#include <Arduino.h>
// #include "DYPlayerArduino.h"
// #include <SoftwareSerial.h>



#define PIR_PIN 3   // PIR sensor input pin
#define BULB_PIN 5  // PWM pin for MOSFET/bulb control
#define MP3_RX 10   // SoftwareSerial RX for MP3
#define MP3_TX 11   // SoftwareSerial TX for MP3

// Initialise on software serial port.
// SoftwareSerial mySerial(MP3_RX, MP3_TX);  // RX, TX
// DY::Player player(&mySerial);

// =========== INIT Conditions ================
const unsigned long INIT_DURATION = 10 * 1000UL;  // 60 seconds
const int INIT_BRIGHTNESS = 25;                   // PIR Init Brightness 10% (255 * 0.1)
int INIT_LED_ON_TIME = 500;                       // LED On time (in milliseconds) during flashing at INIT state
int INIT_LED_OFF_TIME = 3000;                     // LED Off time (in milliseconds) during flashing at INIT state
const int FLASH_BRIGHTNESS = 128;                 // 50% (255 * 0.5) flashing brightness


const int READY_BRIGHTNESS = 77;            // 30% (255 * 0.3)
unsigned long flashInterval = 10 * 1000UL;  // LED Flash Interval during Ready state
const int readyLedOnTime = 500;             // For how long the led needs to be on during Ready flashing

unsigned long lastLedToggleTime = millis() - INIT_LED_OFF_TIME - 20;  // note last time led has toggled

const unsigned long COOLDOWN_DURATION = 30 * 1000UL;  // 2 minutes
unsigned long TRIGGER_LED_ON_TIME = 20 * 1000UL;      // LED On time when PIR triggered
const int MAX_BRIGHTNESS = 255;                       // PWM max
const int PULSE_MAX = 64;                             // 25% (255 * 0.25)
const int volume = 25;                                // Set mp3 volume from 1-30


enum State { INIT,
             READY,
             TRIGGERED };   // System states
State currentState = INIT;  // Start in INIT

unsigned long initStartTime;    // Timestamp for init start
unsigned long fadeStartTime;    // Timestamp for fade start
unsigned long cooldownEndTime;  // Timestamp for cooldown end
bool triggerLedOff = false;     // flag to turn off led when pir triggered after the specified time pass

const unsigned long FADE_DURATION = 2000UL;  // 2 seconds
const unsigned long PULSE_PERIOD = 2000UL;   // Pulse cycle time (ms)
const float PI_TWO = 2.0 * 3.1415926535;     // For sine calculation

bool fullBrightness = false;  // flag to check if light is on full brightness
int brightness = 0;

void setup() {
  // player.begin();
  // Also initiate the hardware serial port so we can use it for debug printing
  // to the console..
  Serial.begin(9600);
  // player.setVolume(volume);  // 50% Volume Set volume from 0-30

  pinMode(PIR_PIN, INPUT_PULLUP);  // PIR as input
  pinMode(BULB_PIN, OUTPUT);       // Bulb PWM as output
  analogWrite(BULB_PIN, 0);        // Start bulb off

  initStartTime = millis();  // Record init start time
  Serial.println("Perform Initialization");
}

void loop() {
  switch (currentState) {
    case INIT:
      // Soft pulsing at ~25% average (sine from 0 to 64)
      {
        doInitSequence();
      }

      break;

    case READY:
      // Steady 50%, wait for PIR trigger
      if (digitalRead(PIR_PIN) == HIGH) {
        currentState = TRIGGERED;
        fadeStartTime = millis();                        // Start fade timer
        cooldownEndTime = millis() + COOLDOWN_DURATION;  // Initial cooldown
        // player.playSpecified(1);                         //Play specified file
        Serial.println("Play Mp3");
      }

      // Indicate led is in ready mode
      if ((millis() - lastLedToggleTime) > flashInterval) {
        Serial.println("flash led once to indicate Redy mode");
        lastLedToggleTime = millis();  //Note current time
        analogWrite(BULB_PIN, READY_BRIGHTNESS);
        delay(readyLedOnTime);
        analogWrite(BULB_PIN, 0);  // Turn off led
      }
      break;

    case TRIGGERED:
      // Handle fade from 0% to 100% over 2 seconds
      {
        if (fullBrightness == false) {
          Serial.println("Set brightness to FULL");
          for (brightness = 0; brightness <= MAX_BRIGHTNESS; brightness++) {
            analogWrite(BULB_PIN, brightness);
            Serial.print("Brightness:");
            Serial.println(brightness);
            delay(16);  // Wait for 16 milliseconds
          }
          Serial.print("Full Brightness:");
          Serial.println(brightness);
          fullBrightness = true;
          triggerLedOff = false;  // Flag to be checked to turn off led after the time finish
        }
      }
      if (!triggerLedOff && (millis() - fadeStartTime) > TRIGGER_LED_ON_TIME) {
        for (brightness = MAX_BRIGHTNESS; brightness >= 0; brightness--) {
          Serial.print("Brightness:");
          Serial.println(brightness);
          analogWrite(BULB_PIN, brightness);
          delay(16);  // Wait for 16 milliseconds
        }
        // analogWrite(BULB_PIN, 0);  // Turn off led
        triggerLedOff = true;  // Set the flag to indicate led is now off
      }

      // Check if cooldown expired (2 min since last movement)
      if (millis() >= cooldownEndTime) {
        // Flash once: Brief off (200ms)
        Serial.println("Cooldown Expired get back to ready state");
        flashBulb();  // Flash bulb
        analogWrite(BULB_PIN, 0);
        Serial.println("Get back to Ready State");
        fullBrightness = false;
        currentState = READY;  // Back to READY
      }
      break;
  }
}
void flashBulb() {
  // Flash bulb 2 times at 50% brightness
  Serial.println("Flash led 2 times");
  for (int i = 0; i < 2; i++) {
    analogWrite(BULB_PIN, FLASH_BRIGHTNESS);  // Set to READY Brightness
    delay(300);                               // Turn on bulb for 300ms
    analogWrite(BULB_PIN, 0);              // Turn off bulb
    delay(500);                               // Keep bulb off for 500ms
  }
  lastLedToggleTime = millis();  // Note current time when led has been toggled
}
void doInitSequence() {
  unsigned long elapsed = millis() - initStartTime;
  bool ledState = false;  //Hold led state
  while (elapsed < INIT_DURATION) {
    elapsed = millis() - initStartTime;
    if (elapsed >= INIT_DURATION) {
      currentState = READY;
      Serial.println("Init Complete");
      analogWrite(BULB_PIN, 0);  // Turn off bulb
      delay(500);                   // wait for 500 milliseconds

      //Flash Bulb 2 times
      flashBulb();
      break;
    }
    if (ledState && (millis() - lastLedToggleTime) > INIT_LED_ON_TIME) {
      Serial.println("turn off led init");
      ledState = false;              // Reset led state
      lastLedToggleTime = millis();  // Note current time
      analogWrite(BULB_PIN, 0);     // Turn off led
    } else if (!ledState && (millis() - lastLedToggleTime) > INIT_LED_OFF_TIME) {
      Serial.println("turn on led init");
      ledState = true;                         // set led state
      lastLedToggleTime = millis();            // Note current time
      analogWrite(BULB_PIN, INIT_BRIGHTNESS);  // Set led state at INIT Brightness
    }
    delay(10);  // wait for small duration
  }
}