import { useEffect, useState } from 'react';
import { Outlet } from 'react-router-dom';

import { usePersistentState } from '../lib/use-persistent-state';
import { Footer } from './Footer';
import { SidebarChromeContext } from './sidebar-chrome';
import { Sidebar } from './Sidebar';
import { clampSidebarWidth, SIDEBAR_DEFAULT_WIDTH_REM, SidebarResizer } from './SidebarResizer';
import { TopBar } from './TopBar';

export function AppLayout(): React.JSX.Element {
  const [sidebarCollapsed, setSidebarCollapsed] = usePersistentState('ui.sidebar.collapsed', false);
  const [sidebarWidth, setSidebarWidth] = usePersistentState(
    'ui.sidebar.width',
    SIDEBAR_DEFAULT_WIDTH_REM,
  );
  const [forcedHidden, setForcedHidden] = useState(false);
  const collapsed = sidebarCollapsed || forcedHidden;
  // Clamp on read too — the persisted value may predate a bounds change.
  const widthRem = clampSidebarWidth(sidebarWidth);

  // Ctrl/Cmd+\ toggles the sidebar (same shortcut as Notion), regardless of
  // which element has focus.
  useEffect(() => {
    function handleKeyDown(event: KeyboardEvent): void {
      if ((event.ctrlKey || event.metaKey) && event.key === '\\') {
        event.preventDefault();
        setSidebarCollapsed(!sidebarCollapsed);
      }
    }
    window.addEventListener('keydown', handleKeyDown);
    return () => window.removeEventListener('keydown', handleKeyDown);
  }, [sidebarCollapsed, setSidebarCollapsed]);

  return (
    <SidebarChromeContext.Provider value={setForcedHidden}>
      <div className="app">
        <TopBar
          sidebarCollapsed={collapsed}
          onToggleSidebar={() => setSidebarCollapsed(!sidebarCollapsed)}
        />
        <div
          className="app-body"
          style={{ '--sidebar-width': `${widthRem}rem` } as React.CSSProperties}
        >
          <Sidebar collapsed={collapsed} />
          {!collapsed && <SidebarResizer widthRem={widthRem} onResize={setSidebarWidth} />}
          <main className="main">
            <Outlet />
            <Footer />
          </main>
        </div>
      </div>
    </SidebarChromeContext.Provider>
  );
}