<?php
/**
 * Plugin Name:       AskAnyDocs Chatbot
 * Description:       Adds an AskAnyDocs AI chatbot widget to your WordPress website.
 * Version:           1.0.1
 * Requires at least: 5.8
 * Requires PHP:      7.4
 * Author:            AskAnyDocs
 * Author URI:        https://askanydocs.com/
 * License:           GPL-2.0-or-later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain:       askanydocs-chatbot
 */

declare(strict_types=1);

if (!defined('ABSPATH')) {
    exit;
}

final class AskAnyDocs_Chatbot
{
    private const OPTION_NAME = 'askanydocs_chatbot_settings';
    private const OPTION_GROUP = 'askanydocs_chatbot';
    private const SETTINGS_PAGE = 'askanydocs-chatbot';
    private const SCRIPT_HANDLE = 'askanydocs-chatbot-widget';
    private const VERSION = '1.0.1';
    private const SERVICE_URL = 'https://app.askanydocs.com';
    private const PRIVACY_URL = 'https://askanydocs.com/privacy';
    private const TERMS_URL = 'https://askanydocs.com/terms';

    public static function boot(): void
    {
        add_action('admin_init', [self::class, 'registerSettings']);
        add_action('admin_init', [self::class, 'registerPrivacyPolicyContent']);
        add_action('admin_menu', [self::class, 'addSettingsPage']);
        add_action('wp_enqueue_scripts', [self::class, 'enqueueWidget']);
        add_filter('script_loader_tag', [self::class, 'addWidgetScriptAttributes'], 10, 3);
        add_filter('plugin_action_links_' . plugin_basename(__FILE__), [self::class, 'addSettingsLink']);
    }

    public static function registerSettings(): void
    {
        register_setting(
            self::OPTION_GROUP,
            self::OPTION_NAME,
            [
                'type' => 'array',
                'sanitize_callback' => [self::class, 'sanitizeSettings'],
                'default' => self::defaults(),
            ]
        );

        add_settings_section(
            'askanydocs_chatbot_connection',
            __('Widget connection', 'askanydocs-chatbot'),
            [self::class, 'renderConnectionSection'],
            self::SETTINGS_PAGE
        );

        add_settings_field('askanydocs_chatbot_enabled', __('Enable widget', 'askanydocs-chatbot'), [self::class, 'renderEnabledField'], self::SETTINGS_PAGE, 'askanydocs_chatbot_connection');
        add_settings_field('askanydocs_chatbot_bot_id', __('Bot ID', 'askanydocs-chatbot'), [self::class, 'renderBotIdField'], self::SETTINGS_PAGE, 'askanydocs_chatbot_connection');
        add_settings_field('askanydocs_chatbot_share_user', __('Signed-in user', 'askanydocs-chatbot'), [self::class, 'renderShareUserField'], self::SETTINGS_PAGE, 'askanydocs_chatbot_connection');
    }

    /**
     * @param mixed $input
     * @return array{enabled: bool, bot_id: string, share_user: bool}
     */
    public static function sanitizeSettings($input): array
    {
        $previous = self::settings();
        $input = is_array($input) ? $input : [];

        $botId = sanitize_text_field((string) ($input['bot_id'] ?? ''));
        if ($botId !== '' && !preg_match('/^[A-Za-z0-9._-]{1,128}$/', $botId)) {
            add_settings_error(
                self::OPTION_NAME,
                'askanydocs_invalid_bot_id',
                __('The Bot ID may contain only letters, numbers, dots, underscores, and hyphens.', 'askanydocs-chatbot')
            );
            $botId = $previous['bot_id'];
        }

        $enabled = !empty($input['enabled']);
        if ($enabled && $botId === '') {
            add_settings_error(
                self::OPTION_NAME,
                'askanydocs_missing_bot_id',
                __('Enter a Bot ID before enabling the chatbot.', 'askanydocs-chatbot')
            );
            $enabled = false;
        }

        return [
            'enabled' => $enabled,
            'bot_id' => $botId,
            'share_user' => !empty($input['share_user']),
        ];
    }

    public static function addSettingsPage(): void
    {
        add_options_page(
            __('AskAnyDocs Chatbot', 'askanydocs-chatbot'),
            __('AskAnyDocs Chatbot', 'askanydocs-chatbot'),
            'manage_options',
            self::SETTINGS_PAGE,
            [self::class, 'renderSettingsPage']
        );
    }

    public static function registerPrivacyPolicyContent(): void
    {
        if (!function_exists('wp_add_privacy_policy_content')) {
            return;
        }

        $content = '<p>' . esc_html__(
            'This site uses the AskAnyDocs chatbot, an external service provided by AskAnyDocs.',
            'askanydocs-chatbot'
        ) . '</p>';
        $content .= '<p>' . esc_html__(
            'When the chatbot is enabled, the visitor browser loads the widget from app.askanydocs.com. Chat messages and technical metadata needed to operate the widget may be sent to AskAnyDocs, including the current page URL, referrer, browser language, platform, time zone, screen size, and viewport size. The widget uses browser local storage to preserve conversation and display state.',
            'askanydocs-chatbot'
        ) . '</p>';
        $content .= '<p>' . esc_html__(
            'If the site administrator enables signed-in user sharing, the WordPress user ID, display name, and email address are also sent to AskAnyDocs.',
            'askanydocs-chatbot'
        ) . '</p>';
        $content .= '<p>' . sprintf(
            wp_kses(
                /* translators: 1: AskAnyDocs privacy policy URL, 2: AskAnyDocs terms URL. */
                __('See the AskAnyDocs <a href="%1$s">Privacy Policy</a> and <a href="%2$s">Terms of Service</a>.', 'askanydocs-chatbot'),
                ['a' => ['href' => []]]
            ),
            esc_url(self::PRIVACY_URL),
            esc_url(self::TERMS_URL)
        ) . '</p>';

        wp_add_privacy_policy_content(
            __('AskAnyDocs Chatbot', 'askanydocs-chatbot'),
            wp_kses_post(wpautop($content))
        );
    }

    public static function renderSettingsPage(): void
    {
        if (!current_user_can('manage_options')) {
            return;
        }

        $settings = self::settings();
        $siteHost = (string) wp_parse_url(home_url('/'), PHP_URL_HOST);
        $registerUrl = self::SERVICE_URL . '/register';
        $botsUrl = self::SERVICE_URL . '/app/bots';
        $logoUrl = plugin_dir_url(__FILE__) . 'assets/icon-64x64.png';
        ?>
        <div class="wrap">
            <h1 style="display: flex; align-items: center; gap: 12px;">
                <img src="<?php echo esc_url($logoUrl); ?>" width="48" height="48" alt="">
                <span><?php echo esc_html__('AskAnyDocs Chatbot', 'askanydocs-chatbot'); ?></span>
            </h1>
            <p><?php echo esc_html__('Connect an AskAnyDocs bot and display it on every public page of this website.', 'askanydocs-chatbot'); ?></p>

            <?php settings_errors(self::OPTION_NAME); ?>

            <div class="notice notice-info inline" style="padding: 16px 20px; margin: 20px 0; max-width: 820px;">
                <h2 style="margin-top: 0;"><?php echo esc_html__('Connect your chatbot in 3 steps', 'askanydocs-chatbot'); ?></h2>
                <ol style="margin-bottom: 16px;">
                    <li>
                        <strong><?php echo esc_html__('Create an AskAnyDocs account.', 'askanydocs-chatbot'); ?></strong>
                        <?php echo esc_html__('If you already have one, continue to the next step.', 'askanydocs-chatbot'); ?>
                    </li>
                    <li>
                        <strong><?php echo esc_html__('Create and configure a bot.', 'askanydocs-chatbot'); ?></strong>
                        <?php echo esc_html__('Add the website pages, documents, or other knowledge that the bot should use.', 'askanydocs-chatbot'); ?>
                    </li>
                    <li>
                        <strong><?php echo esc_html__('Copy the Bot ID.', 'askanydocs-chatbot'); ?></strong>
                        <?php echo esc_html__('In AskAnyDocs, open your bot, go to Settings, and copy the ID shown at the top of the page. Paste it below and save.', 'askanydocs-chatbot'); ?>
                    </li>
                </ol>
                <p style="margin-bottom: 0;">
                    <a class="button button-primary" href="<?php echo esc_url($registerUrl); ?>" target="_blank" rel="noopener noreferrer">
                        <?php echo esc_html__('Create free account', 'askanydocs-chatbot'); ?>
                    </a>
                    <a class="button" href="<?php echo esc_url($botsUrl); ?>" target="_blank" rel="noopener noreferrer">
                        <?php echo esc_html__('Open my bots', 'askanydocs-chatbot'); ?>
                    </a>
                </p>
            </div>

            <form action="options.php" method="post">
                <?php
                settings_fields(self::OPTION_GROUP);
                do_settings_sections(self::SETTINGS_PAGE);
                submit_button();
                ?>
            </form>

            <?php if ($settings['enabled'] && $settings['bot_id'] !== '') : ?>
                <div class="notice notice-success inline" style="max-width: 820px;">
                    <p>
                        <strong><?php echo esc_html__('Chatbot connected.', 'askanydocs-chatbot'); ?></strong>
                        <?php echo esc_html__('Open the public website in a new tab to check the widget.', 'askanydocs-chatbot'); ?>
                    </p>
                </div>
            <?php elseif ($settings['bot_id'] !== '') : ?>
                <div class="notice notice-warning inline" style="max-width: 820px;">
                    <p><?php echo esc_html__('The Bot ID is saved, but the widget is currently disabled.', 'askanydocs-chatbot'); ?></p>
                </div>
            <?php endif; ?>

            <?php if ($siteHost !== '') : ?>
                <div class="notice notice-warning inline" style="max-width: 820px;">
                    <p>
                    <?php
                    printf(
                        /* translators: %s is the WordPress site host name. */
                        wp_kses(__('If you use Allowed domains in the AskAnyDocs widget settings, add <code>%s</code> there. Otherwise the chatbot will not appear on this site.', 'askanydocs-chatbot'), ['code' => []]),
                        esc_html($siteHost)
                    );
                    ?>
                    </p>
                </div>
            <?php endif; ?>
        </div>
        <?php
    }

    public static function renderConnectionSection(): void
    {
        echo '<p>' . esc_html__('Paste the ID of the bot you want to show on this WordPress website.', 'askanydocs-chatbot') . '</p>';
    }

    public static function renderEnabledField(): void
    {
        $settings = self::settings();
        ?>
        <label>
            <input type="checkbox" name="<?php echo esc_attr(self::OPTION_NAME); ?>[enabled]" value="1" <?php checked($settings['enabled']); ?>>
            <?php echo esc_html__('Show the chatbot on public pages', 'askanydocs-chatbot'); ?>
        </label>
        <?php
    }

    public static function renderBotIdField(): void
    {
        $settings = self::settings();
        ?>
        <input class="regular-text code" id="askanydocs_chatbot_bot_id" name="<?php echo esc_attr(self::OPTION_NAME); ?>[bot_id]" type="text" value="<?php echo esc_attr($settings['bot_id']); ?>" maxlength="128" autocomplete="off">
        <p class="description">
            <?php echo esc_html__('Find it in AskAnyDocs under Bots → select your bot → Settings. Example: 0192f3b1-7f3c-7a60-8f20-123456789abc', 'askanydocs-chatbot'); ?>
        </p>
        <?php
    }

    public static function renderShareUserField(): void
    {
        $settings = self::settings();
        ?>
        <label>
            <input type="checkbox" name="<?php echo esc_attr(self::OPTION_NAME); ?>[share_user]" value="1" <?php checked($settings['share_user']); ?>>
            <?php echo esc_html__('Send the WordPress user ID, display name, and email to AskAnyDocs for signed-in visitors', 'askanydocs-chatbot'); ?>
        </label>
        <p class="description"><?php echo esc_html__('Disabled by default. Enable only when your privacy notice permits this transfer.', 'askanydocs-chatbot'); ?></p>
        <?php
    }

    public static function enqueueWidget(): void
    {
        $settings = self::settings();
        $shouldEnqueue = $settings['enabled'] && $settings['bot_id'] !== '';

        /**
         * Filters whether the AskAnyDocs widget should load on the current request.
         *
         * @param bool  $shouldEnqueue Whether the widget should load.
         * @param array $settings      Sanitized plugin settings.
         */
        $shouldEnqueue = (bool) apply_filters('askanydocs_chatbot_should_enqueue', $shouldEnqueue, $settings);

        if (!$shouldEnqueue) {
            return;
        }

        wp_enqueue_script(self::SCRIPT_HANDLE, self::widgetUrl($settings), [], self::VERSION, true);

        if ($settings['share_user'] && is_user_logged_in()) {
            $user = wp_get_current_user();
            $userData = [
                'id' => (string) $user->ID,
                'email' => (string) $user->user_email,
                'name' => (string) $user->display_name,
            ];

            wp_add_inline_script(
                self::SCRIPT_HANDLE,
                'window.AskAnyDocsUser = ' . wp_json_encode(
                    $userData,
                    JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE
                ) . ';',
                'before'
            );
        }
    }

    /**
     * @param string $tag
     * @param string $handle
     * @param string $src
     */
    public static function addWidgetScriptAttributes($tag, $handle, $src): string
    {
        if ($handle !== self::SCRIPT_HANDLE) {
            return $tag;
        }

        $settings = self::settings();

        return wp_get_script_tag([
            'src' => $src,
            'data-bot-id' => $settings['bot_id'],
            'data-api-base' => self::SERVICE_URL,
            'defer' => true,
        ]);
    }

    /**
     * @param array<int, string> $links
     * @return array<int, string>
     */
    public static function addSettingsLink(array $links): array
    {
        $url = admin_url('options-general.php?page=' . self::SETTINGS_PAGE);
        array_unshift($links, '<a href="' . esc_url($url) . '">' . esc_html__('Settings', 'askanydocs-chatbot') . '</a>');

        return $links;
    }

    /**
     * @return array{enabled: bool, bot_id: string, share_user: bool}
     */
    private static function defaults(): array
    {
        return [
            'enabled' => true,
            'bot_id' => '',
            'share_user' => false,
        ];
    }

    /**
     * @return array{enabled: bool, bot_id: string, share_user: bool}
     */
    private static function settings(): array
    {
        $stored = get_option(self::OPTION_NAME, []);
        $stored = is_array($stored) ? $stored : [];
        $settings = array_merge(self::defaults(), $stored);

        return [
            'enabled' => (bool) $settings['enabled'],
            'bot_id' => (string) $settings['bot_id'],
            'share_user' => (bool) $settings['share_user'],
        ];
    }

    /**
     * @param array{bot_id: string} $settings
     */
    private static function widgetUrl(array $settings): string
    {
        if ($settings['bot_id'] === '') {
            return '';
        }

        return self::SERVICE_URL . '/widget/' . rawurlencode($settings['bot_id']) . '.js';
    }
}

AskAnyDocs_Chatbot::boot();