<?php
/**
 * PXSYNC_UTM_Capture — Standalone UTM Parameter Capture
 *
 * Completely independent from the TikTok pixel/CAPI logic.
 * Captures UTM parameters from the browser URL on landing,
 * stores them in the WooCommerce session, then saves them
 * as order meta when the order is created.
 *
 * Meta keys match exactly what your Google Sheet script expects:
 * _pys_utm_source, _pys_utm_medium, _pys_utm_campaign,
 * _pys_utm_content, _pys_utm_term
 *
 * No modifications to any other plugin file needed except
 * the one loader line added to tiktok-bridge.php.
 */

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

class PXSYNC_UTM_Capture {

    /**
     * WooCommerce session key where UTM data is stored
     */
    const SESSION_KEY = 'pxsync_utm_params';

    /**
     * Order meta keys — match your Google Sheet script exactly
     */
    const META_KEYS = [
        'utm_source'   => '_pys_utm_source',
        'utm_medium'   => '_pys_utm_medium',
        'utm_campaign' => '_pys_utm_campaign',
        'utm_content'  => '_pys_utm_content',
        'utm_term'     => '_pys_utm_term',
    ];

    public function __construct() {
        // 1. Inject tiny inline capture script on every front-end page
        add_action( 'wp_footer', [ $this, 'enqueue_capture_script' ] );

        // 2. AJAX endpoint to receive UTMs from the browser
        add_action( 'wp_ajax_pxsync_save_utm',        [ $this, 'ajax_save_utm' ] );
        add_action( 'wp_ajax_nopriv_pxsync_save_utm', [ $this, 'ajax_save_utm' ] );

        // 3. Save UTMs to order meta the moment the order is created
        add_action( 'woocommerce_checkout_order_processed', [ $this, 'save_utm_to_order' ], 5, 1 );

        // 4. Safety net — also runs on payment complete in case hook 3 missed it
        add_action( 'woocommerce_payment_complete', [ $this, 'save_utm_to_order' ], 5, 1 );

        // Ensure UTM meta is included in WooCommerce webhook payload
        add_filter( 'woocommerce_webhook_payload', [ $this, 'inject_utm_into_webhook' ], 10, 4 );
    }

    /**
     * Enqueues a tiny inline script that captures UTM params from the URL
     * and sends them to WordPress via AJAX on the landing page.
     * Uses sessionStorage so it only captures once per browser session
     * preserving first-touch attribution.
     */
    public function enqueue_capture_script() {
        if ( is_admin() ) return;

        $ajax_url = admin_url( 'admin-ajax.php' );
        $nonce    = wp_create_nonce( 'pxsync_utm_nonce' );

        $script = "
        (function() {
            // Only capture once per browser session (first-touch attribution)
            if (sessionStorage.getItem('pxsync_utm_captured')) return;

            var params       = new URLSearchParams(window.location.search);
            var utm_source   = params.get('utm_source')   || '';
            var utm_medium   = params.get('utm_medium')   || '';
            var utm_campaign = params.get('utm_campaign') || '';
            var utm_content  = params.get('utm_content')  || '';
            var utm_term     = params.get('utm_term')     || '';
            var ttclid       = params.get('ttclid')       || '';
            var fbclid       = params.get('fbclid')       || '';

            // Fallback: infer source from referrer if no UTM params in URL
            if (!utm_source && document.referrer) {
                try {
                    var ref = new URL(document.referrer).hostname;
                    if      (ref.indexOf('tiktok')    > -1) { utm_source = 'tiktok';    utm_medium = utm_medium || 'social'; }
                    else if (ref.indexOf('facebook')  > -1) { utm_source = 'facebook';  utm_medium = utm_medium || 'social'; }
                    else if (ref.indexOf('instagram') > -1) { utm_source = 'instagram'; utm_medium = utm_medium || 'social'; }
                    else if (ref.indexOf('google')    > -1) { utm_source = 'google';    utm_medium = utm_medium || 'organic'; }
                    else if (ref.indexOf('bing')      > -1) { utm_source = 'bing';      utm_medium = utm_medium || 'organic'; }
                    else                                     { utm_source = ref; }
                } catch(e) {}
            }

            // Click ID overrides — more reliable than UTM for paid ads
            if (ttclid && !utm_source) { utm_source = 'tiktok';   utm_medium = utm_medium || 'paid'; }
            if (fbclid && !utm_source) { utm_source = 'facebook'; utm_medium = utm_medium || 'paid'; }

            // Nothing to capture — stop here
            if (!utm_source && !utm_medium && !utm_campaign) return;

            // Send to server via AJAX to store in WooCommerce session
            var xhr = new XMLHttpRequest();
            xhr.open('POST', '" . esc_js( $ajax_url ) . "', true);
            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
            xhr.send(
                'action=pxsync_save_utm' +
                '&nonce=" . esc_js( $nonce ) . "' +
                '&utm_source='   + encodeURIComponent(utm_source)   +
                '&utm_medium='   + encodeURIComponent(utm_medium)   +
                '&utm_campaign=' + encodeURIComponent(utm_campaign) +
                '&utm_content='  + encodeURIComponent(utm_content)  +
                '&utm_term='     + encodeURIComponent(utm_term)
            );

            // Mark as captured so this doesn't run again this session
            sessionStorage.setItem('pxsync_utm_captured', '1');
        })();
        ";

        // Inline script — no separate HTTP request for a JS file
        wp_register_script( 'pxsync-utm-capture', false, [], PXSYNC_VERSION, false );
        wp_enqueue_script( 'pxsync-utm-capture' );
        wp_add_inline_script( 'pxsync-utm-capture', $script );
    }

    /**
     * AJAX handler — receives UTM data from the browser
     * and stores it in the WooCommerce session.
     */
    public function ajax_save_utm() {
        $nonce = isset($_POST['nonce']) ? sanitize_text_field( wp_unslash( $_POST['nonce'] ) ) : '';
        if ( ! wp_verify_nonce( $nonce, 'pxsync_utm_nonce' ) ) {
            wp_send_json_error('Invalid nonce');
            return;
        }

        if ( ! WC()->session ) {
            wp_send_json_error('No WC session');
            return;
        }

        // Preserve first-touch: don't overwrite if already captured this session
        $existing = WC()->session->get( self::SESSION_KEY );
        if ( ! empty($existing) ) {
            wp_send_json_success('Already captured');
            return;
        }

        $utm = [
            'utm_source'   => sanitize_text_field( wp_unslash($_POST['utm_source']   ?? '' )),
            'utm_medium'   => sanitize_text_field( wp_unslash($_POST['utm_medium']   ?? '' )),
            'utm_campaign' => sanitize_text_field( wp_unslash($_POST['utm_campaign'] ?? '' )),
            'utm_content'  => sanitize_text_field( wp_unslash($_POST['utm_content']  ?? '' )),
            'utm_term'     => sanitize_text_field( wp_unslash($_POST['utm_term']     ?? '' )),
        ];

        WC()->session->set( self::SESSION_KEY, $utm );
        wp_send_json_success('UTM saved');
    }

    /**
     * Saves UTM data from WooCommerce session to order meta.
     * Runs when the order is created, before the webhook fires.
     * Meta keys match exactly what the Google Sheet script reads.
     */
    public function save_utm_to_order( $order_id ) {
        if ( ! $order_id ) return;

        // Don't overwrite — prevents payment_complete from running twice
        if ( get_post_meta( $order_id, '_pys_utm_source', true ) ) return;

        $utm = [];

        // Primary: WooCommerce session
        if ( WC()->session ) {
            $utm = WC()->session->get( self::SESSION_KEY, [] );
        }

        if ( empty($utm) ) return;

        // Save each UTM field using the meta keys your Google Sheet expects
        foreach ( self::META_KEYS as $utm_key => $meta_key ) {
            if ( ! empty($utm[$utm_key]) ) {
                update_post_meta( $order_id, $meta_key, sanitize_text_field($utm[$utm_key]) );
            }
        }

        // Save combined copy for easy debugging in WP admin
        update_post_meta( $order_id, '_pxsync_utm_data', wp_json_encode($utm) );
    }


    /**
     * Injects UTM meta into the WooCommerce webhook payload.
     * Never forget comments: WooCommerce excludes private meta (prefixed with _)
     * from webhook payloads by default. This forces them in so the Google Sheet
     * App Script can read them.
     */
    public function inject_utm_into_webhook( $payload, $resource, $resource_id, $webhook_id ) {
        if ( $resource !== 'order' || empty($resource_id) ) return $payload;

        $utm_keys = array_values( self::META_KEYS );

        foreach ( $utm_keys as $key ) {
            $value = get_post_meta( $resource_id, $key, true );
            if ( ! $value ) continue;

            // Check if already present to avoid duplicates
            $already_present = false;
            if ( isset($payload['meta_data']) ) {
                foreach ( $payload['meta_data'] as $meta ) {
                    if ( $meta['key'] === $key ) {
                        $already_present = true;
                        break;
                    }
                }
            }

            if ( ! $already_present ) {
                $payload['meta_data'][] = [
                    'id'    => 0,
                    'key'   => $key,
                    'value' => $value,
                ];
            }
        }

        return $payload;
    }

}