#include <Arduino.h>

#define RS_PIN PB11
#define EN_PIN PA12
#define D4_PIN PA7
#define D5_PIN PA4
#define D6_PIN PA5
#define D7_PIN PA6

enum Mode { IDLE_MODE, GSM_SIM, GPS_SIM, BLE_SIM };
Mode activeMode = IDLE_MODE;

uint32_t lastBlinkTime = 0;

uint32_t lastDataTime = 0;
const uint32_t DATA_UPDATE_MS = 2000;
char cmdBuffer[64];

void lcdWriteNibble(uint8_t nibble, uint8_t rsMode) {
  digitalWrite(RS_PIN, rsMode);
  digitalWrite(D4_PIN, (nibble >> 0) & 1);
  digitalWrite(D5_PIN, (nibble >> 1) & 1);
  digitalWrite(D6_PIN, (nibble >> 2) & 1);
  digitalWrite(D7_PIN, (nibble >> 3) & 1);
  digitalWrite(EN_PIN, 1);
  delayMicroseconds(2);
  digitalWrite(EN_PIN, 0);
  delayMicroseconds(50);
}

void lcdSendByte(uint8_t byteVal, uint8_t rsMode) {
  lcdWriteNibble(byteVal >> 4, rsMode);
  lcdWriteNibble(byteVal & 0x0F, rsMode);
}

void lcdCmd(uint8_t command) {
  lcdSendByte(command, 0);
}

void lcdData(uint8_t data) {
  lcdSendByte(data, 1);
}

void lcdSetup() {
  pinMode(RS_PIN, OUTPUT);
  pinMode(EN_PIN, OUTPUT);
  pinMode(D4_PIN, OUTPUT);
  pinMode(D5_PIN, OUTPUT);
  pinMode(D6_PIN, OUTPUT);
  pinMode(D7_PIN, OUTPUT);
  
  delay(45);
  lcdCmd(0x33);
  delay(6);
  lcdCmd(0x32);
  delayMicroseconds(160);
  lcdCmd(0x28);
  delayMicroseconds(160);
  lcdCmd(0x0C);
  delayMicroseconds(160);
  lcdCmd(0x06);
  delayMicroseconds(160);
  lcdCmd(0x01);
  delay(3);
}

void lcdReset() {
  lcdCmd(0x01);
  delay(3);
}

void lcdPosition(uint8_t x, uint8_t y) {
  const uint8_t rowAddr[] = {0x00, 0x40, 0x14, 0x54};
  if (y > 3) y = 3;
  lcdCmd(0x80 | (x + rowAddr[y]));
}

void lcdOutput(const char* str) {
  while (*str) lcdData(*str++);
}

void lcdDisplay(const char* line0, const char* line1 = NULL, const char* line2 = NULL, const char* line3 = NULL) {
  lcdReset();
  lcdPosition(0, 0);
  lcdOutput(line0);
  
  if (line1 && *line1) {
    lcdPosition(0, 1);
    lcdOutput(line1);
  }
  
  if (line2 && *line2) {
    lcdPosition(0, 2);
    lcdOutput(line2);
  }
  
  if (line3 && *line3) {
    lcdPosition(0, 3);
    lcdOutput(line3);
  }
}

void simGSM() {
  const char* smsMsg = "GSM::+79161234567::\"STM32 GSM Test\"";
  Serial.println(smsMsg);
  lcdDisplay("GSM SMS Received", "From: +79161234567", "Text: STM32 GSM", "Test Message");
}

void simGPS() {
  const char* nmeaMsg = "GPS:$GPRMC,093000.00,A,5544.1234,N,03736.9876,E,18.5,290.3,150124,003.2,W*78";
  Serial.println(nmeaMsg);
  lcdDisplay("GPS Coordinates", "55.73539N 37.61646E", "Speed: 18.5 kn", "Status: Active");
}

void simBLE() {
  uint8_t tempC = 22 + (millis() >> 10) % 8;
  uint8_t humidity = 60 + (millis() >> 9) % 15;
  uint16_t pressure = 1013 + (millis() >> 8) % 10;
  
  char sensorData[60];
  snprintf(sensorData, sizeof(sensorData), 
           "BLE::T:%dC::H:%d%%::P:%dhPa", tempC, humidity, pressure);
  Serial.println(sensorData);
  
  char line2[21], line3[21];
  snprintf(line2, sizeof(line2), "T:%dC  H:%d%%", tempC, humidity);
  snprintf(line3, sizeof(line3), "Pressure: %d hPa", pressure);
  lcdDisplay("BLE Sensor Data", line2, line3, "");
}

void setup() {

  
  Serial.begin(115200);
  lcdSetup();
  
  lcdDisplay("Embedded Systems", "Lab Work #6", "GSM/GPS/BLE Sim", "By Student");
  
  Serial.println("=== STM32 Wireless Sim ===");
  Serial.println("Available commands:");
  Serial.println("  GSM - SMS simulation");
  Serial.println("  GPS - Navigation data");
  Serial.println("  BLE - Sensor data");
  Serial.println("  OFF - Stop simulation");
}

void loop() {
  uint32_t currentTime = millis();
  
  
  if (Serial.available()) {
    uint8_t bytesRead = Serial.readBytesUntil('\n', cmdBuffer, sizeof(cmdBuffer) - 1);
    cmdBuffer[bytesRead] = 0;
    
    for (uint8_t i = 0; cmdBuffer[i]; i++) {
      if (cmdBuffer[i] == '\r') cmdBuffer[i] = 0;
    }
    
    if (strcasecmp(cmdBuffer, "GSM") == 0) {
      activeMode = GSM_SIM;
      lcdDisplay("GSM Mode Active", "SMS Simulation", "UART: 9600 baud", "Ready...");
      lastDataTime = currentTime;
      Serial.println("[OK] GSM simulation started");
    } 
    else if (strcasecmp(cmdBuffer, "GPS") == 0) {
      activeMode = GPS_SIM;
      lcdDisplay("GPS Mode Active", "NMEA Data Stream", "Format: GPRMC", "Satellites: 8");
      lastDataTime = currentTime;
      Serial.println("[OK] GPS simulation started");
    }
    else if (strcasecmp(cmdBuffer, "BLE") == 0) {
      activeMode = BLE_SIM;
      lcdDisplay("BLE Mode Active", "Sensor Monitoring", "Update: 2s", "Advertising...");
      lastDataTime = currentTime;
      Serial.println("[OK] BLE simulation started");
    }
    else if (strcasecmp(cmdBuffer, "OFF") == 0 || strcasecmp(cmdBuffer, "STOP") == 0) {
      activeMode = IDLE_MODE;

      lcdDisplay("System Idle", "Send command:", "GSM, GPS, BLE", "to start");
      Serial.println("[OK] Simulation stopped");
    }
  }
  
  if (activeMode != IDLE_MODE && currentTime - lastDataTime >= DATA_UPDATE_MS) {
    lastDataTime = currentTime;
    
    switch (activeMode) {
      case GSM_SIM: simGSM(); break;
      case GPS_SIM: simGPS(); break;
      case BLE_SIM: simBLE(); break;
      default: break;
    }
  }
  
  delay(8);
}