<?php
/**
 * 文章浏览量统计（含防机器人与去重 cookie）。
 * 抽离自主题 functions.php。
 */

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

function itstudio_get_post_views($post_id) {
    $post_id = (int) $post_id;
    if ($post_id <= 0) {
        return 0;
    }

    $meta_keys = array(
        'post_views_count',
        'itstudio_views',
        'views',
        'post_views',
        'view_count',
        'views_count',
    );

    $max_views = 0;
    foreach ($meta_keys as $meta_key) {
        $raw = get_post_meta($post_id, $meta_key, true);
        if ($raw !== '' && is_numeric($raw)) {
            $max_views = max($max_views, (int) $raw);
        }
    }

    return max(0, $max_views);
}

function itstudio_is_probably_bot_request() {
    $user_agent = strtolower(trim((string) ($_SERVER['HTTP_USER_AGENT'] ?? '')));
    if ($user_agent === '') {
        return true;
    }

    $bot_signatures = array(
        'bot',
        'spider',
        'crawl',
        'slurp',
        'headless',
        'preview',
        'facebookexternalhit',
        'discordbot',
        'telegrambot',
        'linkedinbot',
        'applebot',
        'googlebot',
        'bingbot',
        'wget',
        'curl',
        'python-requests',
        'postmanruntime',
    );

    foreach ($bot_signatures as $signature) {
        if (strpos($user_agent, $signature) !== false) {
            return true;
        }
    }

    $purpose = strtolower((string) ($_SERVER['HTTP_PURPOSE'] ?? ''));
    $sec_purpose = strtolower((string) ($_SERVER['HTTP_SEC_PURPOSE'] ?? ''));
    $x_moz = strtolower((string) ($_SERVER['HTTP_X_MOZ'] ?? ''));
    if (strpos($purpose, 'prefetch') !== false || strpos($sec_purpose, 'prefetch') !== false || $x_moz === 'prefetch') {
        return true;
    }

    return false;
}

function itstudio_get_view_cookie_name() {
    return 'itstudio_viewed_posts';
}

function itstudio_read_view_cookie_map() {
    $cookie_name = itstudio_get_view_cookie_name();
    $raw_cookie = isset($_COOKIE[$cookie_name]) ? wp_unslash((string) $_COOKIE[$cookie_name]) : '';
    if ($raw_cookie === '') {
        return array();
    }

    $decoded = json_decode($raw_cookie, true);
    if (!is_array($decoded)) {
        return array();
    }

    $clean = array();
    foreach ($decoded as $post_id => $timestamp) {
        $post_id = (int) $post_id;
        $timestamp = (int) $timestamp;
        if ($post_id > 0 && $timestamp > 0) {
            $clean[(string) $post_id] = $timestamp;
        }
    }

    return $clean;
}

function itstudio_write_view_cookie_map($map, $window_seconds) {
    if (!headers_sent()) {
        $cookie_name = itstudio_get_view_cookie_name();
        $expire_at = time() + max(DAY_IN_SECONDS, (int) $window_seconds * 2);
        $path = defined('COOKIEPATH') && COOKIEPATH ? COOKIEPATH : '/';
        $domain = defined('COOKIE_DOMAIN') ? COOKIE_DOMAIN : '';
        $secure = is_ssl();
        $http_only = true;
        $encoded = wp_json_encode($map);
        if (!is_string($encoded)) {
            return;
        }

        if (PHP_VERSION_ID >= 70300) {
            setcookie($cookie_name, $encoded, array(
                'expires' => $expire_at,
                'path' => $path,
                'domain' => $domain,
                'secure' => $secure,
                'httponly' => $http_only,
                'samesite' => 'Lax',
            ));
        } else {
            setcookie($cookie_name, $encoded, $expire_at, $path, $domain, $secure, $http_only);
        }

        $_COOKIE[$cookie_name] = $encoded;
    }
}

function itstudio_should_count_post_view($post_id) {
    $post_id = (int) $post_id;
    if ($post_id <= 0) {
        return false;
    }

    if (itstudio_is_probably_bot_request()) {
        return false;
    }

    $window_seconds = (int) apply_filters('itstudio_post_view_window_seconds', 12 * HOUR_IN_SECONDS);
    $window_seconds = max(60, $window_seconds);
    $max_entries = (int) apply_filters('itstudio_post_view_cookie_max_entries', 120);
    $max_entries = max(10, $max_entries);

    $now = time();
    $key = (string) $post_id;
    $map = itstudio_read_view_cookie_map();

    foreach ($map as $id => $timestamp) {
        if (($now - (int) $timestamp) > $window_seconds) {
            unset($map[$id]);
        }
    }

    if (isset($map[$key]) && ($now - (int) $map[$key]) < $window_seconds) {
        return false;
    }

    $map[$key] = $now;
    if (count($map) > $max_entries) {
        asort($map, SORT_NUMERIC);
        $map = array_slice($map, -$max_entries, null, true);
    }

    itstudio_write_view_cookie_map($map, $window_seconds);

    return true;
}

function itstudio_track_post_views() {
    if (is_admin() || wp_doing_ajax() || wp_doing_cron()) {
        return;
    }

    if (!is_singular(array('post', 'announcement', 'news')) || is_preview() || is_feed() || is_trackback() || is_embed()) {
        return;
    }

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

    $post_id = (int) get_queried_object_id();
    if ($post_id <= 0) {
        return;
    }

    if (!itstudio_should_count_post_view($post_id)) {
        return;
    }

    $views = itstudio_get_post_views($post_id) + 1;
    update_post_meta($post_id, 'post_views_count', $views);
    update_post_meta($post_id, 'itstudio_views', $views);
}
add_action('template_redirect', 'itstudio_track_post_views', 20);