//BEZDRAT ver2

#define noDEBUG

#define pinLCD      10
#define pinSetup    13
#define btnSelect   0x01 //tlacitka
#define btnLeft     0x02
#define btnRight    0x03
#define btnUp       0x04
#define btnDown     0x05
#define btnSelect2  0x81 //tlacitka s dlouhym stiskem
#define btnLeft2    0x82
#define btnRight2   0x83
#define btnUp2      0x84
#define btnDown2    0x85
#define buflen       250

#include <LiquidCrystal.h>

#ifdef DEBUG
#define pinRX       11 
#define pinTX       12
#include <SoftwareSerial.h>
SoftwareSerial uart(pinRX, pinTX);
#endif

#ifndef DEBUG
#define uart Serial
#endif

LiquidCrystal lcd(8, 9, 4, 5, 6, 7); 

const char AT_M1[]   PROGMEM = "AT+M1";
const char AT_M2[]   PROGMEM = "AT+M2";
const char AT_MT[]   PROGMEM = "AT+MT";
const char AT_MF[]   PROGMEM = "AT+MF";
const char AT_QM[]   PROGMEM = "AT+QM";
const char AT_CM01[] PROGMEM = "AT+CM01";
const char AT_CM02[] PROGMEM = "AT+CM02";
const char AT_CM03[] PROGMEM = "AT+CM03";
const char AT_CB[]   PROGMEM = "AT+CB";
const char AT_CC[]   PROGMEM = "AT+CC";
const char AT_CD[]   PROGMEM = "AT+CD";
const char AT_AA04[] PROGMEM = "AT+AA04";
const char AT_AA05[] PROGMEM = "AT+AA05";
const char AT_AA06[] PROGMEM = "AT+AA06";
const char AT_AA07[] PROGMEM = "AT+AA07";
const char AT_CF[]   PROGMEM = "AT+CF";
const char AT_CE[]   PROGMEM = "AT+CE";
const char AT_MK[]   PROGMEM = "AT+MK";
const char AT_CZ[]   PROGMEM = "AT+CZ";
const char AT_QA[]   PROGMEM = "AT+QA";

char uartBuffer[buflen + 2];
char TS[] = "TS+";   
char MU[] = "MU+"; 
char ER[] = "ER+";  
bool disp, fileName;
byte seq, uartIndex, cmdIndex, currMode, currVol, KB;
unsigned long uartTime, sysTime, currFile, totalFiles, timeFile, elapsedFile;

#ifdef DEBUG
void _printBuffer() {
  Serial.print("buflen: "); Serial.println(uartIndex);
  for (byte i = 0; i < uartIndex; i++) {
    byte c = uartBuffer[i];
    Serial.print(char(c)); Serial.print(":"); Serial.print(c, HEX); Serial.print(" ");
    if (c == 0) Serial.println();
  }
}
#endif

void clearValues() {
  currFile = 0;  totalFiles = 0; timeFile = 0; elapsedFile = 0; currMode = 0;
  fileName = false;
}

//------------------------------------------------------------------------------------------

void showDisplay() {
  digitalWrite(pinLCD, HIGH); 
  disp = true; 
  seq = 1;  
}

void showMode() {
  lcd.setCursor(10, 0);
  for (byte i = 10; i < 16; i++) lcd.print(" ");
  lcd.setCursor(10, 0);
  switch (currMode) {
    case 1: lcd.clear(); lcd.print(F("Bluetooth")); break;
    case 2: lcd.print(F("   USB")); break;
    case 3: lcd.print(F("   TF")); break;
  }
}

void showM12() {
  lcd.setCursor(0, 0);
  for (byte i = 0; i < 10; i++) lcd.print(" ");
  lcd.setCursor(0, 0);
  lcd.print(currFile); lcd.print("/"); lcd.print(totalFiles);
}

void showTime(unsigned long t) {
  int h = t / 60;
  int m = t % 60;
  if (h < 100) lcd.print(" ");
  if (h < 10) lcd.print(" ");
  lcd.print(h); lcd.print(":"); 
  if (m < 10) lcd.print("0");
  lcd.print(m);  
}

void showMT() {
  lcd.setCursor(10, 0);
  for (byte i = 10; i < 16; i++) lcd.print(" ");
  lcd.setCursor(10, 0);
  if (timeFile) showTime(timeFile - elapsedFile); else showTime(elapsedFile);
}

void showStatus(char* stat, bool force) {
  if (force) showDisplay();
  lcd.setCursor(0, 1);
  for (byte i = 0; i < 16; i++) lcd.print(" ");
  lcd.setCursor(0, 1);
  lcd.print(stat);    
}

void showError(char* err) {
  showDisplay();
  lcd.setCursor(10, 0);
  for (byte i = 10; i < 16; i++) lcd.print(" ");
  lcd.setCursor(12, 0);
  lcd.print(err);
}

void showSys() {
  lcd.clear();
  showMode();
  lcd.setCursor(0, 1);
  lcd.print((millis() / 60000) + 1); lcd.print(" min; <"); lcd.print(currVol);
  delay(1000);
  clearValues();
}
//------------------------------------------------------------------------------------------

void flushData() {
  while (uart.available()) byte i = uart.read();
}

void sendCmd(const char* cmd) {
  char c[16];
  byte n = strlen_P(cmd);
  for (byte i = 0; i < n; i++) c[i] = pgm_read_byte_near(cmd + i);
  c[n] = '\0';
  flushData();
  uart.println(c);
  int w = 0;
  while (!uart.available()) { //cekani na odpoved
    delay(1);
    w++;
    if (w > 2048) {
      char e[] = "ER+A";
      showError(e);
      break;
    }
  }
 #ifdef DEBUG
  Serial.print(w); Serial.print("mS ---> "); Serial.println(c);
 #endif 
}

bool testValues() { //currFile, timeFile
  if (totalFiles == 0) {
    sendCmd(AT_M2);
    return true;
  }
  if (currFile == 0) {  
    sendCmd(AT_M1);
    return true;
  }
  if (timeFile == 0) {
    sendCmd(AT_MT);      
    return true;
  }
  if (!fileName) {
    sendCmd(AT_MF);
    return true;
  }  
  return false;
}

byte keyPressed() {
  if (analogRead(0) >= 750) return 0;
  uint8_t result = 0xff;
  unsigned long pressTime = 0;
  word n = 0; //analogRead(0);
  word p = 0;
  for (byte i = 0; i < 8; i++) {
    word k = analogRead(0);
    if (k < 750) {
      n += k;
      p++;
    }
    delay(8);
  }
  if (p < 8) return 0;
  n = n / p;
  if (n < 88) result = btnRight;  //Vpravo(RIGHT)
  if ((n >= 88) && (n < 150)) result = btnUp;  //Nahoru(UP)
  if ((n >= 150) && (n < 350)) result = btnDown;  //Dolu(DOWN)
  if ((n >= 350) && (n < 500)) result = btnLeft;   //Vlevo(LEFT)
  if ((n >= 500) && (n < 750)) result = btnSelect;  //Vyber(SELECT)
  if (result < 0xff) { // test dlouhy stisk
    unsigned long t = millis();
    bool w = true;
    while (analogRead(0) < 750) {
      pressTime = millis() - t;
      if (w && (pressTime > 1200))  {
        w = false;
        lcd.setCursor(14, 0);
        lcd.print(" *");
      }
    }  
    if (pressTime > 1200) result = result | 0x80; //byl dlouhy stisk //if (pressTime < 50) result = 0xff; //prilis kratky stisk
    #ifdef DEBUG
    Serial.print("readKey ------------------ "); Serial.print(result, HEX); 
    Serial.print("; analog: "); Serial.println(n); 
    #endif   
  }
  if (result == 0xff) result = 0;
  return result;
}

void selectMode() {
  byte oldMode = currMode;
  lcd.clear();//1234567890123456
  lcd.print(F("up: TF|down: USB"));
  lcd.setCursor(0, 1);
  lcd.print(F("left: Bluetooth"));
  unsigned long t = millis();
  do {
    byte k = keyPressed();
    if (k) 
      switch (k) {
        case btnUp:   currMode = 3; t = 0; break;
        case btnDown: currMode = 2; t = 0; break;
        case btnLeft: currMode = 1; t = 0; break;
        default:      t = 0; break;
      }
    
  } while ((millis() - t) < 8000);
  if (currMode != oldMode)
    switch (currMode) {
      case 1: sendCmd(AT_CM01); break;
      case 2: sendCmd(AT_CM02); break;
      case 3: sendCmd(AT_CM03); break;
    } 
  clearValues();
}

//------------------------------------------------------------------------------------------

bool evalMV(char* responseStr) { 
  char* p = strstr(responseStr, "QA+");
  if (p == NULL) return false;
  p += 3;
  currVol = strtoul(p, NULL, 10);  
  return true;
}

bool evalM1(char* responseStr) { 
  char* p = strstr(responseStr, "M1+");
  if (p == NULL) return false;
  p += 3;
  currFile = strtoul(p, NULL, 16);  
  return true;
}

bool evalM2(char* responseStr) { 
  char* p = strstr(responseStr, "M2+");
  if (p == NULL) return false;
  p += 3;
  totalFiles = strtoul(p, NULL, 16);
  return true;
}

bool evalMT(char* responseStr) { 
  char* p = strstr(responseStr, "MT+");
  if (p == NULL) return false;
  p += 3;
  timeFile = strtoul(p, NULL, 16);
  return true;
}

bool evalMK(char* responseStr) { 
  char* p = strstr(responseStr, "MK+");
  if (p == NULL) return false;
  p += 3;
  elapsedFile = strtoul(p, NULL, 16);
  return true;
}

bool evalMF(char* responseStr) { 
  char* p = strstr(responseStr, "MF+");
  if (p == NULL) return false;  
 #ifdef DEBUG
  Serial.println("evalMF"); Serial.println(p);
 #endif  
  char fname[48];
  fname[47] = '\0';
  fileName = true;
  p += 3;
  strncpy(fname, p, 47);
  p = fname;
 #ifdef DEBUG
  Serial.println(p);
 #endif  
  lcd.setCursor(0, 1);
  for (byte i = 0; i < 16; i++) lcd.print(" ");
  lcd.setCursor(0, 1); //p += 3;
  int n = strlen(p);
  if (n > 16)
    for (byte i = 1; i < 8; i++) 
      if (p[n - i] == '.') {
        p[n - i] = '\0'; //odrizne priponu
        break;
      }
 #ifdef DEBUG
  Serial.println(p);
 #endif  
  n = strlen(p);
  if (n > 16) {
    p[8] = '\0';
    lcd.print(p); lcd.print("~");
   #ifdef DEBUG
    Serial.println(p);
   #endif  
    p += (n - 7);
  } 
  lcd.print(p); 
 #ifdef DEBUG
  Serial.println(p); Serial.println("---");
 #endif  
  showDisplay();
  return true;
}

bool evalMode(char* responseStr) {
  byte cm = currMode;
  if (strcmp(responseStr, "QM+01") == 0) cm = 1;
  if (strcmp(responseStr, "QM+02") == 0) cm = 2;
  if (strcmp(responseStr, "QM+03") == 0) cm = 3;
  if (currMode != cm) {
    currMode = cm;
    return true;
  }
  return false;
}

unsigned long evalStatus(char* responseStr, char* pattern) {
  char* p = strstr(responseStr, pattern);
  if (p == NULL) return -1;
  p += 3;
  return strtoul(p, NULL, 16);;
}

char* responseItem() {
  char* result = NULL;
  if (cmdIndex < uartIndex) {
    result = &uartBuffer[cmdIndex];
    cmdIndex += (strlen(result) + 1);
  }
  return result;
}

void response() {
 #ifdef DEBUG
 _printBuffer();
 #endif
  cmdIndex = 0;
  char* responseStr;
  do {
    responseStr = responseItem();
    if (responseStr == NULL) break; 
   #ifdef DEBUG
    Serial.println(responseStr);
   #endif 
    if (evalMF(responseStr)) continue;
    if (evalMode(responseStr)) showMode();
    if (evalM1(responseStr)) showM12();
    if (evalM2(responseStr)) showM12();
    if (evalMT(responseStr)) showMT();
    if (evalMK(responseStr)) showMT();
    if (evalMV(responseStr)) ;
    switch (evalStatus(responseStr, TS)) {
      case 0: {char txt[] = "BT odpojen"; showStatus(txt, false);} break;
      case 1: {char txt[] = "BT pripojen"; showStatus(txt, true);} break;
      case 2: {char txt[] = "BT hraje"; showStatus(txt, false);} break;      
    }
    switch (evalStatus(responseStr, MU)) {
      case 1: {char txt[] = "USB vlozen"; showStatus(txt, true);} break;
      case 2: {char txt[] = "USB vyjmut"; showStatus(txt, true);} break;
      case 3: {char txt[] = "TF vlozena"; showStatus(txt, true);} break;      
      case 4: {char txt[] = "TF vyjmuta"; showStatus(txt, true);} break;      
    }
    if (evalStatus(responseStr, ER) != -1) showError(responseStr);
  } while (true);
  uartTime = millis();
  uartIndex = 0;
  return;
}

void addBuffer(char c) { //filtrovani znaku  
  uartTime = millis();
  if (byte(c) == 10) {
    uartBuffer[uartIndex] = '\0'; 
    goto valid;
  }
  if ((c == '+') || (c == '.')) {
    uartBuffer[uartIndex] = c; 
    goto valid;
  }
  if ((byte(c) >= 48) && (byte(c) <= 57)) {
    uartBuffer[uartIndex] = c; 
    goto valid;
  }
  if ((byte(c) >= 65) && (byte(c) <= 90)) {
    uartBuffer[uartIndex] = c; 
    goto valid;
  }
  if ((byte(c) >= 97) && (byte(c) <= 122)) {
    uartBuffer[uartIndex] = c; 
    goto valid;
  }
  return;
valid:
  uartIndex++;
  uartBuffer[uartIndex] = '\0';  
  if (uartIndex >= buflen) {
    uartIndex = 0;
    char err[] = "ER+B";
    showError(err);
    flushData();
  }
}

//------------------------------------------------------------------------------------------

void setup() {
  uartBuffer[buflen + 1] = '\0';
  uartIndex = 0; cmdIndex = 0; currMode = 0; currVol = 0xff; seq = 1; KB = 0;
  pinMode(pinSetup, OUTPUT);
  digitalWrite(pinSetup, HIGH);
  lcd.begin(16, 2);
  lcd.clear();
  showDisplay();
  pinMode(pinLCD, OUTPUT); 
  digitalWrite(pinLCD, HIGH);
  clearValues();
  lcd.print(F("Bezdratak v.2"));
  lcd.setCursor(0, 1);
  lcd.print(F("MP3 a Bluetooth"));
  uart.begin(9600); 
 #ifdef DEBUG
  Serial.begin(9600);
  Serial.println(F("Bezdrat2 start"));
 #endif 
  delay(1000);
  uartTime = millis();
  sysTime = millis();
  sendCmd(AT_QM);
}

void loop() {
  while (uart.available()) addBuffer(uart.read()); 
  if (!KB) KB = keyPressed(); 
  if (uartIndex > 0) {
    if ((millis() - uartTime) > 1000) response(); 
    return;
  }
  if (KB) {
    if (disp) seq = 1; else seq = 3;
    sysTime = millis();
    digitalWrite(pinLCD, HIGH);
    if (disp)
      switch (KB) {
        case btnSelect:  sendCmd(AT_CB); break; //play/pause
        case btnLeft:    if (currMode > 1) sendCmd(AT_CD); break; //zpet o 1
        case btnRight:   if (currMode > 1) sendCmd(AT_CC); break; //vpred o 1
        case btnUp:      sendCmd(AT_CE); currVol = 0xff; break; //zesil
        case btnDown:    sendCmd(AT_CF); currVol = 0xff; break; //zeslab
        case btnSelect2: selectMode(); break;
        case btnLeft2:   if (currMode > 1) sendCmd(AT_AA07); else showSys(); break; //zpet o slozku
        case btnRight2:  if (currMode > 1) sendCmd(AT_AA06); else showSys(); break; //vpred o slozku
        case btnUp2:     sendCmd(AT_CZ); break;
        case btnDown2:   showSys(); break;
      }
    disp = true;
    KB = 0;
    return;
  } 
  if ((millis() - sysTime) > 1000) {
    seq++;
    sysTime = millis();
    if (currMode == 0) sendCmd(AT_QM);
    if (currMode > 1) {
      if (testValues()) seq = 1;
    }
  }
  if ((seq % 5) == 0) {
    seq++;
    if (currVol == 0xff) 
      sendCmd(AT_QA);
    else
      if (disp && (currMode > 1)) sendCmd(AT_MK);    
  }
  if (seq > 80) {
    seq = 1;
    digitalWrite(pinLCD, LOW);
    disp = false;
  }
}