<?php

declare(strict_types=1);

namespace App\Framework\Monitoring;

use App\Framework\Core\ValueObjects\Duration;
use App\Framework\Core\ValueObjects\Percentage;
use App\Framework\Core\ValueObjects\Timestamp;
use App\Framework\DateTime\Clock;
use App\Framework\Logging\Logger;
use App\Framework\StateManagement\StateManager;

/**
 * Advanced monitoring system for circuit breakers and error boundaries
 */
final readonly class AdvancedMonitoring
{
    public function __construct(
        private StateManager     $stateManager,
        private Clock            $clock,
        private ?Logger          $logger = null,
        private MonitoringConfig $config = new MonitoringConfig(),
    ) {
    }

    /**
     * Record circuit breaker metrics
     */
    public function recordCircuitBreakerMetrics(string $circuitName, CircuitBreakerMetrics $metrics): void
    {
        $timestamp = $this->clock->time();
        $key = "monitoring:circuit:{$circuitName}:{$timestamp->toTimestamp()}";

        $this->stateManager->setState(
            $key,
            $metrics->toArray(),
            $this->config->metricsRetention
        );

        // Update aggregated metrics
        $this->updateAggregatedMetrics($circuitName, $metrics, $timestamp);

        // Check for alerts
        $this->checkCircuitBreakerAlerts($circuitName, $metrics);
    }

    /**
     * Record error boundary metrics
     */
    public function recordErrorBoundaryMetrics(string $boundaryName, ErrorBoundaryMetrics $metrics): void
    {
        $timestamp = $this->clock->time();
        $key = "monitoring:boundary:{$boundaryName}:{$timestamp->toTimestamp()}";

        $this->stateManager->setState(
            $key,
            $metrics->toArray(),
            $this->config->metricsRetention
        );

        // Update aggregated metrics
        $this->updateBoundaryAggregatedMetrics($boundaryName, $metrics, $timestamp);

        // Check for alerts
        $this->checkErrorBoundaryAlerts($boundaryName, $metrics);
    }

    /**
     * Get circuit breaker health dashboard
     */
    public function getCircuitBreakerDashboard(): array
    {
        $circuits = $this->getActiveCircuits();
        $dashboard = [
            'timestamp' => $this->clock->time()->toIsoString(),
            'total_circuits' => count($circuits),
            'healthy_circuits' => 0,
            'degraded_circuits' => 0,
            'failed_circuits' => 0,
            'circuits' => [],
        ];

        foreach ($circuits as $circuitName) {
            $health = $this->getCircuitHealth($circuitName);
            $dashboard['circuits'][$circuitName] = $health;

            match ($health['status']) {
                'healthy' => $dashboard['healthy_circuits']++,
                'degraded' => $dashboard['degraded_circuits']++,
                'failed' => $dashboard['failed_circuits']++,
            };
        }

        return $dashboard;
    }

    /**
     * Get error boundary dashboard
     */
    public function getErrorBoundaryDashboard(): array
    {
        $boundaries = $this->getActiveBoundaries();
        $dashboard = [
            'timestamp' => $this->clock->time()->toIsoString(),
            'total_boundaries' => count($boundaries),
            'healthy_boundaries' => 0,
            'degraded_boundaries' => 0,
            'failed_boundaries' => 0,
            'boundaries' => [],
        ];

        foreach ($boundaries as $boundaryName) {
            $health = $this->getBoundaryHealth($boundaryName);
            $dashboard['boundaries'][$boundaryName] = $health;

            match ($health['status']) {
                'healthy' => $dashboard['healthy_boundaries']++,
                'degraded' => $dashboard['degraded_boundaries']++,
                'failed' => $dashboard['failed_boundaries']++,
            };
        }

        return $dashboard;
    }

    /**
     * Get system-wide health summary
     */
    public function getSystemHealthSummary(): SystemHealthSummary
    {
        $circuitMetrics = $this->getAggregatedCircuitMetrics();
        $boundaryMetrics = $this->getAggregatedBoundaryMetrics();

        $totalComponents = count($circuitMetrics) + count($boundaryMetrics);
        $healthyComponents = 0;
        $degradedComponents = 0;
        $failedComponents = 0;

        foreach ($circuitMetrics as $metrics) {
            match ($this->calculateHealthStatus($metrics)) {
                'healthy' => $healthyComponents++,
                'degraded' => $degradedComponents++,
                'failed' => $failedComponents++,
            };
        }

        foreach ($boundaryMetrics as $metrics) {
            match ($this->calculateBoundaryHealthStatus($metrics)) {
                'healthy' => $healthyComponents++,
                'degraded' => $degradedComponents++,
                'failed' => $failedComponents++,
            };
        }

        $overallHealthScore = $totalComponents > 0
            ? Percentage::fromFloat($healthyComponents / $totalComponents)
            : Percentage::fromFloat(1.0);

        return new SystemHealthSummary(
            timestamp: $this->clock->time(),
            totalComponents: $totalComponents,
            healthyComponents: $healthyComponents,
            degradedComponents: $degradedComponents,
            failedComponents: $failedComponents,
            overallHealthScore: $overallHealthScore,
            circuitBreakerCount: count($circuitMetrics),
            errorBoundaryCount: count($boundaryMetrics),
        );
    }

    /**
     * Get trend analysis for circuit breaker
     */
    public function getCircuitBreakerTrends(string $circuitName, Duration $timeWindow): array
    {
        $endTime = $this->clock->time();
        $startTime = Timestamp::fromFloat($endTime->toFloat() - $timeWindow->toSeconds());

        $metrics = $this->getMetricsInTimeRange(
            "monitoring:circuit:{$circuitName}",
            $startTime,
            $endTime
        );

        return $this->analyzeTrends($metrics);
    }

    /**
     * Get performance analytics
     */
    public function getPerformanceAnalytics(Duration $timeWindow): array
    {
        $endTime = $this->clock->time();
        $startTime = Timestamp::fromFloat($endTime->toFloat() - $timeWindow->toSeconds());

        $circuits = $this->getActiveCircuits();
        $boundaries = $this->getActiveBoundaries();

        $analytics = [
            'time_range' => [
                'start' => $startTime->toIsoString(),
                'end' => $endTime->toIsoString(),
                'duration' => $timeWindow->toHumanReadable(),
            ],
            'circuit_breakers' => [],
            'error_boundaries' => [],
            'system_summary' => [
                'total_requests' => 0,
                'total_failures' => 0,
                'average_response_time' => null,
                'peak_response_time' => null,
                'error_rate' => null,
            ],
        ];

        $totalRequests = 0;
        $totalFailures = 0;
        $totalResponseTime = 0;
        $peakResponseTime = Duration::zero();

        // Analyze circuit breakers
        foreach ($circuits as $circuitName) {
            $metrics = $this->getMetricsInTimeRange(
                "monitoring:circuit:{$circuitName}",
                $startTime,
                $endTime
            );

            $circuitAnalysis = $this->analyzeCircuitPerformance($metrics);
            $analytics['circuit_breakers'][$circuitName] = $circuitAnalysis;

            $totalRequests += $circuitAnalysis['total_requests'];
            $totalFailures += $circuitAnalysis['total_failures'];
            $totalResponseTime += $circuitAnalysis['total_response_time_ms'];

            if ($circuitAnalysis['peak_response_time'] > $peakResponseTime->toMilliseconds()) {
                $peakResponseTime = Duration::fromMilliseconds($circuitAnalysis['peak_response_time']);
            }
        }

        // Analyze error boundaries
        foreach ($boundaries as $boundaryName) {
            $metrics = $this->getMetricsInTimeRange(
                "monitoring:boundary:{$boundaryName}",
                $startTime,
                $endTime
            );

            $boundaryAnalysis = $this->analyzeBoundaryPerformance($metrics);
            $analytics['error_boundaries'][$boundaryName] = $boundaryAnalysis;
        }

        // System summary
        if ($totalRequests > 0) {
            $analytics['system_summary'] = [
                'total_requests' => $totalRequests,
                'total_failures' => $totalFailures,
                'average_response_time' => Duration::fromMilliseconds($totalResponseTime / $totalRequests),
                'peak_response_time' => $peakResponseTime,
                'error_rate' => Percentage::fromFloat($totalFailures / $totalRequests),
            ];
        }

        return $analytics;
    }

    /**
     * Generate monitoring alerts
     */
    public function generateAlerts(): array
    {
        $alerts = [];

        // Check circuit breaker alerts
        foreach ($this->getActiveCircuits() as $circuitName) {
            $health = $this->getCircuitHealth($circuitName);
            if ($health['status'] !== 'healthy') {
                $alerts[] = new MonitoringAlert(
                    type: 'circuit_breaker',
                    severity: $health['status'] === 'failed' ? 'critical' : 'warning',
                    component: $circuitName,
                    message: "Circuit breaker '{$circuitName}' is in {$health['status']} state",
                    timestamp: $this->clock->time(),
                    metrics: $health,
                );
            }
        }

        // Check error boundary alerts
        foreach ($this->getActiveBoundaries() as $boundaryName) {
            $health = $this->getBoundaryHealth($boundaryName);
            if ($health['status'] !== 'healthy') {
                $alerts[] = new MonitoringAlert(
                    type: 'error_boundary',
                    severity: $health['status'] === 'failed' ? 'critical' : 'warning',
                    component: $boundaryName,
                    message: "Error boundary '{$boundaryName}' is in {$health['status']} state",
                    timestamp: $this->clock->time(),
                    metrics: $health,
                );
            }
        }

        return $alerts;
    }

    /**
     * Get circuit health status
     */
    private function getCircuitHealth(string $circuitName): array
    {
        $aggregatedKey = "monitoring:circuit:aggregated:{$circuitName}";
        $metrics = $this->stateManager->getState($aggregatedKey);

        if ($metrics === null) {
            return [
                'status' => 'unknown',
                'last_updated' => null,
                'metrics' => null,
            ];
        }

        $status = $this->calculateHealthStatus($metrics);

        return [
            'status' => $status,
            'last_updated' => $metrics['last_updated'] ?? null,
            'metrics' => $metrics,
        ];
    }

    /**
     * Get boundary health status
     */
    private function getBoundaryHealth(string $boundaryName): array
    {
        $aggregatedKey = "monitoring:boundary:aggregated:{$boundaryName}";
        $metrics = $this->stateManager->getState($aggregatedKey);

        if ($metrics === null) {
            return [
                'status' => 'unknown',
                'last_updated' => null,
                'metrics' => null,
            ];
        }

        $status = $this->calculateBoundaryHealthStatus($metrics);

        return [
            'status' => $status,
            'last_updated' => $metrics['last_updated'] ?? null,
            'metrics' => $metrics,
        ];
    }

    /**
     * Calculate health status from metrics
     */
    private function calculateHealthStatus(array $metrics): string
    {
        $errorRate = $metrics['error_rate'] ?? 0.0;
        $responseTime = $metrics['average_response_time'] ?? 0.0;

        if ($errorRate > $this->config->criticalErrorRateThreshold) {
            return 'failed';
        }

        if ($errorRate > $this->config->warningErrorRateThreshold ||
            $responseTime > $this->config->slowResponseThreshold->toMilliseconds()) {
            return 'degraded';
        }

        return 'healthy';
    }

    /**
     * Calculate boundary health status from metrics
     */
    private function calculateBoundaryHealthStatus(array $metrics): string
    {
        $fallbackRate = $metrics['fallback_rate'] ?? 0.0;
        $errorRate = $metrics['error_rate'] ?? 0.0;

        if ($fallbackRate > $this->config->criticalFallbackRateThreshold) {
            return 'failed';
        }

        if ($fallbackRate > $this->config->warningFallbackRateThreshold ||
            $errorRate > $this->config->warningErrorRateThreshold) {
            return 'degraded';
        }

        return 'healthy';
    }

    /**
     * Update aggregated metrics for circuit breaker
     */
    private function updateAggregatedMetrics(
        string $circuitName,
        CircuitBreakerMetrics $metrics,
        Timestamp $timestamp
    ): void {
        $aggregatedKey = "monitoring:circuit:aggregated:{$circuitName}";

        $this->stateManager->updateState($aggregatedKey, function ($existing) use ($metrics, $timestamp) {
            return $this->aggregateCircuitMetrics($existing, $metrics, $timestamp);
        });
    }

    /**
     * Update aggregated metrics for error boundary
     */
    private function updateBoundaryAggregatedMetrics(
        string $boundaryName,
        ErrorBoundaryMetrics $metrics,
        Timestamp $timestamp
    ): void {
        $aggregatedKey = "monitoring:boundary:aggregated:{$boundaryName}";

        $this->stateManager->updateState($aggregatedKey, function ($existing) use ($metrics, $timestamp) {
            return $this->aggregateBoundaryMetrics($existing, $metrics, $timestamp);
        });
    }

    /**
     * Aggregate circuit breaker metrics
     */
    private function aggregateCircuitMetrics(?array $existing, CircuitBreakerMetrics $metrics, Timestamp $timestamp): array
    {
        if ($existing === null) {
            return array_merge($metrics->toArray(), [
                'first_seen' => $timestamp->toIsoString(),
                'last_updated' => $timestamp->toIsoString(),
            ]);
        }

        // Simple aggregation - in production you'd want more sophisticated algorithms
        $totalRequests = ($existing['total_requests'] ?? 0) + $metrics->totalRequests;
        $totalFailures = ($existing['total_failures'] ?? 0) + $metrics->totalFailures;

        return [
            'total_requests' => $totalRequests,
            'total_failures' => $totalFailures,
            'error_rate' => $totalRequests > 0 ? $totalFailures / $totalRequests : 0.0,
            'average_response_time' => $metrics->averageResponseTime->toMilliseconds(),
            'peak_response_time' => max(
                $existing['peak_response_time'] ?? 0,
                $metrics->peakResponseTime->toMilliseconds()
            ),
            'first_seen' => $existing['first_seen'],
            'last_updated' => $timestamp->toIsoString(),
        ];
    }

    /**
     * Aggregate boundary metrics
     */
    private function aggregateBoundaryMetrics(?array $existing, ErrorBoundaryMetrics $metrics, Timestamp $timestamp): array
    {
        if ($existing === null) {
            return array_merge($metrics->toArray(), [
                'first_seen' => $timestamp->toIsoString(),
                'last_updated' => $timestamp->toIsoString(),
            ]);
        }

        $totalExecutions = ($existing['total_executions'] ?? 0) + $metrics->totalExecutions;
        $totalFallbacks = ($existing['total_fallbacks'] ?? 0) + $metrics->totalFallbacks;
        $totalErrors = ($existing['total_errors'] ?? 0) + $metrics->totalErrors;

        return [
            'total_executions' => $totalExecutions,
            'total_fallbacks' => $totalFallbacks,
            'total_errors' => $totalErrors,
            'fallback_rate' => $totalExecutions > 0 ? $totalFallbacks / $totalExecutions : 0.0,
            'error_rate' => $totalExecutions > 0 ? $totalErrors / $totalExecutions : 0.0,
            'average_execution_time' => $metrics->averageExecutionTime->toMilliseconds(),
            'first_seen' => $existing['first_seen'],
            'last_updated' => $timestamp->toIsoString(),
        ];
    }

    // Placeholder methods - implement based on your specific needs
    private function getActiveCircuits(): array
    {
        return [];
    }

    private function getActiveBoundaries(): array
    {
        return [];
    }

    private function getAggregatedCircuitMetrics(): array
    {
        return [];
    }

    private function getAggregatedBoundaryMetrics(): array
    {
        return [];
    }

    private function getMetricsInTimeRange(string $prefix, Timestamp $start, Timestamp $end): array
    {
        return [];
    }

    private function analyzeTrends(array $metrics): array
    {
        return [];
    }

    private function analyzeCircuitPerformance(array $metrics): array
    {
        return [];
    }

    private function analyzeBoundaryPerformance(array $metrics): array
    {
        return [];
    }

    private function checkCircuitBreakerAlerts(string $name, CircuitBreakerMetrics $metrics): void
    {
    }

    private function checkErrorBoundaryAlerts(string $name, ErrorBoundaryMetrics $metrics): void
    {
    }
}