// Loading UI - Manages the visual loading screen and user feedback
class LoadingUI {
  constructor() {
    this.container = null;
    this.progressBar = null;
    this.systemStatusContainer = null;
    this.errorMessage = null;
    this.retryButton = null;
    this.continueButton = null;
    this.isVisible = false;
    this.systemCards = new Map();
  }

  // Initialize loading screen
  initialize() {
    this.createLoadingScreen();
    this.attachEventListeners();
  }

  // Create the loading screen DOM
  createLoadingScreen() {
    this.container = document.createElement('div');
    this.container.id = 'libreportal-loading-screen';
    this.container.className = 'loading-screen aurora-bg aurora-static';
    this.container.innerHTML = `
      <div class="aurora-stars" aria-hidden="true"></div>
      <div class="loading-container">
        <div class="aurora-header">
          <div class="aurora-logo">
            <img src="/icons/libreportal.svg" alt="LibrePortal" onload="this.classList.add('loaded')" onerror="this.style.display='none'">
            <h1>LibrePortal</h1>
          </div>
          <p class="aurora-subtitle">Drifting softly into your private universe...</p>
        </div>

        <div class="loading-progress">
          <div class="progress-bar-container">
            <div class="progress-bar">
              <div class="progress-fill" id="progress-fill"></div>
            </div>
            <div class="progress-text">
              <span id="progress-percentage">0%</span>
              <span id="progress-details">Starting up...</span>
            </div>
          </div>
        </div>

        <div class="loading-systems" id="system-status-container">
          <!-- System status cards will be inserted here -->
        </div>

        <div class="success-message" id="success-message" style="display: none;">
          <h2>✨ Ready! ✨</h2>
          <p>LibrePortal is loaded and ready to use</p>
        </div>

        <div class="loading-actions" id="loading-actions" style="display: none;">
          <button class="btn btn-primary" id="retry-button" style="display: none;">
            <span class="btn-icon">↻</span>
            Retry
          </button>
          <button class="btn btn-secondary" id="continue-button" style="display: none;">
            Continue Anyway
          </button>
        </div>

        <div class="loading-footer">
          <div class="loading-tips">
            <p>💡 <span id="loading-tip">Loading essential components...</span></p>
          </div>
        </div>
      </div>
    `;

    // Add to page
    document.body.appendChild(this.container);
    this.isVisible = true;

    // Get references to elements
    this.progressBar = document.getElementById('progress-fill');
    this.systemStatusContainer = document.getElementById('system-status-container');
    this.errorMessage = null;
    this.retryButton = document.getElementById('retry-button');
    this.continueButton = document.getElementById('continue-button');
    
    // Initialize system cards
    this.initializeSystemCards();
  }

  // Initialize system status cards
  initializeSystemCards() {
    const systems = [
      { id: 'core', name: 'Core System', icon: '🪐' },
      { id: 'data', name: 'Data Loading', icon: '📊' },
      { id: 'components', name: 'UI Components', icon: '🎨' },
      { id: 'task', name: 'Task System', icon: '📋' },
      { id: 'managers', name: 'System Managers', icon: '🔧' },
      { id: 'backend', name: 'Backend Services', icon: '🌐' },
      { id: 'config-validation', name: 'Config Files', icon: '🔍' },
      { id: 'update-lock', name: 'Update Lock', icon: '🔄' },
      { id: 'pause-lock', name: 'Pause Lock', icon: '⏸️' }
    ];

    systems.forEach(system => {
      const card = document.createElement('div');
      card.className = 'system-card';
      card.id = `system-card-${system.id}`;
      card.innerHTML = `
        <div class="system-icon">${system.icon}</div>
        <div class="system-info">
          <div class="system-name">${system.name}</div>
          <div class="system-status">Waiting...</div>
        </div>
        <div class="system-indicator">
          <div class="status-icon">⏳</div>
        </div>
      `;

      this.systemStatusContainer.appendChild(card);
      this.systemCards.set(system.id, card);
    });
  }

  // Update progress
  updateProgress(progress, details = '') {
    if (this.progressBar) {
      this.progressBar.style.width = `${progress}%`;
    }

    const percentageElement = document.getElementById('progress-percentage');
    if (percentageElement) {
      percentageElement.textContent = `${Math.round(progress)}%`;
    }

    const detailsElement = document.getElementById('progress-details');
    if (detailsElement) {
      detailsElement.textContent = details || `${Math.round(progress)}% complete`;
    }

    // Update loading tip
    this.updateLoadingTip(progress);
  }

  // Process message to convert backticks to styled code blocks
  processMessage(message) {
    if (!message) return message;
    
    // Convert backtick-wrapped text to styled code blocks
    return message.replace(/`([^`]+)`/g, '<code class="command-box">$1</code>');
  }

  // Update system check status
  updateSystemCheck(systemId, checkName, status, error = null, message = null) {
    const card = this.systemCards.get(systemId);
    if (!card) return;

    const statusElement = card.querySelector('.system-status');
    const indicatorElement = card.querySelector('.status-icon');
    
    if (!statusElement || !indicatorElement) return;
    
    switch (status) {
      case 'checking':
        statusElement.textContent = `Checking: ${checkName}`;
        indicatorElement.textContent = '⏳';
        card.className = 'system-card checking';
        // Auto-scroll to this card when checking starts
        this.scrollToCard(card);
        break;
        
      case 'retrying':
        statusElement.innerHTML = `Retrying: ${checkName}`;
        indicatorElement.textContent = '🔄';
        card.className = 'system-card retrying';
        // Don't auto-scroll during retry to prevent jumping around
        if (message) {
          statusElement.title = this.processMessage(message);
        }
        break;
        
      case 'waiting':
        statusElement.textContent = `Waiting: ${checkName}`;
        indicatorElement.textContent = '⏰';
        card.className = 'system-card waiting';
        break;
        
      case 'passed':
        statusElement.textContent = 'Operational';
        indicatorElement.textContent = '✅';
        card.className = 'system-card passed';
        break;
        
      case 'failed':
        statusElement.textContent = `Failed: ${checkName}`;
        indicatorElement.textContent = '❌';
        card.className = 'system-card failed';
        if (error) {
          statusElement.title = error;
        }
        break;
        
      case 'skipped':
        statusElement.textContent = 'Skipped';
        indicatorElement.textContent = '⏭️';
        card.className = 'system-card skipped';
        break;
    }
  }

  // Scroll to specific card smoothly
  scrollToCard(card) {
    if (!card || !this.systemStatusContainer) return;
    
    const containerHeight = this.systemStatusContainer.clientHeight;
    const cardHeight = card.offsetHeight;
    const cardOffsetTop = card.offsetTop;
    const containerScrollHeight = this.systemStatusContainer.scrollHeight;
    
    // Calculate target scroll position to center the card
    let targetScrollTop = cardOffsetTop - (containerHeight / 2) + (cardHeight / 2);
    
    // Ensure we don't scroll past the bottom
    const maxScrollTop = containerScrollHeight - containerHeight;
    if (targetScrollTop > maxScrollTop) {
      targetScrollTop = maxScrollTop;
    }
    
    // Ensure we don't scroll before the top
    if (targetScrollTop < 0) {
      targetScrollTop = 0;
    }
    
    // Smooth scroll to the target position
    this.systemStatusContainer.scrollTo({
      top: targetScrollTop,
      behavior: 'smooth'
    });
  }

  // Update loading tip based on progress
  updateLoadingTip(progress) {
    const tipElement = document.getElementById('loading-tip');
    if (!tipElement) return;

    const tips = [
      'Loading essential components...',
      'Preparing your workspace...',
      'Checking system dependencies...',
      'Initializing data connections...',
      'Almost ready...',
      'Finalizing launch...'
    ];

    const tipIndex = Math.floor((progress / 100) * tips.length);
    const tip = tips[Math.min(tipIndex, tips.length - 1)];
    
    if (tipElement.textContent !== tip) {
      tipElement.textContent = tip;
    }
  }

  // Show error message
  showError(errors) {
    // console.log('🔍 LoadingUI.showError called with errors:', errors.length);
    // console.log('🔍 Existing error details elements:', document.querySelectorAll('.error-details').length);
    // console.log('🔍 Call stack:', new Error().stack);
    
    const actionsContainer = document.getElementById('loading-actions');
    
    // Check if this is a missing data files issue
    const hasMissingDataFiles = errors.some(error => 
      error.error && (error.error.includes('Missing required data file') || 
                     error.error.includes('Critical configuration files are missing or empty'))
    );
    
    // Create error details
    const errorDetails = document.createElement('div');
    errorDetails.className = 'error-details';
    
    if (hasMissingDataFiles) {
      // Special handling for missing data files
      errorDetails.innerHTML = `
        <h4>🔧 LibrePortal Setup Required</h4>
        <div style="background: rgba(255, 193, 7, 0.1); border: 1px solid #ffc107; border-radius: 4px; padding: 15px; margin: 10px 0;">
          <p style="margin: 0 0 10px 0; font-weight: bold;">❌ Required data files are missing!</p>
          <p style="margin: 0 0 15px 0;">LibrePortal needs to generate JSON configuration files before it can run properly.</p>
          <div style="background: #2d3748; color: #e2e8f0; padding: 10px; border-radius: 4px; font-family: 'Courier New', monospace; margin: 10px 0;">
            libreportal webui generate all
          </div>
          <p style="margin: 5px 0; font-size: 0.9em; color: #666;">
            Run this command in your terminal to fix the issue.
          </p>
        </div>
        <div class="error-list-container" style="max-height: 150px; overflow-y: auto; border: 1px solid #ff6b6b; border-radius: 4px; padding: 10px; margin: 10px 0; background: rgba(255, 107, 107, 0.1);">
          <ul style="margin: 0; padding-left: 20px;">
            ${errors.map(error => `
              <li style="margin-bottom: 8px;">
                <strong>${error.system || error.checkName || 'Unknown'}:</strong> 
                <div style="white-space: pre-line; margin-top: 4px;">${(error.error || 'Check failed').replace(/\n\n/g, '<br><br>').replace(/\n/g, '<br>')}</div>
              </li>
            `).join('')}
          </ul>
        </div>
        <p style="margin: 10px 0;">After running the setup command, refresh this page to continue.</p>
      `;
    } else {
      // Regular error handling
      errorDetails.innerHTML = `
        <h4>⚠️ Loading Issues Detected</h4>
        <div class="error-list-container" style="max-height: 200px; overflow-y: auto; border: 1px solid #ff6b6b; border-radius: 4px; padding: 10px; margin: 10px 0; background: rgba(255, 107, 107, 0.1);">
          <ul style="margin: 0; padding-left: 20px;">
            ${errors.map(error => `
              <li style="margin-bottom: 8px;">
                <strong>${error.system || error.checkName || 'Unknown'}:</strong> 
                <div style="white-space: pre-line; margin-top: 4px;">${(error.error || 'Check failed').replace(/\n\n/g, '<br><br>').replace(/\n/g, '<br>')}</div>
                ${error.error && error.error.includes('Timeout') ? '<small><br>Try checking your network connection and refresh.</small>' : ''}
              </li>
            `).join('')}
          </ul>
        </div>
        <p>You can retry loading or continue with limited functionality</p>
      `;
    }

    // Insert before actions
    if (actionsContainer && actionsContainer.parentNode) {
      actionsContainer.parentNode.insertBefore(errorDetails, actionsContainer);
      actionsContainer.style.display = 'flex';
      this.retryButton.style.display = 'inline-flex';
      this.continueButton.style.display = 'inline-flex';
    }
  }

  // Hide loading screen
  hide() {
    if (this.container && this.isVisible) {
      // Show success message and trigger animations
      const successMessage = document.getElementById('success-message');
      if (successMessage) {
        successMessage.style.display = 'block';
      }
      
      // Add success class to trigger animations
      this.container.classList.add('success');
      
      // Wait for success animations to play, then hide
      setTimeout(() => {
        this.container.classList.add('hiding');
        setTimeout(() => {
          if (this.container && this.container.parentNode) {
            this.container.parentNode.removeChild(this.container);
          }
          this.isVisible = false;
        }, 500);
      }, 200);
    }
  }

  // Show loading screen
  show() {
    if (!this.isVisible && this.container) {
      if (!this.container.parentNode) {
        document.body.appendChild(this.container);
      }
      this.container.classList.remove('hiding');
      this.isVisible = true;
    }
  }

  // Update status text
  updateStatus(text) {
    const statusElement = document.getElementById('loading-status-text');
    if (statusElement) {
      statusElement.textContent = text;
    }
  }

  // Attach event listeners
  attachEventListeners() {
    if (this.retryButton) {
      this.retryButton.addEventListener('click', () => {
        // console.log('🔄 Retry button clicked - refreshing page');
        window.location.reload();
      });
    }

    if (this.continueButton) {
      this.continueButton.addEventListener('click', () => {
        this.hide();
        // Trigger continue event
        window.dispatchEvent(new CustomEvent('loadingContinue'));
      });
    }
  }

  // Cleanup
  destroy() {
    if (this.container && this.container.parentNode) {
      this.container.parentNode.removeChild(this.container);
    }
    this.isVisible = false;
    this.systemCards.clear();
  }
}