import { useEffect, useRef, useState } from 'react';
import { ArrowLeftRight, ChevronUp } from 'lucide-react';
import { useLocation, useNavigate } from 'react-router-dom';
import { cn } from '@/lib/utils';
import { aiModules, getAiModuleForPath, type AiModuleId } from '@/lib/ai-modules';

const moduleToneClasses: Record<AiModuleId, { active: string; icon: string }> = {
  programming: { active: 'bg-[#DCE6EF]', icon: 'bg-[#DCE6EF]' },
  painting: { active: 'bg-[#DCE6EF]', icon: 'bg-[#DCE6EF]' },
};

export function ModuleSwitcher({ sidebarCollapsed }: { sidebarCollapsed: boolean }) {
  const location = useLocation();
  const navigate = useNavigate();
  const [open, setOpen] = useState(false);
  const switcherRef = useRef<HTMLDivElement | null>(null);
  const activeModuleId = getAiModuleForPath(location.pathname);

  useEffect(() => {
    if (!open) return undefined;

    const handleMouseDown = (event: MouseEvent) => {
      const target = event.target;
      if (target instanceof Node && !switcherRef.current?.contains(target)) {
        setOpen(false);
      }
    };
    const handleKeyDown = (event: KeyboardEvent) => {
      if (event.key === 'Escape') setOpen(false);
    };

    document.addEventListener('mousedown', handleMouseDown);
    document.addEventListener('keydown', handleKeyDown);
    return () => {
      document.removeEventListener('mousedown', handleMouseDown);
      document.removeEventListener('keydown', handleKeyDown);
    };
  }, [open]);

  return (
    <div ref={switcherRef} data-testid="sidebar-module-switcher" className="relative">
      <button
        type="button"
        data-testid="sidebar-module-switcher-trigger"
        aria-label="切换模块"
        aria-expanded={open}
        aria-controls="sidebar-module-switcher-menu"
        onClick={() => setOpen((current) => !current)}
        className={cn(
          'flex min-h-10 w-full items-center gap-2 rounded-lg border-2 border-[#26384D] bg-[#FFFFFF] px-2.5 py-2 text-left text-sm font-black text-[#26384D] shadow-[3px_3px_0_#26384D] transition-[background-color,color,transform] hover:bg-[#EEF3F7] active:scale-[0.96]',
          open && 'bg-[#EEF3F7]',
          sidebarCollapsed ? 'justify-center px-0' : '',
        )}
      >
        <ArrowLeftRight className="h-4 w-4 shrink-0" strokeWidth={2.4} />
        {!sidebarCollapsed ? <span className="min-w-0 flex-1 truncate">切换模块</span> : null}
        {!sidebarCollapsed ? <ChevronUp className={cn('h-4 w-4 shrink-0 transition-transform', !open && 'rotate-180')} /> : null}
      </button>

      {open ? (
        <div
          id="sidebar-module-switcher-menu"
          role="menu"
          data-testid="sidebar-module-switcher-menu"
          className={cn(
            'absolute bottom-[calc(100%+0.5rem)] z-50 grid gap-1.5 rounded-lg border-2 border-[#26384D] bg-[#FFFFFF] p-2 text-[#26384D] shadow-[6px_6px_0_#26384D]',
            sidebarCollapsed ? 'left-0 w-64' : 'inset-x-0',
          )}
        >
          <div className="px-2 py-1 text-[11px] font-black text-[#68788B]">选择模块</div>
          {aiModules.map((module) => {
            const active = module.id === activeModuleId;
            const tone = moduleToneClasses[module.id];
            const ModuleIcon = module.Icon;
            return (
              <button
                key={module.id}
                type="button"
                role="menuitem"
                data-testid={`sidebar-module-${module.id}`}
                aria-label={`${module.title}${module.enabled ? '' : '，即将上线'}`}
                aria-current={active ? 'page' : undefined}
                disabled={!module.enabled}
                onClick={() => {
                  setOpen(false);
                  if (module.route) navigate(module.route);
                }}
                className={cn(
                  'flex min-h-9 w-full items-center gap-2 rounded-md border-2 px-2 py-1.5 text-left text-xs font-black text-[#26384D] transition-[background-color,color,transform,opacity] hover:bg-[#FFFFFF] active:scale-[0.97]',
                  active
                    ? `border-[#26384D] ${tone.active} shadow-[2px_2px_0_#26384D]`
                    : 'border-transparent',
                  !module.enabled && 'cursor-not-allowed border-[#26384D]/20 bg-[#EEF3F7] text-[#8A98A8] opacity-70 hover:bg-[#EEF3F7]',
                )}
              >
                <span className={cn('flex h-6 w-6 shrink-0 items-center justify-center rounded-md border border-[#26384D]/30', tone.icon)}>
                  <ModuleIcon className="h-3.5 w-3.5" strokeWidth={2.4} />
                </span>
                <span className="min-w-0 flex-1 truncate">
                  <span className="block truncate">{module.title}</span>
                  {!module.enabled ? <span className="mt-0.5 block text-[10px] font-bold opacity-80">{module.subtitle}</span> : null}
                </span>
              </button>
            );
          })}
        </div>
      ) : null}
    </div>
  );
}