/**
 * SHOWPAD ADAPTER - TDC Enterprise Content Integration
 *
 * Connects to Showpad API v4 to sync brand assets, presentations,
 * and marketing materials. Extracts images for reuse in presentations.
 *
 * Authentication: OAuth2 or Username/Password
 * Storage: Neo4j Graph Database (cloud)
 *
 * Created: 2025-12-16
 */

import { DataSourceAdapter, IngestedEntity } from '../ingestion/DataIngestionEngine.js';

interface ShowpadConfig {
  subdomain: string;
  baseUrl: string;
  apiVersion: string;
  username?: string;
  password?: string;
  clientId?: string;
  clientSecret?: string;
  cacheTtl: number;
}

interface ShowpadAsset {
  id: string;
  name: string;
  description?: string;
  resourcetype: string;
  slug?: string;
  createdAt: string;
  updatedAt: string;
  fileSize?: number;
  mimeType?: string;
  downloadUrl?: string;
  previewUrl?: string;
  thumbnailUrl?: string;
  tags?: string[];
  divisions?: string[];
  isImage?: boolean;
}

interface ShowpadAuthResponse {
  access_token: string;
  token_type: string;
  expires_in: number;
  refresh_token?: string;
  scope?: string;
}

interface ExtractedImage {
  assetId: string;
  name: string;
  originalUrl: string;
  thumbnailUrl?: string;
  previewUrl?: string;
  mimeType: string;
  width?: number;
  height?: number;
  fileSize?: number;
  tags: string[];
  category?: string;
  extractedAt: Date;
}

export class ShowpadAdapter implements DataSourceAdapter {
  name = 'Showpad';
  type: 'other' = 'other';

  private config: ShowpadConfig;
  private accessToken: string | null = null;
  private tokenExpiry: number = 0;
  private assets: ShowpadAsset[] = [];
  private extractedImages: ExtractedImage[] = [];
  private lastSync: number = 0;

  constructor() {
    this.config = {
      subdomain: process.env.SHOWPAD_SUBDOMAIN || 'tdcerhverv',
      baseUrl: process.env.SHOWPAD_BASE_URL || 'https://tdcerhverv.showpad.biz',
      apiVersion: process.env.SHOWPAD_API_VERSION || 'v4',
      username: process.env.SHOWPAD_USERNAME,
      password: process.env.SHOWPAD_PASSWORD,
      clientId: process.env.SHOWPAD_CLIENT_ID,
      clientSecret: process.env.SHOWPAD_CLIENT_SECRET,
      cacheTtl: parseInt(process.env.SHOWPAD_CACHE_TTL || '86400000', 10)
    };
  }

  /**
   * Get API base URL
   */
  private get apiUrl(): string {
    return `https://${this.config.subdomain}.api.showpad.com/${this.config.apiVersion}`;
  }

  /**
   * Get legacy API URL (for some endpoints)
   */
  private get legacyApiUrl(): string {
    return `${this.config.baseUrl}/api/v3`;
  }

  /**
   * Authenticate with Showpad
   */
  private async authenticate(): Promise<string> {
    // Return cached token if still valid
    if (this.accessToken && Date.now() < this.tokenExpiry - 60000) {
      return this.accessToken;
    }

    console.log('[ShowpadAdapter] Authenticating...');

    // Try OAuth2 client credentials first
    if (this.config.clientId && this.config.clientSecret) {
      return this.authenticateOAuth();
    }

    // Fall back to username/password
    if (this.config.username && this.config.password) {
      return this.authenticateUserPassword();
    }

    throw new Error('[ShowpadAdapter] No authentication credentials configured');
  }

  /**
   * OAuth2 Client Credentials Flow
   */
  private async authenticateOAuth(): Promise<string> {
    const tokenUrl = `${this.legacyApiUrl}/oauth2/token`;

    const params = new URLSearchParams({
      grant_type: 'client_credentials',
      client_id: this.config.clientId!,
      client_secret: this.config.clientSecret!
    });

    const response = await fetch(tokenUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded'
      },
      body: params.toString()
    });

    if (!response.ok) {
      const error = await response.text();
      throw new Error(`[ShowpadAdapter] OAuth failed: ${response.status} - ${error}`);
    }

    const data: ShowpadAuthResponse = await response.json();
    this.accessToken = data.access_token;
    this.tokenExpiry = Date.now() + (data.expires_in * 1000);

    console.log('[ShowpadAdapter] OAuth2 authentication successful');
    return this.accessToken;
  }

  /**
   * Username/Password Authentication (User Credentials Flow)
   */
  private async authenticateUserPassword(): Promise<string> {
    const tokenUrl = `${this.legacyApiUrl}/oauth2/token`;

    const params = new URLSearchParams({
      grant_type: 'password',
      username: this.config.username!,
      password: this.config.password!
    });

    // Add client credentials if available
    if (this.config.clientId && this.config.clientSecret) {
      params.append('client_id', this.config.clientId);
      params.append('client_secret', this.config.clientSecret);
    }

    const response = await fetch(tokenUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded'
      },
      body: params.toString()
    });

    if (!response.ok) {
      const error = await response.text();
      throw new Error(`[ShowpadAdapter] Auth failed: ${response.status} - ${error}`);
    }

    const data: ShowpadAuthResponse = await response.json();
    this.accessToken = data.access_token;
    this.tokenExpiry = Date.now() + (data.expires_in * 1000);

    console.log('[ShowpadAdapter] User/password authentication successful');
    return this.accessToken;
  }

  /**
   * Make authenticated API request
   */
  private async apiRequest<T>(
    endpoint: string,
    options: RequestInit = {},
    useV4: boolean = true
  ): Promise<T> {
    const token = await this.authenticate();
    const baseUrl = useV4 ? this.apiUrl : this.legacyApiUrl;
    const url = `${baseUrl}${endpoint}`;

    const response = await fetch(url, {
      ...options,
      headers: {
        'Authorization': `Bearer ${token}`,
        'Content-Type': 'application/json',
        'Accept': 'application/json',
        ...options.headers
      }
    });

    if (!response.ok) {
      const error = await response.text();
      throw new Error(`[ShowpadAdapter] API error: ${response.status} - ${error}`);
    }

    return response.json();
  }

  /**
   * Fetch all assets from Showpad
   */
  async fetch(): Promise<ShowpadAsset[]> {
    // Return cached if fresh
    if (this.assets.length > 0 && Date.now() - this.lastSync < this.config.cacheTtl) {
      console.log(`[ShowpadAdapter] Using cached assets (${this.assets.length} items)`);
      return this.assets;
    }

    console.log('[ShowpadAdapter] Fetching assets from Showpad...');

    const allAssets: ShowpadAsset[] = [];
    let offset = 0;
    const limit = 100;
    let hasMore = true;

    while (hasMore) {
      try {
        const response = await this.apiRequest<{ items: ShowpadAsset[]; meta?: { total?: number } }>(
          `/assets?limit=${limit}&offset=${offset}`,
          {},
          true
        );

        const items = response.items || [];
        allAssets.push(...items);

        console.log(`[ShowpadAdapter] Fetched ${items.length} assets (total: ${allAssets.length})`);

        hasMore = items.length === limit;
        offset += limit;

        // Rate limiting - be nice to the API
        await new Promise(resolve => setTimeout(resolve, 200));
      } catch (error) {
        console.error('[ShowpadAdapter] Error fetching assets:', error);
        hasMore = false;
      }
    }

    this.assets = allAssets;
    this.lastSync = Date.now();

    // Extract images
    await this.extractImages();

    console.log(`[ShowpadAdapter] Total assets: ${this.assets.length}, Images: ${this.extractedImages.length}`);
    return this.assets;
  }

  /**
   * Extract images from assets for reuse
   */
  private async extractImages(): Promise<void> {
    this.extractedImages = [];

    const imageTypes = ['image/png', 'image/jpeg', 'image/gif', 'image/webp', 'image/svg+xml'];
    const imageExtensions = ['.png', '.jpg', '.jpeg', '.gif', '.webp', '.svg'];

    for (const asset of this.assets) {
      const isImage =
        (asset.mimeType && imageTypes.includes(asset.mimeType)) ||
        (asset.name && imageExtensions.some(ext => asset.name.toLowerCase().endsWith(ext))) ||
        asset.resourcetype === 'image';

      if (isImage) {
        this.extractedImages.push({
          assetId: asset.id,
          name: asset.name,
          originalUrl: asset.downloadUrl || '',
          thumbnailUrl: asset.thumbnailUrl,
          previewUrl: asset.previewUrl,
          mimeType: asset.mimeType || 'image/unknown',
          fileSize: asset.fileSize,
          tags: asset.tags || [],
          category: this.categorizeImage(asset),
          extractedAt: new Date()
        });
      }
    }

    console.log(`[ShowpadAdapter] Extracted ${this.extractedImages.length} images for reuse`);
  }

  /**
   * Categorize image based on name and tags
   */
  private categorizeImage(asset: ShowpadAsset): string {
    const name = asset.name.toLowerCase();
    const tags = (asset.tags || []).map(t => t.toLowerCase());

    if (name.includes('logo') || tags.includes('logo')) return 'logo';
    if (name.includes('icon') || tags.includes('icon')) return 'icon';
    if (name.includes('banner') || tags.includes('banner')) return 'banner';
    if (name.includes('photo') || tags.includes('photo')) return 'photo';
    if (name.includes('diagram') || tags.includes('diagram')) return 'diagram';
    if (name.includes('chart') || tags.includes('chart')) return 'chart';
    if (name.includes('infographic') || tags.includes('infographic')) return 'infographic';
    if (name.includes('background') || tags.includes('background')) return 'background';

    return 'general';
  }

  /**
   * Transform assets to ingestion entities
   */
  async transform(raw: ShowpadAsset[]): Promise<IngestedEntity[]> {
    return raw.map(asset => ({
      id: `showpad-${asset.id}`,
      type: 'asset',
      source: 'Showpad',
      title: asset.name,
      content: asset.description || asset.name,
      metadata: {
        provider: 'Showpad',
        assetId: asset.id,
        resourceType: asset.resourcetype,
        mimeType: asset.mimeType,
        fileSize: asset.fileSize,
        downloadUrl: asset.downloadUrl,
        previewUrl: asset.previewUrl,
        thumbnailUrl: asset.thumbnailUrl,
        tags: asset.tags,
        divisions: asset.divisions,
        isImage: this.extractedImages.some(img => img.assetId === asset.id),
        updatedAt: asset.updatedAt
      },
      timestamp: new Date(asset.updatedAt || asset.createdAt)
    }));
  }

  /**
   * Check if Showpad is configured and reachable
   */
  async isAvailable(): Promise<boolean> {
    try {
      // Check if we have credentials
      const hasOAuth = !!(this.config.clientId && this.config.clientSecret);
      const hasUserPass = !!(this.config.username && this.config.password);

      if (!hasOAuth && !hasUserPass) {
        console.warn('[ShowpadAdapter] No credentials configured');
        return false;
      }

      // Try to authenticate
      await this.authenticate();
      return true;
    } catch (error) {
      console.error('[ShowpadAdapter] Not available:', error);
      return false;
    }
  }

  /**
   * Get extracted images for presentation use
   */
  getExtractedImages(): ExtractedImage[] {
    return this.extractedImages;
  }

  /**
   * Get images by category
   */
  getImagesByCategory(category: string): ExtractedImage[] {
    return this.extractedImages.filter(img => img.category === category);
  }

  /**
   * Search images by tag or name
   */
  searchImages(query: string): ExtractedImage[] {
    const q = query.toLowerCase();
    return this.extractedImages.filter(img =>
      img.name.toLowerCase().includes(q) ||
      img.tags.some(tag => tag.toLowerCase().includes(q))
    );
  }

  /**
   * Download asset binary
   */
  async downloadAsset(assetId: string): Promise<Buffer> {
    const asset = this.assets.find(a => a.id === assetId);
    if (!asset || !asset.downloadUrl) {
      throw new Error(`[ShowpadAdapter] Asset not found or no download URL: ${assetId}`);
    }

    const token = await this.authenticate();
    const response = await fetch(asset.downloadUrl, {
      headers: {
        'Authorization': `Bearer ${token}`
      }
    });

    if (!response.ok) {
      throw new Error(`[ShowpadAdapter] Download failed: ${response.status}`);
    }

    const arrayBuffer = await response.arrayBuffer();
    return Buffer.from(arrayBuffer);
  }

  /**
   * Get sync status
   */
  getStatus(): { lastSync: number; assetCount: number; imageCount: number; categories: Record<string, number> } {
    const categories: Record<string, number> = {};
    for (const img of this.extractedImages) {
      categories[img.category || 'unknown'] = (categories[img.category || 'unknown'] || 0) + 1;
    }

    return {
      lastSync: this.lastSync,
      assetCount: this.assets.length,
      imageCount: this.extractedImages.length,
      categories
    };
  }
}

// Singleton instance
export const showpadAdapter = new ShowpadAdapter();
export default showpadAdapter;