#include <TM1637Display.h>
#include <Preferences.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <Adafruit_NeoPixel.h>

#define CLK 22
#define DIO 21
#define BTN_START 18
#define BTN_RESET 19
#define BTN_LOG 23 // New button for webhook logging
#define NEOPIXEL_PIN 5 // Pin for NeoPixel
#define WIFI_SSID "WOKWI-Guest" 
#define WIFI_PASSWORD "" 
#define WEBHOOK_URL "https://webhook.site/646a4709-2ffc-44bc-851e-8a8cebea64e3"

TM1637Display display(CLK, DIO);
Preferences prefs;
Adafruit_NeoPixel pixel(1, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

bool running = false;
unsigned long lastMillis = 0;
unsigned long lastBlink = 0;
bool colonOn = true;

bool resetPending = false; // Track if waiting for reset confirmation
unsigned long resetStartMillis = 0; // Time when reset flashing started

uint8_t hours = 0;
uint8_t minutes = 0;
uint8_t seconds = 0;

const uint8_t ALL_ON[] = {0xff, 0xff, 0xff, 0xff}; // All segments ON
const uint8_t ALL_OFF[] = {0x00, 0x00, 0x00, 0x00}; // All segments OFF

// NeoPixel colors (R, G, B)
const uint32_t COLOR_BLUE = pixel.Color(0, 0, 255); // Sending request
const uint32_t COLOR_GREEN = pixel.Color(0, 255, 0); // Success
const uint32_t COLOR_RED = pixel.Color(255, 0, 0); // HTTP error
const uint32_t COLOR_ORANGE = pixel.Color(255, 165, 0); // Wi-Fi error
const uint32_t COLOR_OFF = pixel.Color(0, 0, 0); // Off

void saveTime() {
  prefs.begin("timer", false);
  prefs.putUChar("hours", hours);
  prefs.putUChar("minutes", minutes);
  prefs.putUChar("seconds", seconds);
  prefs.end();
}

void loadTime() {
  prefs.begin("timer", true);
  hours = prefs.getUChar("hours", 0);
  minutes = prefs.getUChar("minutes", 0);
  seconds = prefs.getUChar("seconds", 0);
  prefs.end();
  if (hours > 99 || minutes > 59 || seconds > 59) {
    hours = 0;
    minutes = 0;
    seconds = 0;
  }
}

void showTime(bool colon) {
  if (resetPending) {
    // During reset pending, flash all segments ON/OFF
    if ((millis() / 500) % 2 == 0) {
      display.setSegments(ALL_ON);
    } else {
      display.setSegments(ALL_OFF);
    }
  } else {
    // Normal display: show HHMM with colon state
    int displayTime = hours * 100 + minutes; // HHMM
    uint8_t dots = colon ? 0b01000000 : 0;
    display.showNumberDecEx(displayTime, dots, true);
  }
}

void setPixelColor(uint32_t color, unsigned long duration) {
  pixel.setPixelColor(0, color);
  pixel.show();
  if (duration > 0) {
    delay(duration); // Blocking delay to show color
    pixel.setPixelColor(0, COLOR_OFF);
    pixel.show();
  }
}

bool sendWebhook() {
  // Connect to Wi-Fi
  setPixelColor(COLOR_BLUE, 0); // Blue: sending request
  if (WiFi.status() != WL_CONNECTED) {
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    unsigned long startAttempt = millis();
    while (WiFi.status() != WL_CONNECTED && (millis() - startAttempt) < 10000UL) {
      delay(100); // Wait up to 10 seconds for connection
    }
    if (WiFi.status() != WL_CONNECTED) {
      setPixelColor(COLOR_ORANGE, 2000); // Orange: Wi-Fi error
      return false;
    }
  }

  // Format time as HH:MM:SS
  char timeStr[9];
  snprintf(timeStr, sizeof(timeStr), "%02d:%02d:%02d", hours, minutes, seconds);

  // Send POST request
  HTTPClient http;
  http.begin(WEBHOOK_URL);
  http.addHeader("Content-Type", "application/json");
  String payload = "{\"time\": \"" + String(timeStr) + "\"}";
  int httpCode = http.POST(payload);
  http.end();

  if (httpCode == HTTP_CODE_OK) {
    setPixelColor(COLOR_GREEN, 2000); // Green: success
    return true;
  } else {
    setPixelColor(COLOR_RED, 2000); // Red: HTTP error
    return false;
  }
}

void setup() {
  pinMode(BTN_START, INPUT_PULLUP);
  pinMode(BTN_RESET, INPUT_PULLUP);
  pinMode(BTN_LOG, INPUT_PULLUP); // Initialize log button
  display.setBrightness(0x0f);
  pixel.begin();
  pixel.setBrightness(50); // Adjust brightness (0-255)
  setPixelColor(COLOR_OFF, 0); // Ensure NeoPixel is off initially

  loadTime();
  showTime(true);
}

void loop() {
  // --- Start/Stop button ---
  if (digitalRead(BTN_START) == LOW) {
    delay(50); // Simple debouncing
    if (digitalRead(BTN_START) == LOW) {
      running = !running;
      if (running) {
        lastMillis = millis(); // Reset to current time on resume (overflow-safe)
        lastBlink = millis();  // Reset blink timing
        colonOn = true;
      } else {
        saveTime();
        colonOn = true; // Colon steady ON when stopped
      }
      resetPending = false; // Cancel any pending reset
      showTime(colonOn);
      while (digitalRead(BTN_START) == LOW); // Wait for button release
    }
  }

  // --- Reset button ---
  if (digitalRead(BTN_RESET) == LOW) {
    delay(50); // Simple debouncing
    if (digitalRead(BTN_RESET) == LOW) {
      if (!resetPending) {
        // First press: start flashing and reset confirmation window
        resetPending = true;
        resetStartMillis = millis();
        lastBlink = millis(); // Sync flashing with reset
      } else {
        // Second press within 5 seconds: confirm reset
        if ((millis() - resetStartMillis) <= 5000UL) {
          hours = 0;
          minutes = 0;
          seconds = 0;
          saveTime();
          colonOn = true;
          resetPending = false; // Stop flashing
          showTime(true);
        }
      }
      while (digitalRead(BTN_RESET) == LOW); // Wait for button release
    }
  }

  // --- Log button ---
  if (digitalRead(BTN_LOG) == LOW) {
    delay(50); // Simple debouncing
    if (digitalRead(BTN_LOG) == LOW) {
      resetPending = false; // Cancel any pending reset
      if (sendWebhook()) {
        // On success, reset timer
        hours = 0;
        minutes = 0;
        seconds = 0;
        saveTime();
        colonOn = true;
        showTime(true);
      }
      while (digitalRead(BTN_LOG) == LOW); // Wait for button release
    }
  }

  // --- Check if reset confirmation window expired ---
  if (resetPending && (millis() - resetStartMillis) > 5000UL) {
    resetPending = false; // Stop flashing after 5 seconds
    showTime(colonOn); // Restore normal display
  }

  // --- Timer update every 1 second ---
  // Note: (millis() - lastMillis) is overflow-safe due to unsigned arithmetic
  if (running && !resetPending && (millis() - lastMillis) >= 1000UL) {
    unsigned long elapsed = millis() - lastMillis;
    unsigned long secondsToAdd = elapsed / 1000UL; // Calculate full seconds
    lastMillis += secondsToAdd * 1000UL; // Update lastMillis (overflow-safe)

    seconds += secondsToAdd;
    while (seconds >= 60) { // Handle multiple seconds if large time elapsed
      seconds -= 60;
      minutes++;
      if (minutes > 59) {
        minutes = 0;
        hours++;
        if (hours > 99) hours = 0;
      }
      showTime(colonOn); // Update display when minutes change
    }
  }

  // --- Colon blink every 500ms ---
  // Note: (millis() - lastBlink) is overflow-safe
  if ((running || resetPending) && (millis() - lastBlink) >= 500UL) {
    lastBlink += (millis() - lastBlink) / 500UL * 500UL; // Update lastBlink (overflow-safe)
    colonOn = !colonOn;
    showTime(colonOn);
  }
}