<?php
/**
 * 简航 SimpleNav —— 后台操作处理（全部 POST + CSRF）
 * 支持 AJAX：请求带 ajax=1 时返回 JSON（用于列表内原地切换显隐/排序）。
 */
declare(strict_types=1);
require_once __DIR__ . '/_auth.php';
require_login();
send_no_cache();

$isAjax = !empty($_POST['ajax']);

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    header('Location: ' . url('admin/'));
    exit;
}
csrf_check();

$pdo = db();
$action = (string)($_POST['action'] ?? '');
$back = 'admin/';
if (!empty($_POST['p'])) {
    $back = 'admin/?p=' . preg_replace('/[^a-z]/', '', (string)$_POST['p']);
}
function flash(string $m, string $t = 'ok'): void { $_SESSION['flash'] = ['m' => $m, 't' => $t]; }
function post_id(): int { return (int)($_POST['id'] ?? 0); }

/** AJAX 直出 JSON 并结束 */
function json_out(array $data): void
{
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode($data, JSON_UNESCAPED_UNICODE);
    exit;
}

/** 读取某表单状态字段的当前值（用于把最新状态回给前端） */
function state_of(string $table, int $id, string $col): int
{
    $st = db()->prepare("SELECT {$col} FROM {$table} WHERE id=?");
    $st->execute([$id]);
    return (int)$st->fetchColumn();
}

$ajax = null;   // 需要在 AJAX 模式下返回的附加数据

try {
    switch ($action) {

        /* ---------- 网站 ---------- */
        case 'site_save': {
            $id       = post_id();
            $gid      = (int)($_POST['group_id'] ?? 0);
            $url      = norm_url((string)($_POST['url'] ?? ''));
            $name     = trim((string)($_POST['name'] ?? ''));
            $short    = trim((string)($_POST['short_name'] ?? ''));
            $visible  = isset($_POST['is_visible']) ? 1 : 0;
            if ($url === '' || $gid <= 0) {
                flash('网址和板块不能为空', 'err');
                break;
            }

            // 图标文件的命名键：按整条网址算（同域名不同路径必须互不覆盖，见 icon_key()）
            $iconKey = icon_key($url);

            // ---- 图标 ----
            //   icon_auto 勾选 = 允许「全部更新」自动刷新图标（icon_custom=0）
            //   取消勾选 / 上传文件 / 给地址 = 自定义固定（icon_custom=1）
            $iconAuto = isset($_POST['icon_auto']);
            $custom   = $iconAuto ? 0 : 1;
            $iconFile = trim((string)($_POST['icon'] ?? ''));

            $uploaded = !empty($_FILES['icon_file']['tmp_name']) && is_uploaded_file((string)$_FILES['icon_file']['tmp_name']);
            if ($uploaded) {
                $bin = (string)@file_get_contents((string)$_FILES['icon_file']['tmp_name']);
                if ($bin === '' || strlen($bin) > 2 * 1024 * 1024) {
                    flash('图标文件过大或为空（限 2MB）', 'err');
                } else {
                    $new = save_custom_icon($bin, $iconKey);
                    if ($new !== '') {
                        $iconFile = $new;
                        $custom = 1;
                    } else {
                        flash('图标文件无法解析，请换一张（PNG / JPG / SVG，建议正方形）', 'err');
                    }
                }
            } else {
                $iconUrl = trim((string)($_POST['icon_url'] ?? ''));
                if ($iconUrl !== '') {
                    $new = download_best_icon([norm_url($iconUrl)], $iconKey, 1);
                    if ($new !== '') {
                        $iconFile = $new;
                        $custom = 1;
                    } else {
                        flash('自定义图标地址下载失败，请检查地址是否可直接访问', 'err');
                    }
                }
            }
            // 网址换了但没换图标：清掉旧图标，避免张冠李戴
            if ($iconFile !== '' && $custom === 0 && !is_file(ICON_PATH . '/' . $iconFile)) {
                $iconFile = '';
            }

            $now = date('Y-m-d H:i:s');
            if ($id > 0) {
                $st = $pdo->prepare('UPDATE sites SET group_id=?, url=?, name=?, short_name=?, icon=?, icon_custom=?, is_visible=?, updated_at=? WHERE id=?');
                $st->execute([$gid, $url, $name, $short, $iconFile, $custom, $visible, $now, $id]);
                flash($custom ? '已保存（图标已锁定，不再自动更新）' : '已保存网站');
            } else {
                $max = (int)$pdo->query('SELECT COALESCE(MAX(sort_order),0)+1 FROM sites WHERE group_id=' . $gid)->fetchColumn();
                $st = $pdo->prepare('INSERT INTO sites (group_id,url,name,short_name,icon,icon_custom,sort_order,is_visible,created_at,updated_at) VALUES (?,?,?,?,?,?,?,?,?,?)');
                $st->execute([$gid, $url, $name, $short, $iconFile, $custom, $max, $visible, $now, $now]);
                flash($custom ? '已添加网站（图标已锁定，不再自动更新）' : '已添加网站');
            }
            break;
        }
        case 'site_delete': {
            $pdo->prepare('DELETE FROM sites WHERE id=?')->execute([post_id()]);
            flash('已删除网站');
            break;
        }
        case 'site_toggle': {
            $id = post_id();
            $pdo->prepare('UPDATE sites SET is_visible = 1 - is_visible WHERE id=?')->execute([$id]);
            $ajax = ['state' => state_of('sites', $id, 'is_visible')];
            flash('已切换显示状态');
            break;
        }
        case 'site_move': {
            move_sort('sites', post_id(), (string)($_POST['dir'] ?? 'up'), 'group_id');
            break;
        }

        /* ---------- 板块 ---------- */
        case 'group_save': {
            $id      = post_id();
            $name    = trim((string)($_POST['name'] ?? ''));
            $display = ($_POST['display'] ?? 'grid') === 'tabs' ? 'tabs' : 'grid';
            $visible = isset($_POST['is_visible']) ? 1 : 0;
            if ($name === '') { flash('板块名称不能为空', 'err'); break; }
            if ($id > 0) {
                $pdo->prepare('UPDATE groups SET name=?, display=?, is_visible=? WHERE id=?')
                    ->execute([$name, $display, $visible, $id]);
                flash('已保存板块');
            } else {
                $max = (int)$pdo->query('SELECT COALESCE(MAX(sort_order),0)+1 FROM groups')->fetchColumn();
                $pdo->prepare('INSERT INTO groups (name,slug,display,sort_order,is_visible) VALUES (?,?,?,?,?)')
                    ->execute([$name, slugify($name), $display, $max, $visible]);
                flash('已添加板块');
            }
            break;
        }
        case 'group_delete': {
            $pdo->prepare('DELETE FROM groups WHERE id=?')->execute([post_id()]);
            flash('已删除板块（含其下网站）');
            break;
        }
        case 'group_toggle': {
            $id = post_id();
            $pdo->prepare('UPDATE groups SET is_visible = 1 - is_visible WHERE id=?')->execute([$id]);
            $ajax = ['state' => state_of('groups', $id, 'is_visible')];
            flash('已切换显示状态');
            break;
        }
        case 'group_move': {
            move_sort('groups', post_id(), (string)($_POST['dir'] ?? 'up'), null);
            break;
        }

        /* ---------- 搜索引擎 ---------- */
        case 'engine_save': {
            $id      = post_id();
            $name    = trim((string)($_POST['name'] ?? ''));
            $slug    = preg_replace('/[^a-z0-9\-_]/i', '', (string)($_POST['slug'] ?? ''));
            $search  = trim((string)($_POST['search_url'] ?? ''));
            $param   = trim((string)($_POST['param'] ?? 'q'));
            $sugUrl  = trim((string)($_POST['suggest_url'] ?? ''));
            $sugType = preg_replace('/[^a-z0-9_]/i', '', (string)($_POST['suggest_type'] ?? ''));
            $color   = preg_match('/^#[0-9a-fA-F]{3,8}$/', (string)($_POST['color'] ?? '')) ? $_POST['color'] : '#2F6BF7';
            $active  = isset($_POST['is_active']) ? 1 : 0;
            if ($name === '' || $slug === '' || $search === '') { flash('名称/标识/搜索地址不能为空', 'err'); break; }
            if ($id > 0) {
                $pdo->prepare('UPDATE engines SET name=?,slug=?,search_url=?,param=?,suggest_url=?,suggest_type=?,color=?,is_active=? WHERE id=?')
                    ->execute([$name, $slug, $search, $param, $sugUrl, $sugType, $color, $active, $id]);
                flash('已保存搜索引擎');
            } else {
                $max = (int)$pdo->query('SELECT COALESCE(MAX(sort_order),0)+1 FROM engines')->fetchColumn();
                $pdo->prepare('INSERT INTO engines (name,slug,search_url,param,suggest_url,suggest_type,color,is_active,sort_order) VALUES (?,?,?,?,?,?,?,?,?)')
                    ->execute([$name, $slug, $search, $param, $sugUrl, $sugType, $color, $active, $max]);
                flash('已添加搜索引擎');
            }
            break;
        }
        case 'engine_delete': {
            $pdo->prepare('DELETE FROM engines WHERE id=?')->execute([post_id()]);
            flash('已删除搜索引擎');
            break;
        }
        case 'engine_toggle': {
            $id = post_id();
            $pdo->prepare('UPDATE engines SET is_active = 1 - is_active WHERE id=?')->execute([$id]);
            $ajax = ['state' => state_of('engines', $id, 'is_active')];
            flash('已切换启用状态');
            break;
        }
        case 'engine_move': {
            move_sort('engines', post_id(), (string)($_POST['dir'] ?? 'up'), null);
            break;
        }

        /* ---------- 设置 ---------- */
        case 'settings_save': {
            $srcRaw = (string)($_POST['suggest_source'] ?? 'baidu');
            $src    = in_array($srcRaw, ['auto', 'baidu', 'bing', 'so360'], true) ? $srcRaw : 'baidu';
            // 合集区显示方式：flat = 全部平铺；其余一律回到 tabs（标签页折叠）
            $coll   = (string)($_POST['collections_layout'] ?? 'tabs') === 'flat' ? 'flat' : 'tabs';
            $map = [
                'site_name'      => trim((string)($_POST['site_name'] ?? '')),
                'subtitle'       => trim((string)($_POST['subtitle'] ?? '')),
                'default_engine' => preg_replace('/[^a-z0-9\-_]/i', '', (string)($_POST['default_engine'] ?? '')),
                'primary_color'  => preg_match('/^#[0-9a-fA-F]{3,8}$/', (string)($_POST['primary_color'] ?? '')) ? $_POST['primary_color'] : '#2F6BF7',
                'open_blank'     => isset($_POST['open_blank']) ? '1' : '0',
                'icon_services'  => isset($_POST['icon_services']) ? '1' : '0',
                'suggest_source' => $src,
                'collections_layout' => $coll,
            ];
            $st = $pdo->prepare('INSERT INTO settings (k,v) VALUES (?,?) ON CONFLICT(k) DO UPDATE SET v=excluded.v');
            foreach ($map as $k => $v) { $st->execute([$k, $v]); }
            flash('设置已保存');
            $back = 'admin/?p=settings';
            break;
        }
        case 'password_save': {
            $old = (string)($_POST['old_password'] ?? '');
            $new = (string)($_POST['new_password'] ?? '');
            $u = current_user();
            $st = $pdo->prepare('SELECT password_hash FROM users WHERE id=?');
            $st->execute([$u['id']]);
            $hash = (string)$st->fetchColumn();
            if (!password_verify($old, $hash)) { flash('原密码不正确', 'err'); $back = 'admin/?p=settings'; break; }
            if (mb_strlen($new) < 4) { flash('新密码至少 4 位', 'err'); $back = 'admin/?p=settings'; break; }
            $pdo->prepare('UPDATE users SET password_hash=? WHERE id=?')->execute([password_hash($new, PASSWORD_DEFAULT), $u['id']]);
            flash('密码已更新');
            $back = 'admin/?p=settings';
            break;
        }

        default:
            flash('未知操作', 'err');
    }
} catch (Throwable $e) {
    if ($isAjax) {
        json_out(['ok' => false, 'msg' => $e->getMessage()]);
    }
    flash('操作失败：' . $e->getMessage(), 'err');
}

if ($isAjax) {
    unset($_SESSION['flash']);          // AJAX 不产生页面提示，避免下次进后台弹出过期提示
    if ($ajax === null) {
        json_out(['ok' => false, 'msg' => '该操作不支持 AJAX']);
    }
    json_out(['ok' => true] + $ajax);
}

header('Location: ' . url($back));
exit;

/** 上/下移动排序（同组内交换 sort_order） */
function move_sort(string $table, int $id, string $dir, ?string $groupCol): void
{
    if ($id <= 0) return;
    $pdo = db();
    $st = $pdo->prepare("SELECT * FROM {$table} WHERE id=?");
    $st->execute([$id]);
    $cur = $st->fetch();
    if (!$cur) return;

    $where = $groupCol ? " AND {$groupCol}=" . (int)$cur[$groupCol] : '';
    if ($dir === 'up') {
        $sql = "SELECT * FROM {$table} WHERE sort_order < ?{$where} ORDER BY sort_order DESC LIMIT 1";
    } else {
        $sql = "SELECT * FROM {$table} WHERE sort_order > ?{$where} ORDER BY sort_order ASC LIMIT 1";
    }
    $st2 = $pdo->prepare($sql);
    $st2->execute([$cur['sort_order']]);
    $nb = $st2->fetch();
    if (!$nb) return;

    $upd = $pdo->prepare("UPDATE {$table} SET sort_order=? WHERE id=?");
    $upd->execute([$nb['sort_order'], $cur['id']]);
    $upd->execute([$cur['sort_order'], $nb['id']]);
}