<?php
namespace ApplicationInsights\WordPress;

/**
 *  Does server-side instrumentation using the PHP SDK for Application Insights
 */
class Server_Instrumentation
{
    private $_telemetryClient;

    public function __construct()
    {
         /* Necessary check for multi-site installation */
        if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
            require_once( ABSPATH . '/wp-admin/includes/plugin.php' );
        }   
        if ( is_multisite() && is_plugin_active_for_network("application-insights/ApplicationInsightsPlugin.php") ) 
        {
            $application_insights_options = get_site_option("applicationinsights_options");
        } else {
            $application_insights_options = get_option("applicationinsights_options");
        } 
        $this->_telemetryClient = new \ApplicationInsights\Telemetry_Client();
        $this->_telemetryClient->getContext()->setInstrumentationKey($application_insights_options["instrumentation_key"]);
        $sdkVer = $this->_telemetryClient->getContext()->getInternalContext()->getSdkVersion();
        $this->_telemetryClient->getContext()->getInternalContext()->setSdkVersion('wp_' . $sdkVer);

        set_exception_handler(array($this, 'exceptionHandler'));
    }

    function endRequest()
    {
        if (is_page() || is_single() || is_category() || is_home() || is_archive() || is_404())
        {
            $url = $_SERVER["HTTP_HOST"].$_SERVER["REQUEST_URI"];
            $requestName = Common::getPageTitle();
            $startTime = $_SERVER["REQUEST_TIME"];
            $duration = floatval(timer_stop(0, 3)) * 1000;
            $this->_telemetryClient->trackRequest($requestName, $url, $startTime, $duration, http_response_code(), !is_404());

            // Flush all telemetry items
            $this->_telemetryClient->flush();
        }
    }


    function exceptionHandler(\Exception $exception)
    {
        if ($exception != NULL)
        {
            $this->_telemetryClient->trackException($exception);
            $this->_telemetryClient->flush();
        }
    }
}