<?php
/**
 * User template registry + template utils
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

// ============================================================
// 一、模板注册表 — 所有特殊页面的"身份证"
// 修改此处即可增删模板页面，无需改动其他逻辑
// ============================================================
// Only true fixed template pages live in the registry.
$_aksrt_special_templates = [
    'sign' => [
        'file'     => 'templates/pages/page-sign.php',
        'slug'     => 'sign',
        'title'    => '登录/注册',
        'fallback' => '/sign/',
    ],
    'categories' => [
        'file'     => 'templates/pages/page-categories.php',
        'slug'     => 'categories',
        'title'    => '分类目录',
        'fallback' => '/categories/',
    ],
    'friends'  => [
        'file'     => 'templates/pages/page-friends.php',
        'slug'     => 'friends',
        'title'    => '友情链接',
        'fallback' => '/friends/',
    ],
    'profile'  => [
        'file'     => 'templates/pages/page-profile.php',
        'slug'     => 'profile',
        'title'    => '个人中心',
        'fallback' => '/profile/',
    ],
    'submit' => [
        'file'     => 'templates/pages/page-submit.php',
        'slug'     => 'submit',
        'title'    => '发布文章',
        'fallback' => '/submit/',
    ],
];

/** @var array 缓存 key=模板文件路径 => value=WP_Post|null */
$_aksrt_template_page_cache = [];


// ============================================================
// 二、核心工具函数
// ============================================================

/**
 * 查找使用指定模板文件的页面（按模板匹配，自适应任意 slug）
 *
 * @param  string $template_file 相对于主题的模板路径
 * @return WP_Post|null
 */
function aksrt_find_template_page(string $template_file) {
    global $_aksrt_template_page_cache;
    if (isset($_aksrt_template_page_cache[$template_file])) {
        return $_aksrt_template_page_cache[$template_file];
    }

    $page = null;
    $pages = get_pages([
        'meta_key'    => '_wp_page_template',
        'meta_value'  => $template_file,
        'number'      => 1,
        'post_status' => 'publish',
    ]);
    if (!empty($pages)) {
        $page = $pages[0];
    }

    $_aksrt_template_page_cache[$template_file] = $page;
    return $page;
}

/**
 * 获取使用指定模板的页面 URL
 *
 * @param  string $key 注册表 key（当前仅 profile 使用）
 * @return string 页面 URL 或回退地址
 */
function aksrt_get_template_url(string $key): string {
    global $_aksrt_special_templates;
    if (!isset($_aksrt_special_templates[$key])) {
        return home_url('/');
    }

    $cfg  = $_aksrt_special_templates[$key];
    $page = aksrt_find_template_page($cfg['file']);

    if (!$page) {
        aksrt_ensure_template_page($key);
        $page = aksrt_find_template_page($cfg['file']);
    }

    if ($page) {
        return get_permalink($page->ID);
    }

    return home_url($cfg['fallback']);
}

/**
 * 定位模板文件的绝对路径
 *
 * @param  string $template_file 相对于主题的路径
 * @return string|false 文件绝对路径或 false
 */
function aksrt_locate_template_file(string $template_file) {
    $path = locate_template([$template_file]);
    if ($path) return $path;

    $full = AKSRT_DIR . '/' . $template_file;
    return file_exists($full) ? $full : false;
}

/**
 * Resolve a public-facing page template file from stored meta or page slug.
 */
function aksrt_resolve_page_template_file(string $template_file = '', string $post_slug = ''): string {
    $template_file = ltrim($template_file, '/\\');
    $post_slug     = sanitize_title($post_slug);

    if ($template_file !== '') {
		if ($template_file === 'templates/pages/page-messages.php') {
			return '';
		}
		if ($template_file === 'templates/pages/page-sign.php') {
			return $template_file;
        }

        if (strpos($template_file, 'templates/pages/') === 0 && aksrt_locate_template_file($template_file)) {
            return $template_file;
        }
    }

    if ($post_slug !== '') {
		if ($post_slug === 'sign') {
			return 'templates/pages/page-sign.php';
        }

        $slug_map = [
            'categories' => 'templates/pages/page-categories.php',
            'friends'    => 'templates/pages/page-friends.php',
            'profile'    => 'templates/pages/page-profile.php',
        ];

        if (!empty($slug_map[$post_slug]) && aksrt_locate_template_file($slug_map[$post_slug])) {
            return $slug_map[$post_slug];
        }
    }

    return '';
}

/**
 * Normalize auth view keys used by the unified sign page.
 */
function aksrt_normalize_auth_tab(string $tab): string {
    $tab = sanitize_key($tab);

    switch ($tab) {
        case 'signin':
			return 'signin';
        case 'signup':
			return 'signup';
        case 'bind':
            return 'bind';
        case 'resetpassword':
			return 'resetpassword';
		case 'oauth':
			return 'oauth';
        default:
			return 'signin';
    }
}

/**
 * 清除模板页面缓存
 */
function aksrt_clear_template_page_cache(): void {
    global $_aksrt_template_page_cache;
    $_aksrt_template_page_cache = [];
}

/**
 * Prepare the public user-home template context and return its template path.
 */
function aksrt_get_user_home_template_path(): string {
    global $_aksrt_special_templates, $aksrt_profile_user;

    $identifier = (string) get_query_var('aksrt_author_identifier');
    if ($identifier === '') {
        return '';
    }

    $user = function_exists('aksrt_resolve_public_user') ? aksrt_resolve_public_user($identifier) : null;
    if (!$user instanceof WP_User) {
        return '';
    }

    $template_path = aksrt_locate_template_file('templates/pages/page-user-home.php');

    if (!$template_path) {
        return '';
    }

    $aksrt_profile_user = $user;
    return $template_path;
}

/**
 * Resolve the active special-page template path for the current request.
 */
function aksrt_get_current_special_template_path(): string {
	if (get_query_var('aksrt_message_view')) {
		$message_template = aksrt_locate_template_file('templates/pages/page-messages.php');
		return $message_template ?: '';
	}

    if (get_query_var('aksrt_author_identifier')) {
        return aksrt_get_user_home_template_path();
    }

    if (get_query_var('aksrt_user_center')) {
        $profile_template = aksrt_locate_template_file('templates/pages/page-profile.php');
        return $profile_template ?: '';
    }

	if (get_query_var('aksrt_sign')) {
		$auth_template_path = aksrt_locate_template_file('templates/pages/page-sign.php');
        return $auth_template_path ?: '';
    }

    if (is_page()) {
        $page_id = get_queried_object_id();
        if ($page_id > 0) {
            $page_template = get_post_meta($page_id, '_wp_page_template', true);
            $resolved_template = aksrt_resolve_page_template_file(
                is_string($page_template) ? $page_template : '',
                (string) get_post_field('post_name', $page_id)
            );

            if ($resolved_template !== '') {
                $resolved_path = aksrt_locate_template_file($resolved_template);
                if ($resolved_path) {
                    return $resolved_path;
                }
            }
        }
    }

    return '';
}

/**
 * 根据当前请求路径识别系统模板页 key。
 *
 * 用于前台直接访问固定 slug 时的自动补页。
 */
function aksrt_get_requested_template_key(): string {
    global $_aksrt_special_templates;

    $request_uri = isset($_SERVER['REQUEST_URI']) ? (string) $_SERVER['REQUEST_URI'] : '';
    if ($request_uri === '') {
        return '';
    }

    $request_path = wp_parse_url($request_uri, PHP_URL_PATH);
    if (!is_string($request_path) || $request_path === '') {
        return '';
    }

    $home_path = (string) wp_parse_url(home_url('/'), PHP_URL_PATH);
    if ($home_path !== '' && str_starts_with($request_path, $home_path)) {
        $request_path = (string) substr($request_path, strlen($home_path));
    }

    $request_slug = trim($request_path, '/');
    if ($request_slug === '') {
        return '';
    }

    foreach ($_aksrt_special_templates as $key => $cfg) {
        $slug = isset($cfg['slug']) ? sanitize_title((string) $cfg['slug']) : '';
        if ($slug !== '' && $slug === $request_slug) {
            return (string) $key;
        }
    }

    return '';
}

/**
 * 确保使用指定模板的页面存在，缺失则自动创建
 *
 * @param string $key 注册表 key
 */
function aksrt_ensure_template_page(string $key): void {
    global $_aksrt_special_templates;
    if (!isset($_aksrt_special_templates[$key])) return;

    $cfg = $_aksrt_special_templates[$key];
    if (array_key_exists('auto_create', $cfg) && empty($cfg['auto_create'])) {
        return;
    }
    $desired_slug = sanitize_title($cfg['slug'] ?? $key);

    // 已有页面使用此模板？仍校验模板 meta，避免空白默认页。
    $found_page = aksrt_find_template_page($cfg['file']);
    if ($found_page instanceof WP_Post) {
        $current_tpl = get_post_meta((int) $found_page->ID, '_wp_page_template', true);
        if ($current_tpl !== $cfg['file']) {
            update_post_meta((int) $found_page->ID, '_wp_page_template', $cfg['file']);
            aksrt_clear_template_page_cache();
        }
        return;
    }

    if ($desired_slug !== '') {
        $existing_page = get_page_by_path($desired_slug, OBJECT, 'page');
        if ($existing_page instanceof WP_Post) {
            // Slug collisions belong to the administrator. System pages are
            // created only when the slug is completely free.
            return;
        }
    }

    // 自动创建
    $page_id = wp_insert_post([
        'post_title'     => $cfg['title'],
        'post_content'   => '',
        'post_status'    => 'publish',
        'post_type'      => 'page',
        'post_name'      => $desired_slug !== '' ? $desired_slug : $key,
        'comment_status' => 'closed',
        'ping_status'    => 'closed',
    ]);

    if (!is_wp_error($page_id) && $page_id > 0) {
        update_post_meta($page_id, '_wp_page_template', $cfg['file']);
        update_post_meta($page_id, '_aksrt_managed_template_page', (string) $key);
        aksrt_clear_template_page_cache();
    }
}