//Code provided by TheResidentSkeptic, Youtube user.
//Paste bin link https://pastebin.com/RKLbNCQ1
#include <Arduino.h>
#include <ArduinoJson.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define Serial Serial
ESP8266WiFiMulti WiFiMulti;

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

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

float coin;

void setup() {
  Serial.begin(115200);
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  // Serial.setDebugOutput(true);
  Serial.println();
  Serial.println();
  Serial.println();
  for (uint8_t t = 4; t > 0; t--) {
    //  Serial.printf("[SETUP] WAIT %d...\n", t);
    Serial.flush();
  }
  WiFi.mode(WIFI_STA);
  // provide our SSID and Password for WIFI network connection
  WiFiMulti.addAP("SSID", "PASSWORD");
}

void loop() {

  // wait for WiFi connection
  if ((WiFiMulti.run() == WL_CONNECTED)) {
    HTTPClient http;

    http.begin("http://api.coindesk.com/v1/bpi/currentprice/CAD.json"); //HTTP URL for hosted server(local server)
    //192.168.43.161 - HOST     PORT: 3000 and /api is the target api we need to hit to get response
    int httpCode = http.GET();
    // Serial.println("After GET Request");
    // httpCode will be negative on error
    if (httpCode > 0) {
      if (httpCode == HTTP_CODE_OK) {
        //HTTP_CODE_OK means code == 200
        String payload = http.getString();// gives us the message received by the GET Request

        const size_t capacity = JSON_OBJECT_SIZE(2) + 2 * JSON_OBJECT_SIZE(3) + 2 * JSON_OBJECT_SIZE(4) + 480;
        DynamicJsonDocument doc(capacity);

        String json = payload;

        deserializeJson(doc, json);

        JsonObject time = doc["time"];

        const char* time_updateduk = time["updateduk"]; // "Mar 21, 2020 at 02:43 GMT"

        JsonObject bpi_CAD = doc["bpi"]["CAD"];
        const char* bpi_CAD_code = bpi_CAD["code"]; // "CAD"
        const char* bpi_CAD_rate = bpi_CAD["rate"]; // "8,991.6930"
        const char* bpi_CAD_description = bpi_CAD["description"]; // "Canadian Dollar"
        float bpi_CAD_rate_float = bpi_CAD["rate_float"]; // 8991.693

        coin = bpi_CAD_rate_float;

        Serial.println(time_updateduk);
        Serial.print("Current Price: ");
        Serial.print("$");
        Serial.print(coin);
        Serial.println(" CAD");
        Serial.println("");

        display.clearDisplay();

        display.setTextSize(2);      // Normal 1:1 pixel scale
        display.setTextColor(SSD1306_WHITE); // Draw white text
        display.setCursor(20, 10);     // Start at top-left corner
        display.cp437(true);         // Use full 256 char 'Code Page 437' font

        // Not all the characters will fit on the display. This is normal.
        // Library will draw what it can and the rest will be clipped.
        display.println("BITCOIN");


        if ((coin <= 999.99))
        {
          display.setCursor (27, 35);
          display.print("$");
          display.println(coin, 2);
        }

        else if ((coin >= 1000.00) && (coin <= 9999.99))
        {
          display.setCursor(15, 35);
          display.print("$");
          display.println(coin, 2);
        }
        else if ((coin >= 10000.00))
        {
          display.setCursor(5, 35);
          display.print("$");
          display.println(coin, 2);
        }
        
        display.display();
        display.setTextSize(1);      // Normal 1:1 pixel scale
        display.setCursor(5 , 55);
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();
        display.print(". ");
        delay(1000);
        display.display();

      }
    }
    else {
      Serial.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }
    http.end();
  }
}