/*
   __  __                _______         _ _ __  __
  |  \/  |              |__   __|       (_|_)  \/  |
  | \  / | __ _ _ __   __ _| |_   _____  _ _| \  / | __ _ _ __ ___  _   _
  | |\/| |/ _` | '_ \ / _` | \ \ / / _ \| | | |\/| |/ _` | '_ ` _ \| | | |
  | |  | | (_| | |_) | (_| | |\ V / (_) | | | |  | | (_| | | | | | | |_| |
  |_|  |_|\__,_| .__/ \__,_|_| \_/ \___/| |_|_|  |_|\__,_|_| |_| |_|\__, |
              | |                     _/ |                          __/ |
              |_|                    |__/                          |___/

Map with connected display and touch button, downloads data from TMEP.cz for
Czech districts and display temperature/air quality. You can cycle between those with touch
button. Display shows what data are you looking at and min/max value.

More info about map:
https://wiki.tmep.cz/doku.php?id=ruzne:led_mapa_okresu_cr

Used components:
- MapaTvojiMamy
- LaskaKit ESP32-LPkit v2.4
- 0.91" OLED
- Catalex touch sensor v2.0 (simply some capacative touch sensor)
*/

////////////////////
// Variables setup
////////////////////

// Wi-Fi, JSON with data
const char *ssid = "TVOJE_AP";
const char *password = "TVOJE_HESLO";
const char *json_url = "http://cdn.tmep.cz/app/export/okresy-cr-vse.json";

// After how long get new values - default 2 minutes
unsigned long timerDelay = 120000;
// After how go to "sleep" (LEDs off, display off, "wake up" by touching button) - default 5 minutes
unsigned long offDelay = 300000;

// LED strip - MapaTvojiMamy
#define LEDS_COUNT 77
#define LEDS_PIN 14
#define CHANNEL 0
#define LEDS_BRIGHTNESS 10

// Touch button
#define BUTTON_PIN 16

// Display PINs
#define DISPLAY_CLOCK_PIN 25
#define DISPLAY_DATA_PIN 26

// What to show as default - temp or air
char *defaultView = "temp";

// Display hello text
char *displayText1 = "MapaTvojiMamy";
char displayText2[14] = "";

///////////
// Code
///////////

// Libraries
#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h> //https://github.com/bblanchon/ArduinoJson v6+
#include "Freenove_WS2812_Lib_for_ESP32.h"

// Display
#include <U8g2lib.h>
#include <Wire.h>
U8G2_SSD1306_128X32_UNIVISION_1_SW_I2C u8g2(U8G2_R0, DISPLAY_CLOCK_PIN, DISPLAY_DATA_PIN, /* reset=*/U8X8_PIN_NONE);

// Strip
Freenove_ESP32_WS2812 strip = Freenove_ESP32_WS2812(LEDS_COUNT, LEDS_PIN, CHANNEL, TYPE_GRB);

// Variables
unsigned long lastTime = 0;
unsigned long lastTouchTime = 0;

int lastid, value, color, firstTime = 1, isOn = 1;

// Button state
boolean oldState = LOW;

String sensorReadings;
double sensorReadingsArr[3];
// in JSON is h1 used for temperature and h4 for air quality, we will stick with these variables
double h1[77]; // array for temperature measurements
double h4[77]; // array for air quality measurements
double h1min, h1max, h4min, h4max;

void setup()
{
  u8g2.begin();
  pinMode(BUTTON_PIN, INPUT);
  Serial.begin(115200);
  delay(5);
  Serial.println();
  strip.begin();
  strip.setBrightness(LEDS_BRIGHTNESS);
}

void lightenUpYourMamaMap()
{
  // Map value to color, set it to corresponding LED and show it
  // We already have arrays populated 
  if(defaultView == "temp")
  {
    for(int i = 0; i < LEDS_COUNT; i = i + 1)
    {
      color = map(h1[i], -15, 40, 170, 0);
      strip.setLedColorData(i, strip.Wheel(color));
    }
  }
  else
  {
    for(int i = 0; i < LEDS_COUNT; i = i + 1)
    {
      color = map(h4[i], -15, 40, 170, 0);
      strip.setLedColorData(i, strip.Wheel(color));
    }
  }
  strip.show();
}

void setValuesForDisplay()
{
  if(defaultView == "temp")
  {
    displayText1 = "Teplota";
    sprintf(displayText2, "%d.%01d / %d.%01d", (int)h1min, abs((int)(h1min*10)%10), (int)h1max, abs((int)(h1max*10)%10));
  }
  else
  {
    displayText1 = "Ovzdusi";
    sprintf(displayText2, "%d.%01d / %d.%01d", (int)h4min, abs((int)(h4min*10)%10), (int)h4max, abs((int)(h4max*10)%10));
  }
}

String httpGETRequest(const char *serverName)
{
  WiFiClient client;
  HTTPClient http;
  http.begin(client, serverName);
  int httpResponseCode = http.GET();
  String payload = "{}";
  if(httpResponseCode > 0)
  {
    Serial.print("HTTP Response code: ");
    Serial.println(httpResponseCode);
    payload = http.getString();
  }
  else
  {
    Serial.print("Error code: ");
    Serial.println(httpResponseCode);
  }
  http.end();
  return payload;
}

void loop()
{
  boolean newState = digitalRead(BUTTON_PIN);

  // Touching the button?
  if((newState == LOW) && (oldState == HIGH))
  {
    // Short delay to debounce button.
    delay(40);
    // Check if button is still low after debounce.
    newState = digitalRead(BUTTON_PIN);
    
    // Button touched!
    if(newState == LOW)
    {
      Serial.print("Button touched, mode: ");
      
      lastTouchTime = millis();

      // Are we on? Change what to show
      if(isOn == 1)
      {
        if(defaultView == "temp")
        {
          defaultView = "air";
        }
        else
        {
          defaultView = "temp";
        }

        setValuesForDisplay();
        Serial.println(defaultView);

        // Let it shine
        lightenUpYourMamaMap();
      }
      else
      {
        // "Powering up"
        Serial.println("go online");
        isOn = 1;
        strip.setBrightness(LEDS_BRIGHTNESS);
        lightenUpYourMamaMap();
        firstTime = 1;
        u8g2.setPowerSave(false);
      }
    }
  }

  // Let's go "offline"
  if(isOn == 1 && ((millis() - lastTouchTime) > offDelay))
  {
      Serial.println("go offline");
      isOn = 0;
      strip.setBrightness(0);
      lightenUpYourMamaMap();
      u8g2.setPowerSave(true);
  }

  // Set the last-read button state to the old state.
  oldState = newState;

  // Did we wait long enough or was it just powered on?
  // Read JSON and populate variables with measurements from districts
  if(isOn == 1 && ((millis() - lastTime) > timerDelay || firstTime == 1))
  {
    Serial.print("Connecting to ");
    Serial.println(ssid);
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED)
    {
      delay(500);
      Serial.print(".");
    }
    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());

    if(WiFi.status() == WL_CONNECTED)
    {
      firstTime = 0;
      sensorReadings = httpGETRequest(json_url);
      WiFi.disconnect();
      Serial.println("WiFi disconnected");

      DynamicJsonDocument doc(12288);
      DeserializationError error = deserializeJson(doc, sensorReadings);
      if(error)
      {
        Serial.print(F("deserializeJson() failed: "));
        Serial.println(error.f_str());
        return;
      }

      // reset min/max values
      h1min = 100;
      h1max = -100;
      h4min = 1000;
      h4max = 0;

      for (JsonObject item : doc.as<JsonArray>())
      {
        // Index, JSON starts with 1, we need to start with 0 so deduct 1
        int ledIndex = item["id"];
        ledIndex -= 1;
        double temp = item["h1"];
        double air = item["h4"];

        // Set minimums and maximums
        if(temp > h1max)
        {
          h1max = temp;
        }
        if(temp < h1min)
        {
          h1min = temp;
        }
        if(air > h4max)
        {
          h4max = air;
        }
        if(air < h4min)
        {
          h4min = air;
        }

        // Let's map air value to respective color on ColorWheel:
        // https://github.com/Freenove/Freenove_WS2812_Lib_for_ESP32/blob/master/extras/ColorWheel.jpg
        // green
        if(air < 20)
        {
          air = 85;
        }
        // orange
        else if(air < 40)
        {
          air = 45;
        }
        // red
        else if(air < 100)
        {
          air = 10;
        }
        // purple
        else if(air < 5000)
        {
          air = 200;
        }

        // Populate our two arrays
        h1[ledIndex] = temp;
        h4[ledIndex] = air;
      }

      setValuesForDisplay();
      lightenUpYourMamaMap();

      // Debugging values we got
      /*
      for(int i = 0; i < LEDS_COUNT; i = i + 1)
      {
          Serial.print("h1[");
          Serial.print(i);
          Serial.print("] value: ");
          Serial.println(h1[i]);

          Serial.print("h4[");
          Serial.print(i);
          Serial.print("] value: ");
          Serial.println(h4[i]);
      }
      */
    }
    else
    {
      displayText1 = "NO WIFI";
      Serial.println("WiFi not connected :( is reachable?");
    }

    lastTime = millis();
  }

  // Show texts on display
  if(isOn == 1)
  {
    u8g2.firstPage();
    do
    {
      u8g2.setFont(u8g2_font_ncenB10_tr);
      u8g2.drawStr(0, 12, displayText1);
      u8g2.drawStr(0, 26, displayText2);
    } while (u8g2.nextPage());
  }
}