<?php
declare(strict_types=1);

namespace Fendx\Debug;

use Fendx\Debug\Memory\MemorySnapshot;
use Fendx\Debug\Memory\MemoryLeakDetector;
use Fendx\Debug\Memory\MemoryUsageTracker;

class MemoryAnalyzer
{
    protected static ?self $instance = null;
    protected bool $enabled = false;
    protected array $snapshots = [];
    protected MemoryUsageTracker $tracker;
    protected MemoryLeakDetector $leakDetector;
    protected array $config = [];
    protected int $baselineMemory;

    public function __construct(array $config = [])
    {
        $this->config = array_merge($this->getDefaultConfig(), $config);
        $this->tracker = new MemoryUsageTracker();
        $this->leakDetector = new MemoryLeakDetector();
        $this->baselineMemory = memory_get_usage(true);
    }

    /**
     * Get memory analyzer instance.
     */
    public static function getInstance(array $config = []): self
    {
        if (self::$instance === null) {
            self::$instance = new self($config);
        }
        
        return self::$instance;
    }

    /**
     * Enable memory analyzer.
     */
    public function enable(): void
    {
        $this->enabled = true;
        $this->tracker->enable();
        $this->leakDetector->enable();
    }

    /**
     * Disable memory analyzer.
     */
    public function disable(): void
    {
        $this->enabled = false;
        $this->tracker->disable();
        $this->leakDetector->disable();
    }

    /**
     * Check if analyzer is enabled.
     */
    public function isEnabled(): bool
    {
        return $this->enabled;
    }

    /**
     * Take memory snapshot.
     */
    public function snapshot(string $name, array $context = []): MemorySnapshot
    {
        if (!$this->enabled) {
            throw new \RuntimeException('Memory analyzer is not enabled');
        }

        $snapshot = new MemorySnapshot($name, $context);
        $snapshot->capture();
        
        $this->snapshots[$name] = $snapshot;
        
        return $snapshot;
    }

    /**
     * Get memory snapshot by name.
     */
    public function getSnapshot(string $name): ?MemorySnapshot
    {
        return $this->snapshots[$name] ?? null;
    }

    /**
     * Get all snapshots.
     */
    public function getSnapshots(): array
    {
        return $this->snapshots;
    }

    /**
     * Compare two snapshots.
     */
    public function compare(string $from, string $to): array
    {
        $fromSnapshot = $this->getSnapshot($from);
        $toSnapshot = $this->getSnapshot($to);
        
        if (!$fromSnapshot || !$toSnapshot) {
            throw new \InvalidArgumentException('Both snapshots must exist');
        }

        return [
            'from' => $fromSnapshot->getName(),
            'to' => $toSnapshot->getName(),
            'memory_diff' => $toSnapshot->getMemoryUsage() - $fromSnapshot->getMemoryUsage(),
            'memory_diff_percent' => $this->calculatePercentageDiff(
                $fromSnapshot->getMemoryUsage(),
                $toSnapshot->getMemoryUsage()
            ),
            'peak_memory_diff' => $toSnapshot->getPeakMemory() - $fromSnapshot->getPeakMemory(),
            'objects_diff' => $toSnapshot->getObjectCount() - $fromSnapshot->getObjectCount(),
            'time_diff' => $toSnapshot->getTimestamp() - $fromSnapshot->getTimestamp()
        ];
    }

    /**
     * Get memory usage trend.
     */
    public function getTrend(): array
    {
        if (empty($this->snapshots)) {
            return [];
        }

        $trend = [];
        $previousMemory = $this->baselineMemory;
        
        foreach ($this->snapshots as $name => $snapshot) {
            $currentMemory = $snapshot->getMemoryUsage();
            $diff = $currentMemory - $previousMemory;
            
            $trend[] = [
                'name' => $name,
                'timestamp' => $snapshot->getTimestamp(),
                'memory_usage' => $currentMemory,
                'memory_diff' => $diff,
                'memory_diff_percent' => $this->calculatePercentageDiff($previousMemory, $currentMemory),
                'peak_memory' => $snapshot->getPeakMemory(),
                'object_count' => $snapshot->getObjectCount()
            ];
            
            $previousMemory = $currentMemory;
        }
        
        return $trend;
    }

    /**
     * Detect memory leaks.
     */
    public function detectLeaks(): array
    {
        if (!$this->enabled) {
            return [];
        }

        return $this->leakDetector->detect($this->snapshots);
    }

    /**
     * Get memory usage statistics.
     */
    public function getStatistics(): array
    {
        if (empty($this->snapshots)) {
            return [
                'current' => memory_get_usage(true),
                'peak' => memory_get_peak_usage(true),
                'baseline' => $this->baselineMemory,
                'growth' => memory_get_usage(true) - $this->baselineMemory,
                'snapshots_count' => 0
            ];
        }

        $current = memory_get_usage(true);
        $peak = memory_get_peak_usage(true);
        $growth = $current - $this->baselineMemory;
        
        $memoryUsages = array_map(fn($s) => $s->getMemoryUsage(), $this->snapshots);
        $objectCounts = array_map(fn($s) => $s->getObjectCount(), $this->snapshots);
        
        return [
            'current' => $current,
            'peak' => $peak,
            'baseline' => $this->baselineMemory,
            'growth' => $growth,
            'growth_percent' => $this->calculatePercentageDiff($this->baselineMemory, $current),
            'snapshots_count' => count($this->snapshots),
            'min_memory' => min($memoryUsages),
            'max_memory' => max($memoryUsages),
            'avg_memory' => array_sum($memoryUsages) / count($memoryUsages),
            'min_objects' => min($objectCounts),
            'max_objects' => max($objectCounts),
            'avg_objects' => array_sum($objectCounts) / count($objectCounts),
            'memory_efficiency' => $this->calculateMemoryEfficiency(),
            'leak_detected' => !empty($this->detectLeaks())
        ];
    }

    /**
     * Get memory usage by type.
     */
    public function getUsageByType(): array
    {
        if (empty($this->snapshots)) {
            return [];
        }

        $latest = end($this->snapshots);
        return $latest->getUsageByType();
    }

    /**
     * Get largest memory consumers.
     */
    public function getLargestConsumers(int $limit = 10): array
    {
        if (empty($this->snapshots)) {
            return [];
        }

        $latest = end($this->snapshots);
        return $latest->getLargestConsumers($limit);
    }

    /**
     * Generate memory analysis report.
     */
    public function generateReport(): array
    {
        $report = [
            'summary' => $this->getStatistics(),
            'trend' => $this->getTrend(),
            'snapshots' => [],
            'leaks' => $this->detectLeaks(),
            'usage_by_type' => $this->getUsageByType(),
            'largest_consumers' => $this->getLargestConsumers(),
            'recommendations' => $this->generateRecommendations(),
            'generated_at' => time()
        ];

        foreach ($this->snapshots as $name => $snapshot) {
            $report['snapshots'][$name] = $snapshot->toArray();
        }

        return $report;
    }

    /**
     * Save memory analysis report.
     */
    public function saveReport(string $filename): bool
    {
        $report = $this->generateReport();
        $json = json_encode($report, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
        
        return file_put_contents($filename, $json) !== false;
    }

    /**
     * Export memory data.
     */
    public function export(string $format = 'json'): string
    {
        $report = $this->generateReport();
        
        switch (strtolower($format)) {
            case 'json':
                return json_encode($report, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
            
            case 'csv':
                return $this->exportToCsv($report);
            
            case 'html':
                return $this->exportToHtml($report);
            
            default:
                throw new \InvalidArgumentException("Unsupported export format: {$format}");
        }
    }

    /**
     * Export to CSV format.
     */
    protected function exportToCsv(array $report): string
    {
        $csv = "Snapshot,Timestamp,Memory Usage (bytes),Peak Memory (bytes),Object Count\n";
        
        foreach ($report['snapshots'] as $name => $snapshot) {
            $csv .= sprintf(
                "%s,%d,%d,%d,%d\n",
                $name,
                $snapshot['timestamp'],
                $snapshot['memory_usage'],
                $snapshot['peak_memory'],
                $snapshot['object_count']
            );
        }
        
        return $csv;
    }

    /**
     * Export to HTML format.
     */
    protected function exportToHtml(array $report): string
    {
        $html = '<!DOCTYPE html><html><head><title>Memory Analysis Report</title>';
        $html .= '<style>body{font-family:Arial,sans-serif;margin:20px;}';
        $html .= 'table{border-collapse:collapse;width:100%;margin-bottom:20px;}';
        $html .= 'th,td{border:1px solid #ddd;padding:8px;text-align:left;}';
        $html .= 'th{background-color:#f2f2f2;}';
        $html .= '.warning{color:#f39c12;}.error{color:#e74c3c;}.success{color:#27ae60;}</style>';
        $html .= '</head><body>';
        
        $html .= '<h1>Memory Analysis Report</h1>';
        
        // Summary section
        $html .= '<h2>Summary</h2>';
        $html .= '<table><tr><th>Metric</th><th>Value</th></tr>';
        
        foreach ($report['summary'] as $key => $value) {
            if (is_array($value)) {
                $value = json_encode($value);
            } elseif (is_bool($value)) {
                $value = $value ? 'Yes' : 'No';
            }
            
            $class = '';
            if (str_contains($key, 'leak') && $value) {
                $class = 'error';
            } elseif (str_contains($key, 'growth') && $value > 0) {
                $class = 'warning';
            }
            
            $html .= "<tr><td>{$key}</td><td class='{$class}'>{$value}</td></tr>";
        }
        
        $html .= '</table>';
        
        // Snapshots section
        $html .= '<h2>Memory Snapshots</h2>';
        $html .= '<table><tr><th>Name</th><th>Memory (MB)</th><th>Peak (MB)</th><th>Objects</th></tr>';
        
        foreach ($report['snapshots'] as $name => $snapshot) {
            $html .= sprintf(
                "<tr><td>%s</td><td>%.2f</td><td>%.2f</td><td>%d</td></tr>",
                $name,
                $snapshot['memory_usage'] / 1024 / 1024,
                $snapshot['peak_memory'] / 1024 / 1024,
                $snapshot['object_count']
            );
        }
        
        $html .= '</table>';
        
        // Recommendations section
        if (!empty($report['recommendations'])) {
            $html .= '<h2>Recommendations</h2>';
            $html .= '<ul>';
            
            foreach ($report['recommendations'] as $rec) {
                $class = $rec['severity'] === 'error' ? 'error' : 
                        ($rec['severity'] === 'warning' ? 'warning' : '');
                $html .= "<li class='{$class}'>{$rec['message']}</li>";
            }
            
            $html .= '</ul>';
        }
        
        $html .= '</body></html>';
        
        return $html;
    }

    /**
     * Clear all snapshots.
     */
    public function clear(): void
    {
        $this->snapshots = [];
        $this->tracker->clear();
        $this->leakDetector->clear();
    }

    /**
     * Reset analyzer.
     */
    public function reset(): void
    {
        $this->clear();
        $this->baselineMemory = memory_get_usage(true);
    }

    /**
     * Get configuration.
     */
    public function getConfig(): array
    {
        return $this->config;
    }

    /**
     * Set configuration.
     */
    public function setConfig(array $config): void
    {
        $this->config = array_merge($this->config, $config);
    }

    /**
     * Get memory usage tracker.
     */
    public function getTracker(): MemoryUsageTracker
    {
        return $this->tracker;
    }

    /**
     * Get memory leak detector.
     */
    public function getLeakDetector(): MemoryLeakDetector
    {
        return $this->leakDetector;
    }

    /**
     * Calculate percentage difference.
     */
    protected function calculatePercentageDiff(int $from, int $to): float
    {
        if ($from === 0) {
            return $to > 0 ? 100 : 0;
        }
        
        return (($to - $from) / $from) * 100;
    }

    /**
     * Calculate memory efficiency.
     */
    protected function calculateMemoryEfficiency(): float
    {
        if (empty($this->snapshots)) {
            return 100;
        }

        $totalMemory = array_sum(array_map(fn($s) => $s->getMemoryUsage(), $this->snapshots));
        $avgMemory = $totalMemory / count($this->snapshots);
        $peakMemory = memory_get_peak_usage(true);
        
        if ($peakMemory === 0) {
            return 100;
        }
        
        return ($avgMemory / $peakMemory) * 100;
    }

    /**
     * Generate memory recommendations.
     */
    protected function generateRecommendations(): array
    {
        $recommendations = [];
        $stats = $this->getStatistics();
        
        // Check for memory growth
        if ($stats['growth'] > $this->config['growth_threshold']) {
            $recommendations[] = [
                'type' => 'memory',
                'severity' => 'warning',
                'message' => sprintf(
                    'High memory growth detected: %s (%.1f%%)',
                    $this->formatBytes($stats['growth']),
                    $stats['growth_percent']
                ),
                'suggestion' => 'Review memory allocation patterns and consider optimization'
            ];
        }
        
        // Check for memory leaks
        if ($stats['leak_detected']) {
            $recommendations[] = [
                'type' => 'leak',
                'severity' => 'error',
                'message' => 'Memory leaks detected',
                'suggestion' => 'Investigate object references and ensure proper cleanup'
            ];
        }
        
        // Check memory efficiency
        if ($stats['memory_efficiency'] < $this->config['efficiency_threshold']) {
            $recommendations[] = [
                'type' => 'efficiency',
                'severity' => 'info',
                'message' => sprintf(
                    'Low memory efficiency: %.1f%%',
                    $stats['memory_efficiency']
                ),
                'suggestion' => 'Consider memory optimization techniques'
            ];
        }
        
        // Check peak memory usage
        if ($stats['peak'] > $this->config['peak_threshold']) {
            $recommendations[] = [
                'type' => 'peak',
                'severity' => 'warning',
                'message' => sprintf(
                    'High peak memory usage: %s',
                    $this->formatBytes($stats['peak'])
                ),
                'suggestion' => 'Monitor memory usage patterns and optimize peak consumption'
            ];
        }
        
        return $recommendations;
    }

    /**
     * Get default configuration.
     */
    protected function getDefaultConfig(): array
    {
        return [
            'growth_threshold' => 50 * 1024 * 1024, // 50MB
            'peak_threshold' => 100 * 1024 * 1024, // 100MB
            'efficiency_threshold' => 70, // 70%
            'auto_snapshot' => true,
            'snapshot_interval' => 1000, // ms
            'max_snapshots' => 100,
            'track_objects' => true,
            'track_types' => true,
            'detect_leaks' => true
        ];
    }

    /**
     * Format bytes to human readable format.
     */
    protected function formatBytes(int $bytes): string
    {
        $units = ['B', 'KB', 'MB', 'GB', 'TB'];
        $bytes = max($bytes, 0);
        $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
        $pow = min($pow, count($units) - 1);
        
        $bytes /= (1 << (10 * $pow));
        
        return round($bytes, 2) . ' ' . $units[$pow];
    }

    /**
     * Monitor memory usage continuously.
     */
    public function startMonitoring(): void
    {
        if (!$this->enabled || !$this->config['auto_snapshot']) {
            return;
        }

        $interval = $this->config['snapshot_interval'] * 1000; // Convert to microseconds
        
        while ($this->enabled) {
            $this->snapshot('auto_' . time());
            usleep($interval);
            
            // Limit number of snapshots
            if (count($this->snapshots) > $this->config['max_snapshots']) {
                array_shift($this->snapshots);
            }
        }
    }

    /**
     * Get memory heatmap data.
     */
    public function getHeatmap(): array
    {
        if (empty($this->snapshots)) {
            return [];
        }

        $heatmap = [];
        $maxMemory = max(array_map(fn($s) => $s->getMemoryUsage(), $this->snapshots));
        
        foreach ($this->snapshots as $name => $snapshot) {
            $memory = $snapshot->getMemoryUsage();
            $intensity = $maxMemory > 0 ? ($memory / $maxMemory) : 0;
            
            $heatmap[] = [
                'name' => $name,
                'timestamp' => $snapshot->getTimestamp(),
                'memory' => $memory,
                'intensity' => $intensity,
                'color' => $this->getHeatmapColor($intensity)
            ];
        }
        
        return $heatmap;
    }

    /**
     * Get heatmap color based on intensity.
     */
    protected function getHeatmapColor(float $intensity): string
    {
        if ($intensity < 0.3) {
            return '#27ae60'; // Green
        } elseif ($intensity < 0.7) {
            return '#f39c12'; // Orange
        } else {
            return '#e74c3c'; // Red
        }
    }

    /**
     * Analyze memory patterns.
     */
    public function analyzePatterns(): array
    {
        if (empty($this->snapshots)) {
            return [];
        }

        $patterns = [];
        $memoryUsages = array_map(fn($s) => $s->getMemoryUsage(), $this->snapshots);
        
        // Detect growth pattern
        $isGrowing = $memoryUsages[count($memoryUsages) - 1] > $memoryUsages[0];
        $patterns['growth_trend'] = $isGrowing ? 'increasing' : 'stable';
        
        // Detect volatility
        $avg = array_sum($memoryUsages) / count($memoryUsages);
        $variance = array_sum(array_map(fn($m) => pow($m - $avg, 2), $memoryUsages)) / count($memoryUsages);
        $stdDev = sqrt($variance);
        $patterns['volatility'] = $stdDev / $avg; // Coefficient of variation
        
        // Detect spikes
        $spikes = [];
        for ($i = 1; $i < count($memoryUsages) - 1; $i++) {
            $prev = $memoryUsages[$i - 1];
            $current = $memoryUsages[$i];
            $next = $memoryUsages[$i + 1];
            
            if ($current > $prev && $current > $next && $current > $avg + $stdDev) {
                $spikes[] = [
                    'index' => $i,
                    'memory' => $current,
                    'timestamp' => $this->snapshots[$i]->getTimestamp()
                ];
            }
        }
        $patterns['spikes'] = $spikes;
        
        return $patterns;
    }
}