<?php

declare(strict_types=1);

namespace GitContributionGraph\Tests\Unit\Service;

use GitContributionGraph\Service\ContributionAggregator;
use GitContributionGraph\Service\ContributionStore;
use GitContributionGraph\Service\Provider\ProviderInterface;
use PHPUnit\Framework\Attributes\CoversClass;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;
use Psr\Log\LoggerInterface;

#[CoversClass(ContributionAggregator::class)]
final class ContributionAggregatorTest extends TestCase
{
    private LoggerInterface $logger;
    private ContributionStore $store;

    protected function setUp(): void
    {
        $this->logger = $this->createStub(LoggerInterface::class);
        $this->store  = new ContributionStore(':memory:');
    }

    /** @param ?array<string, int> $fresh */
    private function makeProvider(string $name, bool $configured = true, ?array $fresh = null): ProviderInterface
    {
        $provider = $this->createStub(ProviderInterface::class);
        $provider->method('getName')->willReturn($name);
        $provider->method('isConfigured')->willReturn($configured);
        if ($fresh !== null) {
            $provider->method('resolveFetch')->willReturn($fresh);
        }

        return $provider;
    }

    #[Test]
    public function it_returns_empty_array_when_no_providers_are_given(): void
    {
        $aggregator = new ContributionAggregator([], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([], $result);
    }

    #[Test]
    public function it_skips_unconfigured_providers(): void
    {
        $provider = $this->makeProvider('github', configured: false);

        $aggregator = new ContributionAggregator([$provider], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([], $result);
    }

    #[Test]
    public function it_returns_contributions_from_a_configured_provider(): void
    {
        $date     = (new \DateTimeImmutable('-1 day'))->format('Y-m-d');
        $provider = $this->makeProvider('github', fresh: [$date => 3]);

        $aggregator = new ContributionAggregator([$provider], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([$date => 3], $result);
    }

    #[Test]
    public function it_sums_contributions_from_multiple_providers_on_the_same_date(): void
    {
        $dateA = (new \DateTimeImmutable('-1 day'))->format('Y-m-d');
        $dateB = (new \DateTimeImmutable('-2 days'))->format('Y-m-d');

        $providerA = $this->makeProvider('github', fresh: [$dateA => 3, $dateB => 1]);
        $providerB = $this->makeProvider('gitlab', fresh: [$dateA => 2]);

        $aggregator = new ContributionAggregator([$providerA, $providerB], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([$dateB => 1, $dateA => 5], $result);
    }

    #[Test]
    public function it_continues_fetching_remaining_providers_when_one_throws_on_start(): void
    {
        $date = (new \DateTimeImmutable('-1 day'))->format('Y-m-d');

        $failing = $this->createStub(ProviderInterface::class);
        $failing->method('getName')->willReturn('gitlab');
        $failing->method('isConfigured')->willReturn(true);
        $failing->method('startFetch')->willThrowException(new \RuntimeException('Network error'));

        $healthy = $this->makeProvider('github', fresh: [$date => 7]);

        $aggregator = new ContributionAggregator([$failing, $healthy], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([$date => 7], $result);
    }

    #[Test]
    public function it_continues_fetching_remaining_providers_when_one_throws_on_resolve(): void
    {
        $date = (new \DateTimeImmutable('-1 day'))->format('Y-m-d');

        $failing = $this->createStub(ProviderInterface::class);
        $failing->method('getName')->willReturn('gitlab');
        $failing->method('isConfigured')->willReturn(true);
        $failing->method('resolveFetch')->willThrowException(new \RuntimeException('Network error'));

        $healthy = $this->makeProvider('github', fresh: [$date => 7]);

        $aggregator = new ContributionAggregator([$failing, $healthy], $this->store, $this->logger);

        $result = $aggregator->aggregate();

        $this->assertSame([$date => 7], $result);
    }

    #[Test]
    public function it_logs_a_warning_when_a_provider_start_fetch_throws(): void
    {
        $logger = $this->createMock(LoggerInterface::class);
        $logger->expects($this->once())->method('warning');

        $provider = $this->createStub(ProviderInterface::class);
        $provider->method('getName')->willReturn('github');
        $provider->method('isConfigured')->willReturn(true);
        $provider->method('startFetch')->willThrowException(new \RuntimeException('fail'));

        (new ContributionAggregator([$provider], $this->store, $logger))->aggregate();
    }

    #[Test]
    public function it_logs_a_warning_when_a_provider_resolve_fetch_throws(): void
    {
        $logger = $this->createMock(LoggerInterface::class);
        $logger->expects($this->once())->method('warning');

        $provider = $this->createStub(ProviderInterface::class);
        $provider->method('getName')->willReturn('github');
        $provider->method('isConfigured')->willReturn(true);
        $provider->method('resolveFetch')->willThrowException(new \RuntimeException('fail'));

        (new ContributionAggregator([$provider], $this->store, $logger))->aggregate();
    }

    #[Test]
    public function it_consults_latest_date_and_narrows_the_since_window_by_three_days(): void
    {
        $latest = (new \DateTimeImmutable('-30 days'))->getTimestamp();
        $this->store->add('github', $latest, 1);

        $provider = $this->createMock(ProviderInterface::class);
        $provider->method('getName')->willReturn('github');
        $provider->method('isConfigured')->willReturn(true);
        $provider->expects($this->once())
            ->method('startFetch')
            ->with($this->callback(
                fn (?\DateTimeImmutable $since): bool => $since !== null
                    && $since->getTimestamp() === $latest - 3 * 86400
            ))
            ->willReturn(null);
        $provider->method('resolveFetch')->willReturn([]);

        (new ContributionAggregator([$provider], $this->store, $this->logger))->aggregate();
    }

    #[Test]
    public function it_merges_freshly_fetched_contributions_into_the_store(): void
    {
        $date     = (new \DateTimeImmutable('-1 day'))->format('Y-m-d');
        $provider = $this->makeProvider('github', fresh: [$date => 4]);

        (new ContributionAggregator([$provider], $this->store, $this->logger))->aggregate();

        $stored = iterator_to_array($this->store->all('github'));
        $this->assertCount(1, $stored);
        $this->assertSame(4, $stored[0]->count);
    }

    #[Test]
    public function it_prunes_the_store_once_per_aggregate_call(): void
    {
        $store = $this->createMock(ContributionStore::class);
        $store->method('latestDate')->willReturn(null);
        $store->method('all')->willReturn(new \GitContributionGraph\Entity\ContributionCollection());
        $store->expects($this->once())->method('prune');

        $provider = $this->makeProvider('github', fresh: []);

        (new ContributionAggregator([$provider], $store, $this->logger))->aggregate();
    }

    #[Test]
    public function it_leaves_other_providers_stored_data_intact_when_one_provider_fails(): void
    {
        $date = (new \DateTimeImmutable('-1 day'))->getTimestamp();
        $this->store->add('gitlab', $date, 9);

        $failing = $this->createStub(ProviderInterface::class);
        $failing->method('getName')->willReturn('gitlab');
        $failing->method('isConfigured')->willReturn(true);
        $failing->method('startFetch')->willThrowException(new \RuntimeException('Network error'));

        $healthy = $this->makeProvider('github', fresh: []);

        (new ContributionAggregator([$failing, $healthy], $this->store, $this->logger))->aggregate();

        $stored = iterator_to_array($this->store->all('gitlab'));
        $this->assertCount(1, $stored);
        $this->assertSame(9, $stored[0]->count);
    }
}