#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
// WiFi
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASS ""
// TFT pins (match your wiring)
#define TFT_CS    10
#define TFT_DC     9
#define TFT_RST   -1   // ILI9341 RST tied to ESP32 RST (no GPIO control)
#define TFT_SCLK  12
#define TFT_MOSI  11
#define TFT_MISO  13
// Route public API calls through Cirkit's data gateway so shared demos
// use cached responses and don't hammer third-party APIs directly.
// This is the avoid rate-limiting in public demos.
String cachedUrl(const char* url) {
  String encoded = String(url);
  encoded.replace("&", "%26");
  return "https://app.cirkitdesigner.com/api/data-gateway/fetch?url=" + encoded;
}
// CoinGecko (one request for multiple coins)
String priceUrl = cachedUrl("https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum,solana&vs_currencies=usd");

Adafruit_ILI9341 tft(TFT_CS, TFT_DC, TFT_RST);
WiFiClientSecure tls;
// Simple text writer
static int gY = 34;
inline void tftResetCursor() {
  gY = 34;
}

void tftHeader(const char* title) {
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextWrap(false);
  tft.setTextSize(2);
  tft.setTextColor(ILI9341_CYAN, ILI9341_BLACK);
  tft.setCursor(4, 4);
  tft.print(title);
  tft.drawLine(0, 26, tft.width(), 26, ILI9341_DARKGREY);
  tftResetCursor();
}

void tftLine(const String& s, uint16_t color = ILI9341_WHITE) {
  const int lineH = 20;
  if (gY > (tft.height() - lineH)) gY = 34;
  tft.fillRect(0, gY, tft.width(), lineH, ILI9341_BLACK);
  tft.setCursor(4, gY);
  tft.setTextSize(2);
  tft.setTextColor(color, ILI9341_BLACK);
  tft.print(s);
  gY += lineH;
}

static String bodyBuf;

static int httpsGet(const char* url, String& bodyOut) {
  HTTPClient https;
  https.setUserAgent("ESP32-CRYPTO/1.0");
  https.setTimeout(15000);
  if (!https.begin(tls, url)) return -1000;
  int code = https.GET();
  if (code > 0) bodyOut = https.getString();
  https.end();
  return code;
}
// Minimal JSON extractor: finds "<coin>":{"usd":<number>}
static String getUsd(const String& json, const char* coin) {
  String key = String("\"") + coin + String("\"");
  int k = json.indexOf(key);
  if (k < 0) return "";
  int u = json.indexOf("\"usd\":", k);
  if (u < 0) return "";
  int i = u + 6;
  while (i < (int)json.length() && isspace((unsigned char)json[i])) i++;
  int j = i;
  while (j < (int)json.length()) {
    char c = json[j];
    if (!(isDigit((unsigned char)c) || c == '.' || c == 'e' || c == 'E' || c == '+' || c == '-')) break;
    j++;
  }
  if (j > i) return json.substring(i, j);
  return "";
}

static void connectWiFiOnce() {
  WiFi.mode(WIFI_STA);
  WiFi.setSleep(false);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  unsigned long t0 = millis();
  const unsigned long TIMEOUT = 20000;

  tftLine("Connecting WiFi...");
  while (WiFi.status() != WL_CONNECTED && millis() - t0 < TIMEOUT) {
    delay(300);
  }
  if (WiFi.status() == WL_CONNECTED) {
    tftLine("WiFi: connected", ILI9341_GREEN);
    tftLine("IP: " + WiFi.localIP().toString(), ILI9341_DARKGREY);
  } else {
    tftLine("WiFi: FAILED", ILI9341_RED);
  }
}

static void showPricesOnce() {
  if (WiFi.status() != WL_CONNECTED) {
    tftLine("No WiFi", ILI9341_RED);
    return;
  }

  bodyBuf = "";
  int code = httpsGet(priceUrl.c_str(), bodyBuf);
  if (code != 200 || bodyBuf.length() == 0) {
    tftLine("Fail code:" + String(code), ILI9341_RED);
    return;
  }

  String btc = getUsd(bodyBuf, "bitcoin");
  String eth = getUsd(bodyBuf, "ethereum");
  String sol = getUsd(bodyBuf, "solana");

  if (!btc.length() && !eth.length() && !sol.length()) {
    tftLine("Parse failed", ILI9341_RED);
    return;
  }
  // Draw a price block
  const int barH = 26;
  if (gY > (tft.height() - 3 * barH)) gY = 34;

  auto drawRow = [&](const char* sym, const String& v, uint16_t fg, uint16_t bg) {
    tft.fillRect(0, gY, tft.width(), barH, bg);
    tft.setCursor(4, gY + 4);
    tft.setTextSize(2);
    tft.setTextColor(fg, bg);
    tft.print(sym);
    tft.print(": $");
    tft.print(v.length() ? v : String("-"));
    gY += barH;
  };

  drawRow("BTC", btc, ILI9341_YELLOW, ILI9341_DARKGREY);
  drawRow("ETH", eth, ILI9341_CYAN,   ILI9341_BLACK);
  drawRow("SOL", sol, ILI9341_GREEN,  ILI9341_DARKGREY);
}

void setup() {
  // Prepare SPI before TFT
  pinMode(TFT_CS, OUTPUT); digitalWrite(TFT_CS, HIGH);
  pinMode(TFT_DC, OUTPUT);
  if (TFT_RST >= 0) {
    pinMode(TFT_RST, OUTPUT);
    digitalWrite(TFT_RST, HIGH);
  }
  SPI.begin(TFT_SCLK, TFT_MISO, TFT_MOSI, TFT_CS);

  tft.begin(8000000);
  tft.setRotation(1);

  tftHeader("Crypto Prices");

  connectWiFiOnce();
  // TLS: accept all certs for demo
  tls.setInsecure();
  tls.setTimeout(15000);

  showPricesOnce();
}

void loop() {
  static unsigned long tPrev = 0;
  const unsigned long PERIOD_MS = 60000; // update every 60s

  unsigned long now = millis();
  if (now - tPrev >= PERIOD_MS) {
    tPrev = now;
    // Redraw header region occasionally to avoid artifacts
    tftHeader("Crypto Prices");
    showPricesOnce();
  }
  delay(50);
}