<?php

declare(strict_types=1);

namespace KTXT\ProviderPreviewImageMagick\Unit;

use Imagick;
use ImagickPixel;
use KTXC\Resource\ProviderManager;
use KTXF\Preview\PreviewGenerationException;
use KTXF\Preview\PreviewRequest;
use KTXF\Preview\PreviewSource;
use KTXF\Resource\BinaryResource;
use KTXF\Resource\Provider\ProviderInterface;
use KTXM\ProviderPreviewImageMagick\Module;
use KTXM\ProviderPreviewImageMagick\Provider;
use PHPUnit\Framework\Attributes\DataProvider;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;

final class ProviderTest extends TestCase
{
    #[Test]
    public function moduleRegistersThePreviewProvider(): void
    {
        $providers = $this->createMock(ProviderManager::class);
        $providers->expects(self::once())->method('register')->with(
            ProviderInterface::TYPE_PREVIEW,
            'imagemagick',
            Provider::class,
        );

        (new Module($providers))->boot();
    }

    public static function inputFormats(): iterable
    {
        yield 'JPEG' => ['JPEG', 'image/jpeg'];
        yield 'PNG' => ['PNG', 'image/png'];
        yield 'WebP' => ['WEBP', 'image/webp'];
        yield 'GIF' => ['GIF', 'image/gif'];
    }

    #[Test]
    #[DataProvider('inputFormats')]
    public function generatesBoundedWebpFromSupportedInputs(string $format, string $mimeType): void
    {
        $provider = new Provider();
        $result = $provider->generate(
            $this->source($this->image($format, 800, 400), $mimeType),
            $this->request(),
        );
        $output = $this->content($result->resource);
        $image = new Imagick();
        $image->readImageBlob($output);

        self::assertSame('image/webp', $result->resource->mimeType());
        self::assertSame(640, $result->width);
        self::assertSame(320, $result->height);
        self::assertSame('WEBP', $image->getImageFormat());
        self::assertSame(640, $image->getImageWidth());
        self::assertSame(320, $image->getImageHeight());
        $image->clear();
    }

    #[Test]
    public function doesNotUpscaleSmallImages(): void
    {
        $result = (new Provider())->generate(
            $this->source($this->image('PNG', 100, 50), 'image/png'),
            $this->request(),
        );

        self::assertSame(100, $result->width);
        self::assertSame(50, $result->height);
    }

    public static function outputFormats(): iterable
    {
        yield 'JPEG' => ['image/jpeg', 'JPEG'];
        yield 'PNG' => ['image/png', 'PNG'];
        yield 'WebP' => ['image/webp', 'WEBP'];
    }

    #[Test]
    #[DataProvider('outputFormats')]
    public function encodesEveryAdvertisedOutputFormat(string $mimeType, string $format): void
    {
        $request = new PreviewRequest(640, 440, $mimeType, 80);
        $result = (new Provider())->generate(
            $this->source($this->image('PNG', 20, 20, 'rgba(255, 0, 0, 0.25)'), 'image/png'),
            $request,
        );
        $image = new Imagick();
        $image->readImageBlob($this->content($result->resource));

        self::assertSame($mimeType, $result->resource->mimeType());
        self::assertSame($format, $image->getImageFormat());
        $image->clear();
    }

    #[Test]
    public function preservesTransparencyInPngOutput(): void
    {
        $request = new PreviewRequest(640, 440, 'image/png', 80);
        $result = (new Provider())->generate(
            $this->source($this->image('PNG', 20, 20, 'rgba(255, 0, 0, 0.25)'), 'image/png'),
            $request,
        );
        $image = new Imagick();
        $image->readImageBlob($this->content($result->resource));
        $color = $image->getImagePixelColor(0, 0)->getColor(1);

        self::assertSame('image/png', $result->resource->mimeType());
        self::assertLessThan(0.5, $color['a']);
        $image->clear();
    }

    #[Test]
    public function usesOnlyTheFirstAnimatedFrame(): void
    {
        $animation = new Imagick();
        foreach (['red', 'blue'] as $color) {
            $frame = new Imagick();
            $frame->newImage(20, 20, new ImagickPixel($color));
            $frame->setImageFormat('GIF');
            $frame->setImageDelay(10);
            $animation->addImage($frame);
            $frame->clear();
        }
        $content = $animation->getImagesBlob();
        $animation->clear();

        $result = (new Provider())->generate($this->source($content, 'image/gif'), $this->request());
        $output = new Imagick();
        $output->readImageBlob($this->content($result->resource));

        self::assertSame(1, $output->getNumberImages());
        $color = $output->getImagePixelColor(0, 0)->getColor();
        self::assertGreaterThan($color['b'], $color['r']);
        $output->clear();
    }

    #[Test]
    public function rejectsMalformedOrMismatchedImages(): void
    {
        $provider = new Provider();

        try {
            $provider->generate($this->source('not an image', 'image/png'), $this->request());
            self::fail('Malformed input should fail');
        } catch (PreviewGenerationException) {
            self::addToAssertionCount(1);
        }

        $this->expectException(PreviewGenerationException::class);
        $this->expectExceptionMessage('does not match');
        $provider->generate(
            $this->source($this->image('PNG', 20, 20), 'image/jpeg'),
            $this->request(),
        );
    }

    #[Test]
    public function enforcesTheSourceSizeLimitWhileReading(): void
    {
        $content = $this->image('PNG', 20, 20);
        $request = new PreviewRequest(
            640,
            440,
            'image/webp',
            80,
            maxSourceSize: strlen($content) - 1,
        );

        $this->expectException(PreviewGenerationException::class);
        $this->expectExceptionMessage('size limit');
        (new Provider())->generate($this->source($content, 'image/png', size: null), $request);
    }

    private function request(): PreviewRequest
    {
        return new PreviewRequest(640, 440, 'image/webp', 80);
    }

    private function source(string $content, string $mimeType, ?int $size = null): PreviewSource
    {
        return new PreviewSource(
            'document',
            'image',
            hash('sha256', $content),
            $mimeType,
            $size ?? strlen($content),
            static fn(): BinaryResource => new BinaryResource(
                'source.bin',
                $mimeType,
                (static function () use ($content): \Generator {
                    $middle = intdiv(strlen($content), 2);
                    yield substr($content, 0, $middle);
                    yield substr($content, $middle);
                })(),
            ),
        );
    }

    private function image(string $format, int $width, int $height, string $color = 'red'): string
    {
        $image = new Imagick();
        $image->newImage($width, $height, new ImagickPixel($color));
        $image->setImageFormat($format);
        $content = $image->getImageBlob();
        $image->clear();
        return $content;
    }

    private function content(BinaryResource $resource): string
    {
        $content = '';
        foreach ($resource->stream() as $chunk) {
            $content .= $chunk;
        }
        return $content;
    }
}