/**
 * Smart Document Ingestion Service
 * Combines Modal's serverless compute with Nebius AI analysis
 */

import { modalClient, type DocumentProcessingTask } from './modal-client';
import { nebiusClient } from './nebius-client';
import { storage } from './storage';
import type { InsertDocument } from '@shared/schema';

interface DocumentUpload {
  file: Buffer | string;
  filename: string;
  contentType: string;
  metadata?: Record<string, any>;
}

interface IngestionResult {
  documentId: number;
  processingTaskId: string;
  analysis: {
    category: string;
    summary: string;
    keyPoints: string[];
    qualityScore: number;
  };
  embeddings: number[];
  status: 'processing' | 'completed' | 'failed';
}

class SmartIngestionService {
  /**
   * Process uploaded document with full AI pipeline
   */
  async ingestDocument(upload: DocumentUpload): Promise<IngestionResult> {
    try {
      // Step 1: Extract text content using Modal OCR if needed
      let textContent: string;
      
      if (upload.contentType.includes('pdf') || upload.contentType.includes('image')) {
        const ocrTask = await modalClient.extractTextFromDocuments([
          this.uploadToTempStorage(upload)
        ]);
        
        // Wait for OCR completion (simplified for demo)
        textContent = await this.waitForTaskCompletion(ocrTask.taskId);
      } else {
        textContent = upload.file.toString();
      }

      // Step 2: Analyze document using Nebius AI
      const [
        categoryAnalysis,
        summaryAnalysis,
        keyPointsAnalysis,
        qualityAnalysis
      ] = await Promise.all([
        nebiusClient.analyzeDocument({
          content: textContent,
          analysisType: 'classification'
        }),
        nebiusClient.analyzeDocument({
          content: textContent,
          analysisType: 'summary'
        }),
        nebiusClient.analyzeDocument({
          content: textContent,
          analysisType: 'key_points'
        }),
        nebiusClient.analyzeDocument({
          content: textContent,
          analysisType: 'quality_score'
        })
      ]);

      // Step 3: Generate embeddings using Nebius
      const embeddingResponse = await nebiusClient.createEmbeddings({
        input: textContent.substring(0, 8000), // Limit for token constraints
        model: 'text-embedding-3-large'
      });

      // Step 4: Create document in storage
      const documentData: InsertDocument = {
        title: upload.filename,
        content: textContent,
        sourceType: this.extractSourceType(categoryAnalysis.analysis),
        source: upload.filename,
        url: upload.metadata?.url,
        metadata: {
          ...upload.metadata,
          analysis: {
            category: categoryAnalysis.analysis,
            summary: summaryAnalysis.analysis,
            keyPoints: keyPointsAnalysis.analysis,
            qualityScore: this.extractQualityScore(qualityAnalysis.analysis)
          },
          contentType: upload.contentType,
          fileSize: Buffer.isBuffer(upload.file) ? upload.file.length : upload.file.length,
          processingTimestamp: new Date().toISOString()
        }
      };

      const document = await storage.createDocument(documentData);

      // Step 5: Queue vector indexing with Modal
      const indexTask = await modalClient.buildVectorIndex([{
        id: document.id.toString(),
        content: textContent,
        embeddings: embeddingResponse.data[0].embedding,
        metadata: document.metadata
      }]);

      return {
        documentId: document.id,
        processingTaskId: indexTask.taskId,
        analysis: {
          category: this.extractCategory(categoryAnalysis.analysis),
          summary: summaryAnalysis.analysis,
          keyPoints: this.parseKeyPoints(keyPointsAnalysis.analysis),
          qualityScore: this.extractQualityScore(qualityAnalysis.analysis)
        },
        embeddings: embeddingResponse.data[0].embedding,
        status: 'completed'
      };

    } catch (error) {
      console.error('Document ingestion failed:', error);
      throw new Error(`Ingestion failed: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  /**
   * Batch process multiple documents using Modal's distributed compute
   */
  async batchIngestDocuments(uploads: DocumentUpload[]): Promise<{
    taskId: string;
    estimatedCompletion: Date;
    documentsQueued: number;
  }> {
    // Prepare documents for batch processing
    const documents = uploads.map((upload, index) => ({
      id: `batch_${Date.now()}_${index}`,
      content: upload.file.toString(),
      metadata: {
        filename: upload.filename,
        contentType: upload.contentType,
        ...upload.metadata
      }
    }));

    // Submit to Modal for distributed processing
    const task = await modalClient.batchProcessDocuments({
      documents,
      modelName: 'text-embedding-3-large',
      batchSize: 20
    });

    return {
      taskId: task.taskId,
      estimatedCompletion: new Date(Date.now() + uploads.length * 2000), // 2s per doc estimate
      documentsQueued: uploads.length
    };
  }

  /**
   * Enhanced search using both Modal vector search and Nebius query understanding
   */
  async enhancedSearch(query: string, options: {
    maxResults?: number;
    searchType?: 'semantic' | 'hybrid';
    useQueryEnhancement?: boolean;
  } = {}): Promise<{
    results: any[];
    enhancedQuery?: any;
    searchInsights?: any;
  }> {
    const { maxResults = 10, searchType = 'semantic', useQueryEnhancement = true } = options;

    // Step 1: Enhance query using Nebius AI
    let enhancedQueryData;
    let searchQuery = query;
    
    if (useQueryEnhancement) {
      enhancedQueryData = await nebiusClient.enhanceQuery(query);
      searchQuery = enhancedQueryData.enhancedQuery;
    }

    // Step 2: Perform vector search using Modal's high-performance endpoint
    let modalResults = [];
    
    // Skip Modal if not configured properly
    if (process.env.MODAL_TOKEN_ID && process.env.MODAL_TOKEN_SECRET) {
      try {
        console.log('🔄 Attempting Modal vector search...');
        const modalResponse = await modalClient.vectorSearch(
          searchQuery,
          'main_index', // Assuming we have a main index
          maxResults
        );
        modalResults = modalResponse.results || [];
        console.log(`✅ Modal search returned ${modalResults.length} results`);
      } catch (error) {
        console.log('❌ Modal search failed:', error instanceof Error ? error.message : String(error));
        console.log('🔄 Falling back to local search');
      }
    } else {
      console.log('⚠️ Modal not configured, using local search only');
    }

    // Step 3: Get local results as backup/supplement
    const localResults = await storage.searchDocuments({
      query: searchQuery,
      searchType: searchType as "semantic" | "keyword" | "hybrid",
      limit: maxResults,
      offset: 0
    });

    // Step 4: Combine and rank results using Nebius AI
    const combinedResults = [...modalResults, ...localResults.results]
      .slice(0, maxResults * 2); // Get more for re-ranking

    // Step 5: Score relevance using Nebius AI
    const scoredResults = await Promise.all(
      combinedResults.map(async (result) => {
        try {
          const relevanceData = await nebiusClient.scoreCitationRelevance(query, {
            title: result.title,
            content: result.content,
            snippet: result.snippet || result.content.substring(0, 200)
          });
          
          return {
            ...result,
            relevanceScore: relevanceData.relevanceScore,
            aiExplanation: relevanceData.explanation,
            keyReasons: relevanceData.keyReasons
          };
        } catch (error) {
          return { ...result, relevanceScore: result.relevanceScore || 0.5 };
        }
      })
    );

    // Step 6: Sort by AI-enhanced relevance scores
    const finalResults = scoredResults
      .sort((a, b) => (b.relevanceScore || 0) - (a.relevanceScore || 0))
      .slice(0, maxResults);

    return {
      results: finalResults,
      enhancedQuery: enhancedQueryData,
      searchInsights: {
        totalResults: finalResults.length,
        avgRelevanceScore: finalResults.reduce((acc, r) => acc + (r.relevanceScore || 0), 0) / finalResults.length,
        modalResultsCount: modalResults.length,
        localResultsCount: localResults.results.length
      }
    };
  }

  /**
   * Generate research synthesis using Nebius AI
   */
  async generateResearchSynthesis(query: string, documents: any[]): Promise<any> {
    if (documents.length === 0) {
      return {
        synthesis: 'No documents available for synthesis',
        keyFindings: [],
        gaps: ['Insufficient source material'],
        recommendations: ['Search for more relevant documents']
      };
    }

    return nebiusClient.generateResearchInsights(
      documents.map(doc => ({
        title: doc.title,
        content: doc.content,
        metadata: doc.metadata
      })),
      query
    );
  }

  // Helper methods
  private uploadToTempStorage(upload: DocumentUpload): string {
    // In production, upload to cloud storage and return URL
    return `temp://documents/${upload.filename}`;
  }

  private async waitForTaskCompletion(taskId: string): Promise<string> {
    // Simplified polling for demo - in production use webhooks
    const maxAttempts = 30;
    let attempts = 0;
    
    while (attempts < maxAttempts) {
      const status = await modalClient.getTaskStatus(taskId);
      if (status.status === 'completed') {
        return status.result?.extractedText || 'Text extraction completed';
      } else if (status.status === 'failed') {
        throw new Error(`Task failed: ${status.error}`);
      }
      
      await new Promise(resolve => setTimeout(resolve, 2000));
      attempts++;
    }
    
    throw new Error('Task timed out');
  }

  private extractSourceType(analysis: string): string {
    const types: Record<string, string> = {
      'academic_paper': 'academic',
      'technical_documentation': 'technical',
      'research_report': 'research',
      'code_repository': 'code',
      'blog_post': 'web',
      'news_article': 'news'
    };
    
    for (const [key, value] of Object.entries(types)) {
      if (analysis.toLowerCase().includes(key)) {
        return value;
      }
    }
    
    return 'general';
  }

  private extractCategory(analysis: string): string {
    return analysis.split('\n')[0] || 'Unknown';
  }

  private parseKeyPoints(analysis: string): string[] {
    return analysis.split('\n')
      .filter(line => line.trim().startsWith('-') || line.trim().startsWith('•') || line.match(/^\d+\./))
      .map(line => line.replace(/^[-•\d.]\s*/, '').trim())
      .slice(0, 5);
  }

  private extractQualityScore(analysis: string): number {
    const scoreMatch = analysis.match(/(\d+(?:\.\d+)?)\s*\/?\s*10/);
    if (scoreMatch) {
      return parseFloat(scoreMatch[1]);
    }
    return 7.0; // Default score
  }
}

export const smartIngestionService = new SmartIngestionService();
export type { DocumentUpload, IngestionResult };