veza/veza-backend-api/internal/handlers/analytics_handler.go

package handlers

import (
	"context"
	"net/http"
	"strconv"
	"time"

	apperrors "veza-backend-api/internal/errors"
	"veza-backend-api/internal/services"
	"veza-backend-api/internal/types"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
	"go.uber.org/zap"
)

// AnalyticsServiceInterface defines the interface for AnalyticsService
type AnalyticsServiceInterface interface {
	RecordPlay(ctx context.Context, trackID uuid.UUID, userID *uuid.UUID, duration int, device, ipAddress string) error
	GetTrackStats(ctx context.Context, trackID uuid.UUID) (*types.TrackStats, error)
	GetTopTracks(ctx context.Context, limit int, startDate, endDate *time.Time) ([]services.TopTrack, error)
	GetPlaysOverTime(ctx context.Context, trackID uuid.UUID, startDate, endDate time.Time, interval string) ([]services.PlayTimePoint, error)
	GetUserStats(ctx context.Context, userID uuid.UUID) (*types.UserStats, error)
}

// AnalyticsJobWorkerInterface defines the interface for JobWorker (analytics related)
type AnalyticsJobWorkerInterface interface {
	EnqueueAnalyticsJob(eventName string, userID *uuid.UUID, payload map[string]interface{})
}

// AnalyticsHandler gère les opérations d'analytics de lecture de tracks
type AnalyticsHandler struct {
	analyticsService AnalyticsServiceInterface
	jobWorker        AnalyticsJobWorkerInterface
	commonHandler    *CommonHandler
}

// NewAnalyticsHandler crée un nouveau handler d'analytics
func NewAnalyticsHandler(analyticsService *services.AnalyticsService, logger *zap.Logger) *AnalyticsHandler {
	return &AnalyticsHandler{
		analyticsService: analyticsService,
		commonHandler:    NewCommonHandler(logger),
	}
}

// NewAnalyticsHandlerWithInterface creates a new analytics handler with interfaces for testing
func NewAnalyticsHandlerWithInterface(analyticsService AnalyticsServiceInterface, logger *zap.Logger) *AnalyticsHandler {
	return &AnalyticsHandler{
		analyticsService: analyticsService,
		commonHandler:    NewCommonHandler(logger),
	}
}

// SetJobWorker définit le JobWorker pour enregistrer des événements analytics
func (h *AnalyticsHandler) SetJobWorker(jobWorker AnalyticsJobWorkerInterface) {
	h.jobWorker = jobWorker
}

// RecordPlayRequest représente la requête pour enregistrer une lecture
// MOD-P1-001: Ajout tags validate pour validation systématique
type RecordPlayRequest struct {
	Duration int    `json:"duration" binding:"required,min=1" validate:"required,min=1"`
	Device   string `json:"device,omitempty" validate:"omitempty,max=100"`
}

// RecordPlay gère l'enregistrement d'une lecture de track
// @Summary      Record play
// @Description  Record a play event for a track. Can be called anonymously or with authentication.
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Param        id       path      string  true  "Track ID (UUID)"
// @Param        request  body      handlers.RecordPlayRequest  true  "Play event data"
// @Success      200  {object}  handlers.APIResponse{data=object{message=string}}
// @Failure      400  {object}  handlers.APIResponse "Validation error"
// @Failure      404  {object}  handlers.APIResponse "Track not found"
// @Failure      500  {object}  handlers.APIResponse "Internal server error"
// @Router       /tracks/{id}/play [post]
func (h *AnalyticsHandler) RecordPlay(c *gin.Context) {
	trackIDStr := c.Param("id")
	if trackIDStr == "" {
		RespondWithAppError(c, apperrors.NewValidationError("track id is required"))
		return
	}

	trackID, err := uuid.Parse(trackIDStr) // Changed to uuid.Parse
	if err != nil {
		RespondWithAppError(c, apperrors.NewValidationError("invalid track id"))
		return
	}

	var req RecordPlayRequest
	if appErr := h.commonHandler.BindAndValidateJSON(c, &req); appErr != nil {
		RespondWithAppError(c, appErr)
		return
	}

	// Récupérer user_id si authentifié (optionnel pour analytics anonymes)
	var userID *uuid.UUID
	if uid, ok := c.Get("user_id"); ok {
		if uidUUID, ok := uid.(uuid.UUID); ok {
			userID = &uidUUID
		}
	}

	// Récupérer IP address et device
	ipAddress := c.ClientIP()
	device := req.Device
	if device == "" {
		device = c.GetHeader("User-Agent")
	}

	err = h.analyticsService.RecordPlay(c.Request.Context(), trackID, userID, req.Duration, device, ipAddress)
	if err != nil {
		if err.Error() == "track not found" {
			RespondWithAppError(c, apperrors.NewNotFoundError("track"))
			return
		}
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to record play", err))
		return
	}

	RespondSuccess(c, http.StatusOK, gin.H{"message": "play recorded"})
}

// GetTrackStats gère la récupération des statistiques d'un track
// @Summary      Get track statistics
// @Description  Get statistics for a track (plays, likes, etc.)
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Param        id       path      string  true  "Track ID (UUID)"
// @Success      200  {object}  handlers.APIResponse{data=object{stats=object}}
// @Failure      400  {object}  handlers.APIResponse "Validation error"
// @Failure      404  {object}  handlers.APIResponse "Track not found"
// @Failure      500  {object}  handlers.APIResponse "Internal server error"
// @Router       /tracks/{id}/stats [get]
func (h *AnalyticsHandler) GetTrackStats(c *gin.Context) {
	trackIDStr := c.Param("id")
	if trackIDStr == "" {
		RespondWithAppError(c, apperrors.NewValidationError("track id is required"))
		return
	}

	trackID, err := uuid.Parse(trackIDStr) // Changed to uuid.Parse
	if err != nil {
		RespondWithAppError(c, apperrors.NewValidationError("invalid track id"))
		return
	}

	stats, err := h.analyticsService.GetTrackStats(c.Request.Context(), trackID)
	if err != nil {
		if err.Error() == "track not found" {
			RespondWithAppError(c, apperrors.NewNotFoundError("track"))
			return
		}
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to get track stats", err))
		return
	}

	RespondSuccess(c, http.StatusOK, gin.H{"stats": stats})
}

// GetTopTracks gère la récupération des tracks les plus écoutés
// @Summary      Get top tracks
// @Description  Get list of top tracks by play count, optionally filtered by date range
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Param        limit       query     int     false "Number of tracks to return" default(10) minimum(1) maximum(100)
// @Param        start_date  query     string  false "Start date filter (RFC3339 format)"
// @Param        end_date    query     string  false "End date filter (RFC3339 format)"
// @Success      200  {object}  handlers.APIResponse{data=object{tracks=array}}
// @Failure      400  {object}  handlers.APIResponse "Validation error"
// @Failure      500  {object}  handlers.APIResponse "Internal server error"
// @Router       /analytics/tracks/top [get]
func (h *AnalyticsHandler) GetTopTracks(c *gin.Context) {
	// Parse limit
	limit := 10
	if limitStr := c.Query("limit"); limitStr != "" {
		if l, err := strconv.Atoi(limitStr); err == nil && l > 0 && l <= 100 {
			limit = l
		} else {
			RespondWithAppError(c, apperrors.NewValidationError("invalid limit (must be between 1 and 100)"))
			return
		}
	}

	// Parse start_date (optionnel)
	var startDate *time.Time
	if startDateStr := c.Query("start_date"); startDateStr != "" {
		parsed, err := time.Parse(time.RFC3339, startDateStr)
		if err != nil {
			RespondWithAppError(c, apperrors.NewValidationError("invalid start_date format (use RFC3339)"))
			return
		}
		startDate = &parsed
	}

	// Parse end_date (optionnel)
	var endDate *time.Time
	if endDateStr := c.Query("end_date"); endDateStr != "" {
		parsed, err := time.Parse(time.RFC3339, endDateStr)
		if err != nil {
			RespondWithAppError(c, apperrors.NewValidationError("invalid end_date format (use RFC3339)"))
			return
		}
		endDate = &parsed
	}

	topTracks, err := h.analyticsService.GetTopTracks(c.Request.Context(), limit, startDate, endDate)
	if err != nil {
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to get top tracks", err))
		return
	}

	RespondSuccess(c, http.StatusOK, gin.H{"tracks": topTracks})
}

// GetPlaysOverTime gère la récupération des lectures sur une période
// @Summary      Get plays over time
// @Description  Get play statistics over time for a track, grouped by time period
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Param        id          path      string  true  "Track ID (UUID)"
// @Param        start_date  query     string  false "Start date (RFC3339 format)"
// @Param        end_date    query     string  false "End date (RFC3339 format)"
// @Param        interval    query     string  false "Time period grouping (hour, day, week, month)" default(day)
// @Success      200  {object}  handlers.APIResponse{data=object{points=array}}
// @Failure      400  {object}  handlers.APIResponse "Validation error"
// @Failure      404  {object}  handlers.APIResponse "Track not found"
// @Failure      500  {object}  handlers.APIResponse "Internal server error"
// @Router       /tracks/{id}/analytics/plays [get]
func (h *AnalyticsHandler) GetPlaysOverTime(c *gin.Context) {
	trackIDStr := c.Param("id")
	if trackIDStr == "" {
		RespondWithAppError(c, apperrors.NewValidationError("track id is required"))
		return
	}

	trackID, err := uuid.Parse(trackIDStr) // Changed to uuid.Parse
	if err != nil {
		RespondWithAppError(c, apperrors.NewValidationError("invalid track id"))
		return
	}

	// Parse start_date (optionnel, défaut: 30 jours)
	startDate := time.Now().AddDate(0, 0, -30)
	if startDateStr := c.Query("start_date"); startDateStr != "" {
		parsed, err := time.Parse(time.RFC3339, startDateStr)
		if err != nil {
			RespondWithAppError(c, apperrors.NewValidationError("invalid start_date format (use RFC3339)"))
			return
		}
		startDate = parsed
	}

	// Parse end_date (optionnel, défaut: maintenant)
	endDate := time.Now()
	if endDateStr := c.Query("end_date"); endDateStr != "" {
		parsed, err := time.Parse(time.RFC3339, endDateStr)
		if err != nil {
			RespondWithAppError(c, apperrors.NewValidationError("invalid end_date format (use RFC3339)"))
			return
		}
		endDate = parsed
	}

	// Parse interval (optionnel, défaut: day)
	interval := c.DefaultQuery("interval", "day")
	validIntervals := map[string]bool{"hour": true, "day": true, "week": true, "month": true}
	if !validIntervals[interval] {
		RespondWithAppError(c, apperrors.NewValidationError("invalid interval (must be: hour, day, week, month)"))
		return
	}

	points, err := h.analyticsService.GetPlaysOverTime(c.Request.Context(), trackID, startDate, endDate, interval)
	if err != nil {
		if err.Error() == "track not found" {
			RespondWithAppError(c, apperrors.NewNotFoundError("track"))
			return
		}
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to get plays over time", err))
		return
	}

	RespondSuccess(c, http.StatusOK, gin.H{"points": points})
}

// GetUserStats gère la récupération des statistiques d'un utilisateur
// @Summary      Get user statistics
// @Description  Get analytics statistics for a user (total plays, tracks, etc.)
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Security     BearerAuth
// @Param        id       path      string  true  "User ID (UUID)"
// @Success      200  {object}  handlers.APIResponse{data=object{stats=object}}
// @Failure      400  {object}  handlers.APIResponse "Validation error"
// @Failure      401  {object}  handlers.APIResponse "Unauthorized"
// @Failure      403  {object}  handlers.APIResponse "Forbidden - can only view own stats"
// @Failure      404  {object}  handlers.APIResponse "User not found"
// @Failure      500  {object}  handlers.APIResponse "Internal server error"
// @Router       /users/{id}/analytics/stats [get]
func (h *AnalyticsHandler) GetUserStats(c *gin.Context) {
	userIDStr := c.Param("id")
	if userIDStr == "" {
		RespondWithAppError(c, apperrors.NewValidationError("user id is required"))
		return
	}

	userID, err := uuid.Parse(userIDStr)
	if err != nil {
		RespondWithAppError(c, apperrors.NewValidationError("invalid user id"))
		return
	}

	// Vérifier que l'utilisateur peut accéder à ses propres stats
	var authenticatedUserID *uuid.UUID
	if uid, ok := c.Get("user_id"); ok {
		if uidUUID, ok := uid.(uuid.UUID); ok {
			authenticatedUserID = &uidUUID
		}
	}
	if authenticatedUserID != nil && *authenticatedUserID != userID {
		RespondWithAppError(c, apperrors.NewForbiddenError("cannot access other user's stats"))
		return
	}

	stats, err := h.analyticsService.GetUserStats(c.Request.Context(), userID)
	if err != nil {
		if err.Error() == "user not found" {
			RespondWithAppError(c, apperrors.NewNotFoundError("user"))
			return
		}
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to get user stats", err))
		return
	}

	RespondSuccess(c, http.StatusOK, gin.H{"stats": stats})
}

// GetTrackAnalyticsDashboard gère la récupération du dashboard d'analytics complet pour un track
// BE-API-036: GET /api/v1/analytics/tracks/:id returns comprehensive track analytics
// @Summary      Get Track Analytics Dashboard
// @Description  Get comprehensive analytics dashboard for a track
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Security     BearerAuth
// @Param        id   path      string  true  "Track ID"
// @Success      200  {object}  APIResponse{data=object{dashboard=object}}
// @Failure      400  {object}  APIResponse "Validation Error"
// @Failure      404  {object}  APIResponse "Track not found"
// @Failure      500  {object}  APIResponse "Internal Error"
// @Router       /analytics/tracks/{id} [get]
func (h *AnalyticsHandler) GetTrackAnalyticsDashboard(c *gin.Context) {
	trackIDStr := c.Param("id")
	if trackIDStr == "" {
		RespondWithAppError(c, apperrors.NewValidationError("track id is required"))
		return
	}

	trackID, err := uuid.Parse(trackIDStr)
	if err != nil {
		RespondWithAppError(c, apperrors.NewValidationError("invalid track id"))
		return
	}

	// Récupérer les statistiques de base
	stats, err := h.analyticsService.GetTrackStats(c.Request.Context(), trackID)
	if err != nil {
		if err.Error() == "track not found" {
			RespondWithAppError(c, apperrors.NewNotFoundError("track"))
			return
		}
		RespondWithAppError(c, apperrors.Wrap(apperrors.ErrCodeInternal, "Failed to get track stats", err))
		return
	}

	// Récupérer les lectures sur une période (30 derniers jours)
	startDate := time.Now().AddDate(0, 0, -30)
	endDate := time.Now()
	playsOverTime, err := h.analyticsService.GetPlaysOverTime(c.Request.Context(), trackID, startDate, endDate, "day")
	if err != nil {
		// Ne pas échouer si on ne peut pas récupérer les données temporelles
		playsOverTime = []services.PlayTimePoint{}
	}

	// Construire le dashboard complet
	dashboard := gin.H{
		"track_id": trackID.String(),
		"stats": gin.H{
			"total_plays":      stats.TotalPlays,
			"unique_listeners": stats.UniqueListeners,
			"average_duration": stats.AverageDuration,
			"completion_rate":  stats.CompletionRate,
		},
		"plays_over_time": playsOverTime,
		"period": gin.H{
			"start_date": startDate.Format(time.RFC3339),
			"end_date":   endDate.Format(time.RFC3339),
			"days":       30,
		},
	}

	RespondSuccess(c, http.StatusOK, gin.H{
		"dashboard": dashboard,
	})
}

// RecordEventRequest représente la requête pour enregistrer un événement analytics personnalisé
// BE-API-035: POST /api/v1/analytics/events to record custom analytics events
type RecordEventRequest struct {
	EventName string                 `json:"event_name" binding:"required,min=1,max=100" validate:"required,min=1,max=100"`
	Payload   map[string]interface{} `json:"payload,omitempty" validate:"omitempty"`
}

// RecordEvent gère l'enregistrement d'un événement analytics personnalisé
// BE-API-035: Implement analytics events endpoint
// @Summary      Record Analytics Event
// @Description  Record a custom analytics event
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Security     BearerAuth
// @Param        request body RecordEventRequest true "Event Data"
// @Success      200  {object}  APIResponse{data=object{message=string}}
// @Failure      400  {object}  APIResponse "Validation Error"
// @Failure      401  {object}  APIResponse "Unauthorized"
// @Failure      500  {object}  APIResponse "Internal Error"
// @Router       /analytics/events [post]
func (h *AnalyticsHandler) RecordEvent(c *gin.Context) {
	var req RecordEventRequest
	if appErr := h.commonHandler.BindAndValidateJSON(c, &req); appErr != nil {
		RespondWithAppError(c, appErr)
		return
	}

	// Récupérer user_id si authentifié (optionnel pour analytics anonymes)
	var userID *uuid.UUID
	if uid, ok := c.Get("user_id"); ok {
		if uidUUID, ok := uid.(uuid.UUID); ok {
			userID = &uidUUID
		}
	}

	// Vérifier que le JobWorker est disponible
	if h.jobWorker == nil {
		RespondWithAppError(c, apperrors.New(apperrors.ErrCodeInternal, "analytics service not available"))
		return
	}

	// Enqueue l'événement analytics via le JobWorker
	h.jobWorker.EnqueueAnalyticsJob(req.EventName, userID, req.Payload)

	RespondSuccess(c, http.StatusOK, gin.H{
		"message":    "event recorded",
		"event_name": req.EventName,
	})
}

// GetAnalytics gère la récupération des analytics agrégées pour l'utilisateur
// BE-API-037: GET /api/v1/analytics endpoint for aggregated analytics
// @Summary      Get Analytics Data
// @Description  Get aggregated analytics data for tracks and playlists
// @Tags         Analytics
// @Accept       json
// @Produce      json
// @Security     BearerAuth
// @Param        days        query     int     false  "Number of days (default: 30)"
// @Param        start_date   query     string  false  "Start date (ISO 8601)"
// @Param        end_date     query     string  false  "End date (ISO 8601)"
// @Success      200  {object}  APIResponse{data=object{tracks=object,playlists=object,period=object}}
// @Failure      401  {object}  APIResponse "Unauthorized"
// @Failure      500  {object}  APIResponse "Internal Error"
// @Router       /analytics [get]
func (h *AnalyticsHandler) GetAnalytics(c *gin.Context) {
	// Récupérer l'utilisateur authentifié
	userIDInterface, exists := c.Get("user_id")
	if !exists {
		RespondWithAppError(c, apperrors.New(apperrors.ErrCodeUnauthorized, "authentication required"))
		return
	}

	userID, ok := userIDInterface.(uuid.UUID)
	if !ok {
		RespondWithAppError(c, apperrors.New(apperrors.ErrCodeInternal, "invalid user id"))
		return
	}

	// Parser les paramètres de date
	daysStr := c.DefaultQuery("days", "30")
	days, err := strconv.Atoi(daysStr)
	if err != nil || days < 1 {
		days = 30
	}

	var startDate, endDate *time.Time
	if startDateStr := c.Query("start_date"); startDateStr != "" {
		if parsed, err := time.Parse(time.RFC3339, startDateStr); err == nil {
			startDate = &parsed
		}
	}
	if endDateStr := c.Query("end_date"); endDateStr != "" {
		if parsed, err := time.Parse(time.RFC3339, endDateStr); err == nil {
			endDate = &parsed
		}
	}

	// Si les dates ne sont pas fournies, calculer depuis days
	if startDate == nil || endDate == nil {
		now := time.Now()
		if endDate == nil {
			endDate = &now
		}
		if startDate == nil {
			calculatedStart := endDate.AddDate(0, 0, -days)
			startDate = &calculatedStart
		}
	}

	ctx := c.Request.Context()

	// Accéder à la DB via le service (nécessite un cast)
	analyticsSvc, ok := h.analyticsService.(*services.AnalyticsService)
	if !ok {
		RespondWithAppError(c, apperrors.New(apperrors.ErrCodeInternal, "analytics service type error"))
		return
	}

	// Récupérer les tracks de l'utilisateur avec leurs stats
	var tracks []struct {
		ID            uuid.UUID `gorm:"column:id"`
		Title         string    `gorm:"column:title"`
		PlayCount     int64     `gorm:"column:play_count"`
		LikeCount     int64     `gorm:"column:like_count"`
		DownloadCount int64     `gorm:"column:download_count"`
	}

	if err := analyticsSvc.GetDB().WithContext(ctx).
		Table("tracks").
		Select("id, title, play_count, like_count, COALESCE(download_count, 0) as download_count").
		Where("creator_id = ?", userID).
		Find(&tracks).Error; err != nil {
		h.commonHandler.logger.Error("Failed to fetch user tracks", zap.Error(err))
		RespondWithAppError(c, apperrors.New(apperrors.ErrCodeInternal, "failed to fetch tracks"))
		return
	}

	// Calculer les stats des tracks
	totalTracks := len(tracks)
	var totalPlays, totalLikes, totalDownloads int64
	for _, track := range tracks {
		totalPlays += track.PlayCount
		totalLikes += track.LikeCount
		totalDownloads += track.DownloadCount
	}

	avgPlayCount := float64(0)
	if totalTracks > 0 {
		avgPlayCount = float64(totalPlays) / float64(totalTracks)
	}

	// Top 5 tracks
	topTracks := make([]gin.H, 0, 5)
	sortedTracks := make([]struct {
		ID        uuid.UUID
		Title     string
		PlayCount int64
		LikeCount int64
	}, len(tracks))
	for i, t := range tracks {
		sortedTracks[i] = struct {
			ID        uuid.UUID
			Title     string
			PlayCount int64
			LikeCount int64
		}{t.ID, t.Title, t.PlayCount, t.LikeCount}
	}

	// Trier par play_count
	for i := 0; i < len(sortedTracks)-1; i++ {
		for j := i + 1; j < len(sortedTracks); j++ {
			if sortedTracks[i].PlayCount < sortedTracks[j].PlayCount {
				sortedTracks[i], sortedTracks[j] = sortedTracks[j], sortedTracks[i]
			}
		}
	}

	for i := 0; i < 5 && i < len(sortedTracks); i++ {
		topTracks = append(topTracks, gin.H{
			"id":         sortedTracks[i].ID.String(),
			"title":      sortedTracks[i].Title,
			"play_count": sortedTracks[i].PlayCount,
			"like_count": sortedTracks[i].LikeCount,
		})
	}

	// Récupérer les playlists de l'utilisateur
	// CRITIQUE FIX #15: Gérer gracieusement l'erreur si la table playlists n'existe pas ou est vide
	var playlists []struct {
		ID         uuid.UUID `gorm:"column:id"`
		Name       string    `gorm:"column:title"`
		PlayCount  int64     `gorm:"column:play_count"`
		LikeCount  int64     `gorm:"column:like_count"`
		ShareCount int64     `gorm:"column:share_count"`
	}

	playlistsError := analyticsSvc.GetDB().WithContext(ctx).
		Table("playlists").
		Select("id, title as name, COALESCE(play_count, 0) as play_count, COALESCE(like_count, 0) as like_count, COALESCE(share_count, 0) as share_count").
		Where("user_id = ?", userID).
		Find(&playlists).Error

	// Si erreur lors de la récupération des playlists, logger mais continuer avec des données vides
	// Cela permet de retourner les analytics des tracks même si les playlists ne sont pas disponibles
	if playlistsError != nil {
		h.commonHandler.logger.Warn("Failed to fetch user playlists, continuing with empty playlists data", zap.Error(playlistsError))
		playlists = []struct {
			ID         uuid.UUID `gorm:"column:id"`
			Name       string    `gorm:"column:title"`
			PlayCount  int64     `gorm:"column:play_count"`
			LikeCount  int64     `gorm:"column:like_count"`
			ShareCount int64     `gorm:"column:share_count"`
		}{}
	}

	// Calculer les stats des playlists
	totalPlaylists := len(playlists)
	var playlistPlays, playlistLikes, playlistShares int64
	for _, playlist := range playlists {
		playlistPlays += playlist.PlayCount
		playlistLikes += playlist.LikeCount
		playlistShares += playlist.ShareCount
	}

	avgPlaylistPlayCount := float64(0)
	if totalPlaylists > 0 {
		avgPlaylistPlayCount = float64(playlistPlays) / float64(totalPlaylists)
	}

	// Top 5 playlists
	topPlaylists := make([]gin.H, 0, 5)
	sortedPlaylists := make([]struct {
		ID        uuid.UUID
		Name      string
		PlayCount int64
		LikeCount int64
	}, len(playlists))
	for i, p := range playlists {
		sortedPlaylists[i] = struct {
			ID        uuid.UUID
			Name      string
			PlayCount int64
			LikeCount int64
		}{p.ID, p.Name, p.PlayCount, p.LikeCount}
	}

	// Trier par play_count
	for i := 0; i < len(sortedPlaylists)-1; i++ {
		for j := i + 1; j < len(sortedPlaylists); j++ {
			if sortedPlaylists[i].PlayCount < sortedPlaylists[j].PlayCount {
				sortedPlaylists[i], sortedPlaylists[j] = sortedPlaylists[j], sortedPlaylists[i]
			}
		}
	}

	for i := 0; i < 5 && i < len(sortedPlaylists); i++ {
		topPlaylists = append(topPlaylists, gin.H{
			"id":         sortedPlaylists[i].ID.String(),
			"name":       sortedPlaylists[i].Name,
			"play_count": sortedPlaylists[i].PlayCount,
			"like_count": sortedPlaylists[i].LikeCount,
		})
	}

	// Construire la réponse
	analyticsData := gin.H{
		"tracks": gin.H{
			"total_tracks":       totalTracks,
			"total_plays":        totalPlays,
			"total_likes":        totalLikes,
			"total_downloads":    totalDownloads,
			"average_play_count": avgPlayCount,
			"top_tracks":         topTracks,
		},
		"playlists": gin.H{
			"total_playlists":    totalPlaylists,
			"total_plays":        playlistPlays,
			"total_likes":        playlistLikes,
			"total_shares":       playlistShares,
			"average_play_count": avgPlaylistPlayCount,
			"top_playlists":      topPlaylists,
		},
		"period": gin.H{
			"start_date": startDate.Format(time.RFC3339),
			"end_date":   endDate.Format(time.RFC3339),
			"days":       days,
		},
	}

	RespondSuccess(c, http.StatusOK, analyticsData)
}