#include <Wire.h>
#include <SparkFun_MS5803_I2C.h>

MS5803 sensor(ADDRESS_HIGH);

// Create variables to store results
float temperature_c;
double pressure_abs;
float pressurePSI;  // variable to hold pressure in PSI

// Define LED pins
const byte led1Pin = 2;           // Assign to LED-1
const byte led2Pin = 3;           // Assign to LED-2
const byte led3Pin = 4;           // Assign to LED-3
const byte led4Pin = 5;           // Assign to LED-4
const byte buttonPin = 6;         // Assign to the button
const byte upTrendPotPin = 32;    // Potentiometer pins for up trend set points
const byte downTrendPotPin = 33;  // Potentiometer pins for down trend set points



// Calibration variables
const unsigned long calibrationDuration = 5000;  // 5 seconds

byte upTrendCount = 0;    // variable to increase count when pressure changes
byte downTrendCount = 0;  // variable to increase count when pressure changes

byte minUpTrendPoints = 2;       // Minimum points to find a trend
byte maxUpTrendPoints = 12;      // maximum points to find a trend
byte minDownTrendPoints = 2;     // minimum points to find a trend
byte maxDownTrendPoints = 12;    // Maximum points to find a trend
byte pUpPoint, pDownPoint = 2;   // variables to hold previous min and max trend points
int maxAnalogResolution = 4095;  // maximum analog resolution value (for arduino it's 1023, for esp32 it's 4095)


// Trend detection variables
bool noTrend = false;
bool noTrendLedState = LOW;  // last led state for NO Trend
unsigned long trendStartTime;
unsigned long noTrendTime = millis();

int minThreshold = 0;  // variable to hold minimum threshold pressure value
int maxThreshold = 0;  // variable to hold maximum threshold pressure value

const int trendThresholdUp = 0;    // Adjust this threshold
const int trendThresholdDown = 0;  // Adjust this threshold
const int trendChangeCount = 4;    // Number of consecutive data changes needed for a trend

void setup() {
  // Start your preferred I2C object
  Wire.begin();
  // Initialize Serial Monitor
  Serial.begin(115200);
  // Retrieve calibration constants for conversion math.
  sensor.reset();
  sensor.begin();

  // Set LED pins as OUTPUT
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  pinMode(led3Pin, OUTPUT);
  pinMode(led4Pin, OUTPUT);
  pinMode(upTrendPotPin, INPUT);
  pinMode(downTrendPotPin, INPUT);

  // Set button pin as INPUT
  pinMode(buttonPin, INPUT_PULLUP);
  // Start calibration Mode
  unsigned long cTime = millis();  // Note current time
  unsigned long ledTime = millis();
  bool ledState = HIGH;
  Serial.println("Starting Calibration Mode");
  while ((millis() - cTime) < calibrationDuration) {  // start calibration for 5 seconds = 5000 milliseconds
    pressure_abs = sensor.getPressure(ADC_4096);      // Read pressure from the sensor in mbar.
    pressurePSI = pressure_abs * 0.0145038;           // convert pressure into PSI
    if (pressurePSI < minThreshold) {
      minThreshold = pressurePSI;  // Update minimum pressure threshold
    } else if (pressurePSI > maxThreshold) {
      maxThreshold = pressurePSI;  // Update maximum pressure threshold
    }
    if ((millis() - ledTime) > 300) {
      digitalWrite(led1Pin, ledState);
      ledState = !ledState;  // revert led state
      ledTime = millis();
    }
    delay(150);  /// wait for 150 milliseconds before taking next reading
  }
  digitalWrite(led1Pin, LOW);  // Turn off LED-1
  Serial.print("Min Pressure Threshold:");
  Serial.print(minThreshold);
  Serial.print(" | ");
  Serial.print("Max Pressure Threshold:");
  Serial.println(maxThreshold);
}

void loop() {
  // Read potentiometer to get up/down trend point values
  byte readUpPot = map(analogRead(upTrendPotPin), 0, maxAnalogResolution, minUpTrendPoints, maxUpTrendPoints);
  byte readDownPot = map(analogRead(downTrendPotPin), 0, maxAnalogResolution, minDownTrendPoints, maxDownTrendPoints);
  if (pUpPoint != readUpPot) {  // If pot has rotated change the set point values
    pUpPoint = readUpPot;
    Serial.print("Up Trend Points value:");
    Serial.println(pUpPoint);
  }
  if (pDownPoint != readDownPot) {  // If pot has rotated change the set point values
    pDownPoint = readUpPot;
    Serial.print("Down Trend Points value:");
    Serial.println(pDownPoint);
  }
  // Read temperature from the sensor in deg C.
  temperature_c = sensor.getTemperature(CELSIUS, ADC_512);

  // Read pressure from the sensor in mbar.
  pressure_abs = sensor.getPressure(ADC_4096);
  pressurePSI = pressure_abs * 0.0145038;  // convert pressure into PSI
    // Report values via UART
  Serial.print("Temperature C = ");
  Serial.print(temperature_c);

  Serial.print(" | Pressure abs (mbar) = ");
  Serial.print(pressure_abs);

  Serial.print(" | Pressure abs (PSI) = ");
  Serial.println(pressurePSI);

  upTrendCount, downTrendCount;
  if ((pressurePSI > maxThreshold) && (upTrendCount < pUpPoint)) {              // Check if pressure is greater than maxThrehsold
    upTrendCount += 1;                                                          // increase up trend count with 1
  } else if ((pressurePSI < minThreshold) && (downTrendCount < pDownPoint)) {   // Check if pressure is less than min threshold
    downTrendCount += 1;                                                        // increase up trend count with 1
  } else if ((pressurePSI >= minThreshold) && (pressurePSI <= maxThreshold)) {  // Check if pressure is in normal range
    upTrendCount = 0;                                                           // Reset to zero
    downTrendCount = 0;                                                         // Reset to zero
    digitalWrite(led2Pin, LOW);                                                 // Turn off LED-2
    digitalWrite(led3Pin, LOW);                                                 // Turn off LED-3
    if ((millis() - noTrendTime) > 300) {
      digitalWrite(led4Pin, noTrendLedState);  // Turn off LED-4
      noTrendLedState = !noTrendLedState;
      noTrendTime = millis();
    }
  }
  if (upTrendCount >= pUpPoint) {  // Check if uptrend has beed detected
    digitalWrite(led2Pin, HIGH);   // Turn On LED 2 when up trend has found
  }
  if (downTrendCount >= pDownPoint) {  // Check if Dwon trend has beed detected
    digitalWrite(led3Pin, HIGH);       // Turn On LED 3 when up trend has found
  }


  // Check the button state
  if (digitalRead(buttonPin) == LOW) {
    upTrendCount = 0;                                                           // Reset to zero
    downTrendCount = 0;                                                         // Reset to zero
    
    // Button is pressed, reset and restart testing process
    digitalWrite(led2Pin, LOW);  // Turn off LED-2
    digitalWrite(led3Pin, LOW);  // Turn off LED-3
    digitalWrite(led4Pin, LOW);  // Turn off LED-4
  }

  delay(500);
}