<?php
declare(strict_types=1);
namespace App\Tests;

use App\Alert\MultiDownWatch;
use App\Tests\Support\InMemoryEventRepository;
use PHPUnit\Framework\TestCase;

/**
 * 같은 자리에서 짧은 시간에 둘이 쓰러지면 그것은 넘어짐 두 건이 아니라 질식·가스·폭발이다.
 *
 * 이 테스트가 지키는 두 가지: (1) 진짜 무리를 놓치지 않는다, (2) 무관한 넘어짐을 묶지 않는다.
 * 넓은 공장에서 2분 안의 무관한 넘어짐 두 건은 실제로 일어나므로 (2)가 (1)만큼 중요하다.
 */
final class MultiDownWatchTest extends TestCase
{
    private const NOW = 1_700_000_000;

    private function ev(InMemoryEventRepository $repo, array $over = []): int
    {
        return $repo->insert($over + [
            'event_uuid' => bin2hex(random_bytes(16)),
            'device_id' => 'pi-01', 'site' => 'site-a', 'camera_id' => 'cam-01',
            'event_type' => 'fall', 'severity' => 'high', 'track_id' => 1,
            'zone_id' => null, 'occurred_at' => (float)(self::NOW - 60),
            'duration_s' => 0.0, 'metrics' => [],
            'spatial_x' => 0.50, 'spatial_y' => 0.50,
        ]);
    }

    public function testTwoPeopleDownInTheSameSpotFilesOneCriticalEvent(): void
    {
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'spatial_x' => 0.50, 'spatial_y' => 0.50]);
        $this->ev($repo, ['track_id' => 2, 'spatial_x' => 0.55, 'spatial_y' => 0.52,
                          'occurred_at' => (float)(self::NOW - 30)]);

        $filed = (new MultiDownWatch($repo))->run(self::NOW);

        self::assertCount(1, $filed);
        self::assertSame(2, $filed[0]['people']);
        $row = $repo->find($filed[0]['event_id']);
        self::assertSame('multi_down', $row['event_type']);
        self::assertSame('critical', $row['severity']);
        self::assertCount(2, $row['metrics']['origin_event_ids']);
    }

    public function testOnePersonFallingTwiceIsNotAGroup(): void
    {
        // 넘어졌다 회복했다 다시 넘어진 것은 한 명이다.
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 7]);
        $this->ev($repo, ['track_id' => 7, 'occurred_at' => (float)(self::NOW - 20)]);

        self::assertSame([], (new MultiDownWatch($repo))->run(self::NOW));
    }

    public function testFarApartFallsAreNotAGroup(): void
    {
        // 같은 카메라라도 화면 반대편은 다른 사건이다.
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'spatial_x' => 0.05, 'spatial_y' => 0.05]);
        $this->ev($repo, ['track_id' => 2, 'spatial_x' => 0.95, 'spatial_y' => 0.95,
                          'occurred_at' => (float)(self::NOW - 30)]);

        self::assertSame([], (new MultiDownWatch($repo))->run(self::NOW, ['radius' => 0.35]));
    }

    public function testFallsOutsideTheWindowAreNotAGroup(): void
    {
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'occurred_at' => (float)(self::NOW - 1000)]);
        $this->ev($repo, ['track_id' => 2, 'occurred_at' => (float)(self::NOW - 10)]);

        self::assertSame([], (new MultiDownWatch($repo))->run(self::NOW, ['window_s' => 120]));
    }

    public function testSameZoneGroupsEvenWithoutSpatialProximity(): void
    {
        // 운영자가 "여기가 한 공간"이라고 선언한 것이 좌표 거리보다 정확하다.
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'zone_id' => 'z-tank', 'spatial_x' => 0.05, 'spatial_y' => 0.05]);
        $this->ev($repo, ['track_id' => 2, 'zone_id' => 'z-tank', 'spatial_x' => 0.95, 'spatial_y' => 0.95,
                          'occurred_at' => (float)(self::NOW - 20)]);

        $filed = (new MultiDownWatch($repo))->run(self::NOW);
        self::assertCount(1, $filed);
        self::assertSame('zone:z-tank', $filed[0]['scope']);
    }

    public function testRepeatedRunsDoNotDuplicate(): void
    {
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1]);
        $this->ev($repo, ['track_id' => 2, 'occurred_at' => (float)(self::NOW - 30)]);
        $w = new MultiDownWatch($repo);

        self::assertCount(1, $w->run(self::NOW));
        self::assertSame([], $w->run(self::NOW + 60));
        self::assertSame([], $w->run(self::NOW + 90));
    }

    public function testAThirdPersonRaisesItAgain(): void
    {
        // 사람이 늘어난 것은 상황이 악화된 것이다 — 한 번 더 올라와야 한다.
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1]);
        $this->ev($repo, ['track_id' => 2, 'occurred_at' => (float)(self::NOW - 30)]);
        $w = new MultiDownWatch($repo);
        self::assertCount(1, $w->run(self::NOW));

        $this->ev($repo, ['track_id' => 3, 'occurred_at' => (float)(self::NOW - 10)]);
        $again = $w->run(self::NOW + 5);
        self::assertCount(1, $again);
        self::assertSame(3, $again[0]['people']);
    }

    public function testNonDownTypesAreIgnored(): void
    {
        // 니어미스·자세부담은 사람이 쓰러진 것이 아니다.
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'event_type' => 'near_fall']);
        $this->ev($repo, ['track_id' => 2, 'event_type' => 'ergo_report',
                          'occurred_at' => (float)(self::NOW - 30)]);

        self::assertSame([], (new MultiDownWatch($repo))->run(self::NOW));
    }

    public function testFallFromHeightCountsAsDown(): void
    {
        $repo = new InMemoryEventRepository();
        $this->ev($repo, ['track_id' => 1, 'event_type' => 'fall_from_height']);
        $this->ev($repo, ['track_id' => 2, 'event_type' => 'no_motion',
                          'occurred_at' => (float)(self::NOW - 30)]);

        self::assertCount(1, (new MultiDownWatch($repo))->run(self::NOW));
    }
}