feat(alerts): refactor AlertsBell component to support dynamic positioning and improve alert display with a new panel layout

frontend/src/components/AlertsBell.jsx

@@ -1,3 +1,5 @@
+import { useState, useRef, useEffect, useLayoutEffect } from 'react';
+import { createPortal } from 'react-dom';
 import { Link } from 'react-router-dom';
 import { IconBell, IconAlertTriangle, IconServerOff, IconCpu, IconDeviceDesktop, IconDatabase } from '@tabler/icons-react';
 import { useAlerts } from '../contexts/AlertsContext.jsx';
@@ -21,11 +23,182 @@ function AlertIcon({ type, severity }) {
   return <Icon size={18} className={colorClass} />;
 }
 
+const PANEL_WIDTH = 320;
+const PANEL_MAX_HEIGHT = 320;
+const Z_INDEX = 1050;
+
+function AlertsPanelContent({ loading, refresh, alerts, onClose }) {
+  return (
+    <>
+      <div className="card-header d-flex align-items-center justify-content-between py-2 px-3">
+        <span className="fw-semibold">Оповещения</span>
+        <button
+          type="button"
+          className="btn btn-ghost-secondary btn-sm"
+          onClick={(e) => { e.preventDefault(); refresh(); }}
+          disabled={loading}
+          title="Обновить"
+        >
+          {loading ? '…' : '↻'}
+        </button>
+      </div>
+      <div className="list-group list-group-flush list-group-hoverable" style={{ maxHeight: `${PANEL_MAX_HEIGHT}px`, overflowY: 'auto' }}>
+        {alerts.length === 0 && !loading && (
+          <div className="list-group-item text-muted small text-center py-3">
+            Нет активных оповещений
+          </div>
+        )}
+        {alerts.slice(0, 20).map((alert) => (
+          <Link
+            key={alert.id}
+            to={alert.link || '/dashboard'}
+            className="list-group-item list-group-item-action py-2"
+            onClick={onClose}
+          >
+            <div className="d-flex align-items-start gap-2">
+              <span className="flex-shrink-0 mt-1">
+                <AlertIcon type={alert.type} severity={alert.severity} />
+              </span>
+              <div className="min-w-0 flex-grow-1">
+                <div className="fw-medium small">{alert.title}</div>
+                <div className="text-muted small text-truncate" title={alert.description}>
+                  {alert.entity}
+                </div>
+              </div>
+            </div>
+          </Link>
+        ))}
+        {alerts.length > 20 && (
+          <div className="list-group-item text-muted small text-center py-2">
+            и ещё {alerts.length - 20}…
+          </div>
+        )}
+      </div>
+      <div className="card-footer py-2 px-3 d-flex align-items-center gap-2 flex-nowrap">
+        <Link to="/settings#alerts" className="btn btn-sm btn-ghost-secondary text-nowrap" onClick={onClose}>
+          Настройки
+        </Link>
+        <Link to="/dashboard" className="btn btn-sm btn-outline-primary text-nowrap" onClick={onClose}>
+          Панель
+        </Link>
+      </div>
+    </>
+  );
+}
+
 export default function AlertsBell({ dropup = false }) {
   const { alerts, total, loading, refresh } = useAlerts();
+  const [open, setOpen] = useState(false);
+  const triggerRef = useRef(null);
+  const panelRef = useRef(null);
+  const [position, setPosition] = useState({ top: 0, left: 0 });
+
+  const updatePosition = () => {
+    const el = triggerRef.current;
+    if (!el) return;
+    const rect = el.getBoundingClientRect();
+    const padding = 4;
+    const maxLeft = window.innerWidth - PANEL_WIDTH - padding;
+    if (dropup) {
+      setPosition({
+        left: Math.max(padding, Math.min(rect.left, maxLeft)),
+        bottom: window.innerHeight - rect.top + padding,
+      });
+    } else {
+      setPosition({
+        top: rect.bottom + padding,
+        left: Math.max(padding, Math.min(rect.left, maxLeft)),
+      });
+    }
+  };
+
+  useLayoutEffect(() => {
+    if (open) updatePosition();
+  }, [open, dropup]);
+
+  useEffect(() => {
+    if (!open) return;
+    const onScroll = () => updatePosition();
+    const onResize = () => updatePosition();
+    const onKey = (e) => { if (e.key === 'Escape') setOpen(false); };
+    const onClickOutside = (e) => {
+      const panel = panelRef.current;
+      const trigger = triggerRef.current;
+      if (!panel || !trigger) return;
+      if (!panel.contains(e.target) && !trigger.contains(e.target)) setOpen(false);
+    };
+    window.addEventListener('scroll', onScroll, true);
+    window.addEventListener('resize', onResize);
+    document.addEventListener('keydown', onKey);
+    document.addEventListener('mousedown', onClickOutside);
+    return () => {
+      window.removeEventListener('scroll', onScroll, true);
+      window.removeEventListener('resize', onResize);
+      document.removeEventListener('keydown', onKey);
+      document.removeEventListener('mousedown', onClickOutside);
+    };
+  }, [open]);
+
+  const handleTriggerClick = (e) => {
+    e.preventDefault();
+    if (dropup) {
+      setOpen((v) => !v);
+    }
+  };
+
+  if (dropup) {
+    return (
+      <>
+        <div className="nav-item">
+          <a
+            ref={triggerRef}
+            href="#"
+            className="nav-link px-2 d-inline-flex align-items-center justify-content-center"
+            onClick={handleTriggerClick}
+            aria-expanded={open}
+            aria-haspopup="true"
+            aria-label={`Оповещения: ${total} активных`}
+            title="Оповещения о проблемах"
+          >
+            <span className="position-relative d-inline-flex">
+              <IconBell size={20} />
+              {total > 0 && (
+                <span className="badge badge-sm bg-danger position-absolute rounded-pill" style={{ top: '-2px', right: '-2px' }}>
+                  {total > 99 ? '99+' : total}
+                </span>
+              )}
+            </span>
+          </a>
+        </div>
+        {open && typeof document !== 'undefined' && createPortal(
+          <div
+            ref={panelRef}
+            className="dropdown-menu dropdown-menu-card show overflow-hidden shadow-lg border"
+            data-bs-theme="light"
+            style={{
+              position: 'fixed',
+              left: position.left,
+              ...(position.bottom !== undefined ? { bottom: position.bottom } : { top: position.top }),
+              width: `${PANEL_WIDTH}px`,
+              maxWidth: 'calc(100vw - 1rem)',
+              zIndex: Z_INDEX,
+            }}
+          >
+            <AlertsPanelContent
+              loading={loading}
+              refresh={refresh}
+              alerts={alerts}
+              onClose={() => setOpen(false)}
+            />
+          </div>,
+          document.body
+        )}
+      </>
+    );
+  }
 
   return (
-    <div className={`nav-item dropdown${dropup ? ' dropup' : ''}`}>
+    <div className="nav-item dropdown">
       <a
         href="#"
         className="nav-link px-2 dropdown-toggle position-relative d-inline-flex align-items-center justify-content-center"
@@ -43,58 +216,8 @@ export default function AlertsBell({ dropup = false }) {
           )}
         </span>
       </a>
-      <div className="dropdown-menu dropdown-menu-end dropdown-menu-card overflow-hidden" style={{ width: '320px', maxWidth: '95vw' }}>
+      <div className="dropdown-menu dropdown-menu-end dropdown-menu-card overflow-hidden" style={{ width: `${PANEL_WIDTH}px`, maxWidth: '95vw' }}>
-        <div className="card-header d-flex align-items-center justify-content-between py-2 px-3">
+        <AlertsPanelContent loading={loading} refresh={refresh} alerts={alerts} onClose={() => {}} />
-          <span className="fw-semibold">Оповещения</span>
-          <button
-            type="button"
-            className="btn btn-ghost-secondary btn-sm"
-            onClick={(e) => { e.preventDefault(); refresh(); }}
-            disabled={loading}
-            title="Обновить"
-          >
-            {loading ? '…' : '↻'}
-          </button>
-        </div>
-        <div className="list-group list-group-flush list-group-hoverable" style={{ maxHeight: '320px', overflowY: 'auto' }}>
-          {alerts.length === 0 && !loading && (
-            <div className="list-group-item text-muted small text-center py-3">
-              Нет активных оповещений
-            </div>
-          )}
-          {alerts.slice(0, 20).map((alert) => (
-            <Link
-              key={alert.id}
-              to={alert.link || '/dashboard'}
-              className="list-group-item list-group-item-action py-2"
-            >
-              <div className="d-flex align-items-start gap-2">
-                <span className="flex-shrink-0 mt-1">
-                  <AlertIcon type={alert.type} severity={alert.severity} />
-                </span>
-                <div className="min-w-0 flex-grow-1">
-                  <div className="fw-medium small">{alert.title}</div>
-                  <div className="text-muted small text-truncate" title={alert.description}>
-                    {alert.entity}
-                  </div>
-                </div>
-              </div>
-            </Link>
-          ))}
-          {alerts.length > 20 && (
-            <div className="list-group-item text-muted small text-center py-2">
-              и ещё {alerts.length - 20}…
-            </div>
-          )}
-        </div>
-        <div className="card-footer py-2 px-3 d-flex align-items-center gap-2 flex-nowrap">
-          <Link to="/settings#alerts" className="btn btn-sm btn-ghost-secondary text-nowrap">
-            Настройки
-          </Link>
-          <Link to="/dashboard" className="btn btn-sm btn-outline-primary text-nowrap">
-            Панель
-          </Link>
-        </div>
       </div>
     </div>
   );