<?php

declare(strict_types=1);

namespace App\Service\Provider;

use Psr\Log\LoggerInterface;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Contracts\HttpClient\HttpClientInterface;

/**
 * Fetches the last 365 days of push/merge events from the GitLab REST API.
 *
 * Required token scopes: read_user, read_api
 * Works with both gitlab.com and self-hosted instances.
 */
final class GitLabProvider implements ProviderInterface
{
    use ProbeTrait;

    public function __construct(
        private readonly HttpClientInterface $client,
        private readonly string $username,
        private readonly string $token,
        private readonly LoggerInterface $logger,
        private readonly string $baseUrl = '',
    ) {}

    public function getName(): string
    {
        return 'gitlab';
    }

    public function isConfigured(): bool
    {
        return $this->username !== '' && $this->token !== '';
    }

    public function ping(): void
    {
        $baseUrl = rtrim($this->baseUrl !== '' ? $this->baseUrl : 'https://gitlab.com', '/');

        $this->client->request('GET', "$baseUrl/api/v4/user", [
            'headers' => ['PRIVATE-TOKEN' => $this->token],
        ])->getContent();
    }

    /**
     * @return array<string, int>  date (Y-m-d) => event count
     */
    public function fetch(): array
    {
        $baseUrl = rtrim($this->baseUrl !== '' ? $this->baseUrl : 'https://gitlab.com', '/');

        $this->logger->debug('GitLabProvider: fetching contributions', ['user' => $this->username, 'url' => $baseUrl]);

        $userResponse = $this->client->request('GET', "$baseUrl/api/v4/users", [
            'headers' => ['PRIVATE-TOKEN' => $this->token],
            'query'   => ['username' => $this->username],
        ]);

        $users = $userResponse->toArray();
        if (empty($users)) {
            throw new NotFoundHttpException("GitLab: user '{$this->username}' not found on $baseUrl");
        }
        $userId = $users[0]['id'];

        $result = [];
        $after  = (new \DateTimeImmutable('-365 days'))->format('Y-m-d');
        $page   = 1;

        do {
            $response = $this->client->request('GET', "$baseUrl/api/v4/users/$userId/events", [
                'headers' => ['PRIVATE-TOKEN' => $this->token],
                'query'   => [
                    'after'    => $after,
                    'per_page' => 100,
                    'page'     => $page,
                ],
            ]);

            $events = $response->toArray();

            foreach ($events as $event) {
                $date          = substr($event['created_at'], 0, 10);
                $result[$date] = ($result[$date] ?? 0) + 1;
            }

            $page++;
        } while (count($events) === 100);

        $this->logger->info('GitLabProvider: fetched contributions', [
            'user'  => $this->username,
            'pages' => $page - 1,
            'days'  => count($result),
            'total' => array_sum($result),
        ]);

        return $result;
    }
}