/**
 * Privacy Manager for ConversionIQ SDK
 * Handles GDPR/CCPA compliance with progressive consent management
 */

import { ConversionIQConfig, PrivacySettings, DataType } from '../types/index';
import { ShadowDOMManager } from './ShadowDOMManager';

interface ConsentData {
  version: string;
  timestamp: number;
  settings: PrivacySettings;
  jurisdiction: string;
  expiresAt: number;
}

export class PrivacyManager {
  private config: ConversionIQConfig;
  private shadowDOM?: ShadowDOMManager;
  private consentData: ConsentData | null = null;
  private readonly STORAGE_KEY = 'conversioniq_consent';
  private readonly CONSENT_VERSION = '1.0';
  private readonly CONSENT_DURATION = 13 * 30 * 24 * 60 * 60 * 1000; // 13 months

  // Default consent levels
  private readonly DEFAULT_CONSENT: PrivacySettings = {
    essential: true,    // Always allowed
    functional: false,  // Requires consent
    analytics: false,   // Requires consent
    marketing: false    // Requires consent
  };

  constructor(config: ConversionIQConfig) {
    this.config = config;
    // Load existing consent data immediately so canTrack() works before init()
    this.loadConsentData();
  }

  /**
   * Initialize privacy manager
   */
  public async init(): Promise<void> {
    try {
      // Load existing consent
      this.loadConsentData();

      // Check if we need to show consent UI
      if (this.needsConsent()) {
        await this.showConsentUI();
      }

      // Clean up expired consent data
      this.cleanupExpiredData();

    } catch (error) {
      console.warn('ConversionIQ: Privacy manager initialization failed:', error);
      // Fall back to essential cookies only
      this.consentData = {
        version: this.CONSENT_VERSION,
        timestamp: Date.now(),
        settings: { ...this.DEFAULT_CONSENT },
        jurisdiction: 'unknown',
        expiresAt: Date.now() + this.CONSENT_DURATION
      };
    }
  }

  /**
   * Check if tracking is allowed for a specific data type
   */
  public canTrack(dataType: DataType): boolean {
    if (!this.consentData) {
      // If no consent data, only allow essential
      return dataType === 'essential';
    }

    // Check if consent has expired
    if (Date.now() > this.consentData.expiresAt) {
      this.clearConsentData();
      return dataType === 'essential';
    }

    return this.consentData.settings[dataType] || false;
  }

  /**
   * Update consent settings
   */
  public updateConsent(settings: Partial<PrivacySettings>): void {
    if (!this.consentData) {
      this.consentData = {
        version: this.CONSENT_VERSION,
        timestamp: Date.now(),
        settings: { ...this.DEFAULT_CONSENT },
        jurisdiction: this.detectJurisdiction(),
        expiresAt: Date.now() + this.CONSENT_DURATION
      };
    }

    // Update settings
    this.consentData.settings = {
      ...this.consentData.settings,
      ...settings,
      essential: true // Essential is always true
    };

    this.consentData.timestamp = Date.now();
    this.saveConsentData();

    // Hide consent UI if it's visible
    if (this.shadowDOM) {
      this.hideConsentUI();
    }
  }

  /**
   * Get current consent status
   */
  public getConsentStatus(): PrivacySettings {
    return this.consentData?.settings || { ...this.DEFAULT_CONSENT };
  }

  /**
   * Check if consent UI needs to be shown
   */
  public needsConsent(): boolean {
    // No consent data exists
    if (!this.consentData) {
      return this.requiresConsent();
    }

    // Consent has expired
    if (Date.now() > this.consentData.expiresAt) {
      return this.requiresConsent();
    }

    // Version has changed
    if (this.consentData.version !== this.CONSENT_VERSION) {
      return this.requiresConsent();
    }

    return false;
  }

  /**
   * Check if jurisdiction requires consent
   */
  private requiresConsent(): boolean {
    const jurisdiction = this.detectJurisdiction();

    // EU countries require GDPR consent
    const gdprCountries = [
      'AT', 'BE', 'BG', 'HR', 'CY', 'CZ', 'DK', 'EE', 'FI', 'FR',
      'DE', 'GR', 'HU', 'IE', 'IT', 'LV', 'LT', 'LU', 'MT', 'NL',
      'PL', 'PT', 'RO', 'SK', 'SI', 'ES', 'SE', 'IS', 'LI', 'NO',
      'GB' // UK has GDPR-equivalent laws (UK GDPR)
    ];

    // California requires CCPA consent
    const ccpaRegions = ['CA', 'US-CA'];

    return gdprCountries.includes(jurisdiction) ||
           jurisdiction === 'EU' || // Generic EU detection
           ccpaRegions.includes(jurisdiction) ||
           this.config.enablePrivacyMode === true;
  }

  /**
   * Detect user's jurisdiction for privacy compliance
   */
  private detectJurisdiction(): string {
    // Try to detect from timezone
    try {
      const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;

      // European timezones (simplified)
      if (timezone.startsWith('Europe/')) {
        const country = timezone.split('/')[1];
        const countryMap: Record<string, string> = {
          'London': 'GB', 'Berlin': 'DE', 'Paris': 'FR', 'Rome': 'IT',
          'Madrid': 'ES', 'Amsterdam': 'NL', 'Vienna': 'AT', 'Brussels': 'BE',
          'Prague': 'CZ', 'Warsaw': 'PL', 'Stockholm': 'SE', 'Oslo': 'NO'
        };
        return countryMap[country] || 'EU';
      }

      // US timezones
      if (timezone.includes('Los_Angeles') || timezone.includes('San_Francisco')) {
        return 'US-CA';
      }
      if (timezone.startsWith('America/')) {
        return 'US';
      }

    } catch (error) {
      // Fallback detection methods
    }

    // Try to detect from language
    const language = navigator.language || navigator.languages?.[0] || '';
    if (language.startsWith('en-GB') || language.startsWith('en-EU')) {
      return 'EU';
    }
    if (language.startsWith('en-US')) {
      return 'US';
    }

    return 'unknown';
  }

  /**
   * Show consent UI
   */
  private async showConsentUI(): Promise<void> {
    if (!this.shadowDOM) {
      this.shadowDOM = new ShadowDOMManager();
    }

    const jurisdiction = this.detectJurisdiction();
    const isGDPR = jurisdiction.startsWith('EU') || jurisdiction === 'GB';
    const isCCPA = jurisdiction === 'US-CA';

    const consentModal = this.shadowDOM.createModal({
      title: isGDPR ? 'Cookie Preferences' : 'Privacy Preferences',
      content: this.createConsentContent(isGDPR, isCCPA),
      persistent: true,
      className: 'consent-modal',
      allowHTML: true // Consent UI contains safe internal HTML
    });

    // Add event listeners
    this.attachConsentHandlers(consentModal, isGDPR, isCCPA);

    // Show modal
    this.shadowDOM.show(consentModal);
  }

  /**
   * Create consent UI content
   */
  private createConsentContent(isGDPR: boolean, isCCPA: boolean): string {
    const title = isGDPR ? 'We value your privacy' : 'Your Privacy Choices';
    const description = isGDPR
      ? 'We use cookies and similar technologies to provide, protect and improve our services. You can choose which types of cookies you allow.'
      : 'We collect and use personal information to provide and improve our services. You can control how we use this information.';

    return `
      <div class="ciq-consent-content">
        <h3>${title}</h3>
        <p>${description}</p>
        
        <div class="ciq-consent-options">
          <div class="ciq-consent-option">
            <label class="ciq-checkbox-label">
              <input type="checkbox" id="essential" checked disabled>
              <span class="ciq-checkmark"></span>
              <div class="ciq-option-details">
                <strong>Essential</strong>
                <p>Required for basic website functionality. Always active.</p>
              </div>
            </label>
          </div>
          
          <div class="ciq-consent-option">
            <label class="ciq-checkbox-label">
              <input type="checkbox" id="functional">
              <span class="ciq-checkmark"></span>
              <div class="ciq-option-details">
                <strong>Functional</strong>
                <p>Enables enhanced features like click tracking and user interface improvements.</p>
              </div>
            </label>
          </div>
          
          <div class="ciq-consent-option">
            <label class="ciq-checkbox-label">
              <input type="checkbox" id="analytics">
              <span class="ciq-checkmark"></span>
              <div class="ciq-option-details">
                <strong>Analytics</strong>
                <p>Helps us understand how you use our website to improve your experience.</p>
              </div>
            </label>
          </div>
          
          <div class="ciq-consent-option">
            <label class="ciq-checkbox-label">
              <input type="checkbox" id="marketing">
              <span class="ciq-checkmark"></span>
              <div class="ciq-option-details">
                <strong>Marketing</strong>
                <p>Allows us to measure the effectiveness of our optimization recommendations.</p>
              </div>
            </label>
          </div>
        </div>
        
        <div class="ciq-consent-actions">
          ${isGDPR ? '<button id="reject-all" class="ciq-btn ciq-btn-secondary">Reject All</button>' : ''}
          <button id="accept-selected" class="ciq-btn ciq-btn-primary">Save Preferences</button>
          <button id="accept-all" class="ciq-btn ciq-btn-primary">Accept All</button>
        </div>
        
        <div class="ciq-consent-footer">
          <p>You can change these settings at any time. For more information, see our privacy policy.</p>
        </div>
      </div>
    `;
  }

  /**
   * Attach event handlers to consent UI
   */
  private attachConsentHandlers(modal: HTMLElement, isGDPR: boolean, isCCPA: boolean): void {
    const shadowRoot = modal.getRootNode() as ShadowRoot;

    // Accept all button
    const acceptAllBtn = shadowRoot.getElementById('accept-all');
    acceptAllBtn?.addEventListener('click', () => {
      this.updateConsent({
        essential: true,
        functional: true,
        analytics: true,
        marketing: true
      });
    });

    // Reject all button (GDPR only)
    if (isGDPR) {
      const rejectAllBtn = shadowRoot.getElementById('reject-all');
      rejectAllBtn?.addEventListener('click', () => {
        this.updateConsent({
          essential: true,
          functional: false,
          analytics: false,
          marketing: false
        });
      });
    }

    // Save selected preferences
    const saveBtn = shadowRoot.getElementById('accept-selected');
    saveBtn?.addEventListener('click', () => {
      const functional = (shadowRoot.getElementById('functional') as HTMLInputElement)?.checked || false;
      const analytics = (shadowRoot.getElementById('analytics') as HTMLInputElement)?.checked || false;
      const marketing = (shadowRoot.getElementById('marketing') as HTMLInputElement)?.checked || false;

      this.updateConsent({
        essential: true,
        functional,
        analytics,
        marketing
      });
    });
  }

  /**
   * Hide consent UI
   */
  private hideConsentUI(): void {
    if (this.shadowDOM) {
      this.shadowDOM.hideAll();
    }
  }

  /**
   * Load consent data from storage
   */
  private loadConsentData(): void {
    try {
      const stored = localStorage.getItem(this.STORAGE_KEY);
      if (stored) {
        const data = JSON.parse(stored) as ConsentData;

        // Validate data structure
        if (data.version && data.timestamp && data.settings && data.expiresAt) {
          this.consentData = data;
        }
      }
    } catch (error) {
      // Invalid data in storage, ignore
    }
  }

  /**
   * Save consent data to storage
   */
  private saveConsentData(): void {
    if (!this.consentData) {
      return;
    }

    try {
      localStorage.setItem(this.STORAGE_KEY, JSON.stringify(this.consentData));
    } catch (error) {
      // Storage might be full or disabled, continue without persistence
      console.warn('ConversionIQ: Could not save consent data:', error);
    }
  }

  /**
   * Clear consent data
   */
  private clearConsentData(): void {
    this.consentData = null;
    try {
      localStorage.removeItem(this.STORAGE_KEY);
    } catch (error) {
      // Ignore storage errors
    }
  }

  /**
   * Clean up expired consent data
   */
  private cleanupExpiredData(): void {
    try {
      const keys = Object.keys(localStorage);
      const now = Date.now();

      keys.forEach(key => {
        if (key.startsWith('conversioniq_') && key.includes('_consent_')) {
          try {
            const data = JSON.parse(localStorage.getItem(key) || '{}');
            if (data.expiresAt && now > data.expiresAt) {
              localStorage.removeItem(key);
            }
          } catch (error) {
            // Invalid data, remove it
            localStorage.removeItem(key);
          }
        }
      });
    } catch (error) {
      // Ignore cleanup errors
    }
  }

  /**
   * Get privacy-compliant user ID
   */
  public getPrivacyCompliantUserId(): string | null {
    if (!this.canTrack('analytics')) {
      return null;
    }

    // Generate or retrieve anonymous user ID
    const key = 'conversioniq_user_id';
    try {
      let userId = localStorage.getItem(key);
      if (!userId) {
        userId = 'ciq_' + Date.now().toString(36) + Math.random().toString(36).substring(2);
        localStorage.setItem(key, userId);
      }
      return userId;
    } catch (error) {
      // Generate session-only ID if storage fails
      return 'ciq_session_' + Date.now().toString(36) + Math.random().toString(36).substring(2);
    }
  }

  /**
   * Clean up privacy manager
   */
  public destroy(): void {
    this.hideConsentUI();
    if (this.shadowDOM) {
      this.shadowDOM.destroy();
    }
  }
}