<?php

declare(strict_types=1);

namespace Tests\Framework\Queue\Performance;

use App\Framework\Queue\Jobs\Job;
use App\Framework\Queue\Jobs\JobRequest;
use App\Framework\Queue\Jobs\JobStatus;
use App\Framework\Queue\Queue\JobPriority;
use App\Framework\Queue\Queue\QueueName;
use App\Framework\Queue\Workers\Worker;
use App\Framework\Queue\Workers\WorkerCapacity;
use App\Framework\Queue\Workers\WorkerId;
use App\Framework\Queue\Workers\WorkerStatus;

final readonly class PerformanceTestHelper
{
    public static function createTestWorker(
        string $id = null,
        int $capacity = 10,
        WorkerStatus $status = WorkerStatus::AVAILABLE
    ): Worker {
        return new Worker(
            id: new WorkerId($id ?? uniqid('worker_')),
            queueNames: [new QueueName('test_queue')],
            capacity: new WorkerCapacity($capacity),
            status: $status,
            lastHeartbeat: new \DateTimeImmutable(),
            metadata: []
        );
    }

    public static function createTestJob(
        string $id = null,
        JobPriority $priority = JobPriority::NORMAL,
        array $payload = []
    ): Job {
        return new Job(
            id: $id ?? uniqid('job_'),
            request: new JobRequest(
                type: 'test_job',
                payload: $payload ?: ['test' => 'data'],
                queue: new QueueName('test_queue'),
                priority: $priority
            ),
            status: JobStatus::PENDING,
            createdAt: new \DateTimeImmutable(),
            attempts: 0
        );
    }

    public static function createBulkJobs(int $count, JobPriority $priority = JobPriority::NORMAL): array
    {
        $jobs = [];
        for ($i = 0; $i < $count; $i++) {
            $jobs[] = self::createTestJob(
                id: "job_{$i}",
                priority: $priority,
                payload: ['batch_id' => $i, 'data' => str_repeat('x', 100)]
            );
        }

        return $jobs;
    }

    public static function measureTime(callable $operation): float
    {
        $start = microtime(true);
        $operation();
        $end = microtime(true);

        return ($end - $start) * 1000; // Return milliseconds
    }

    public static function measureTimeWithResult(callable $operation): array
    {
        $start = microtime(true);
        $result = $operation();
        $end = microtime(true);

        return [
            'result' => $result,
            'time_ms' => ($end - $start) * 1000,
        ];
    }

    public static function calculateStatistics(array $measurements): array
    {
        if (empty($measurements)) {
            return [
                'count' => 0,
                'min' => 0,
                'max' => 0,
                'avg' => 0,
                'median' => 0,
                'p95' => 0,
                'p99' => 0,
                'stddev' => 0,
            ];
        }

        sort($measurements);
        $count = count($measurements);

        $min = $measurements[0];
        $max = $measurements[$count - 1];
        $avg = array_sum($measurements) / $count;

        $median = $count % 2 === 0
            ? ($measurements[$count / 2 - 1] + $measurements[$count / 2]) / 2
            : $measurements[intval($count / 2)];

        $p95Index = intval($count * 0.95) - 1;
        $p99Index = intval($count * 0.99) - 1;

        $p95 = $measurements[max(0, $p95Index)];
        $p99 = $measurements[max(0, $p99Index)];

        // Calculate standard deviation
        $sumSquaredDiff = 0;
        foreach ($measurements as $value) {
            $sumSquaredDiff += pow($value - $avg, 2);
        }
        $stddev = sqrt($sumSquaredDiff / $count);

        return [
            'count' => $count,
            'min' => round($min, 3),
            'max' => round($max, 3),
            'avg' => round($avg, 3),
            'median' => round($median, 3),
            'p95' => round($p95, 3),
            'p99' => round($p99, 3),
            'stddev' => round($stddev, 3),
        ];
    }

    public static function formatStatistics(array $stats, string $unit = 'ms'): string
    {
        return sprintf(
            "Count: %d, Min: %.3f%s, Max: %.3f%s, Avg: %.3f%s, P95: %.3f%s, P99: %.3f%s, StdDev: %.3f%s",
            $stats['count'],
            $stats['min'],
            $unit,
            $stats['max'],
            $unit,
            $stats['avg'],
            $unit,
            $stats['p95'],
            $unit,
            $stats['p99'],
            $unit,
            $stats['stddev'],
            $unit
        );
    }

    public static function assertPerformance(
        array $measurements,
        float $expectedAvg,
        float $expectedP95,
        string $operation
    ): void {
        $stats = self::calculateStatistics($measurements);

        if ($stats['avg'] > $expectedAvg) {
            throw new \AssertionError(
                sprintf(
                    "%s average performance exceeded: expected ≤%.3fms, got %.3fms",
                    $operation,
                    $expectedAvg,
                    $stats['avg']
                )
            );
        }

        if ($stats['p95'] > $expectedP95) {
            throw new \AssertionError(
                sprintf(
                    "%s P95 performance exceeded: expected ≤%.3fms, got %.3fms",
                    $operation,
                    $expectedP95,
                    $stats['p95']
                )
            );
        }
    }

    public static function getMemoryUsage(): array
    {
        return [
            'current_mb' => round(memory_get_usage(true) / 1024 / 1024, 2),
            'peak_mb' => round(memory_get_peak_usage(true) / 1024 / 1024, 2),
            'current_real_mb' => round(memory_get_usage(false) / 1024 / 1024, 2),
            'peak_real_mb' => round(memory_get_peak_usage(false) / 1024 / 1024, 2),
        ];
    }

    public static function warmupDatabase(\PDO $pdo): void
    {
        // Execute simple queries to warm up connections
        $pdo->query('SELECT 1');
        $pdo->query('SELECT COUNT(*) FROM workers');
        $pdo->query('SELECT COUNT(*) FROM jobs');
    }

    public static function createConcurrentOperation(callable $operation, int $concurrency): \Generator
    {
        $operations = [];

        for ($i = 0; $i < $concurrency; $i++) {
            $operations[] = function () use ($operation, $i) {
                return $operation($i);
            };
        }

        foreach ($operations as $op) {
            yield $op;
        }
    }

    public static function simulateLoad(
        callable $operation,
        int $totalOperations,
        int $concurrency,
        float $durationSeconds = null
    ): array {
        $results = [];
        $startTime = microtime(true);
        $endTime = $durationSeconds ? $startTime + $durationSeconds : PHP_FLOAT_MAX;

        $operationsCompleted = 0;
        $batch = 0;

        while ($operationsCompleted < $totalOperations && microtime(true) < $endTime) {
            $batchSize = min($concurrency, $totalOperations - $operationsCompleted);
            $batchResults = [];

            // Execute concurrent operations
            for ($i = 0; $i < $batchSize; $i++) {
                $result = self::measureTimeWithResult(function () use ($operation, $batch, $i) {
                    return $operation($batch * $concurrency + $i);
                });
                $batchResults[] = $result;
            }

            $results = array_merge($results, $batchResults);
            $operationsCompleted += $batchSize;
            $batch++;

            // Small delay to prevent overwhelming the system
            if (microtime(true) < $endTime) {
                usleep(1000); // 1ms
            }
        }

        return [
            'results' => $results,
            'operations_completed' => $operationsCompleted,
            'duration_seconds' => microtime(true) - $startTime,
            'throughput_ops_per_sec' => $operationsCompleted / (microtime(true) - $startTime),
        ];
    }

    public static function generatePerformanceReport(array $testResults): string
    {
        $report = "\n" . str_repeat("=", 80) . "\n";
        $report .= "PERFORMANCE TEST REPORT\n";
        $report .= str_repeat("=", 80) . "\n\n";

        foreach ($testResults as $testName => $results) {
            $report .= "Test: {$testName}\n";
            $report .= str_repeat("-", 40) . "\n";

            if (isset($results['statistics'])) {
                $report .= "Statistics: " . self::formatStatistics($results['statistics']) . "\n";
            }

            if (isset($results['throughput'])) {
                $report .= "Throughput: {$results['throughput']} ops/sec\n";
            }

            if (isset($results['memory'])) {
                $report .= sprintf(
                    "Memory: Current: %.2fMB, Peak: %.2fMB\n",
                    $results['memory']['current_mb'],
                    $results['memory']['peak_mb']
                );
            }

            if (isset($results['notes'])) {
                $report .= "Notes: {$results['notes']}\n";
            }

            $report .= "\n";
        }

        return $report;
    }
}