<?php

namespace Modules\Core\Shipping\Carriers\Acs;

use Illuminate\Support\Facades\Cache;
use Modules\Core\Shipping\Carriers\Acs\Exceptions\AcsApiException;

class AreaResolver
{
    public const CACHE_KEY = 'acs.areas';

    public function __construct(private readonly AcsClient $client) {}

    /**
     * Resolve a Greek postcode to its ACS station/branch codes.
     *
     * Reads from the table warmed daily by WarmAcsAreaCacheJob. Falls
     * back to a live lookup for that single postcode if the warmed cache is
     * missing (e.g. the daily job never ran or failed) or doesn't contain it.
     */
    public function resolve(string $postcode): AcsArea
    {
        $areas = Cache::get(self::CACHE_KEY);

        if ($areas !== null && isset($areas[$postcode])) {
            return $this->toArea($areas[$postcode]);
        }

        return $this->toArea($this->fetch($postcode));
    }

    /**
     * Fetch and cache the full country's postcode-to-station map in one call.
     */
    public function warmAll(): void
    {
        $areas = [];

        foreach ($this->fetchAll() as $row) {
            $areas[$row['Zip_Code']] = $row;
        }

        Cache::forever(self::CACHE_KEY, $areas);
    }

    private function fetch(string $postcode): array
    {
        $response = $this->client->call('ACS_Area_Find_By_Zip_Code', [
            'Zip_Code' => $postcode,
            'Show_Only_Inaccessible_Areas' => 0,
            'Country' => 'GR',
        ])->throwIfError();

        $area = $response->tableOutput['Table_Data'][0] ?? null;

        if (! $area) {
            throw new AcsApiException("No ACS area found for postcode {$postcode}");
        }

        return $area;
    }

    private function fetchAll(): array
    {
        $response = $this->client->call('ACS_Area_Find_By_Zip_Code', [
            'Zip_Code' => null,
            'Show_Only_Inaccessible_Areas' => 0,
            'Country' => 'GR',
        ])->throwIfError();

        return $response->tableOutput['Table_Data'] ?? [];
    }

    private function toArea(array $row): AcsArea
    {
        return new AcsArea(
            stationId: $row['Station_ID'],
            branchId: (int) $row['Branch_ID'],
        );
    }
}