<?php
namespace Relay;

use Relay\Support\RelayError;

final class Settings
{
    public const OPTION = 'relay_settings';

    public const DEFAULTS = [
        'request_size' => 1048576,
        'delay_ms' => 0,
        'history_limit' => 200,
        'restore_points_limit' => 2,
        'backups_limit' => 3,
    ];

    private const RANGES = [
        'request_size' => [524288, 26214400],
        'delay_ms' => [0, 10000],
        'history_limit' => [10, 5000],
        'restore_points_limit' => [0, 10],
        'backups_limit' => [1, 20],
    ];

    public function all(): array
    {
        $stored = get_site_option(self::OPTION, []);
        $stored = is_array($stored) ? array_intersect_key($stored, self::DEFAULTS) : [];
        return array_merge(self::DEFAULTS, array_map('intval', $stored));
    }

    /** @return int */
    public function get(string $key)
    {
        $all = $this->all();
        if (!array_key_exists($key, $all)) {
            throw new \InvalidArgumentException(esc_html("Unknown setting {$key}"));
        }
        return $all[$key];
    }

    public function update(array $changes): array
    {
        $current = $this->all();
        foreach ($changes as $key => $value) {
            if (!array_key_exists($key, self::DEFAULTS)) {
                /* translators: %s: setting name */
                throw new RelayError('settings.unknown_key', esc_html(sprintf(__('Unknown setting: %s', 'siterelay'), $key)));
            }
            if (!is_numeric($value) || (float) $value !== (float) (int) $value) {
                /* translators: %s: setting name */
                throw new RelayError('settings.invalid', esc_html(sprintf(__('%s must be a whole number.', 'siterelay'), $key)));
            }
            [$min, $max] = self::RANGES[$key];
            $current[$key] = max($min, min($max, (int) $value));
        }
        update_site_option(self::OPTION, $current);
        return $current;
    }
}