<?php

declare(strict_types=1);

namespace Tests\Unit\Game;

use App\Game\StressTestHarness;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;

final class StressTestHarnessTest extends TestCase
{
    private function harness(): StressTestHarness
    {
        return new StressTestHarness;
    }

    #[Test]
    public function tick_report_has_expected_shape(): void
    {
        $report = $this->harness()->measureTickTime(50, players: 2, ticks: 20);

        $this->assertSame(50, $report['entities']);
        $this->assertArrayHasKey('zombies', $report['scenarios']);
        $this->assertArrayHasKey('projectiles', $report['scenarios']);
        foreach ($report['scenarios'] as $result) {
            $this->assertArrayHasKey('avgMs', $result);
            $this->assertArrayHasKey('medianMs', $result);
            $this->assertArrayHasKey('maxMs', $result);
            $this->assertArrayHasKey('budgetOk', $result);
        }
    }

    #[Test]
    public function tick_time_is_measured_as_positive(): void
    {
        $report = $this->harness()->measureTickTime(50, players: 2, ticks: 20);

        foreach ($report['scenarios'] as $result) {
            $this->assertGreaterThan(0.0, $result['avgMs']);
            $this->assertGreaterThan(0.0, $result['maxMs']);
        }
    }

    #[Test]
    public function snapshot_bytes_grow_with_entity_count(): void
    {
        $small = $this->harness()->measureSnapshotBytes(50, players: 2, scenarios: ['zombies']);
        $large = $this->harness()->measureSnapshotBytes(400, players: 2, scenarios: ['zombies']);

        $this->assertGreaterThan(
            $small['scenarios']['zombies']['bytes'],
            $large['scenarios']['zombies']['bytes'],
            'snapshot payload should grow as entity count grows',
        );
    }

    #[Test]
    public function snapshot_report_tracks_bytes_per_entity(): void
    {
        $report = $this->harness()->measureSnapshotBytes(100, players: 2, scenarios: ['zombies']);

        $this->assertGreaterThan(0, $report['scenarios']['zombies']['bytes']);
        $this->assertGreaterThan(0.0, $report['scenarios']['zombies']['bytesPerEntity']);
    }

    #[Test]
    public function reverb_cap_flag_flips_between_small_and_large_rooms(): void
    {
        $small = $this->harness()->measureSnapshotBytes(50, players: 2, scenarios: ['zombies']);
        $large = $this->harness()->measureSnapshotBytes(2000, players: 2, scenarios: ['zombies']);

        $this->assertFalse($small['scenarios']['zombies']['exceedsReverb']);
        $this->assertTrue($large['scenarios']['zombies']['exceedsReverb']);
    }
}