<?php
// SPDX-License-Identifier: GPL-3.0-or-later
declare(strict_types=1);

namespace Aiwend\Chat;

/** Validated, non-executable floating placement settings. No migration required. */
final class DisplayRules
{
    public const DEFAULTS = [
        'side' => 'right', 'launcher_label' => 'Chat with us',
        'desktop_offset' => 24, 'mobile_offset' => 16,
        'include_pages' => '', 'exclude_pages' => '', 'devices' => 'all',
    ];

    public static function normalize(array $input): array
    {
        $out = array_intersect_key($input, self::DEFAULTS) + self::DEFAULTS;
        if (!in_array($out['side'], ['left', 'right'], true) || !in_array($out['devices'], ['all', 'desktop', 'mobile'], true)) {
            throw new \InvalidArgumentException('Invalid display rules.');
        }
        $label = trim((string) $out['launcher_label']);
        if ($label === '' || !mb_check_encoding($label, 'UTF-8') || mb_strlen($label) > 60 || preg_match('/[<>\x00-\x1f]/', $label)) {
            throw new \InvalidArgumentException('Launcher label must be plain text, 1–60 characters.');
        }
        $out['launcher_label'] = $label;
        foreach (['desktop_offset', 'mobile_offset'] as $key) {
            $value = filter_var($out[$key], FILTER_VALIDATE_INT);
            if ($value === false || $value < 8 || $value > 160) {
                throw new \InvalidArgumentException('Offsets must be 8–160 pixels.');
            }
            $out[$key] = $value;
        }
        foreach (['include_pages', 'exclude_pages'] as $key) {
            $value = trim((string) $out[$key]);
            if (strlen($value) > 1000 || ($value !== '' && !preg_match('/^[1-9][0-9]*(\s*,\s*[1-9][0-9]*)*$/D', $value))) {
                throw new \InvalidArgumentException('Use comma-separated positive page IDs.');
            }
            $out[$key] = $value === '' ? '' : implode(',', array_unique(array_map('intval', preg_split('/\s*,\s*/', $value))));
        }
        return $out;
    }

    public static function eligible(array $bot, int $pageId): bool
    {
        if ($bot['status'] !== 'active' || !$bot['is_public']) {
            return false;
        }
        $look = BotRepository::appearance($bot);
        if ($look['placement'] !== 'floating') {
            return false;
        }
        $includes = $look['include_pages'] === '' ? [] : explode(',', $look['include_pages']);
        $excludes = $look['exclude_pages'] === '' ? [] : explode(',', $look['exclude_pages']);
        return !in_array((string) $pageId, $excludes, true)
            && ($includes === [] || in_array((string) $pageId, $includes, true));
    }
}