<?php

//
// Configurations & Constants
//

const CLARITY_COLLECT_ENDPOINT = 'https://ai.clarity.ms/collect';

require_once plugin_dir_path(__FILE__) . '/clarity-collect-storage.php';
require_once plugin_dir_path(__FILE__) . '/clarity-collect-batch.php';

/**
 * Collects and sends Clarity events in batches.
 */
function clarity_collect_event()
{
    try {
        if (is_admin()) {
            return;
        }

        if (!isset($_SERVER['REQUEST_METHOD']) || $_SERVER['REQUEST_METHOD'] !== 'GET') {
            return;
        }

        $clarity_project_id = get_option('clarity_project_id');
        $clarity_wp_site = get_option('clarity_wordpress_site_id');

        // Ensure required identifiers are present
        if (empty($clarity_project_id) || empty($clarity_wp_site)) {
            return;
        }

        // Construct and buffer the collect event payload for batch sending
        $event = clarity_construct_collect_event($clarity_project_id);
        clarity_insert_collect_event($event);
    } catch (\Throwable $e) {
        // Silently fail on any error (incl. fatals)
    }
}

add_action('shutdown', 'clarity_collect_event');

//
// Helper Functions
//

/**
 * Constructs the event payload for the collect endpoint.
 *
 * @param string $clarity_project_id The Clarity project ID.
 * @return array The constructed event payload.
 */
function clarity_construct_collect_event($clarity_project_id)
{
    $envelope = array(
        'projectId' => $clarity_project_id,
        'sessionId' => clarity_safe_get_session_token(),
        'version'   => get_installed_plugin_version(),
    );

    $analytics = array(
        'time'   => time(),
        'ip'     => clarity_get_ip_address(),
        'ua'     => isset($_SERVER['HTTP_USER_AGENT']) ? sanitize_text_field($_SERVER['HTTP_USER_AGENT']) : 'Unknown',
        'url'    => home_url($_SERVER['REQUEST_URI']),
        'method' => isset($_SERVER['REQUEST_METHOD']) ? $_SERVER['REQUEST_METHOD'] : 'Unknown',
        'response_content_type' => clarity_get_response_content_type(),
    );

    $payload = array(
        'envelope'  => $envelope,
        'analytics' => $analytics,
    );

    return $payload;
}

/**
 * Safely retrieves the WordPress session token without triggering a fatal
 * error when pluggable functions (like wp_parse_auth_cookies) are not yet loaded.
 *
 * @return string The session token, or an empty string when unavailable.
 */
function clarity_safe_get_session_token()
{
    try {
        return (string) wp_get_session_token();
    } catch (\Throwable $e) {
        return '';
    }
}

/**
 * Sends a batch of events to the Clarity collect endpoint.
 *
 * @param array $events The batch of events to send.
 */
function clarity_send_collect_event_batch($events)
{
    $request = array(
        'body'     => json_encode($events),
        'headers'  => array('Content-Type' => 'application/json'),
        'blocking' => false,
        'timeout'     => '1',
        'redirection' => '5',
        'httpversion' => '1.0'
    );

    wp_remote_post(CLARITY_COLLECT_ENDPOINT, $request);
}

/**
 * Retrieves the response content type from headers.
 *
 * @return string The sanitized content type, or empty string if not found.
 */
function clarity_get_response_content_type()
{
    $headers = headers_list();
    $contentType = '';
    
    foreach ($headers as $header) {
        if (strncasecmp($header, 'Content-Type:', 13) === 0) {
            $contentType = trim(substr($header, 13));
            break;
        }
    }
    
    return $contentType;
}

/**
 * Retrieves the client's IP address, excluding private and reserved ranges.
 */
function clarity_get_ip_address()
{
    foreach (array('HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'REMOTE_ADDR') as $key) {
        if (empty($_SERVER[$key])) {
            continue;
        }

        foreach (explode(',', $_SERVER[$key]) as $ip) {
            $ip = trim($ip);

            if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
                return $ip;
            }
        }
    }

    return 'Unknown';
}