<?php

declare(strict_types=1);

namespace NetBoxStore\Sync\Adapter;

use RuntimeException;

final class GitHubAdapter extends AbstractAdapter
{
    private const MAX_REPOSITORY_PAGES = 200;
    private const MAX_RELEASE_PAGES = 100;

    protected function authorizationValue(string $token): string
    {
        return 'Bearer ' . $token;
    }

    protected function apiHeaders(string $accept = 'application/vnd.github+json'): array
    {
        return array_merge(parent::apiHeaders($accept), ['X-GitHub-Api-Version: 2022-11-28']);
    }

    public function listRepositories(): array
    {
        $owner = rawurlencode((string) $this->source['owner']);
        $kind = $this->source['ownerKind'] ?? 'user';
        $endpoints = $kind === 'auto'
            ? ['orgs/' . $owner . '/repos', 'users/' . $owner . '/repos']
            : [($kind === 'organization' ? 'orgs/' : 'users/') . $owner . '/repos'];
        $payload = null;
        foreach ($endpoints as $endpoint) {
            $payload = $this->paged($endpoint);
            if ($payload !== null && ($payload !== [] || $kind !== 'auto')) {
                break;
            }
        }
        if ($payload === null) {
            throw new RuntimeException('GitHub owner was not found.');
        }
        return array_map(function (array $item): array {
            $repository = [
                'externalId' => (string) ($item['id'] ?? $item['full_name'] ?? ''),
                'owner' => (string) ($item['owner']['login'] ?? $this->source['owner']),
                'name' => (string) ($item['name'] ?? ''),
                'fullName' => (string) ($item['full_name'] ?? ''),
                'htmlUrl' => (string) ($item['html_url'] ?? ''),
                'defaultBranch' => (string) ($item['default_branch'] ?? 'main'),
                'description' => (string) ($item['description'] ?? ''),
                'homepageUrl' => (string) ($item['homepage'] ?? ''),
                'topics' => array_values(array_map('strval', is_array($item['topics'] ?? null) ? $item['topics'] : [])),
                'archived' => (bool) ($item['archived'] ?? false),
                'fork' => (bool) ($item['fork'] ?? false),
                'empty' => isset($item['size']) ? (int) $item['size'] === 0 : false,
                'private' => (bool) ($item['private'] ?? false),
            ];
            $this->validateRepository($repository);
            return $repository;
        }, $payload);
    }

    public function getCommitSha(array $repository, ?string $ref = null): string
    {
        $ref ??= (string) $repository['defaultBranch'];
        $data = $this->apiJson('repos/' . $repository['fullName'] . '/commits/' . rawurlencode($ref), [], true);
        $sha = strtolower((string) ($data['sha'] ?? ''));
        return preg_match('/^[a-f0-9]{40,64}$/', $sha) ? $sha : '';
    }

    public function fetchText(array $repository, string $path, string $commitSha): ?string
    {
        $this->validateRepository($repository);
        $this->assertCommit($commitSha);
        $url = $this->apiUrl . '/repos/' . $repository['fullName'] . '/contents/' . $this->encodedPath($path)
            . '?ref=' . rawurlencode($commitSha);
        return $this->http->getText($url, $this->apiHeaders('application/vnd.github.raw+json'), $this->apiOrigin, true);
    }

    public function rawFileUrl(array $repository, string $path, string $commitSha): string
    {
        $this->validateRepository($repository);
        $this->assertCommit($commitSha);
        return 'https://raw.githubusercontent.com/' . $repository['fullName'] . '/' . $commitSha . '/' . $this->encodedPath($path);
    }

    public function listReleases(array $repository): array
    {
        if (!empty($repository['private'])) {
            return [];
        }
        $payload = [];
        for ($page = 1; $page <= self::MAX_RELEASE_PAGES; $page++) {
            $chunk = $this->apiJson('repos/' . $repository['fullName'] . '/releases', ['per_page' => 100, 'page' => $page]);
            if (!is_array($chunk) || !array_is_list($chunk)) {
                throw new RuntimeException('GitHub release response is invalid.');
            }
            $this->accountReleasePage($chunk);
            foreach ($chunk as $item) {
                $payload[] = $item;
            }
            if (count($chunk) < 100) {
                break;
            }
            if ($page === self::MAX_RELEASE_PAGES) {
                throw new RuntimeException('GitHub release pagination exceeded the safety limit.');
            }
        }
        $releases = [];
        foreach ($payload as $item) {
            if (!is_array($item) || trim((string) ($item['tag_name'] ?? '')) === '') {
                continue;
            }
            $tag = trim((string) $item['tag_name']);
            $commit = $this->getCommitSha($repository, $tag);
            $assets = is_array($item['assets'] ?? null) ? $item['assets'] : [];
            $assets = array_values(array_filter($assets, static fn (mixed $asset): bool => is_array($asset) && self::assetRank($asset) < 99));
            usort($assets, static fn (array $a, array $b): int => (self::assetRank($a) <=> self::assetRank($b))
                ?: strcasecmp((string) ($a['name'] ?? ''), (string) ($b['name'] ?? '')));
            $asset = $assets[0] ?? [];
            if ($asset === []) {
                continue;
            }
            $digest = preg_replace('/^sha256:/i', '', (string) ($asset['digest'] ?? '')) ?? '';
            $releases[] = [
                'externalId' => (string) ($item['id'] ?? 'tag:' . $tag),
                'version' => $this->normalizeVersion($tag),
                'title' => (string) ($item['name'] ?? $tag),
                'releaseUrl' => (string) ($item['html_url'] ?? ''),
                'downloadUrl' => (string) ($asset['browser_download_url'] ?? ''),
                'expectedSha256' => preg_match('/^[a-f0-9]{64}$/i', $digest) ? strtolower($digest) : '',
                'commitSha' => $commit,
                'prerelease' => (bool) ($item['prerelease'] ?? false),
                'draft' => (bool) ($item['draft'] ?? false),
                'changelog' => (string) ($item['body'] ?? ''),
                'publishedAt' => self::date((string) ($item['published_at'] ?? $item['created_at'] ?? '')),
            ];
        }
        return $releases;
    }

    public function sourceArchiveUrl(array $repository, string $commitSha): ?string
    {
        if (!empty($repository['private'])) {
            return null;
        }
        $this->validateRepository($repository);
        $this->assertCommit($commitSha);
        return 'https://codeload.github.com/' . $repository['fullName'] . '/tar.gz/' . $commitSha;
    }

    /** @return list<array<string,mixed>>|null */
    private function paged(string $endpoint): ?array
    {
        $repositories = [];
        for ($page = 1; $page <= self::MAX_REPOSITORY_PAGES; $page++) {
            $data = $this->apiJson($endpoint, ['page' => $page, 'per_page' => 50, 'type' => 'owner'], true);
            if ($data === null) {
                return null;
            }
            if (!array_is_list($data)) {
                throw new RuntimeException('GitHub repository response is invalid.');
            }
            $this->accountRepositoryPage($data);
            foreach ($data as $item) {
                $repositories[] = $item;
            }
            if (count($data) < 50) {
                return $repositories;
            }
        }
        throw new RuntimeException('GitHub repository pagination exceeded the 10,000 repository safety limit.');
    }

    private static function assetRank(array $asset): int
    {
        $name = strtolower((string) ($asset['name'] ?? ''));
        if (!str_ends_with($name, '.whl')) {
            return 99;
        }
        return str_ends_with($name, 'py3-none-any.whl') ? 0 : 1;
    }

    private static function date(string $value): ?string
    {
        try {
            return $value === '' ? null : (new \DateTimeImmutable($value))->format(DATE_ATOM);
        } catch (\Throwable) {
            return null;
        }
    }
}