<?php

namespace App\Services\Intune;

use App\Models\Policy;
use App\Models\PolicyVersion;
use App\Models\Tenant;
use Carbon\CarbonImmutable;

class VersionService
{
    public function __construct(
        private readonly AuditLogger $auditLogger,
        private readonly PolicySnapshotService $snapshotService,
    ) {}

    public function captureVersion(
        Policy $policy,
        array $payload,
        ?string $createdBy = null,
        array $metadata = [],
    ): PolicyVersion {
        $versionNumber = $this->nextVersionNumber($policy);

        $version = PolicyVersion::create([
            'tenant_id' => $policy->tenant_id,
            'policy_id' => $policy->id,
            'version_number' => $versionNumber,
            'policy_type' => $policy->policy_type,
            'platform' => $policy->platform,
            'created_by' => $createdBy,
            'captured_at' => CarbonImmutable::now(),
            'snapshot' => $payload,
            'metadata' => $metadata,
        ]);

        $this->auditLogger->log(
            tenant: $policy->tenant,
            action: 'policy.versioned',
            context: [
                'metadata' => [
                    'policy_id' => $policy->id,
                    'version_number' => $versionNumber,
                ],
            ],
            actorEmail: $createdBy,
            resourceType: 'policy',
            resourceId: (string) $policy->id
        );

        return $version;
    }

    public function captureFromGraph(
        Tenant $tenant,
        Policy $policy,
        ?string $createdBy = null,
        array $metadata = [],
    ): PolicyVersion {
        $snapshot = $this->snapshotService->fetch($tenant, $policy, $createdBy);

        if (isset($snapshot['failure'])) {
            $reason = $snapshot['failure']['reason'] ?? 'Unable to fetch policy snapshot';

            throw new \RuntimeException($reason);
        }

        $metadata = array_merge(['source' => 'version_capture'], $metadata);

        return $this->captureVersion(
            policy: $policy,
            payload: $snapshot['payload'],
            createdBy: $createdBy,
            metadata: $metadata,
        );
    }

    private function nextVersionNumber(Policy $policy): int
    {
        $current = PolicyVersion::query()
            ->where('policy_id', $policy->id)
            ->max('version_number');

        return (int) ($current ?? 0) + 1;
    }
}