#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <Arduino_GFX_Library.h>

// ============== CONFIGURATION ==============
const char* ssid = "iot-2GHz";
const char* password = "lesson-greater";

const char* alertTopic = "http://ntfy.sh/ALERT_klubhaus_topic/json?poll=1";
const char* silenceTopic = "http://ntfy.sh/SILENCE_klubhaus_topic/json?poll=1";

const unsigned long POLL_INTERVAL = 15000;
const unsigned long SILENCE_POLL_INTERVAL = 15000;
const unsigned long BLINK_DURATION = 180000;
const unsigned long BLINK_PERIOD = 1000;

// Hardware pins (from working Waveshare demo)
#define BACKLIGHT_PIN 22
#define BUTTON_PIN     9

// Display colors
#define COLOR_BLACK  0x0000
#define COLOR_RED    0xF800
#define COLOR_GREEN  0x07E0
#define COLOR_BLUE   0x001F
#define COLOR_WHITE  0xFFFF

// ===========================================

// Arduino_GFX setup for Waveshare ESP32-C6-LCD-1.47
// ST7789, 172x320, with column offset 34 【2】
Arduino_DataBus *bus = new Arduino_HWSPI(
    15 /* DC */, 14 /* CS */,
    7 /* SCK */, 6 /* MOSI */, -1 /* MISO */);

Arduino_GFX *gfx = new Arduino_ST7789(
    bus, 21 /* RST */, 0 /* rotation */, true /* IPS */,
    172 /* width */, 320 /* height */,
    34 /* col offset 1 */, 0 /* row offset 1 */,
    34 /* col offset 2 */, 0 /* row offset 2 */);

// ===========================================

enum State { STATE_SILENT, STATE_ALARM };

State currentState = STATE_SILENT;

unsigned long lastPoll = 0;
unsigned long lastSilencePoll = 0;
unsigned long blinkStartTime = 0;
bool blinkState = false;

String lastAlertId = "";
String lastSilenceId = "";
bool lastButtonState = false;

void setup() {
  Serial.begin(115200);
  delay(3000);
  Serial.println("\n=== GFX DOORBELL ===");

  // Init backlight
  pinMode(BACKLIGHT_PIN, OUTPUT);
  digitalWrite(BACKLIGHT_PIN, HIGH);
  Serial.println("Backlight ON");

  // Init button
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  Serial.println("Button ready");

  // Init display
  Serial.println("Init GFX...");
  gfx->begin();
  Serial.println("GFX begin OK");

  gfx->fillScreen(COLOR_BLACK);
  Serial.println("Screen cleared");

  // Test pattern
  Serial.println("Display test...");
  testDisplay();

  // Start silent
  transitionTo(STATE_SILENT);

  // WiFi
  Serial.println("Connecting WiFi...");
  WiFi.begin(ssid, password);

  int wifiTimeout = 0;
  while (WiFi.status() != WL_CONNECTED && wifiTimeout < 40) {
    delay(500);
    Serial.print(".");
    wifiTimeout++;
  }

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("\nWiFi FAILED");
    gfx->fillScreen(COLOR_RED);
    gfx->setTextColor(COLOR_WHITE, COLOR_RED);
    gfx->setTextSize(2);
    gfx->setCursor(10, 140);
    gfx->println("NO WIFI");
  } else {
    Serial.println("\nWiFi OK: " + WiFi.localIP().toString());
    gfx->setTextColor(COLOR_GREEN, COLOR_BLACK);
    gfx->setTextSize(2);
    gfx->setCursor(10, 10);
    gfx->println("WiFi OK");
    delay(500);
    gfx->fillScreen(COLOR_BLACK);
  }

  Serial.println("=== SETUP COMPLETE ===");
  Serial.println(String("State: ") + getStateName(currentState));
}

void loop() {
  unsigned long now = millis();
  handleButton();

  switch (currentState) {
    case STATE_SILENT:
      if (now - lastSilencePoll >= SILENCE_POLL_INTERVAL) {
        lastSilencePoll = now;
        checkSilenceTopic();
      }
      if (now - lastPoll >= POLL_INTERVAL) {
        lastPoll = now;
        checkAlertTopic();
      }
      break;

    case STATE_ALARM:
      if (now - lastSilencePoll >= SILENCE_POLL_INTERVAL) {
        lastSilencePoll = now;
        checkSilenceTopic();
      }
      updateBlink(now);
      if (now - blinkStartTime >= BLINK_DURATION) {
        Serial.println("ALARM TIMEOUT");
        transitionTo(STATE_SILENT);
      }
      break;
  }

  delay(10);
}

// ============== STATE MANAGEMENT ==============

void transitionTo(State newState) {
  if (newState == currentState) return;

  Serial.print("STATE: ");
  Serial.print(getStateName(currentState));
  Serial.print(" -> ");
  Serial.println(getStateName(newState));

  currentState = newState;

  switch (currentState) {
    case STATE_SILENT:
      gfx->fillScreen(COLOR_BLACK);
      Serial.println("Screen BLACK (silent)");
      break;

    case STATE_ALARM:
      blinkStartTime = millis();
      blinkState = false;
      gfx->fillScreen(COLOR_RED);
      Serial.println("Screen ALARM started (red/white blink)");
      break;
  }
}

const char* getStateName(State s) {
  return (s == STATE_SILENT) ? "SILENT" : "ALARM";
}

// ============== BUTTON HANDLING ==============

void handleButton() {
  bool pressed = (digitalRead(BUTTON_PIN) == LOW);

  if (pressed && !lastButtonState) {
    Serial.println("BUTTON PRESSED");
    gfx->fillScreen(COLOR_WHITE);
    Serial.println("Screen WHITE (held)");
  }
  else if (!pressed && lastButtonState) {
    Serial.println("BUTTON RELEASED");

    if (currentState == STATE_ALARM) {
      Serial.println("Reset ALARM -> SILENT");
      transitionTo(STATE_SILENT);
      // Green flash confirmation
      gfx->fillScreen(COLOR_GREEN);
      delay(300);
      gfx->fillScreen(COLOR_BLACK);
    } else {
      gfx->fillScreen(COLOR_BLACK);
      Serial.println("Screen BLACK (silent)");
    }
  }

  lastButtonState = pressed;
}

// ============== NETWORK FUNCTIONS ==============

void checkAlertTopic() {
  Serial.println("Poll alert...");
  String response = fetchNtfy(alertTopic);
  if (response.length() == 0) {
    Serial.println("  No response");
    return;
  }

  StaticJsonDocument<512> doc;
  DeserializationError error = deserializeJson(doc, response);
  if (error) {
    Serial.print("  JSON error: ");
    Serial.println(error.c_str());
    return;
  }

  String id = doc["id"] | "";
  String message = doc["message"] | "";

  if (id == lastAlertId) {
    Serial.println("  Same ID, skip");
    return;
  }

  lastAlertId = id;
  Serial.print("  New: ");
  Serial.println(message);

  if (message.equalsIgnoreCase("SILENCE")) {
    Serial.println("  -> SILENCE");
    transitionTo(STATE_SILENT);
    gfx->fillScreen(COLOR_GREEN);
    gfx->setTextColor(COLOR_BLACK, COLOR_GREEN);
    gfx->setTextSize(3);
    gfx->setCursor(20, 140);
    gfx->println("SILENCE");
    delay(1000);
    gfx->fillScreen(COLOR_BLACK);
  } else {
    Serial.println("  -> ALARM");
    transitionTo(STATE_ALARM);
  }
}

void checkSilenceTopic() {
  String response = fetchNtfy(silenceTopic);
  if (response.length() == 0) return;

  StaticJsonDocument<512> doc;
  DeserializationError error = deserializeJson(doc, response);
  if (error) return;

  String id = doc["id"] | "";
  if (id == lastSilenceId) return;

  lastSilenceId = id;
  Serial.print("Silence: ");
  Serial.println((const char*)doc["message"]);

  if (currentState == STATE_ALARM) {
    Serial.println("  -> Stop alarm");
    transitionTo(STATE_SILENT);
    gfx->fillScreen(COLOR_GREEN);
    gfx->setTextColor(COLOR_BLACK, COLOR_GREEN);
    gfx->setTextSize(3);
    gfx->setCursor(20, 140);
    gfx->println("SILENCED");
    delay(1000);
    gfx->fillScreen(COLOR_BLACK);
  }
}

String fetchNtfy(const char* url) {
  HTTPClient http;
  http.begin(url);
  http.setTimeout(5000);

  int code = http.GET();
  Serial.print("  HTTP ");
  Serial.println(code);

  if (code != 200) {
    http.end();
    return "";
  }

  String payload = http.getString();
  http.end();

  int newline = payload.indexOf('\n');
  if (newline > 0) payload = payload.substring(0, newline);

  return payload;
}

// ============== DISPLAY FUNCTIONS ==============

void testDisplay() {
  Serial.println("  RED");
  gfx->fillScreen(COLOR_RED);
  delay(200);

  Serial.println("  GREEN");
  gfx->fillScreen(COLOR_GREEN);
  delay(200);

  Serial.println("  BLUE");
  gfx->fillScreen(COLOR_BLUE);
  delay(200);

  Serial.println("  WHITE");
  gfx->fillScreen(COLOR_WHITE);
  delay(200);

  Serial.println("  BLACK");
  gfx->fillScreen(COLOR_BLACK);
  delay(200);

  Serial.println("Test complete");
}

void updateBlink(unsigned long now) {
  unsigned long elapsed = now - blinkStartTime;
  bool newState = ((elapsed / BLINK_PERIOD) % 2) == 1;

  if (newState != blinkState) {
    blinkState = newState;
    gfx->fillScreen(blinkState ? COLOR_WHITE : COLOR_RED);
    Serial.println(blinkState ? "WHITE" : "RED");
  }
}