<?php
require_once __DIR__ . '/../classes/CompanySettingManager.php';

class PostingWindowGuard
{
    private CompanySettingManager $settings;
    private ?array $window = null;

    public function __construct(PDO $settingsPdo, int $company_id)
    {
        $this->settings = new CompanySettingManager($settingsPdo, $company_id);
    }

    public function assertOpenDate(?string $posting_date, string $context = 'GL posting'): void
    {
        $date = $this->normalizeDate($posting_date);
        if ($date === '') {
            throw new Exception("{$context} date is required for posting-window validation.");
        }

        $window = $this->getWindow();
        $from = $window['open_from'];
        $to = $window['open_to'];

        if ($from !== '' && $date < $from) {
            throw new Exception("{$context} date {$date} is before the open posting window ({$from} to " . ($to ?: 'no upper limit') . ").");
        }

        if ($to !== '' && $date > $to) {
            throw new Exception("{$context} date {$date} is after the open posting window (" . ($from ?: 'no lower limit') . " to {$to}).");
        }
    }

    private function getWindow(): array
    {
        if ($this->window === null) {
            $open_from = $this->settings->get('posting_open_from');
            if ($open_from === null || $open_from === '') {
                $open_from = $this->settings->get('gl_open_from') ?: '';
            }

            $open_to = $this->settings->get('posting_open_to');
            if ($open_to === null || $open_to === '') {
                $open_to = $this->settings->get('gl_open_to') ?: '';
            }

            $this->window = [
                'open_from' => $this->normalizeDate($open_from ?: ''),
                'open_to'   => $this->normalizeDate($open_to ?: ''),
            ];
        }

        return $this->window;
    }

    private function normalizeDate(?string $date): string
    {
        $date = trim((string)$date);
        if ($date === '') {
            return '';
        }

        if (preg_match('#^(\d{2})/(\d{2})/(\d{4})$#', $date, $m)) {
            $date = "{$m[3]}-{$m[2]}-{$m[1]}";
        }

        if (preg_match("#^([0-9]{4}-[0-9]{2}-[0-9]{2})[ T]#", $date, $m)) {
            $date = $m[1];
        }

        if (!preg_match("#^[0-9]{4}-[0-9]{2}-[0-9]{2}$#", $date)) {
            throw new Exception("Invalid posting date {$date}. Use YYYY-MM-DD.");
        }

        return $date;
    }
}