import { BlacklistStorageManager } from './BlacklistStorageManager.js';
import BrandLogoRegistry from './BrandLogoRegistry.js';

/**
 * BlacklistPanelManager - Manages the Blacklist Panel UI and functionality
 * 
 * Provides UI for adding/removing brands from the blacklist and displays
 * the current list of blacklisted brands with their logos.
 * 
 * Requirements: 2.1, 2.4, 3.1, 3.2, 3.3, 3.4
 */
export class BlacklistPanelManager {
  constructor(blacklistStorage = null, logoRegistry = null) {
    this.blacklistStorage = blacklistStorage || new BlacklistStorageManager();
    this.logoRegistry = logoRegistry || new BrandLogoRegistry();
    this.container = null;
    this.eventBus = null;
    
    // Initialize event bus connection
    this.initializeEventBus();
  }

  /**
   * Initializes connection to the global event bus
   */
  initializeEventBus() {
    if (typeof window !== 'undefined' && window.amazonExtEventBus) {
      this.eventBus = window.amazonExtEventBus;
      this.setupEventListeners();
    } else {
      setTimeout(() => {
        if (typeof window !== 'undefined' && window.amazonExtEventBus) {
          this.eventBus = window.amazonExtEventBus;
          this.setupEventListeners();
        }
      }, 100);
    }
  }

  /**
   * Sets up event listeners for blacklist updates
   */
  setupEventListeners() {
    if (!this.eventBus) return;
    
    this.eventBus.on('blacklist:updated', () => {
      this.loadBrands();
    });
  }

  /**
   * Emits an event through the event bus
   * @param {string} eventName - Event name
   * @param {*} data - Event data
   */
  emitEvent(eventName, data) {
    if (this.eventBus) {
      this.eventBus.emit(eventName, data);
    }
  }


  /**
   * Creates the Blacklist Panel content HTML structure
   * Requirement 2.1: Display input field for brand names
   * @returns {HTMLElement}
   */
  createBlacklistContent() {
    const container = document.createElement('div');
    container.className = 'amazon-ext-blacklist-content';
    
    container.innerHTML = `
      <div class="blacklist-header">
        <h2>Blacklist</h2>
        <p class="blacklist-description">Markennamen hinzufügen, um Produkte zu markieren</p>
      </div>
      
      <div class="add-brand-form">
        <input 
          type="text" 
          class="brand-input" 
          placeholder="Markenname eingeben (z.B. Nike, Adidas)..."
          aria-label="Brand name input"
        />
        <button class="add-brand-btn" type="button">Hinzufügen</button>
      </div>
      
      <div class="blacklist-message" style="display: none;"></div>
      
      <div class="brand-list-container">
        <div class="brand-list"></div>
      </div>
    `;

    this.container = container;
    this.attachEventListeners();
    this.loadBrands();
    
    return container;
  }

  /**
   * Attaches event listeners to the Blacklist Panel elements
   */
  attachEventListeners() {
    if (!this.container) return;

    const input = this.container.querySelector('.brand-input');
    const addBtn = this.container.querySelector('.add-brand-btn');

    if (addBtn) {
      addBtn.addEventListener('click', () => this.handleAddBrand());
    }
    
    if (input) {
      input.addEventListener('keypress', (e) => {
        if (e.key === 'Enter') {
          this.handleAddBrand();
        }
      });
    }
  }

  /**
   * Handles adding a new brand to the blacklist
   * Requirements: 2.2, 2.4, 2.5, 2.6
   */
  async handleAddBrand() {
    if (!this.container) return;

    const input = this.container.querySelector('.brand-input');
    const brandName = input ? input.value.trim() : '';

    // Clear previous messages
    this.clearMessage();

    if (!brandName) {
      this.showMessage('Bitte einen Markennamen eingeben', 'error');
      if (input) input.focus();
      return;
    }

    try {
      await this.blacklistStorage.addBrand(brandName);
      
      // Requirement 2.4: Clear input field after saving
      if (input) {
        input.value = '';
      }
      
      this.showMessage(`"${brandName}" zur Blacklist hinzugefügt`, 'success');
      this.loadBrands();
      
    } catch (error) {
      // Requirement 2.5: Display message for duplicate entry
      if (error.message === 'Brand already exists') {
        this.showMessage('Diese Marke ist bereits in der Blacklist', 'error');
      } else if (error.message.includes('quota')) {
        this.showMessage('Speicher voll. Bitte löschen Sie einige Marken.', 'error');
      } else {
        this.showMessage('Fehler beim Speichern', 'error');
      }
      
      if (input) input.focus();
    }
  }


  /**
   * Loads and renders all blacklisted brands
   * Requirement 3.1: Display all saved brand names in a list
   */
  async loadBrands() {
    if (!this.container) return;

    try {
      const brands = await this.blacklistStorage.getBrands();
      this.renderBrandList(brands);
    } catch (error) {
      console.error('Error loading brands:', error);
      this.showMessage('Fehler beim Laden der Marken', 'error');
    }
  }

  /**
   * Renders the brand list in the Blacklist Panel
   * Requirements: 3.1, 3.2, 3.3
   * @param {Array} brands - Array of blacklisted brands
   */
  renderBrandList(brands) {
    if (!this.container) return;

    const listContainer = this.container.querySelector('.brand-list');
    if (!listContainer) return;

    if (!brands || brands.length === 0) {
      listContainer.innerHTML = '<p class="empty-message">Keine Marken in der Blacklist</p>';
      return;
    }

    // Requirement 3.1: Display all saved brand names
    // Requirement 3.2: Display each brand with its logo
    // Requirement 3.3: Provide delete button for each brand
    listContainer.innerHTML = brands.map(brand => `
      <div class="brand-item" data-id="${brand.id}">
        <div class="brand-logo">
          ${this.logoRegistry.getLogo(brand.name)}
        </div>
        <span class="brand-name">${this.escapeHtml(brand.name)}</span>
        <button class="delete-brand-btn" data-id="${brand.id}" aria-label="Marke löschen">×</button>
      </div>
    `).join('');

    // Attach delete button event listeners
    this.attachDeleteListeners(listContainer);
  }

  /**
   * Attaches event listeners to delete buttons
   * @param {HTMLElement} listContainer - Brand list container element
   */
  attachDeleteListeners(listContainer) {
    const deleteButtons = listContainer.querySelectorAll('.delete-brand-btn');
    deleteButtons.forEach(btn => {
      btn.addEventListener('click', (e) => {
        const brandId = e.target.dataset.id;
        if (brandId) {
          this.handleDeleteBrand(brandId);
        }
      });
    });
  }

  /**
   * Handles deleting a brand from the blacklist
   * Requirement 3.4: Remove brand from storage and update display
   * @param {string} brandId - Brand ID to delete
   */
  async handleDeleteBrand(brandId) {
    try {
      const brands = await this.blacklistStorage.getBrands();
      const brand = brands.find(b => b.id === brandId);
      const brandName = brand ? brand.name : '';
      
      await this.blacklistStorage.deleteBrand(brandId);
      
      if (brandName) {
        this.showMessage(`"${brandName}" entfernt`, 'success');
      }
      
      this.loadBrands();
      
    } catch (error) {
      console.error('Error deleting brand:', error);
      this.showMessage('Fehler beim Löschen der Marke', 'error');
    }
  }


  /**
   * Shows a feedback message (success or error)
   * @param {string} text - Message text
   * @param {string} type - Message type ('success' or 'error')
   */
  showMessage(text, type) {
    if (!this.container) return;

    const messageEl = this.container.querySelector('.blacklist-message');
    if (!messageEl) return;

    messageEl.textContent = text;
    messageEl.className = `blacklist-message ${type}`;
    messageEl.style.display = 'block';
    
    // Auto-hide after 3 seconds
    setTimeout(() => {
      if (messageEl) {
        messageEl.style.display = 'none';
      }
    }, 3000);
  }

  /**
   * Clears the feedback message
   */
  clearMessage() {
    if (!this.container) return;

    const messageEl = this.container.querySelector('.blacklist-message');
    if (messageEl) {
      messageEl.style.display = 'none';
      messageEl.textContent = '';
    }
  }

  /**
   * Shows the Blacklist Panel (called when menu item is clicked)
   */
  showBlacklistPanel() {
    this.loadBrands();
  }

  /**
   * Hides the Blacklist Panel (called when menu is closed)
   */
  hideBlacklistPanel() {
    // Cleanup if needed
  }

  /**
   * Escapes HTML special characters to prevent XSS
   * @param {string} text - Text to escape
   * @returns {string} Escaped text
   */
  escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
  }
}