<?php

namespace App\Services;

use App\Models\AnalyticsEvent;
use App\Models\User;
use App\Models\Ad;
use App\Models\ChatMessage;
use App\Models\Notification as NotificationModel;
use App\Models\Transaction;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Collection;

class AdvancedAnalyticsService
{
    /**
     * Get comprehensive business intelligence dashboard
     */
    public function getBusinessIntelligenceDashboard($startDate = null, $endDate = null)
    {
        return [
            'kpi_overview' => $this->getKPIOverview($startDate, $endDate),
            'revenue_analytics' => $this->getRevenueAnalytics($startDate, $endDate),
            'user_behavior_analysis' => $this->getUserBehaviorAnalysis($startDate, $endDate),
            'market_trends' => $this->getMarketTrends($startDate, $endDate),
            'predictive_insights' => $this->getPredictiveInsights($startDate, $endDate),
            'performance_metrics' => $this->getPerformanceMetrics($startDate, $endDate),
            'conversion_funnels' => $this->getConversionFunnels($startDate, $endDate),
            'customer_lifetime_value' => $this->getCustomerLifetimeValue($startDate, $endDate),
            'churn_analysis' => $this->getChurnAnalysis($startDate, $endDate),
        ];
    }

    /**
     * Get Key Performance Indicators
     */
    private function getKPIOverview($startDate, $endDate)
    {
        $totalUsers = User::when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
            return $query->whereBetween('created_at', [$startDate, $endDate]);
        })->count();

        $activeUsers = $this->getActiveUsers($startDate, $endDate);
        $totalAds = Ad::when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
            return $query->whereBetween('created_at', [$startDate, $endDate]);
        })->count();
        
        $totalRevenue = $this->getTotalRevenue($startDate, $endDate);
        $avgSessionDuration = $this->getAverageSessionDuration($startDate, $endDate);
        $conversionRate = $this->getConversionRate($startDate, $endDate);

        return [
            'total_users' => $totalUsers,
            'active_users' => $activeUsers,
            'total_ads' => $totalAds,
            'total_revenue' => $totalRevenue,
            'avg_session_duration' => $avgSessionDuration,
            'conversion_rate' => $conversionRate,
            'user_growth_rate' => $this->getUserGrowthRate($startDate, $endDate),
            'revenue_growth_rate' => $this->getRevenueGrowthRate($startDate, $endDate),
            'ads_growth_rate' => $this->getAdsGrowthRate($startDate, $endDate),
        ];
    }

    /**
     * Get Revenue Analytics with advanced metrics
     */
    private function getRevenueAnalytics($startDate, $endDate)
    {
        $revenueData = Transaction::selectRaw('DATE(created_at) as date, SUM(amount) as revenue, COUNT(*) as transactions')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->where('status', 'completed')
            ->groupBy('date')
            ->orderBy('date')
            ->get();

        $revenueBySource = $this->getRevenueBySource($startDate, $endDate);
        $arpu = $this->getARPU($startDate, $endDate);
        $ltv = $this->getLTV($startDate, $endDate);
        $mrr = $this->getMRR($startDate, $endDate);

        return [
            'daily_revenue' => $revenueData,
            'revenue_by_source' => $revenueBySource,
            'arpu' => $arpu,
            'ltv' => $ltv,
            'mrr' => $mrr,
            'revenue_trend' => $this->getRevenueTrend($startDate, $endDate),
            'top_performing_plans' => $this->getTopPerformingPlans($startDate, $endDate),
        ];
    }

    /**
     * Get User Behavior Analysis
     */
    private function getUserBehaviorAnalysis($startDate, $endDate)
    {
        $userJourney = $this->getUserJourneyAnalysis($startDate, $endDate);
        $featureUsage = $this->getFeatureUsage($startDate, $endDate);
        $userSegments = $this->getUserSegments($startDate, $endDate);
        $engagementMetrics = $this->getEngagementMetrics($startDate, $endDate);

        return [
            'user_journey' => $userJourney,
            'feature_usage' => $featureUsage,
            'user_segments' => $userSegments,
            'engagement_metrics' => $engagementMetrics,
            'peak_usage_times' => $this->getPeakUsageTimes($startDate, $endDate),
            'user_retention_cohorts' => $this->getUserRetentionCohorts($startDate, $endDate),
        ];
    }

    /**
     * Get Market Trends Analysis
     */
    private function getMarketTrends($startDate, $endDate)
    {
        $categoryTrends = $this->getCategoryTrends($startDate, $endDate);
        $priceAnalysis = $this->getPriceAnalysis($startDate, $endDate);
        $geographicDistribution = $this->getGeographicDistribution($startDate, $endDate);
        $seasonalPatterns = $this->getSeasonalPatterns($startDate, $endDate);

        return [
            'category_trends' => $categoryTrends,
            'price_analysis' => $priceAnalysis,
            'geographic_distribution' => $geographicDistribution,
            'seasonal_patterns' => $seasonalPatterns,
            'market_competition' => $this->getMarketCompetition($startDate, $endDate),
            'demand_forecasting' => $this->getDemandForecasting($startDate, $endDate),
        ];
    }

    /**
     * Get Predictive Insights
     */
    private function getPredictiveInsights($startDate, $endDate)
    {
        return [
            'user_acquisition_forecast' => $this->getUserAcquisitionForecast($startDate, $endDate),
            'revenue_projection' => $this->getRevenueProjection($startDate, $endDate),
            'churn_prediction' => $this->getChurnPrediction($startDate, $endDate),
            'trend_prediction' => $this->getTrendPrediction($startDate, $endDate),
            'risk_assessment' => $this->getRiskAssessment($startDate, $endDate),
        ];
    }

    /**
     * Get Performance Metrics
     */
    private function getPerformanceMetrics($startDate, $endDate)
    {
        return [
            'system_performance' => $this->getSystemPerformance($startDate, $endDate),
            'user_satisfaction' => $this->getUserSatisfaction($startDate, $endDate),
            'feature_performance' => $this->getFeaturePerformance($startDate, $endDate),
            'error_rates' => $this->getErrorRates($startDate, $endDate),
            'response_times' => $this->getResponseTimes($startDate, $endDate),
        ];
    }

    /**
     * Get Conversion Funnels
     */
    private function getConversionFunnels($startDate, $endDate)
    {
        return [
            'registration_funnel' => $this->getRegistrationFunnel($startDate, $endDate),
            'ad_posting_funnel' => $this->getAdPostingFunnel($startDate, $endDate),
            'purchase_funnel' => $this->getPurchaseFunnel($startDate, $endDate),
            'engagement_funnel' => $this->getEngagementFunnel($startDate, $endDate),
        ];
    }

    /**
     * Get Customer Lifetime Value Analysis
     */
    private function getCustomerLifetimeValue($startDate, $endDate)
    {
        $clvByCohort = $this->getCLVByCohort($startDate, $endDate);
        $clvBySegment = $this->getCLVBySegment($startDate, $endDate);
        $clvTrends = $this->getCLVTrends($startDate, $endDate);

        return [
            'clv_by_cohort' => $clvByCohort,
            'clv_by_segment' => $clvBySegment,
            'clv_trends' => $clvTrends,
            'high_value_customers' => $this->getHighValueCustomers($startDate, $endDate),
        ];
    }

    /**
     * Get Churn Analysis
     */
    private function getChurnAnalysis($startDate, $endDate)
    {
        return [
            'churn_rate' => $this->getChurnRate($startDate, $endDate),
            'churn_prediction' => $this->getChurnPrediction($startDate, $endDate),
            'churn_factors' => $this->getChurnFactors($startDate, $endDate),
            'retention_strategies' => $this->getRetentionStrategies($startDate, $endDate),
        ];
    }

    // Helper Methods

    private function getActiveUsers($startDate, $endDate)
    {
        return AnalyticsEvent::where('event_type', 'page_view')
            ->whereNotNull('user_id')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->distinct('user_id')
            ->count('user_id');
    }

    private function getTotalRevenue($startDate, $endDate)
    {
        return Transaction::where('status', 'completed')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->sum('amount') ?? 0;
    }

    private function getAverageSessionDuration($startDate, $endDate)
    {
        // Implementation for average session duration
        return 0;
    }

    private function getConversionRate($startDate, $endDate)
    {
        $registrations = User::when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
            return $query->whereBetween('created_at', [$startDate, $endDate]);
        })->count();

        $adsPosted = Ad::when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
            return $query->whereBetween('created_at', [$startDate, $endDate]);
        })->count();

        return $registrations > 0 ? ($adsPosted / $registrations) * 100 : 0;
    }

    private function getUserGrowthRate($startDate, $endDate)
    {
        // Implementation for user growth rate
        return 0;
    }

    private function getRevenueGrowthRate($startDate, $endDate)
    {
        // Implementation for revenue growth rate
        return 0;
    }

    private function getAdsGrowthRate($startDate, $endDate)
    {
        // Implementation for ads growth rate
        return 0;
    }

    private function getRevenueBySource($startDate, $endDate)
    {
        return Transaction::select('transaction_type', DB::raw('SUM(amount) as total'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->where('status', 'completed')
            ->groupBy('transaction_type')
            ->get();
    }

    private function getARPU($startDate, $endDate)
    {
        $totalRevenue = $this->getTotalRevenue($startDate, $endDate);
        $activeUsers = $this->getActiveUsers($startDate, $endDate);
        
        return $activeUsers > 0 ? ($totalRevenue / $activeUsers) : 0;
    }

    private function getLTV($startDate, $endDate)
    {
        // Implementation for Customer Lifetime Value
        return 0;
    }

    private function getMRR($startDate, $endDate)
    {
        return Transaction::where('transaction_type', 'subscription')
            ->where('status', 'completed')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->sum('amount') ?? 0;
    }

    private function getRevenueTrend($startDate, $endDate)
    {
        return Transaction::selectRaw('DATE(created_at) as date, SUM(amount) as revenue')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->where('status', 'completed')
            ->groupBy('date')
            ->orderBy('date')
            ->get();
    }

    private function getTopPerformingPlans($startDate, $endDate)
    {
        return Transaction::select('plan_type', DB::raw('COUNT(*) as count, SUM(amount) as revenue'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->where('status', 'completed')
            ->groupBy('plan_type')
            ->orderBy('revenue', 'desc')
            ->limit(5)
            ->get();
    }

    private function getUserJourneyAnalysis($startDate, $endDate)
    {
        // Implementation for user journey analysis
        return [];
    }

    private function getFeatureUsage($startDate, $endDate)
    {
        return AnalyticsEvent::select('event_type', DB::raw('COUNT(*) as count'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('event_type')
            ->orderBy('count', 'desc')
            ->limit(10)
            ->get();
    }

    private function getUserSegments($startDate, $endDate)
    {
        // Implementation for user segmentation
        return [];
    }

    private function getEngagementMetrics($startDate, $endDate)
    {
        return [
            'daily_active_users' => $this->getDailyActiveUsers($startDate, $endDate),
            'monthly_active_users' => $this->getMonthlyActiveUsers($startDate, $endDate),
            'session_frequency' => $this->getSessionFrequency($startDate, $endDate),
            'time_on_site' => $this->getTimeOnSite($startDate, $endDate),
        ];
    }

    private function getDailyActiveUsers($startDate, $endDate)
    {
        return AnalyticsEvent::selectRaw('DATE(created_at) as date, COUNT(DISTINCT user_id) as dau')
            ->whereNotNull('user_id')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('date')
            ->orderBy('date')
            ->get();
    }

    private function getMonthlyActiveUsers($startDate, $endDate)
    {
        return AnalyticsEvent::selectRaw('DATE_FORMAT(created_at, "%Y-%m") as month, COUNT(DISTINCT user_id) as mau')
            ->whereNotNull('user_id')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('month')
            ->orderBy('month')
            ->get();
    }

    private function getSessionFrequency($startDate, $endDate)
    {
        return AnalyticsEvent::selectRaw('user_id, COUNT(*) as session_count')
            ->whereNotNull('user_id')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('user_id')
            ->orderBy('session_count', 'desc')
            ->limit(10)
            ->get();
    }

    private function getTimeOnSite($startDate, $endDate)
    {
        // Implementation for time on site
        return 0;
    }

    private function getPeakUsageTimes($startDate, $endDate)
    {
        return AnalyticsEvent::selectRaw('HOUR(created_at) as hour, COUNT(*) as count')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('hour')
            ->orderBy('count', 'desc')
            ->get();
    }

    private function getUserRetentionCohorts($startDate, $endDate)
    {
        // Implementation for user retention cohorts
        return [];
    }

    private function getCategoryTrends($startDate, $endDate)
    {
        return Ad::select('category_id', DB::raw('COUNT(*) as count, DATE(created_at) as date'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('category_id', 'date')
            ->orderBy('date')
            ->get();
    }

    private function getPriceAnalysis($startDate, $endDate)
    {
        return Ad::selectRaw('category_id, AVG(price) as avg_price, MIN(price) as min_price, MAX(price) as max_price')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->whereNotNull('price')
            ->groupBy('category_id')
            ->get();
    }

    private function getGeographicDistribution($startDate, $endDate)
    {
        return AnalyticsEvent::select('country', DB::raw('COUNT(*) as count'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->whereNotNull('country')
            ->groupBy('country')
            ->orderBy('count', 'desc')
            ->limit(10)
            ->get();
    }

    private function getSeasonalPatterns($startDate, $endDate)
    {
        return AnalyticsEvent::selectRaw('MONTH(created_at) as month, COUNT(*) as count')
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('month')
            ->orderBy('month')
            ->get();
    }

    private function getMarketCompetition($startDate, $endDate)
    {
        // Implementation for market competition analysis
        return [];
    }

    private function getDemandForecasting($startDate, $endDate)
    {
        // Implementation for demand forecasting
        return [];
    }

    private function getUserAcquisitionForecast($startDate, $endDate)
    {
        // Implementation for user acquisition forecast
        return [];
    }

    private function getRevenueProjection($startDate, $endDate)
    {
        // Implementation for revenue projection
        return [];
    }

    private function getChurnPrediction($startDate, $endDate)
    {
        // Implementation for churn prediction
        return [];
    }

    private function getTrendPrediction($startDate, $endDate)
    {
        // Implementation for trend prediction
        return [];
    }

    private function getRiskAssessment($startDate, $endDate)
    {
        // Implementation for risk assessment
        return [];
    }

    private function getSystemPerformance($startDate, $endDate)
    {
        // Implementation for system performance metrics
        return [];
    }

    private function getUserSatisfaction($startDate, $endDate)
    {
        // Implementation for user satisfaction metrics
        return [];
    }

    private function getFeaturePerformance($startDate, $endDate)
    {
        return AnalyticsEvent::select('event_type', DB::raw('COUNT(*) as usage_count, AVG(created_at) as avg_usage_time'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->groupBy('event_type')
            ->orderBy('usage_count', 'desc')
            ->get();
    }

    private function getErrorRates($startDate, $endDate)
    {
        // Implementation for error rates
        return [];
    }

    private function getResponseTimes($startDate, $endDate)
    {
        // Implementation for response times
        return [];
    }

    private function getRegistrationFunnel($startDate, $endDate)
    {
        // Implementation for registration funnel
        return [];
    }

    private function getAdPostingFunnel($startDate, $endDate)
    {
        // Implementation for ad posting funnel
        return [];
    }

    private function getPurchaseFunnel($startDate, $endDate)
    {
        // Implementation for purchase funnel
        return [];
    }

    private function getEngagementFunnel($startDate, $endDate)
    {
        // Implementation for engagement funnel
        return [];
    }

    private function getCLVByCohort($startDate, $endDate)
    {
        // Implementation for CLV by cohort
        return [];
    }

    private function getCLVBySegment($startDate, $endDate)
    {
        // Implementation for CLV by segment
        return [];
    }

    private function getCLVTrends($startDate, $endDate)
    {
        // Implementation for CLV trends
        return [];
    }

    private function getHighValueCustomers($startDate, $endDate)
    {
        return Transaction::select('user_id', DB::raw('SUM(amount) as total_spent'))
            ->when($startDate && $endDate, function ($query) use ($startDate, $endDate) {
                return $query->whereBetween('created_at', [$startDate, $endDate]);
            })
            ->where('status', 'completed')
            ->groupBy('user_id')
            ->orderBy('total_spent', 'desc')
            ->limit(10)
            ->get();
    }

    private function getChurnRate($startDate, $endDate)
    {
        // Implementation for churn rate calculation
        return 0;
    }

    private function getChurnFactors($startDate, $endDate)
    {
        // Implementation for churn factors analysis
        return [];
    }

    private function getRetentionStrategies($startDate, $endDate)
    {
        // Implementation for retention strategies
        return [];
    }
}
