<?php

namespace Modules\Countries\Support;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Modules\Countries\Models\Country;

class CountryUsageReport
{
    /**
     * Tables commonly using country_id in WMS and SaaS workflows.
     *
     * @var array<string, string>
     */
    private array $countryIdTables = [
        'companies' => 'Companies',
        'warehouses' => 'Warehouses',
        'users' => 'Users',
        'suppliers' => 'Suppliers',
        'customers' => 'Customers',
        'carriers' => 'Carriers',
        'addresses' => 'Addresses',
        'billing_addresses' => 'Billing addresses',
        'shipping_addresses' => 'Shipping addresses',
    ];

    /**
     * Tables commonly storing ISO alpha-2 country codes.
     *
     * @var array<string, string>
     */
    private array $alpha2Tables = [
        'companies' => 'Companies by ISO code',
        'warehouses' => 'Warehouses by ISO code',
        'addresses' => 'Addresses by ISO code',
        'billing_addresses' => 'Billing addresses by ISO code',
        'shipping_addresses' => 'Shipping addresses by ISO code',
    ];

    /**
     * Return usage counts without failing when optional business tables do not exist.
     *
     * @return array<int, array{label: string, table: string, column: string, count: int}>
     */
    public function forCountry(Country $country): array
    {
        $rows = [];

        foreach ($this->countryIdTables as $table => $label) {
            if (! Schema::hasTable($table) || ! Schema::hasColumn($table, 'country_id')) {
                continue;
            }

            $rows[] = [
                'label' => $label,
                'table' => $table,
                'column' => 'country_id',
                'count' => (int) DB::table($table)->where('country_id', $country->id)->count(),
            ];
        }

        foreach ($this->alpha2Tables as $table => $label) {
            foreach (['country_code', 'country_alpha2', 'iso_country_code'] as $column) {
                if (! Schema::hasTable($table) || ! Schema::hasColumn($table, $column)) {
                    continue;
                }

                $rows[] = [
                    'label' => $label,
                    'table' => $table,
                    'column' => $column,
                    'count' => (int) DB::table($table)->where($column, $country->alpha2)->count(),
                ];
            }
        }

        return $rows;
    }
}