tercul-backend/linguistics/work_analysis_service.go

package linguistics

import (
	"context"
	"fmt"
	"tercul/internal/models"
	"time"

	"tercul/internal/platform/log"
)

// WorkAnalysisService defines the interface for work-specific analysis operations
type WorkAnalysisService interface {
	// AnalyzeWork performs linguistic analysis on a work
	AnalyzeWork(ctx context.Context, workID uint) error

	// GetWorkAnalytics retrieves analytics data for a work
	GetWorkAnalytics(ctx context.Context, workID uint) (*WorkAnalytics, error)
}

// WorkAnalytics contains analytics data for a work
type WorkAnalytics struct {
	WorkID              uint
	ViewCount           int64
	LikeCount           int64
	CommentCount        int64
	BookmarkCount       int64
	TranslationCount    int64
	ReadabilityScore    float64
	SentimentScore      float64
	TopKeywords         []string
	PopularTranslations []TranslationAnalytics
}

// TranslationAnalytics contains analytics data for a translation
type TranslationAnalytics struct {
	TranslationID uint
	Language      string
	ViewCount     int64
	LikeCount     int64
}

// workAnalysisService implements the WorkAnalysisService interface
type workAnalysisService struct {
	textAnalyzer  TextAnalyzer
	analysisCache AnalysisCache
	analysisRepo  AnalysisRepository
	concurrency   int
	cacheEnabled  bool
}

// NewWorkAnalysisService creates a new WorkAnalysisService
func NewWorkAnalysisService(
	textAnalyzer TextAnalyzer,
	analysisCache AnalysisCache,
	analysisRepo AnalysisRepository,
	concurrency int,
	cacheEnabled bool,
) WorkAnalysisService {
	return &workAnalysisService{
		textAnalyzer:  textAnalyzer,
		analysisCache: analysisCache,
		analysisRepo:  analysisRepo,
		concurrency:   concurrency,
		cacheEnabled:  cacheEnabled,
	}
}

// AnalyzeWork performs linguistic analysis on a work and stores the results
func (s *workAnalysisService) AnalyzeWork(ctx context.Context, workID uint) error {
	if workID == 0 {
		return fmt.Errorf("invalid work ID")
	}

	// Check cache first if enabled
	if s.cacheEnabled && s.analysisCache.IsEnabled() {
		cacheKey := fmt.Sprintf("work_analysis:%d", workID)

		if result, err := s.analysisCache.Get(ctx, cacheKey); err == nil {
			log.LogInfo("Cache hit for work analysis",
				log.F("workID", workID))

			// Store directly to database
			return s.analysisRepo.StoreAnalysisResults(ctx, workID, result)
		}
	}

	// Get work content from database
	content, err := s.analysisRepo.GetWorkContent(ctx, workID, "")
	if err != nil {
		log.LogError("Failed to get work content for analysis",
			log.F("workID", workID),
			log.F("error", err))
		return fmt.Errorf("failed to get work content: %w", err)
	}

	// Skip analysis if content is empty
	if content == "" {
		log.LogWarn("Skipping analysis for work with empty content",
			log.F("workID", workID))
		return nil
	}

	// Get work to determine language (via repository to avoid leaking GORM)
	work, err := s.analysisRepo.GetWorkByID(ctx, workID)
	if err != nil {
		log.LogError("Failed to fetch work for analysis",
			log.F("workID", workID),
			log.F("error", err))
		return fmt.Errorf("failed to fetch work: %w", err)
	}

	// Analyze the text
	start := time.Now()
	log.LogInfo("Analyzing work",
		log.F("workID", workID),
		log.F("language", work.Language),
		log.F("contentLength", len(content)))

	var result *AnalysisResult

	// Use concurrent processing for large texts
	if len(content) > 10000 && s.concurrency > 1 {
		result, err = s.textAnalyzer.AnalyzeTextConcurrently(ctx, content, work.Language, s.concurrency)
	} else {
		result, err = s.textAnalyzer.AnalyzeText(ctx, content, work.Language)
	}

	if err != nil {
		log.LogError("Failed to analyze work text",
			log.F("workID", workID),
			log.F("error", err))
		return fmt.Errorf("failed to analyze work text: %w", err)
	}

	// Store results in database
	if err := s.analysisRepo.StoreAnalysisResults(ctx, workID, result); err != nil {
		log.LogError("Failed to store analysis results",
			log.F("workID", workID),
			log.F("error", err))
		return fmt.Errorf("failed to store analysis results: %w", err)
	}

	// Cache the result if caching is enabled
	if s.cacheEnabled && s.analysisCache.IsEnabled() {
		cacheKey := fmt.Sprintf("work_analysis:%d", workID)
		if err := s.analysisCache.Set(ctx, cacheKey, result); err != nil {
			log.LogWarn("Failed to cache work analysis result",
				log.F("workID", workID),
				log.F("error", err))
		}
	}

	log.LogInfo("Successfully analyzed work",
		log.F("workID", workID),
		log.F("wordCount", result.WordCount),
		log.F("readabilityScore", result.ReadabilityScore),
		log.F("sentiment", result.Sentiment),
		log.F("durationMs", time.Since(start).Milliseconds()))

	return nil
}

// GetWorkAnalytics retrieves analytics data for a work
func (s *workAnalysisService) GetWorkAnalytics(ctx context.Context, workID uint) (*WorkAnalytics, error) {
	if workID == 0 {
		return nil, fmt.Errorf("invalid work ID")
	}

	// Get the work to ensure it exists
	work, err := s.analysisRepo.GetWorkByID(ctx, workID)
	if err != nil {
		return nil, fmt.Errorf("work not found: %w", err)
	}

	// Get analysis results from database
	_, readabilityScore, languageAnalysis, _ := s.analysisRepo.GetAnalysisData(ctx, workID)

	// Extract keywords from JSONB
	var keywords []string
	if languageAnalysis.Analysis != nil {
		if keywordsData, ok := languageAnalysis.Analysis["keywords"].([]interface{}); ok {
			for _, kw := range keywordsData {
				if keywordMap, ok := kw.(map[string]interface{}); ok {
					if text, ok := keywordMap["text"].(string); ok {
						keywords = append(keywords, text)
					}
				}
			}
		}
	}

	// For now, return placeholder analytics with actual analysis data
	return &WorkAnalytics{
		WorkID:              work.ID,
		ViewCount:           0, // TODO: Implement view counting
		LikeCount:           0, // TODO: Implement like counting
		CommentCount:        0, // TODO: Implement comment counting
		BookmarkCount:       0, // TODO: Implement bookmark counting
		TranslationCount:    0, // TODO: Implement translation counting
		ReadabilityScore:    readabilityScore.Score,
		SentimentScore:      extractSentimentFromAnalysis(languageAnalysis.Analysis),
		TopKeywords:         keywords,
		PopularTranslations: []TranslationAnalytics{}, // TODO: Implement translation analytics
	}, nil
}

// extractSentimentFromAnalysis extracts sentiment from the Analysis JSONB field
func extractSentimentFromAnalysis(analysis models.JSONB) float64 {
	if analysis == nil {
		return 0.0
	}
	if sentiment, ok := analysis["sentiment"].(float64); ok {
		return sentiment
	}
	return 0.0
}