// ══════════════════════════════════════════════════════════════════════════════
// Mode Manager - Strict Mode Separation System
// แยกโหมดการทำงานแบบเด็ดขาด ไม่ให้ทับซ้อนกัน
// ══════════════════════════════════════════════════════════════════════════════

import { setDisplayMode } from './presentation-config.js';

/**
 * Mode Manager Class
 * ควบคุมโหมดการทำงานทั้งหมด แยกอย่างเด็ดขาด
 */
export class ModeManager {
  constructor() {
    this.currentMode = 'intro';
    this.modes = {
      intro: null,
      presentation: null,
      editor: null
    };
    
    // Track all active systems
    this.activeSystems = {
      smartLayout: false,
      dragDrop: false,
      contentEditable: false,
      resizeObserver: false,
      keyboardNav: false,
      safeZoneBorder: false
    };
    
    // System references
    this.systems = {
      smartLayoutControl: null,
      dragDropManager: null,
      resizeObserver: null,
      eventListeners: []
    };
    
    console.log('[ModeManager] Initialized');
  }

  /**
   * Switch to a specific mode (EXCLUSIVE - ปิดโหมดอื่นทั้งหมด)
   */
  switchMode(newMode) {
    if (!['intro', 'presentation', 'editor'].includes(newMode)) {
      console.error(`[ModeManager] Invalid mode: ${newMode}`);
      return false;
    }

    if (this.currentMode === newMode) {
      console.log(`[ModeManager] Already in ${newMode} mode`);
      return true;
    }

    console.log(`[ModeManager]  SWITCHING: ${this.currentMode} → ${newMode}`);

    // 1. SHUTDOWN current mode completely
    this.shutdownMode(this.currentMode);

    // 2. UPDATE mode
    this.currentMode = newMode;
    setDisplayMode(newMode);

    // 3. ACTIVATE new mode exclusively
    this.activateMode(newMode);

    // 4. Dispatch event
    window.dispatchEvent(new CustomEvent('modeChanged', {
      detail: { 
        mode: newMode,
        timestamp: Date.now()
      }
    }));

    console.log(`[ModeManager]  Now in ${newMode} mode (ALL OTHER MODES DISABLED)`);
    return true;
  }

  /**
   * Shutdown a mode completely (ปิดทุกระบบในโหมดนั้น)
   */
  shutdownMode(mode) {
    console.log(`[ModeManager]  Shutting down ${mode} mode...`);

    switch (mode) {
      case 'intro':
        this.shutdownIntroMode();
        break;
      case 'presentation':
        this.shutdownPresentationMode();
        break;
      case 'editor':
        this.shutdownEditorMode();
        break;
    }

    console.log(`[ModeManager] ${mode} mode shut down completely`);
  }

  /**
   * Activate a mode exclusively (เปิดเฉพาะระบบในโหมดนั้น)
   */
  activateMode(mode) {
    console.log(`[ModeManager]  Activating ${mode} mode...`);

    switch (mode) {
      case 'intro':
        this.activateIntroMode();
        break;
      case 'presentation':
        this.activatePresentationMode();
        break;
      case 'editor':
        this.activateEditorMode();
        break;
    }

    console.log(`[ModeManager] ${mode} mode activated exclusively`);
  }

  // ═══════════════════════════════════════════════════════════════════════
  // INTRO MODE - เฉพาะหน้า Intro
  // ═══════════════════════════════════════════════════════════════════════

  activateIntroMode() {
    // Intro mode: ไม่มีระบบอะไรทำงานเลย เป็นหน้าคงที่
    this.disableAllSystems();
    
    // ปิด Smart Layout อย่างเด็ดขาด
    if (window.smartLayoutControl) {
      window.smartLayoutControl.detach();
    }

    //  ซ่อน UI ของโหมดอื่นทั้งหมด
    this.hideAllModeUI();

    // แสดงเฉพาะ intro scene
    const scenes = document.querySelectorAll('[data-scene]');
    scenes.forEach(scene => {
      if (scene.dataset.scene === 'intro') {
        scene.classList.add('active');
      } else {
        scene.classList.remove('active');
      }
    });

    console.log('[ModeManager] Intro mode: Static display only (no systems)');
  }

  shutdownIntroMode() {
    // Intro ไม่มีอะไรต้องปิด
    console.log('[ModeManager] Intro mode: No systems to shutdown');
  }

  // ═══════════════════════════════════════════════════════════════════════
  // PRESENTATION MODE - สำหรับนำเสนอเท่านั้น
  // ═══════════════════════════════════════════════════════════════════════

  activatePresentationMode() {
    // ปิดทุกระบบก่อน
    this.disableAllSystems();

    // เปิดเฉพาะ Keyboard Navigation
    this.activeSystems.keyboardNav = true;

    //  เปิด Smart Layout เฉพาะ Presentation Mode
    this.activeSystems.smartLayout = true;
    
    //  Reattach Smart Layout observers สำหรับ Presentation
    if (window.smartLayoutControl) {
      this.systems.smartLayoutControl = window.smartLayoutControl;
      window.smartLayoutControl.reattach();
    }
    
    // ปิด Safe Zone Border
    this.activeSystems.safeZoneBorder = false;

    //  แสดงเฉพาะ UI ของ Presentation Mode
    this.showPresentationUI();

    console.log('[ModeManager] Presentation mode: Keyboard nav + Smart Layout ENABLED');
  }

  shutdownPresentationMode() {
    // ปิด Keyboard Navigation
    this.activeSystems.keyboardNav = false;

    // ปิด Smart Layout และ detach observers
    this.activeSystems.smartLayout = false;
    if (window.smartLayoutControl) {
      window.smartLayoutControl.detach();
    }

    // ✅ ซ่อน UI ของ Presentation Mode
    this.hideAllModeUI();

    console.log('[ModeManager] Presentation mode: Shut down');
  }

  // ═══════════════════════════════════════════════════════════════════════
  // EDITOR MODE - สำหรับแก้ไข/ลากย้ายเท่านั้น
  // ═══════════════════════════════════════════════════════════════════════

  activateEditorMode() {
    // ปิดทุกระบบก่อน
    this.disableAllSystems();

    // เปิด Content Editable
    this.activeSystems.contentEditable = true;

    // เปิด Drag & Drop
    this.activeSystems.dragDrop = true;

    // เปิด Safe Zone Border (กรอบสีแดง)
    this.activeSystems.safeZoneBorder = true;
    this.showSafeZoneBorder();

    // ปิด Smart Layout อย่างเด็ดขาด (ห้ามทำงานใน Editor Mode)
    this.activeSystems.smartLayout = false;
    if (window.smartLayoutControl) {
      window.smartLayoutControl.detach();
    }

    // ปิด Resize Observer
    this.activeSystems.resizeObserver = false;

    //  แสดงเฉพาะ UI ของ Editor Mode
    this.showEditorUI();

    console.log('[ModeManager] Editor mode: Edit/Drag only (Smart Layout DISABLED)');
  }

  shutdownEditorMode() {
    // ปิด Content Editable
    this.activeSystems.contentEditable = false;
    this.disableContentEditable();

    // ปิด Drag & Drop
    this.activeSystems.dragDrop = false;

    // ปิด Safe Zone Border
    this.activeSystems.safeZoneBorder = false;
    this.hideSafeZoneBorder();

    // ✅ ซ่อน UI ของ Editor Mode
    this.hideAllModeUI();

    console.log('[ModeManager] Editor mode: Shut down');
  }

  // ═══════════════════════════════════════════════════════════════════════
  // SYSTEM CONTROL - ควบคุมระบบย่อยๆ
  // ═══════════════════════════════════════════════════════════════════════

  /**
   * ปิดทุกระบบ (ไม่ต้อง detach Smart Layout เพราะแต่ละโหมดจัดการเอง)
   */
  disableAllSystems() {
    // ไม่ detach Smart Layout ที่นี่ ให้แต่ละโหมดจัดการเอง
    
    // ปิด Content Editable
    this.disableContentEditable();

    // ซ่อน Safe Zone Border
    this.hideSafeZoneBorder();

    // รีเซ็ต active systems
    Object.keys(this.activeSystems).forEach(key => {
      this.activeSystems[key] = false;
    });

    console.log('[ModeManager] All systems disabled (except Smart Layout - handled per mode)');
  }

  /**
   * ปิด Content Editable ทุกอัน
   */
  disableContentEditable() {
    const editables = document.querySelectorAll('[contenteditable="true"]');
    editables.forEach(el => {
      el.contentEditable = false;
      el.blur();
    });

    // ลบ class editable
    const stage = document.getElementById('stage');
    if (stage) {
      stage.classList.remove('slide-editable');
    }
  }

  /**
   * ซ่อน Safe Zone Border
   */
  hideSafeZoneBorder() {
    const safeZone = document.querySelector('.safe-zone-overlay');
    if (safeZone) {
      safeZone.classList.add('hidden');
    }
  }

  /**
   * แสดง Safe Zone Border
   */
  showSafeZoneBorder() {
    const safeZone = document.querySelector('.safe-zone-overlay');
    if (safeZone) {
      safeZone.classList.remove('hidden');
    }
  }

  /**
   * Get current mode
   */
  getCurrentMode() {
    return this.currentMode;
  }

  /**
   * Check if specific system is active
   */
  isSystemActive(systemName) {
    return this.activeSystems[systemName] || false;
  }

  /**
   * Get all active systems
   */
  getActiveSystems() {
    return Object.entries(this.activeSystems)
      .filter(([key, value]) => value)
      .map(([key]) => key);
  }

  /**
   * Register system reference
   */
  registerSystem(name, reference) {
    this.systems[name] = reference;
    console.log(`[ModeManager] Registered system: ${name}`);
  }

  // ═══════════════════════════════════════════════════════════════════════
  // UI CONTROL - ควบคุม UI elements ของแต่ละโหมด
  // ═══════════════════════════════════════════════════════════════════════

  /**
   * ซ่อน UI ของทุกโหมด
   */
  hideAllModeUI() {
    // Presentation Mode UI
    const navControls = document.getElementById('navControls');
    const exitPresentationBtn = document.getElementById('exitPresentationBtn');
    const fullscreenBtn = document.getElementById('fullscreenBtn');
    const editSlideBtn = document.getElementById('editSlideBtn');

    if (navControls) navControls.classList.add('hidden');
    if (exitPresentationBtn) exitPresentationBtn.classList.add('hidden');
    if (fullscreenBtn) fullscreenBtn.classList.add('hidden');
    if (editSlideBtn) editSlideBtn.classList.add('hidden');

    // Editor Mode UI
    const saveSlideBtn = document.getElementById('saveSlideBtn');
    const cancelEditBtn = document.getElementById('cancelEditBtn');
    
    if (saveSlideBtn) saveSlideBtn.classList.add('hidden');
    if (cancelEditBtn) cancelEditBtn.classList.add('hidden');

    console.log('[ModeManager] All mode UI hidden');
  }

  /**
   * แสดง UI ของ Presentation Mode เท่านั้น
   */
  showPresentationUI() {
    this.hideAllModeUI();

    const navControls = document.getElementById('navControls');
    const exitPresentationBtn = document.getElementById('exitPresentationBtn');
    const fullscreenBtn = document.getElementById('fullscreenBtn');
    const editSlideBtn = document.getElementById('editSlideBtn');

    if (navControls) navControls.classList.remove('hidden');
    if (exitPresentationBtn) exitPresentationBtn.classList.remove('hidden');
    if (fullscreenBtn) fullscreenBtn.classList.remove('hidden');
    if (editSlideBtn) editSlideBtn.classList.remove('hidden');

    console.log('[ModeManager] Presentation UI shown exclusively');
  }

  /**
   * แสดง UI ของ Editor Mode เท่านั้น
   */
  showEditorUI() {
    this.hideAllModeUI();

    const saveSlideBtn = document.getElementById('saveSlideBtn');
    const cancelEditBtn = document.getElementById('cancelEditBtn');
    const exitPresentationBtn = document.getElementById('exitPresentationBtn');

    if (saveSlideBtn) saveSlideBtn.classList.remove('hidden');
    if (cancelEditBtn) cancelEditBtn.classList.remove('hidden');
    if (exitPresentationBtn) exitPresentationBtn.classList.remove('hidden');

    console.log('[ModeManager] Editor UI shown exclusively');
  }

  /**
   * Force shutdown all (emergency)
   */
  emergencyShutdown() {
    console.warn('[ModeManager]  EMERGENCY SHUTDOWN');
    this.disableAllSystems();
    
    // Stop all observers
    if (this.systems.resizeObserver) {
      this.systems.resizeObserver.disconnect();
    }

    // Remove all event listeners
    this.systems.eventListeners.forEach(({ element, event, handler }) => {
      element.removeEventListener(event, handler);
    });
    this.systems.eventListeners = [];

    console.log('[ModeManager] Emergency shutdown complete');
  }
}

// Singleton instance
let modeManagerInstance = null;

/**
 * Get Mode Manager instance (Singleton)
 */
export function getModeManager() {
  if (!modeManagerInstance) {
    modeManagerInstance = new ModeManager();
  }
  return modeManagerInstance;
}

/**
 * Quick access functions
 */
export function switchToIntroMode() {
  return getModeManager().switchMode('intro');
}

export function switchToPresentationMode() {
  return getModeManager().switchMode('presentation');
}

export function switchToEditorMode() {
  return getModeManager().switchMode('editor');
}

export default ModeManager;