#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#include "button.h"
#include "relay.h"
#include "temperature_sensor.h"
#include "queue.h"

#define AIR_TEMP_SENSOR_PIN A1

#define RELAY_PIN 6
#define SPEAKER_PIN 7
#define BUTTON_RIGHT_PIN 8
#define BUTTON_LEFT_PIN 9
#define BUTTON_DOWN_PIN 10
#define BUTTON_UP_PIN 11

#define MAX_STATE 4 // Amount of display states

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define TEMP_DELTA 4 // Minimum temperature difference before relay is toggled
#define ALARM_TEMP_DELTA 15 // Minimum temperature difference before the alarm wil sound
#define TEMP_PLOT_INTERVAL 60000 // Amount of milliseconds between temperature measuring points in the plot

byte state = 0;

int targetTemp = 70;
int alarmState = 0;

long lastTempQueue = -1000000;

Button buttonUp(BUTTON_UP_PIN);
Button buttonDown(BUTTON_DOWN_PIN);
Button buttonLeft(BUTTON_LEFT_PIN);
Button buttonRight(BUTTON_RIGHT_PIN);

Relay relay(RELAY_PIN);

// Pass pin, reference voltage, and a,b,c coefficients
TemperatureSensor airTempSensor(AIR_TEMP_SENSOR_PIN, 10000, 0.0010626977757858514, 0.00025567427237838396, -8.706543235296982e-8);

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

Queue tempQueue;

void setup() {
  pinMode(SPEAKER_PIN, OUTPUT);
  digitalWrite(SPEAKER_PIN, LOW);

  //Serial.begin(9600);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    //Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.setRotation(2);
  display.clearDisplay();
  display.setTextColor(WHITE);
  airTempSensor.preload();
}

void loop() {
  updateAirTemp();
  byte bUp = buttonUp.getState();
  byte bDown = buttonDown.getState();
  byte bLeft = buttonLeft.getState();
  byte bRight = buttonRight.getState();

  if (bRight >= 1) {
    if (state >= MAX_STATE) state = 0;
    else state += 1;
  }
  if (bLeft >= 1) {
    if (state <= 0) state = MAX_STATE;
    else state -= 1;
  }

  display.clearDisplay();
  displayMenuBar();

  switch (state) {
    case 0:
      targetTempState(bUp, bDown);
      break;
    case 1:
      manualState(bUp, bDown);
      break;
    case 2:
      uptimeState(bUp, bDown);
      break;
    case 3:
      tempPlotState(bUp, bDown);
      break;
    case 4:
      alarmSettingState(bUp, bDown);
      break;
  }
  display.display();
}

void updateAirTemp() {
  airTempSensor.update();
  if (millis() - lastTempQueue > TEMP_PLOT_INTERVAL) {
    tempQueue.push(airTempSensor.getTemperature());
    lastTempQueue = millis();
  }
}

void updateRelay() {
  float temperature = airTempSensor.getTemperature();
  if (temperature - targetTemp >= TEMP_DELTA) { //Temp too high
    relay.off();
  } else if (targetTemp - temperature >= TEMP_DELTA) { //Temp too low
    relay.on();
  }
  if (temperature - targetTemp >= ALARM_TEMP_DELTA) {
    int second = millis() % 1000;
    if (alarmState == 0 and second < 100) {
      alarmState = 1;
      digitalWrite(SPEAKER_PIN, HIGH);
    } else if (alarmState == 1 and second > 500 and second < 600) {
      alarmState = 0;
      digitalWrite(SPEAKER_PIN, LOW);
    } else if (alarmState == -1) {
      digitalWrite(SPEAKER_PIN, LOW);
    }
  } else {
    digitalWrite(SPEAKER_PIN, LOW);
  }
}

void targetTempState(byte bUp, byte bDown) {
  updateRelay();

  switch (bUp) {
    case 1:
      targetTemp += 1;
      break;
    case 2:
      targetTemp += 1;
      break;
    case 3:
      targetTemp += 3;
      break;
  }
  switch (bDown) {
    case 1:
      targetTemp -= 1;
      break;
    case 2:
      targetTemp -= 1;
      break;
    case 3:
      targetTemp -= 3;
      break;
  }

  displayCurrentTemp();

  // Target Temp
  display.setTextSize(1);
  display.setCursor(0, 40);
  display.print("Target: ");
  display.setTextSize(2);
  display.setCursor(0, 50);
  display.print(targetTemp);
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(2);
  display.print("C");

  //display.drawRect(0, 0, display.width(), display.height(), SSD1306_WHITE);
}

void manualState(byte bUp, byte bDown) {
  if (bUp == 1) {
    relay.on();
  }
  if (bDown == 1) {
    relay.off();
  }

  displayCurrentTemp();

  display.setTextSize(1);
  display.setCursor(0, 40);
  display.print("Manual Mode");
  display.setTextSize(2);
  display.setCursor(0, 50);
  if (relay.getState()) {
    display.print("Heater ON");
  } else {
    display.print("Heater OFF");
  }
}

void uptimeState(byte bUp, byte bDown) {
  updateRelay();
  unsigned int seconds = millis() / 1000; //convect milliseconds to seconds
  unsigned int minutes = seconds / 60; //convert seconds to minutes
  unsigned int hours = minutes / 60; //convert minutes to hours
  seconds = seconds - (minutes * 60); //subtract the coverted seconds to minutes in order to display 59 secs max
  minutes = minutes - (hours * 60); //subtract the coverted minutes to hours in order to display 59 minutes max

  displayCurrentTemp();

  display.setTextSize(1);
  display.setCursor(0, 40);
  display.print("Uptime:");
  display.setTextSize(2);
  display.setCursor(0, 50);
  if (hours < 10) display.print(0);
  display.print(hours);
  display.print(":");
  if (minutes < 10) display.print(0);
  display.print(minutes);
  display.print(":");
  if (seconds < 10) display.print(0);
  display.print(seconds);
}

void displayMenuBar() {
  byte space = display.width() / (MAX_STATE + 1);
  for (byte i = 0; i < MAX_STATE + 1; i++) {
    if (i == state) display.fillCircle(space * i + space / 2, 3, 3, WHITE);
    else display.drawCircle(space * i + space / 2, 3, 3, WHITE);
  }
}

void tempPlotState(byte bUp, byte bDown) {
  updateRelay();

  byte maxValue = tempQueue.getMax();
  byte minValue = tempQueue.getMin();

  if (minValue > 99) minValue = 99;

  display.setTextSize(1);
  if (maxValue > 99)display.setCursor(110, 8);
  else display.setCursor(116, 8);
  display.print(maxValue);
  display.setCursor(116, 57);
  display.print(minValue);

  if (maxValue - minValue < 10) {
    minValue -= 1;
    maxValue += 1;
  }

  for (int i = 0; i < TEMP_QUEUE_LENGTH; i++) {
    byte barHeight = tempQueue.lookup(i);
    if (barHeight < minValue) barHeight = minValue;
    barHeight = map(barHeight, minValue, maxValue, 2, 58);
    display.fillRect(i * 2, SCREEN_HEIGHT - barHeight, 1, barHeight, WHITE);
  }
}

void alarmSettingState(byte bUp, byte bDown) {
  updateRelay();

  if (bUp == 1) {
    alarmState = 0;
  }
  if (bDown == 1) {
    alarmState = -1;
  }

  displayCurrentTemp();

  display.setTextSize(1);
  display.setCursor(0, 40);
  display.print("Alarm temp: ");
  display.print(targetTemp + ALARM_TEMP_DELTA);
  display.print(" ");
  display.cp437(true);
  display.write(167);
  display.setTextSize(1);
  display.print("C");

  display.setTextSize(2);
  display.setCursor(0, 50);
  if (alarmState == -1) {
    display.print("Alarm OFF");
  } else {
    display.print("Alarm ON");
  }
}

void displayCurrentTemp() {
  display.setTextSize(1);
  display.setCursor(0, 10);
  display.print("Current: ");
  display.setTextSize(2);
  display.setCursor(0, 20);
  display.print(airTempSensor.getTemperature());
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(2);
  display.print("C");
}