<?php
declare(strict_types=1);
namespace KTXM\ServiceWopi\Host;

use KTXC\Db\DataStore;

class SessionStore
{
    public function __construct(private readonly DataStore $db) {}

    public function fileId(string $tenant, string $user, string $resource): string
    {
        // Personal storage identity includes the owner. Shared aliases are not yet supported.
        $key = 'file:' . hash('sha256', json_encode([$tenant, $user, $resource], JSON_THROW_ON_ERROR));
        $files = $this->db->selectCollection('service_wopi_files');
        $files->updateOne(['_id' => $key], ['$setOnInsert' => [
            'tenant' => $tenant, 'user' => $user, 'resource' => $resource, 'file' => bin2hex(random_bytes(16)),
        ]], ['upsert' => true]);
        return $files->findOne(['_id' => $key])['file'];
    }

    public function save(string $token, array $session): void
    {
        $this->db->selectCollection('service_wopi_sessions')->insertOne([
            '_id' => 'token:' . hash('sha256', $token), ...$session,
        ]);
    }

    public function find(string $tenant, string $file, string $token, int $now): ?array
    {
        return $this->db->selectCollection('service_wopi_sessions')->findOne([
            '_id' => 'token:' . hash('sha256', $token), 'tenant' => $tenant,
            'file' => $file, 'expires' => ['$gt' => $now], 'mode' => 'view',
        ]);
    }

    public function cached(string $tenant, string $server, int $now): ?string
    {
        $entry = $this->db->selectCollection('service_wopi_discovery')->findOne([
            '_id' => $this->cacheKey($tenant, $server), 'expires' => ['$gt' => $now],
        ]);
        return $entry['xml'] ?? null;
    }

    public function cache(string $tenant, string $server, string $xml, int $expires): void
    {
        $this->db->selectCollection('service_wopi_discovery')->updateOne(
            ['_id' => $this->cacheKey($tenant, $server)],
            ['$set' => ['tenant' => $tenant, 'xml' => $xml, 'expires' => $expires]], ['upsert' => true],
        );
    }

    public function cleanup(int $now): void
    {
        foreach (['service_wopi_sessions', 'service_wopi_discovery'] as $collection) {
            $this->db->selectCollection($collection)->deleteMany(['expires' => ['$lte' => $now]]);
        }
    }

    private function cacheKey(string $tenant, string $server): string
    {
        return 'discovery:' . hash('sha256', json_encode([$tenant, $server], JSON_THROW_ON_ERROR));
    }
}