128) {
        serconn.write(isolatin12ddr[zeichen]);
        spalte++;
      }
      else {
        Serial.print(zeichen);
        if      (zeichen == 0xc39f ) {serconn.write(0x47); }//ß
        else if (zeichen == 0xc3a4 ) {serconn.write(0x65); }//ä
        else if (zeichen == 0xc3b6 ) {serconn.write(0x66); }//ö
        else if (zeichen == 0xc3bc ) {serconn.write(0x67); }//ü
        else if (zeichen == 0xc384 ) {serconn.write(0x3F); }//Ä
        else if (zeichen == 0xc396 ) {serconn.write(0x3C); }//Ö
        else if (zeichen == 0xc39c ) {serconn.write(0x3A); }//Ü
        else if (zeichen == 0xc2b0 ) {serconn.write(0x39); }//°
        else if (zeichen == 0xc2a7 ) {serconn.write(0x3D); }//§
        else {serconn.write(27);}
      }
      spalte++;
    }
    //char z = (char)uni2ddr[c];
    //serconn.write(z);
    //spalte++;
  }*/

  void Write(String wstring)
  {    
    int i = 0;
    int length = wstring.length();
    SetDuplexMode();

    while (i <= length)
    {
      if (IsReady()) {        
        int zeichen = wstring[i];

        int charsToSpace = wstring.indexOf(' ', i) - i; //how far is the next space away?

        if (charsToSpace > 0) {
          if ((spalte + charsToSpace) >= num_spalten) { //next word will not fit on the remaining space of the line
            NewLine();
          }
        }

        if (spalte >= num_spalten) {
          NewLine();
        }

      //TODO: avoid "\n " what would create a space as first character on new line

        if(zeichen=='@')
        {
          serconn.write(uni2ddr['O']);
          serconn.write(114); // Backtab
          serconn.write(uni2ddr['a']);
        }
        else {
          if (zeichen < 128) {
            if (zeichen == '\n') {
              NewLine();
            }
            else {
              serconn.write(uni2ddr[zeichen]);
            }
          }
          else {
            i++;
            uint8_t zeichen2 = wstring[i];//utf8chars[i];
            zeichen = (zeichen<<8) | zeichen2;

            if      (zeichen == 0xc39f ) {serconn.write(0x47); }//ß
            else if (zeichen == 0xc3a4 ) {serconn.write(0x65); }//ä
            else if (zeichen == 0xc3b6 ) {serconn.write(0x66); }//ö
            else if (zeichen == 0xc3bc ) {serconn.write(0x67); }//ü
            else if (zeichen == 0xc384 ) {serconn.write(0x3F); }//Ä
            else if (zeichen == 0xc396 ) {serconn.write(0x3C); }//Ö
            else if (zeichen == 0xc39c ) {serconn.write(0x3A); }//Ü
            else if (zeichen == 0xc2b0 ) {serconn.write(0x39); }//°
            else if (zeichen == 0xc2a7 ) {serconn.write(0x3D); }//§
            else {serconn.write(27);} // write an asteriks * for any unsupported UTF char
          }
          
        }
        spalte++;
        i++;
        _wait = true;
        delay(50);  // RTS will not change stange instantly 
      }
      else {
        delay(10);
      }
    }
    SetSimplexMode();
  }

  void WriteLn(String wstring)
  {
    Write(wstring);
    NewLine();
  }

  void NewLine()
  {
    serconn.write(uni2ddr['\n']);
    //serconn.write(ascii2ddr['\r']);
    spalte = 0;
  }

  // Maschine bereit für nächstes Zeichen
  bool IsReady()
  {
    int rtsState = digitalRead(_rtsPin);
    if (rtsState == LOW) {
        neopixelShowReady();  // I know, bad style...
    }
    else {
        neopixelShowBusy();  // I know, bad style...
    }
    return rtsState == LOW; 
  }

  void writeCommand(int commandCode) {
    if(IsReady()) {
      serconn.write(commandCode);
      delay(100);
    }
  }

  /*
  Trennmode aktivieren (Trennung von Tastatur und Druckwerk)
  Duplexbetrieb: Alle Tasteninformationen werden nur nach TxD ausgegeben und
  nur die von RxD kommenden gelangen zum Druck (Korr, CREL und CRL sind nicht wirksam!)
  */ 
  void SetDuplexMode(){
    delay(500);
    writeCommand(0x91);
    delay(100);
  }

  /*
  Trennmode aufheben
  Simplexbetrieb: Alle Tasteninformationen werden gedruckt
  */
  void SetSimplexMode(){
    delay(1000);
    writeCommand(0x92);
    delay(100);
  }

};

//int max_tokens = 356;          // Für längere Antworten erhöhen
//char Nachricht_array[6096];    // Bei größeren max_tokens das Nachricht_array auch vergrößern

// Instantiiere die Schreibmaschine
ErikaSchreibmaschine erika(ERIKA_RX, ERIKA_TX, RTS_PIN, ERIKA_BAUD);

void WiFiEvent(WiFiEvent_t event) {
    Serial.printf("[WiFi-event] event: %d\n", event);

    switch (event) {
        case ARDUINO_EVENT_WIFI_READY: 
            Serial.println("WiFi interface ready");
            break;
        case ARDUINO_EVENT_WIFI_SCAN_DONE:
            Serial.println("Completed scan for access points");
            break;
        case ARDUINO_EVENT_WIFI_STA_START:
            Serial.println("WiFi client started");
            Serial.println("Connected to access point");
            neopixel.setPixelColor(0, neopixel.Color(0, 0, 255));
            neopixel.show();
            break;
        case ARDUINO_EVENT_WIFI_STA_STOP:
            Serial.println("WiFi clients stopped");
            break;
        case ARDUINO_EVENT_WIFI_STA_CONNECTED:
            Serial.println("Connected to access point");
            neopixel.setPixelColor(0, neopixel.Color(0, 255, 0));
            neopixel.show();
            break;
        case ARDUINO_EVENT_WIFI_STA_DISCONNECTED:
            Serial.println("Disconnected from WiFi access point");
            neopixel.setPixelColor(0, neopixel.Color(255, 0, 0));
            neopixel.show();
            break;
        case ARDUINO_EVENT_WIFI_STA_AUTHMODE_CHANGE:
            Serial.println("Authentication mode of access point has changed");
            break;
        case ARDUINO_EVENT_WIFI_STA_GOT_IP:
            Serial.print("Obtained IP address: ");
            Serial.println(WiFi.localIP());
            break;
        case ARDUINO_EVENT_WIFI_STA_LOST_IP:
            Serial.println("Lost IP address and IP address is reset to 0");
            break;
        case ARDUINO_EVENT_WIFI_AP_STACONNECTED:
            Serial.println("Client connected");
            break;
        case ARDUINO_EVENT_WIFI_AP_STADISCONNECTED:
            Serial.println("Client disconnected");
            break;
        case ARDUINO_EVENT_WIFI_AP_STAIPASSIGNED:
            Serial.println("Assigned IP address to client");
            break;
        case ARDUINO_EVENT_WIFI_AP_PROBEREQRECVED:
            Serial.println("Received probe request");
            break;
        case ARDUINO_EVENT_WIFI_AP_GOT_IP6:
            Serial.println("AP IPv6 is preferred");
            break;
        case ARDUINO_EVENT_WIFI_STA_GOT_IP6:
            Serial.println("STA IPv6 is preferred");
            break;
        default: break;
    }
}

void setup()
{
  delay(1000);
  Serial.begin(115200);
  delay(1000);
  Serial.println("geht los ...");
  neopixelInit();
  erika.Init();
  // Mit dem WLan verbinden 
  WiFi.mode(WIFI_STA); 
  WiFi.onEvent(WiFiEvent);
  if (password != "") {
    WiFi.begin(ssid, password);
  }
  else {
    WiFi.begin(ssid);
  }

  WiFi.setAutoReconnect(true);
  delay(3000);

  erika.NewLine();
  erika.WriteLn(helloMsg);
  erika.NewLine();

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


void loop()
{
  // EINGABE ###############################################################################
  String eingabe= erika.ReadLine(); //waits until \n

  Serial.println(eingabe);
  
  // EINGABE ENDE ##########################################################################

  // AUSGABE ###############################################################################

  if (eingabe.length() == 0) {
    Serial.println("leere Zeile");
  }
  else {
    // Request
    
    Serial.println();
    Serial.print("Sende API Request an: "); Serial.println(url);

    WiFiClientSecure client;
    client.setInsecure();   // we do not check certificates or checksums

    JsonDocument jsonaiapi;
    jsonaiapi["model"] = model;
    jsonaiapi["messages"][0]["role"] = "system";
    jsonaiapi["messages"][0]["content"] = systemPrompt;
    jsonaiapi["messages"][1]["role"] = "user";
    jsonaiapi["messages"][1]["content"] = eingabe;
    jsonaiapi["temperature"] = 0.7;

    String request;
    serializeJson(jsonaiapi, request);
    //eingabe.replace("\"", "\\\""); // sanitize hyphens before we encode the input in JSON      
    //request = "{\"model\":\"" + model + "\",\"messages\": [{\"role\":\"system\",\"content\":\"You are a helpful assistant\"},{\"role\":\"user\",\"content\":\"" + eingabe + "\"}], \"temperature\":0.7}";          
    //request = "{\"model\":\"" + model + "\",\"messages\": [{\"role\":\"system\",\"content\":\"" + systemPrompt + "\"},{\"role\":\"user\",\"content\":\"" + eingabe + "\"}], \"temperature\":0.7}";

    Serial.print("request: "); Serial.println(request);

    HTTPClient http;
    http.setTimeout(60000); //server response might take a while

    http.addHeader("Content-Type", "application/json; charset=utf-8");
    http.addHeader("Authorization", authMode + " " + authToken);
    http.addHeader("Accept", "application/json");

    neopixelShowConnect();  

    if (http.begin(client, url)) {  // HTTPS
      Serial.print("[HTTPS] POST...\n");

      unsigned long millisStart = millis();

      int httpCode = http.POST(request);

      // httpCode will be negative on error
      if (httpCode > 0) {
        // HTTP header has been send and Server response header has been handled
        Serial.printf("[HTTPS] POST... code: %d\n", httpCode);

        // file found at server
        if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {
          unsigned long millisDuration = millis()-millisStart;
          neopixelShowReady();
          String payload = http.getString();
          Serial.println(payload);

          JsonDocument jsondoc;
          deserializeJson(jsondoc, payload);
          payload.clear();            
          Serial.println("geparst: ");
          
          http.end();

          String antwort = jsondoc["choices"][0]["message"]["content"];
          Serial.println(antwort);

          erika.NewLine();
          erika.WriteLn(antwort);

          WiFiClientSecure clientlog;
          clientlog.setInsecure();  

          HTTPClient httplog;
          httplog.setTimeout(10000);
          httplog.addHeader("Content-Type", "application/json; charset=utf-8");  
          //httplog.addHeader("Accept", "application/json; charset=UTF-8");

          if (httplog.begin(clientlog, logURL)) {  // HTTPS
            Serial.print("[HTTPS] POST Logging ...\n");

            JsonDocument jsonlog;
            jsonlog["request"] = eingabe;
            jsonlog["response"] = antwort;
            jsonlog["systemprompt"] = systemPrompt;
            jsonlog["model"] = model;
            jsonlog["duration"] = millisDuration;
            
            //String logString = "{\"request\":\"" + eingabe + "\", \"response\":\"" + antwort + "\", \"systemprompt\":\"" + systemPrompt + "\", \"model\":\"" + model + "\", \"duration\":" + millisDuration + "}"; 
            String logString;
            serializeJson(jsonlog, logString);

            Serial.println(logString);

            int httpCodeLog = httplog.POST(logString);

            // httpCode will be negative on error
            if (httpCodeLog > 0) {
              Serial.println("geloggt");
               httplog.end();
            } else {
              Serial.printf("[HTTPS] POST Logging... failed, error: %s\n", http.errorToString(httpCodeLog).c_str());
              httplog.end();
            }
          } else {
            Serial.printf("[HTTPS] Unable to connect to log\n");            
          }
        }
      } else {
        Serial.printf("[HTTPS] POST... failed, error: %s\n", http.errorToString(httpCode).c_str());
        http.end();
        neopixelShowFail();
        delay(1000);
      }
    } else {
      Serial.printf("[HTTPS] Unable to connect\n");
      neopixelShowFail();
      delay(1000);
    }

    Serial.println("Request+response fertig");
    erika.WriteLn("======");
    erika.NewLine();
    // AUSGABE ENDE ##########################################################################  
  }
}