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

#define BOOT_KEY_PIN 0

// 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;

// Click gesture timers
uint32_t lastButtonReleaseTime = 0;
uint32_t buttonPressStartTime = 0;
uint8_t clickCount = 0;
bool isButtonPressed = false;
bool longPressTriggered = false;

void setup() {
  Serial.begin(115200);
  delay(1000);
  
  printf("\r\n==========================================\r\n");
  printf("Starting Sound and Picture Player...\r\n");
  printf("==========================================\r\n");
  
  // Initialize Display and Backlight first so the screen lights up immediately
  LCD_Init();
  Set_Backlight(90);
  
  // Initialize other peripherals
  Flash_test();
  SD_Init();
  
  // Setup button
  pinMode(BOOT_KEY_PIN, INPUT_PULLUP);
  
  // Retrieve media files from SD Card
  Search_Images("/");
  Search_Audio("/");
  
  // Initialize ESP32-audioI2S player
  initAudioPlayer();
  
  printf("Initialization complete!\r\n");
  printf("Found %d PNG images and %d Audio files (.mp3/.wav).\r\n", Image_Count, Audio_Count);
  
  if (Image_Count == 0 || Audio_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;
  }
  
  // Start the SoftAP and local Web Server
  initWebServer();
}

void playCurrentPair() {
  if (Image_Count == 0 && Audio_Count == 0) {
    printf("Cannot play: missing PNG images and Audio files!\r\n");
    return;
  }
  
  // Stop current playing audio if any
  stopAudio();
  
  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 audio bite
  if (Audio_Count > 0) {
    uint16_t audioIndex = currentIndex % Audio_Count;
    String soundPath = String("/") + Audio_Names[audioIndex];
    printf("Playing audio: %s\r\n", soundPath.c_str());
    playAudio(soundPath.c_str());
  }
}

void handleSinglePress() {
  printf("Gesture: Single Click - Next Slide\r\n");
  if (!hasError) {
    if (currentState == STATE_AUTOPLAY) {
      currentState = STATE_IDLE;
      printf("Autoplay Disabled.\r\n");
    }
    currentIndex = (currentIndex + 1) % std::max(Image_Count, Audio_Count);
    playCurrentPair();
  }
}

void handleDoublePress() {
  printf("Gesture: Double Click - Pause / Resume Audio\r\n");
  if (!hasError) {
    pauseResumeAudio();
  }
}

void handleTriplePress() {
  printf("Gesture: Triple Click - Previous Slide\r\n");
  if (!hasError) {
    if (currentState == STATE_AUTOPLAY) {
      currentState = STATE_IDLE;
      printf("Autoplay Disabled.\r\n");
    }
    uint16_t totalMedia = std::max(Image_Count, Audio_Count);
    currentIndex = (currentIndex + totalMedia - 1) % totalMedia;
    playCurrentPair();
  }
}

void handleQuadruplePress() {
  if (!hasError) {
    uint8_t nextVol = getPlayerVolume() + 4;
    if (nextVol > 20) nextVol = 4; // Loop back
    setPlayerVolume(nextVol);
  }
}

void handleLongPress() {
  printf("Gesture: Long Press - Toggle Autoplay Slideshow\r\n");
  if (!hasError) {
    if (currentState == STATE_AUTOPLAY) {
      currentState = STATE_IDLE;
      printf("Autoplay Disabled. Manual Mode active.\r\n");
      stopAudio();
    } else {
      currentState = STATE_AUTOPLAY;
      printf("Autoplay Enabled! Cycling slides every %d ms.\r\n", slideShowInterval);
      lastSlideTime = millis();
      playCurrentPair();
    }
  }
}

void updateLEDStatus() {
  // Disabled NeoPixel code to resolve hardware conflict with SPI SCLK (GPIO 38)
}

void loop() {
  bool currentButtonReading = digitalRead(BOOT_KEY_PIN);
  uint32_t now = millis();
  
  // Detect state transitions for debouncing and gesture capturing
  if (currentButtonReading == LOW && lastButtonState == HIGH) {
    // Button Pressed down
    lastDebounceTime = now;
    buttonPressStartTime = now;
    isButtonPressed = true;
    longPressTriggered = false;
  } 
  else if (currentButtonReading == LOW && lastButtonState == LOW && isButtonPressed) {
    // Button is held down
    if (!longPressTriggered && (now - buttonPressStartTime > 1500)) {
      longPressTriggered = true;
      handleLongPress();
    }
  }
  else if (currentButtonReading == HIGH && lastButtonState == LOW) {
    // Button Released
    isButtonPressed = false;
    uint32_t pressDuration = now - buttonPressStartTime;
    
    if (!longPressTriggered && pressDuration > 50) { // Debounced release
      clickCount++;
      lastButtonReleaseTime = now;
    }
  }
  
  // Process click gestures after 300ms timeout has elapsed since last release
  if (clickCount > 0 && !isButtonPressed && (now - lastButtonReleaseTime > 300)) {
    if (clickCount == 1) {
      handleSinglePress();
    } else if (clickCount == 2) {
      handleDoublePress();
    } else if (clickCount == 3) {
      handleTriplePress();
    } else if (clickCount >= 4) {
      handleQuadruplePress();
    }
    clickCount = 0; // Reset counter
  }
  
  // Handle slideshow auto-advance in Autoplay mode
  if (currentState == STATE_AUTOPLAY && !hasError) {
    // Only advance when the audio stops playing and slideShowInterval (5s) has passed
    if (!isAudioPlaying() && (now - lastSlideTime > slideShowInterval)) {
      lastSlideTime = now;
      currentIndex = (currentIndex + 1) % std::max(Image_Count, Audio_Count);
      playCurrentPair();
    }
  }
  
  lastButtonState = currentButtonReading;
  
  // Handle incoming web server clients
  handleWebServer();
  
  // Update status RGB LED
  updateLEDStatus();
  
  delay(10); // Yield to other RTOS tasks
}