import React, { useState, useEffect, useRef } from 'react';
import { Link, Outlet, useLocation } from '@tanstack/react-router';
import { cn } from '@/lib/utils';
import { StatusBar } from '@/components/StatusBar';
import {
  LayoutDashboard,
  Settings,
  Network,
  ChevronLeft,
  ChevronRight,
  RefreshCw,
  BarChart3,
} from 'lucide-react';
import { useTranslation } from 'react-i18next';
import { Button } from '@/components/ui/button';
import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/components/ui/tooltip';
import { ErrorBoundary } from 'react-error-boundary';
import { useToast } from '@/components/ui/use-toast';
import { getLocalizedErrorMessage } from '@/utils/errorMessages';
import iconPng from '@/assets/icon.png';

export const MainLayout: React.FC = () => {
  const location = useLocation();
  const { t } = useTranslation();
  const { toast } = useToast();
  const hasShownRouteErrorToastRef = useRef(false);

  // Initialize state from localStorage if available, default to false (expanded)
  const [isCollapsed, setIsCollapsed] = useState(() => {
    const saved = localStorage.getItem('sidebar-collapsed');
    return saved ? JSON.parse(saved) : false;
  });

  // Persist state changes
  useEffect(() => {
    localStorage.setItem('sidebar-collapsed', JSON.stringify(isCollapsed));
  }, [isCollapsed]);

  const navItems = [
    {
      to: '/',
      icon: LayoutDashboard,
      label: t('nav.accounts'),
    },
    {
      to: '/usage',
      icon: BarChart3,
      label: t('nav.usage'),
    },
    {
      to: '/proxy',
      icon: Network,
      label: t('nav.proxy'),
    },
    {
      to: '/settings',
      icon: Settings,
      label: t('nav.settings'),
    },
  ];

  return (
    <div className="bg-background text-foreground flex h-screen flex-col overflow-hidden">
      <div className="flex flex-1 overflow-hidden">
        {/* Sidebar */}
        <aside
          className={cn(
            'relative flex flex-col border-r border-white/[0.06] transition-all duration-300 ease-[cubic-bezier(0.4,0,0.2,1)]',
            isCollapsed ? 'w-[60px]' : 'w-56',
          )}
        >
          {/* Collapse toggle */}
          <button
            className={cn(
              'absolute -right-3 top-7 z-10 flex h-6 w-6 items-center justify-center rounded-full',
              'bg-muted border border-white/[0.1] text-muted-foreground',
              'opacity-0 transition-all duration-200 hover:bg-white/[0.1] hover:text-foreground',
              'group-hover:opacity-100',
            )}
            style={{ opacity: 0 }}
            onMouseEnter={(e) => (e.currentTarget.style.opacity = '1')}
            onMouseLeave={(e) => (e.currentTarget.style.opacity = '0')}
            onClick={() => setIsCollapsed(!isCollapsed)}
          >
            {isCollapsed ? (
              <ChevronRight className="h-3 w-3" />
            ) : (
              <ChevronLeft className="h-3 w-3" />
            )}
          </button>

          {/* Brand */}
          <div className={cn('flex flex-col', isCollapsed ? 'items-center p-3' : 'px-4 py-5')}>
            <div className="flex items-center gap-2.5 overflow-hidden whitespace-nowrap">
              <div className="flex h-7 w-7 shrink-0 items-center justify-center overflow-hidden rounded-lg bg-transparent">
                <img
                  src={iconPng}
                  alt="Gemini Nexus Logo"
                  className="h-full w-full object-contain"
                />
              </div>
              <div
                className={cn(
                  'overflow-hidden transition-all duration-300',
                  isCollapsed ? 'w-0 opacity-0' : 'w-auto opacity-100',
                )}
              >
                <h1 className="text-[15px] font-semibold tracking-tight">Gemini Nexus</h1>
              </div>
            </div>
          </div>

          {/* Navigation */}
          <nav className="flex-1 space-y-1 px-2 pt-2">
            <TooltipProvider>
              {navItems.map((item) => {
                const isActive = location.pathname === item.to;

                if (isCollapsed) {
                  return (
                    <Tooltip key={item.to} delayDuration={0}>
                      <TooltipTrigger asChild>
                        <Link
                          to={item.to}
                          className={cn(
                            'mx-auto flex h-9 w-9 items-center justify-center rounded-lg transition-all duration-200',
                            isActive
                              ? 'bg-white/[0.08] text-foreground'
                              : 'text-muted-foreground hover:bg-white/[0.04] hover:text-foreground',
                          )}
                        >
                          <item.icon className="h-[18px] w-[18px]" />
                          <span className="sr-only">{item.label}</span>
                        </Link>
                      </TooltipTrigger>
                      <TooltipContent side="right" className="text-xs">
                        {item.label}
                      </TooltipContent>
                    </Tooltip>
                  );
                }

                return (
                  <Link
                    key={item.to}
                    to={item.to}
                    className={cn(
                      'flex items-center gap-3 rounded-lg px-3 py-2 text-[13px] font-medium transition-all duration-200',
                      isActive
                        ? 'bg-white/[0.08] text-foreground'
                        : 'text-muted-foreground hover:bg-white/[0.04] hover:text-foreground',
                    )}
                  >
                    <item.icon className="h-[18px] w-[18px]" />
                    {item.label}
                  </Link>
                );
              })}
            </TooltipProvider>
          </nav>

          {/* Status bar */}
          <div className="border-t border-white/[0.06] p-2">
            <StatusBar isCollapsed={isCollapsed} />
          </div>
        </aside>

        {/* Content Area */}
        <main className="flex-1 overflow-auto transition-all duration-300">
          <ErrorBoundary
            resetKeys={[location.pathname]}
            onReset={() => {
              hasShownRouteErrorToastRef.current = false;
            }}
            onError={(error) => {
              if (hasShownRouteErrorToastRef.current) {
                return;
              }

              toast({
                title: t('error.generic'),
                description: getLocalizedErrorMessage(error, t),
                variant: 'destructive',
              });
              hasShownRouteErrorToastRef.current = true;
            }}
            fallbackRender={({ resetErrorBoundary }) => (
              <div className="mx-auto max-w-3xl p-6">
                <div className="rounded-xl border border-white/[0.06] border-dashed p-8 text-center">
                  <div className="text-sm font-semibold">{t('error.generic')}</div>
                  <div className="text-muted-foreground mt-2 text-xs">{t('action.retry')}</div>
                  <Button className="mt-4" variant="outline" onClick={resetErrorBoundary}>
                    <RefreshCw className="mr-2 h-4 w-4" />
                    {t('action.retry')}
                  </Button>
                </div>
              </div>
            )}
          >
            <Outlet />
          </ErrorBoundary>
        </main>
      </div>
    </div>
  );
};