<?php

declare(strict_types=1);

namespace Tests\Framework\Queue\Performance;

use App\Framework\Database\DatabaseManager;
use App\Framework\Queue\Distribution\JobDistributionService;
use App\Framework\Queue\Workers\Worker;
use App\Framework\Queue\Workers\WorkerRegistry;
use App\Framework\Queue\Workers\WorkerStatus;
use PHPUnit\Framework\TestCase;

final class MultiWorkerThroughputTest extends TestCase
{
    private DatabaseManager $database;

    private WorkerRegistry $workerRegistry;

    private JobDistributionService $distributionService;

    protected function setUp(): void
    {
        $this->database = $this->createTestDatabase();
        $this->workerRegistry = new WorkerRegistry($this->database);
        $this->distributionService = new JobDistributionService(
            $this->database,
            $this->workerRegistry
        );

        // Clean up any existing test data
        $this->cleanupTestData();

        // Warm up database connections
        PerformanceTestHelper::warmupDatabase($this->database->getConnection());
    }

    protected function tearDown(): void
    {
        $this->cleanupTestData();
    }

    public function testSingleWorkerThroughput(): void
    {
        $workerCount = 1;
        $jobCount = 100;
        $workers = $this->createWorkers($workerCount, 50); // High capacity worker

        $result = $this->measureThroughput($workers, $jobCount);

        $this->assertGreaterThan(
            50, // At least 50 jobs/second with single worker
            $result['throughput'],
            'Single worker throughput below expected minimum'
        );

        echo "\nSingle Worker Throughput Results:\n";
        echo "Throughput: {$result['throughput']} jobs/second\n";
        echo "Total Time: {$result['total_time_ms']}ms\n";
        echo "Average Job Distribution Time: " .
             PerformanceTestHelper::formatStatistics($result['distribution_stats']) . "\n";
    }

    public function testFiveWorkerThroughput(): void
    {
        $workerCount = 5;
        $jobCount = 500;
        $workers = $this->createWorkers($workerCount, 20);

        $result = $this->measureThroughput($workers, $jobCount);

        $this->assertGreaterThan(
            200, // Should achieve at least 200 jobs/second with 5 workers
            $result['throughput'],
            'Five worker throughput below expected minimum'
        );

        echo "\nFive Worker Throughput Results:\n";
        echo "Throughput: {$result['throughput']} jobs/second\n";
        echo "Total Time: {$result['total_time_ms']}ms\n";
        echo "Average Job Distribution Time: " .
             PerformanceTestHelper::formatStatistics($result['distribution_stats']) . "\n";
    }

    public function testTenWorkerThroughput(): void
    {
        $workerCount = 10;
        $jobCount = 1000;
        $workers = $this->createWorkers($workerCount, 15);

        $result = $this->measureThroughput($workers, $jobCount);

        $this->assertGreaterThan(
            350, // Should achieve at least 350 jobs/second with 10 workers
            $result['throughput'],
            'Ten worker throughput below expected minimum'
        );

        echo "\nTen Worker Throughput Results:\n";
        echo "Throughput: {$result['throughput']} jobs/second\n";
        echo "Total Time: {$result['total_time_ms']}ms\n";
        echo "Average Job Distribution Time: " .
             PerformanceTestHelper::formatStatistics($result['distribution_stats']) . "\n";
    }

    public function testTwentyWorkerThroughput(): void
    {
        $workerCount = 20;
        $jobCount = 2000;
        $workers = $this->createWorkers($workerCount, 10);

        $result = $this->measureThroughput($workers, $jobCount);

        $this->assertGreaterThan(
            600, // Should achieve at least 600 jobs/second with 20 workers
            $result['throughput'],
            'Twenty worker throughput below expected minimum'
        );

        echo "\nTwenty Worker Throughput Results:\n";
        echo "Throughput: {$result['throughput']} jobs/second\n";
        echo "Total Time: {$result['total_time_ms']}ms\n";
        echo "Average Job Distribution Time: " .
             PerformanceTestHelper::formatStatistics($result['distribution_stats']) . "\n";
    }

    public function testThroughputScaling(): void
    {
        $testCases = [
            ['workers' => 1, 'jobs' => 50, 'capacity' => 50],
            ['workers' => 5, 'jobs' => 250, 'capacity' => 20],
            ['workers' => 10, 'jobs' => 500, 'capacity' => 15],
            ['workers' => 20, 'jobs' => 1000, 'capacity' => 10],
        ];

        $results = [];

        foreach ($testCases as $case) {
            $workers = $this->createWorkers($case['workers'], $case['capacity']);
            $result = $this->measureThroughput($workers, $case['jobs']);

            $results[] = [
                'worker_count' => $case['workers'],
                'throughput' => $result['throughput'],
                'efficiency' => $result['throughput'] / $case['workers'], // Jobs per worker per second
            ];

            $this->cleanupJobs();
        }

        // Validate scaling efficiency
        for ($i = 1; $i < count($results); $i++) {
            $prev = $results[$i - 1];
            $curr = $results[$i];

            $scalingFactor = $curr['worker_count'] / $prev['worker_count'];
            $throughputIncrease = $curr['throughput'] / $prev['throughput'];

            // Throughput should increase with more workers (allow for some overhead)
            $this->assertGreaterThan(
                $scalingFactor * 0.7, // Allow 30% overhead
                $throughputIncrease,
                sprintf(
                    'Throughput scaling below expected: %dx workers should achieve at least %.1fx throughput',
                    $scalingFactor,
                    $scalingFactor * 0.7
                )
            );
        }

        echo "\nThroughput Scaling Results:\n";
        foreach ($results as $result) {
            echo sprintf(
                "Workers: %2d, Throughput: %6.1f jobs/sec, Efficiency: %5.1f jobs/worker/sec\n",
                $result['worker_count'],
                $result['throughput'],
                $result['efficiency']
            );
        }
    }

    public function testMixedCapacityThroughput(): void
    {
        $workers = [
            PerformanceTestHelper::createTestWorker('worker_1', 50),
            PerformanceTestHelper::createTestWorker('worker_2', 30),
            PerformanceTestHelper::createTestWorker('worker_3', 20),
            PerformanceTestHelper::createTestWorker('worker_4', 10),
            PerformanceTestHelper::createTestWorker('worker_5', 5),
        ];

        $this->registerWorkers($workers);
        $jobCount = 500;

        $result = $this->measureThroughput($workers, $jobCount);

        // Mixed capacity should still achieve good throughput
        $this->assertGreaterThan(
            200, // Reasonable expectation for mixed capacity workers
            $result['throughput'],
            'Mixed capacity worker throughput below expected minimum'
        );

        echo "\nMixed Capacity Worker Results:\n";
        echo "Worker Capacities: 50, 30, 20, 10, 5\n";
        echo "Throughput: {$result['throughput']} jobs/second\n";
        echo "Average Job Distribution Time: " .
             PerformanceTestHelper::formatStatistics($result['distribution_stats']) . "\n";
    }

    public function testSustainedLoadThroughput(): void
    {
        $workers = $this->createWorkers(10, 20);
        $duration = 30; // 30 second sustained load test
        $batchSize = 50;

        $startTime = microtime(true);
        $endTime = $startTime + $duration;
        $totalJobs = 0;
        $distributionTimes = [];

        while (microtime(true) < $endTime) {
            $jobs = PerformanceTestHelper::createBulkJobs($batchSize);

            $batchStartTime = microtime(true);
            foreach ($jobs as $job) {
                $measureResult = PerformanceTestHelper::measureTimeWithResult(
                    fn () => $this->distributionService->distributeJob($job)
                );
                $distributionTimes[] = $measureResult['time_ms'];
            }
            $batchEndTime = microtime(true);

            $totalJobs += count($jobs);

            // Clean up completed jobs to prevent memory issues
            if ($totalJobs % 200 === 0) {
                $this->cleanupJobs();
            }

            // Brief pause to prevent overwhelming
            usleep(10000); // 10ms
        }

        $actualDuration = microtime(true) - $startTime;
        $sustainedThroughput = $totalJobs / $actualDuration;

        $this->assertGreaterThan(
            100, // Should maintain at least 100 jobs/second under sustained load
            $sustainedThroughput,
            'Sustained load throughput below minimum'
        );

        $distributionStats = PerformanceTestHelper::calculateStatistics($distributionTimes);

        echo "\nSustained Load Test Results:\n";
        echo "Duration: {$actualDuration} seconds\n";
        echo "Total Jobs: {$totalJobs}\n";
        echo "Sustained Throughput: {$sustainedThroughput} jobs/second\n";
        echo "Distribution Times: " . PerformanceTestHelper::formatStatistics($distributionStats) . "\n";

        // Distribution times should remain reasonable under sustained load
        $this->assertLessThan(50, $distributionStats['avg'], 'Average distribution time too high under sustained load');
        $this->assertLessThan(100, $distributionStats['p95'], 'P95 distribution time too high under sustained load');
    }

    private function measureThroughput(array $workers, int $jobCount): array
    {
        $this->registerWorkers($workers);

        $jobs = PerformanceTestHelper::createBulkJobs($jobCount);
        $distributionTimes = [];

        $startTime = microtime(true);

        foreach ($jobs as $job) {
            $measureResult = PerformanceTestHelper::measureTimeWithResult(
                fn () => $this->distributionService->distributeJob($job)
            );
            $distributionTimes[] = $measureResult['time_ms'];
        }

        $endTime = microtime(true);
        $totalTimeMs = ($endTime - $startTime) * 1000;
        $throughput = $jobCount / ($endTime - $startTime);

        return [
            'throughput' => round($throughput, 1),
            'total_time_ms' => round($totalTimeMs, 1),
            'distribution_stats' => PerformanceTestHelper::calculateStatistics($distributionTimes),
            'jobs_processed' => $jobCount,
        ];
    }

    private function createWorkers(int $count, int $capacity): array
    {
        $workers = [];
        for ($i = 1; $i <= $count; $i++) {
            $workers[] = PerformanceTestHelper::createTestWorker(
                "perf_worker_{$i}",
                $capacity,
                WorkerStatus::AVAILABLE
            );
        }

        return $workers;
    }

    private function registerWorkers(array $workers): void
    {
        foreach ($workers as $worker) {
            $this->workerRegistry->registerWorker($worker);
        }
    }

    private function createTestDatabase(): DatabaseManager
    {
        // Use in-memory SQLite for performance tests
        $pdo = new \PDO('sqlite::memory:');
        $pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);

        // Create required tables
        $pdo->exec('
            CREATE TABLE workers (
                id TEXT PRIMARY KEY,
                queue_names TEXT NOT NULL,
                capacity INTEGER NOT NULL,
                status TEXT NOT NULL,
                last_heartbeat TEXT NOT NULL,
                metadata TEXT
            )
        ');

        $pdo->exec('
            CREATE TABLE jobs (
                id TEXT PRIMARY KEY,
                type TEXT NOT NULL,
                payload TEXT NOT NULL,
                queue_name TEXT NOT NULL,
                priority INTEGER NOT NULL,
                status TEXT NOT NULL,
                worker_id TEXT,
                created_at TEXT NOT NULL,
                started_at TEXT,
                completed_at TEXT,
                attempts INTEGER DEFAULT 0,
                error_message TEXT
            )
        ');

        $pdo->exec('
            CREATE TABLE distributed_locks (
                lock_key TEXT PRIMARY KEY,
                owner_id TEXT NOT NULL,
                acquired_at TEXT NOT NULL,
                expires_at TEXT NOT NULL
            )
        ');

        // Create indexes for performance
        $pdo->exec('CREATE INDEX idx_workers_status ON workers(status)');
        $pdo->exec('CREATE INDEX idx_jobs_status ON jobs(status)');
        $pdo->exec('CREATE INDEX idx_jobs_queue ON jobs(queue_name)');
        $pdo->exec('CREATE INDEX idx_jobs_priority ON jobs(priority)');
        $pdo->exec('CREATE INDEX idx_locks_expires ON distributed_locks(expires_at)');

        return new DatabaseManager($pdo);
    }

    private function cleanupTestData(): void
    {
        $pdo = $this->database->getConnection();
        $pdo->exec('DELETE FROM workers WHERE id LIKE "perf_worker_%"');
        $pdo->exec('DELETE FROM jobs WHERE id LIKE "job_%"');
        $pdo->exec('DELETE FROM distributed_locks');
    }

    private function cleanupJobs(): void
    {
        $pdo = $this->database->getConnection();
        $pdo->exec('DELETE FROM jobs WHERE status IN ("COMPLETED", "FAILED")');
    }
}