<?php

declare(strict_types=1);

namespace App\Tests\Unit\Service;

use App\Entity\Device;
use App\Entity\DeviceImageHistory;
use App\Entity\Image;
use App\Entity\RenderedAsset;
use App\Enum\DeviceModel;
use App\Enum\Orientation;
use App\Enum\RenderStatus;
use App\Enum\RotationMode;
use App\Service\RotationService;
use App\Tests\AppKernelTestCase;

/**
 * Integration tests for RotationService (requires real DB + dama rollback).
 */
class RotationServiceTest extends AppKernelTestCase
{
    private RotationService $rotation;

    protected function setUp(): void
    {
        parent::setUp();
        $this->rotation = static::getContainer()->get(RotationService::class);
    }

    /**
     * Creates a User+Device approved for a ready Image with V1/Landscape asset.
     * Returns [Device, Image].
     */
    private function createDeviceWithReadyImage(
        string $email = 'test@example.com',
        RenderStatus $status = RenderStatus::Ready,
        bool $approveForDevice = true,
        ?\DateTimeImmutable $uploadedAt = null,
    ): array {
        $user = $this->createUser($email);

        $device = new Device();
        $device->setMac(strtoupper(bin2hex(random_bytes(3)) . ':' . bin2hex(random_bytes(3)) . ':AA'));
        $device->setName('Test Device');
        $device->setUser($user);
        $device->setModel(DeviceModel::V1);
        $device->setOrientation(Orientation::Landscape);
        self::em()->persist($device);

        $image = new Image();
        $image->setUser($user);
        $image->setOriginalFilename('test.jpg');
        $image->setStoragePath('var/storage/images/test/original.jpg');
        if ($uploadedAt !== null) {
            // Use reflection to set uploadedAt since it's set in constructor
            $ref = new \ReflectionProperty(Image::class, 'uploadedAt');
            $ref->setAccessible(true);
            $ref->setValue($image, $uploadedAt);
        }
        if ($approveForDevice) {
            $image->approveForDevice($device);
        }
        self::em()->persist($image);

        $asset = (new RenderedAsset())
            ->setImage($image)
            ->setDeviceModel(DeviceModel::V1)
            ->setOrientation(Orientation::Landscape)
            ->setStatus($status)
            ->setFilePath('var/storage/images/test/v1_landscape.bin');
        self::em()->persist($asset);

        self::em()->flush();

        return [$device, $image];
    }

    public function test_advance_returns_null_when_pool_empty(): void
    {
        $user = $this->createUser('empty@example.com');
        $device = new Device();
        $device->setMac('AA:BB:CC:DD:EE:FF');
        $device->setName('Empty Device');
        $device->setUser($user);
        self::em()->persist($device);
        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNull($result);
    }

    public function test_advance_picks_oldest_image(): void
    {
        $user = $this->createUser('oldest@example.com');

        $device = new Device();
        $device->setMac('AA:BB:CC:DD:EE:01');
        $device->setName('Device');
        $device->setUser($user);
        self::em()->persist($device);

        $older = new Image();
        $older->setUser($user)->setOriginalFilename('old.jpg')->setStoragePath('x');
        $ref = new \ReflectionProperty(Image::class, 'uploadedAt');
        $ref->setAccessible(true);
        $ref->setValue($older, new \DateTimeImmutable('2024-01-01'));
        $older->approveForDevice($device);
        self::em()->persist($older);

        $assetOld = (new RenderedAsset())->setImage($older)->setDeviceModel(DeviceModel::V1)
            ->setOrientation(Orientation::Landscape)->setStatus(RenderStatus::Ready)->setFilePath('x/old.bin');
        self::em()->persist($assetOld);

        $newer = new Image();
        $newer->setUser($user)->setOriginalFilename('new.jpg')->setStoragePath('y');
        $ref->setValue($newer, new \DateTimeImmutable('2024-06-01'));
        $newer->approveForDevice($device);
        self::em()->persist($newer);

        $assetNew = (new RenderedAsset())->setImage($newer)->setDeviceModel(DeviceModel::V1)
            ->setOrientation(Orientation::Landscape)->setStatus(RenderStatus::Ready)->setFilePath('y/new.bin');
        self::em()->persist($assetNew);

        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($older->getId(), $result->getId());
    }

    public function test_advance_skips_recently_shown(): void
    {
        [$device, $imageA] = $this->createDeviceWithReadyImage('skip@example.com');

        $imageB = new Image();
        $imageB->setUser($device->getUser())->setOriginalFilename('b.jpg')->setStoragePath('b');
        $imageB->approveForDevice($device);
        self::em()->persist($imageB);

        $assetB = (new RenderedAsset())->setImage($imageB)->setDeviceModel(DeviceModel::V1)
            ->setOrientation(Orientation::Landscape)->setStatus(RenderStatus::Ready)->setFilePath('b.bin');
        self::em()->persist($assetB);

        // Put imageA in history
        $history = new DeviceImageHistory($device, $imageA);
        self::em()->persist($history);

        $device->setUniquenessWindow(2);
        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($imageB->getId(), $result->getId());
    }

    public function test_advance_resets_when_all_in_window(): void
    {
        [$device, $imageA] = $this->createDeviceWithReadyImage('reset@example.com');

        $imageB = new Image();
        $imageB->setUser($device->getUser())->setOriginalFilename('b.jpg')->setStoragePath('b');
        $imageB->approveForDevice($device);
        self::em()->persist($imageB);

        $assetB = (new RenderedAsset())->setImage($imageB)->setDeviceModel(DeviceModel::V1)
            ->setOrientation(Orientation::Landscape)->setStatus(RenderStatus::Ready)->setFilePath('b.bin');
        self::em()->persist($assetB);

        $histA = new DeviceImageHistory($device, $imageA);
        $histB = new DeviceImageHistory($device, $imageB);
        self::em()->persist($histA);
        self::em()->persist($histB);

        $device->setUniquenessWindow(2);
        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
    }

    public function test_advance_respects_uniqueness_window(): void
    {
        $user = $this->createUser('window@example.com');

        $device = new Device();
        $device->setMac('AA:BB:CC:DD:EE:02');
        $device->setName('Window Device');
        $device->setUser($user);
        $device->setUniquenessWindow(1);
        self::em()->persist($device);

        $images = [];
        for ($i = 0; $i < 3; $i++) {
            $img = new Image();
            $img->setUser($user)->setOriginalFilename("img{$i}.jpg")->setStoragePath("p{$i}");
            $ref = new \ReflectionProperty(Image::class, 'uploadedAt');
            $ref->setAccessible(true);
            $ref->setValue($img, new \DateTimeImmutable("2024-01-0" . ($i + 1)));
            $img->approveForDevice($device);
            self::em()->persist($img);
            $asset = (new RenderedAsset())->setImage($img)->setDeviceModel(DeviceModel::V1)
                ->setOrientation(Orientation::Landscape)->setStatus(RenderStatus::Ready)->setFilePath("p{$i}.bin");
            self::em()->persist($asset);
            $images[] = $img;
        }

        // Put image[0] in history (most recent)
        $hist = new DeviceImageHistory($device, $images[0]);
        self::em()->persist($hist);
        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertNotSame($images[0]->getId(), $result->getId());
    }

    public function test_advance_persists_history(): void
    {
        [$device] = $this->createDeviceWithReadyImage('history@example.com');

        $this->rotation->advance($device);

        $count = self::em()->createQueryBuilder()
            ->select('COUNT(h.id)')
            ->from(DeviceImageHistory::class, 'h')
            ->where('h.device = :device')
            ->setParameter('device', $device)
            ->getQuery()
            ->getSingleScalarResult();

        $this->assertSame(1, (int) $count);
    }

    public function test_advance_updates_current_image(): void
    {
        [$device, $image] = $this->createDeviceWithReadyImage('current@example.com');

        $this->rotation->advance($device);

        self::em()->refresh($device);

        $this->assertNotNull($device->getCurrentImage());
        $this->assertSame($image->getId(), $device->getCurrentImage()->getId());
    }

    public function test_advance_excludes_pending_asset(): void
    {
        [$device, ] = $this->createDeviceWithReadyImage('pending@example.com', RenderStatus::Pending);

        $result = $this->rotation->advance($device);

        $this->assertNull($result);
    }

    public function test_advance_excludes_unapproved_image(): void
    {
        [$device, ] = $this->createDeviceWithReadyImage('unapproved@example.com', RenderStatus::Ready, false);

        $result = $this->rotation->advance($device);

        $this->assertNull($result);
    }

    /**
     * Builds a device approved for N ready images with explicit uploadedAt
     * timestamps. Returns [device, [image, ...]] with images in upload-time
     * order (oldest first, newest last).
     *
     * @param string[] $uploadedAt ISO-8601 dates, oldest first
     * @return array{0: Device, 1: Image[]}
     */
    private function setupDeviceAndImages(string $email, array $uploadedAt): array
    {
        $user = $this->createUser($email);
        $device = new Device();
        $device->setMac(strtoupper(bin2hex(random_bytes(3)) . ':' . bin2hex(random_bytes(3)) . ':BB'));
        $device->setName('Test Device');
        $device->setUser($user);
        // Loose window so the uniqueness filter never empties the candidate set
        // unintentionally — we want each test to drive its own filter behavior.
        $device->setUniquenessWindow(1);
        self::em()->persist($device);

        $images = [];
        $ref = new \ReflectionProperty(Image::class, 'uploadedAt');
        $ref->setAccessible(true);
        foreach ($uploadedAt as $i => $ts) {
            $img = new Image();
            $img->setUser($user)
                ->setOriginalFilename("img{$i}.jpg")
                ->setStoragePath("p{$i}");
            $ref->setValue($img, new \DateTimeImmutable($ts));
            $img->approveForDevice($device);
            self::em()->persist($img);
            $asset = (new RenderedAsset())
                ->setImage($img)
                ->setDeviceModel(DeviceModel::V1)
                ->setOrientation(Orientation::Landscape)
                ->setStatus(RenderStatus::Ready)
                ->setFilePath("p{$i}.bin");
            self::em()->persist($asset);
            $images[] = $img;
        }
        self::em()->flush();
        return [$device, $images];
    }

    /** Backdate a history row so least-recently-shown ordering is testable. */
    private function recordHistoryAt(Device $device, Image $image, string $servedAt): void
    {
        $history = new DeviceImageHistory($device, $image);
        $ref = new \ReflectionProperty(DeviceImageHistory::class, 'servedAt');
        $ref->setAccessible(true);
        $ref->setValue($history, new \DateTimeImmutable($servedAt));
        self::em()->persist($history);
        self::em()->flush();
    }

    // RM-01: NewestUpload picks the most recent upload.
    public function test_newest_upload_mode_picks_newest(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('newest@example.com', [
            '2024-01-01', '2024-06-01', '2024-12-01',
        ]);
        $device->setRotationMode(RotationMode::NewestUpload);
        self::em()->flush();

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($images[2]->getId(), $result->getId(), 'newest upload should win');
    }

    // RM-02: Random returns *some* eligible candidate. Run a few times so a
    // freak coincidence with a deterministic mode would still be unlikely to
    // pass. We can't assert exact distribution without a seedable RNG, but we
    // can assert randomness produces more than one distinct outcome over a
    // handful of calls (probabilistic; failure is ~1/3^7 = 0.05%).
    public function test_random_mode_yields_variety(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('random@example.com', [
            '2024-01-01', '2024-06-01', '2024-12-01',
        ]);
        $device->setRotationMode(RotationMode::Random);
        $device->setUniquenessWindow(1);  // only the very last is forbidden
        self::em()->flush();

        $imageIds = array_map(static fn(Image $i) => $i->getId(), $images);
        $seen = [];
        for ($i = 0; $i < 7; $i++) {
            $result = $this->rotation->advance($device);
            $this->assertNotNull($result);
            $this->assertContains($result->getId(), $imageIds, 'random pick must come from the candidate pool');
            $seen[$result->getId()] = true;
        }
        $this->assertGreaterThan(1, count($seen), 'random over 7 picks should yield more than 1 distinct image');
    }

    // RM-03: LeastRecentlyShown sorts by oldest most-recent serve.
    public function test_least_recently_shown_picks_oldest_history(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('lrs@example.com', [
            '2024-01-01', '2024-06-01', '2024-12-01',
        ]);
        $device->setRotationMode(RotationMode::LeastRecentlyShown);
        $device->setUniquenessWindow(1); // allow image[0] back in the candidate pool
        self::em()->flush();

        // Serve history: image[0] longest ago, image[1] middle, image[2] most recent.
        // We expect image[0] to be picked.
        $this->recordHistoryAt($device, $images[0], '2025-01-01');
        $this->recordHistoryAt($device, $images[1], '2025-06-01');
        $this->recordHistoryAt($device, $images[2], '2025-12-01');

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($images[0]->getId(), $result->getId(), 'oldest last-served should win');
    }

    // RM-04: LeastRecentlyShown — never-shown sorts before any shown image.
    public function test_least_recently_shown_prefers_never_shown(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('lrs-never@example.com', [
            '2024-01-01', '2024-06-01',
        ]);
        $device->setRotationMode(RotationMode::LeastRecentlyShown);
        $device->setUniquenessWindow(1);
        self::em()->flush();

        // image[0] has been shown; image[1] never has.
        $this->recordHistoryAt($device, $images[0], '2024-12-01');

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($images[1]->getId(), $result->getId(), 'never-shown image beats any history');
    }

    // RM-05: prioritizeNeverShown narrows the candidate set to never-shown
    // images before the mode runs, even when the mode would normally pick
    // a shown image.
    public function test_prioritize_never_shown_narrows_candidate_set(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('prio@example.com', [
            '2024-01-01',  // oldest — Oldest mode would normally pick this
            '2024-06-01',
            '2024-12-01',  // newest, but never-shown
        ]);
        $device->setRotationMode(RotationMode::OldestUpload);
        $device->setPrioritizeNeverShown(true);
        $device->setUniquenessWindow(1);
        self::em()->flush();

        // Mark the older two as already shown. Only image[2] is never-shown.
        $this->recordHistoryAt($device, $images[0], '2025-06-01');
        $this->recordHistoryAt($device, $images[1], '2025-06-02');

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame(
            $images[2]->getId(),
            $result->getId(),
            'never-shown narrowing must override the OldestUpload mode',
        );
    }

    // RM-06: prioritizeNeverShown is a no-op when no never-shown images
    // remain — falls through to the mode.
    public function test_prioritize_never_shown_falls_through_when_all_shown(): void
    {
        [$device, $images] = $this->setupDeviceAndImages('prio-fall@example.com', [
            '2024-01-01', '2024-12-01',
        ]);
        $device->setRotationMode(RotationMode::NewestUpload);
        $device->setPrioritizeNeverShown(true);
        $device->setUniquenessWindow(1);
        self::em()->flush();

        // Both shown — never-shown set is empty, so mode (NewestUpload) takes over.
        $this->recordHistoryAt($device, $images[0], '2025-06-01');
        $this->recordHistoryAt($device, $images[1], '2025-06-02');

        $result = $this->rotation->advance($device);

        $this->assertNotNull($result);
        $this->assertSame($images[1]->getId(), $result->getId(), 'falls through to NewestUpload mode');
    }
}