#include "Display_ST7789.h"
#include "SD_Card.h"
#include "Display_PNG.h"
#include "Audio_Player.h"
#include <algorithm>

#define BOOT_KEY_PIN 9
#define PIN_NEOPIXEL 38

// Playback states
enum AppState {
  STATE_IDLE,
  STATE_PLAYING,
  STATE_AUTOPLAY,
  STATE_ERROR
};

AppState currentState = STATE_IDLE;
bool hasError = false;

uint16_t currentIndex = 0;
bool lastButtonState = HIGH;
uint32_t lastDebounceTime = 0;
const uint32_t debounceDelay = 50;

// Slide Show timing
uint32_t lastSlideTime = 0;
const uint32_t slideShowInterval = 5000; // 5 seconds

// Pulse control for RGB LED
uint32_t lastLedPulseTime = 0;
uint8_t pulseBrightness = 0;
bool pulseDirection = true;

void setup() {
  Serial.begin(115200);
  delay(1000);
  
  printf("\r\n==========================================\r\n");
  printf("Starting Sound and Picture Player...\r\n");
  printf("==========================================\r\n");
  
  // Setup NeoPixel
  pinMode(PIN_NEOPIXEL, OUTPUT);
  neopixelWrite(PIN_NEOPIXEL, 0, 0, 0); // turn off initially
  
  // Initialize peripherals
  Flash_test();
  SD_Init();
  LCD_Init();
  Set_Backlight(90);
  
  // Setup button
  pinMode(BOOT_KEY_PIN, INPUT_PULLUP);
  
  // Retrieve media files from SD Card
  Search_Images("/");
  Search_Wavs("/");
  
  printf("Initialization complete!\r\n");
  printf("Found %d PNG images and %d WAV soundbites.\r\n", Image_Count, Wav_Count);
  
  if (Image_Count == 0 || Wav_Count == 0) {
    hasError = true;
    currentState = STATE_ERROR;
    printf("ERROR: No media found on microSD card!\r\n");
  } else {
    printf("Displaying initial image (index 0): %s\r\n", Image_Names[0]);
    Display_Image_By_Index("/", 0);
    currentState = STATE_IDLE;
  }
}

void playCurrentPair() {
  if (Image_Count == 0 && Wav_Count == 0) {
    printf("Cannot play: missing PNG images and WAV soundbites!\r\n");
    return;
  }
  
  // Stop current playing audio if any
  stopWav();
  
  printf("Playing item index %d:\r\n", currentIndex);
  
  // Display the image
  if (Image_Count > 0) {
    uint16_t pngIndex = currentIndex % Image_Count;
    Display_Image_By_Index("/", pngIndex);
  }
  
  // Play the soundbite
  if (Wav_Count > 0) {
    uint16_t wavIndex = currentIndex % Wav_Count;
    String soundPath = String("/") + Wav_Names[wavIndex];
    printf("Playing sound: %s\r\n", soundPath.c_str());
    playWav(soundPath.c_str());
  }
}

void updateLEDStatus() {
  uint32_t now = millis();
  
  // Pulse animation frequency
  if (now - lastLedPulseTime > 15) {
    lastLedPulseTime = now;
    if (pulseDirection) {
      pulseBrightness += 2;
      if (pulseBrightness >= 120) pulseDirection = false;
    } else {
      pulseBrightness -= 2;
      if (pulseBrightness <= 10) pulseDirection = true;
    }
  }

  // Update LED color based on state
  if (hasError) {
    // Flashing red
    if ((now / 250) % 2 == 0) {
      neopixelWrite(PIN_NEOPIXEL, 64, 0, 0); // Dim Red
    } else {
      neopixelWrite(PIN_NEOPIXEL, 0, 0, 0);
    }
  } 
  else if (isWavPlaying()) {
    // Pulsing Green
    neopixelWrite(PIN_NEOPIXEL, 0, pulseBrightness, 0);
  } 
  else if (currentState == STATE_AUTOPLAY) {
    // Pulsing Purple (Red + Blue)
    neopixelWrite(PIN_NEOPIXEL, pulseBrightness / 2, 0, pulseBrightness);
  } 
  else {
    // Solid Blue
    neopixelWrite(PIN_NEOPIXEL, 0, 0, 32);
  }
}

void loop() {
  bool currentButtonReading = digitalRead(BOOT_KEY_PIN);
  static uint32_t buttonPressStartTime = 0;
  static bool buttonWasHeld = false;
  
  // Detect changes in button state
  if (currentButtonReading != lastButtonState) {
    lastDebounceTime = millis();
    if (currentButtonReading == LOW) {
      buttonPressStartTime = millis();
      buttonWasHeld = false;
    }
  }
  
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (currentButtonReading == LOW) {
      // Button is being held down. Check if it exceeds long-press threshold (1.5 seconds)
      if (!buttonWasHeld && (millis() - buttonPressStartTime > 1500)) {
        buttonWasHeld = true; // Mark as held to prevent repeated triggers
        if (!hasError) {
          if (currentState == STATE_AUTOPLAY) {
            currentState = STATE_IDLE;
            printf("Autoplay Disabled. Manual Mode active.\r\n");
            stopWav();
          } else {
            currentState = STATE_AUTOPLAY;
            printf("Autoplay Enabled! Cycling slides every %d ms.\r\n", slideShowInterval);
            lastSlideTime = millis();
            playCurrentPair();
          }
        }
      }
    } else {
      // Button was released
      if (lastButtonState == LOW && !buttonWasHeld) {
        // Single press trigger
        printf("Single press detected!\r\n");
        if (!hasError) {
          if (currentState == STATE_AUTOPLAY) {
            currentState = STATE_IDLE;
            printf("Autoplay Disabled via manual navigation.\r\n");
          }
          playCurrentPair();
          currentIndex = (currentIndex + 1) % std::max(Image_Count, Wav_Count);
        } else {
          printf("System in error state (missing files). Can't cycle.\r\n");
        }
      }
      buttonWasHeld = false;
    }
  }
  
  // Handle slideshow auto-advance in Autoplay mode
  if (currentState == STATE_AUTOPLAY && !hasError) {
    // Advance if the audio finished playing and 5 seconds has elapsed
    if (!isWavPlaying() && (millis() - lastSlideTime > slideShowInterval)) {
      lastSlideTime = millis();
      currentIndex = (currentIndex + 1) % std::max(Image_Count, Wav_Count);
      playCurrentPair();
    }
  }
  
  lastButtonState = currentButtonReading;
  
  // Update status RGB LED
  updateLEDStatus();
  
  delay(10); // Yield to other RTOS tasks
}