<?php

namespace App\Services\Imports;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use RuntimeException;
use App\Services\Imports\Concerns\ParsesSqlDump;
use App\Services\Imports\Concerns\ImportsAdminZoneCustomers;
use App\Services\Imports\Concerns\ImportsAdminZoneDns;

class AdminZoneDnsSqlImporter
{
    use ParsesSqlDump;
    use ImportsAdminZoneCustomers;
    use ImportsAdminZoneDns;

    private ?int $canonicalServerId = null;

    public function import(
        string $path,
        bool $preview = false,
        bool $importCustomers = true,
        bool $importDns = true,
    ): array {
        if (! is_file($path)) {
            throw new RuntimeException("SQL file not found: {$path}");
        }

        $this->assertRequiredSchema();

        $tables = $this->parseSqlDump($path, [
            'users',
            'dns_manager_domain',
            'dns_domain_user',
            'dns_manager_ns',
        ]);

        $summary = [
            'source' => [
                'users' => count($tables['users']),
                'dns_manager_domain' => count($tables['dns_manager_domain']),
                'dns_domain_user' => count($tables['dns_domain_user']),
                'dns_manager_ns' => count($tables['dns_manager_ns']),
            ],
            'customers' => [
                'created' => 0,
                'updated' => 0,
                'restored' => 0,
                'skipped' => 0,
            ],
            'dns_domains' => [
                'created' => 0,
                'updated' => 0,
                'skipped' => 0,
            ],
            'dns_records' => [
                'created' => 0,
                'updated' => 0,
                'skipped' => 0,
            ],
            'dns_links' => [
                'created' => 0,
                'updated' => 0,
                'skipped' => 0,
            ],
        ];

        if (! $importCustomers && ! $importDns) {
            return $summary;
        }

        $callback = function () use ($tables, &$summary, $preview, $importCustomers, $importDns) {
            $customerIdMap = [];
            $domainIdMap = [];

            if ($importCustomers) {
                $customerIdMap = $this->importCustomers($tables['users'], $summary, $preview);
            }

            if ($importDns) {
                $domainIdMap = $this->importDnsDomains($tables['dns_manager_domain'], $summary, $preview);
                $this->importDnsRecords($tables['dns_manager_ns'], $domainIdMap, $summary, $preview);
                $this->importDnsCustomerLinks($tables['dns_domain_user'], $customerIdMap, $domainIdMap, $summary, $preview);
            }
        };

        if ($preview) {
            $callback();
            return $summary;
        }

        DB::transaction($callback);

        return $summary;
    }

    private function assertRequiredSchema(): void
    {
        foreach (['username', 'email_verified_at', 'type'] as $column) {
            if (! Schema::hasColumn('customers', $column)) {
                throw new RuntimeException(
                    "Missing customers.{$column}. Run migrations before importing admin_zonedns data."
                );
            }
        }
    }

    private function normalizeDateTime(mixed $value): ?string
    {
        $value = $this->nullableString($value);
        if (! $value || $value === '0000-00-00 00:00:00') {
            return null;
        }

        return $value;
    }

    private function nullableString(mixed $value, ?string $default = null): ?string
    {
        if ($value === null) {
            return $default;
        }

        $value = trim((string) $value);

        if ($value === '') {
            return $default;
        }

        return $value;
    }

    private function nullableInt(mixed $value): ?int
    {
        if ($value === null || $value === '') {
            return null;
        }

        return (int) $value;
    }
}