import { useMemo, useState, type ReactNode } from 'react';
import { Bell, ChevronDown, ChevronRight, Menu, Search, UserRound } from 'lucide-react';
import { Button } from '../components/ui';
import { cn } from '../lib/utils';
import { navGroups } from './navigation';

type AppLayoutProps = {
  children: ReactNode;
  currentPath: string;
  onNavigate: (path: string) => void;
};

function isChildActive(item: { path?: string; children?: Array<{ path: string }> }, currentPath: string) {
  if (item.path === currentPath) return true;
  return item.children?.some((child) => child.path === currentPath) ?? false;
}

export function AppLayout({ children, currentPath, onNavigate }: AppLayoutProps) {
  const [openGroups, setOpenGroups] = useState<Record<string, boolean>>({});
  const [menuSearch, setMenuSearch] = useState('');
  const normalizedSearch = menuSearch.trim().toLowerCase();

  const visibleGroups = useMemo(() => {
    if (!normalizedSearch) return navGroups;

    return navGroups
      .map((group) => ({
        ...group,
        items: group.items.flatMap((item) => {
          const parentMatched = item.label.toLowerCase().includes(normalizedSearch);
          if ('children' in item && item.children) {
            const children = item.children.filter((child) => child.label.toLowerCase().includes(normalizedSearch));
            if (parentMatched) return [item];
            if (children.length) return [{ ...item, children }];
            return [];
          }
          return parentMatched ? [item] : [];
        })
      }))
      .filter((group) => group.items.length > 0);
  }, [normalizedSearch]);

  return (
    <div className="min-h-screen overflow-hidden bg-background text-foreground">
      <div className="min-h-screen lg:pl-[17rem]">
        <aside className="fixed inset-y-0 left-0 hidden w-[17rem] flex-col border-r border-border bg-sidebar px-3 py-4 lg:flex">
          <div className="mb-8 flex shrink-0 justify-center px-4 py-3">
            <img className="h-5 w-auto object-contain" src="/assets/brand/header.webp" alt="Autonomy Studio" />
          </div>

          <nav className="scrollbar-stable min-h-0 flex-1 space-y-5 overflow-y-auto pr-2">
            {visibleGroups.map((group) => (
              <div key={group.label}>
                <p className="mb-2 px-2 text-xs font-medium text-muted-foreground">{group.label}</p>
                <div className="space-y-1">
                  {group.items.map((item) => {
                    const Icon = item.icon;
                    const children = item.children;
                    const hasChildren = Boolean(children?.length);
                    const active = isChildActive(item, currentPath);
                    const expanded = Boolean(normalizedSearch) || openGroups[item.label] || active;

                    return (
                      <div key={item.label}>
                        <button
                          type="button"
                          onClick={() => {
                            if (hasChildren) {
                              setOpenGroups((prev) => ({ ...prev, [item.label]: !prev[item.label] }));
                              return;
                            }
                            if ('path' in item && item.path) onNavigate(item.path);
                          }}
                          className={cn(
                            'flex h-9 w-full items-center gap-2 rounded-md px-2 text-sm text-muted-foreground transition-colors hover:bg-sidebar-accent hover:text-white',
                            active && 'font-semibold text-white'
                          )}
                        >
                          <Icon className={cn('size-4', active && 'text-white')} />
                          <span className="min-w-0 flex-1 text-left">{item.label}</span>
                          {hasChildren ? (
                            expanded ? <ChevronDown className="size-3.5" /> : <ChevronRight className="size-3.5" />
                          ) : null}
                        </button>

                        {hasChildren && expanded && children ? (
                          <div className="mt-1 space-y-1 pl-6">
                            {children.map((child) => {
                              const childActive = child.path === currentPath;
                              return (
                                <button
                                  type="button"
                                  key={child.path}
                                  onClick={() => onNavigate(child.path)}
                                  className={cn(
                                    'flex h-8 w-full items-center gap-2 rounded-md px-2 text-left text-xs font-bold text-muted-foreground transition-colors hover:bg-sidebar-accent hover:text-white',
                                    childActive && 'text-white'
                                  )}
                                >
                                  <span className={cn('h-3 w-1 rounded-full', childActive ? 'bg-white' : 'bg-transparent')} />
                                  <span>{child.label}</span>
                                </button>
                              );
                            })}
                          </div>
                        ) : null}
                      </div>
                    );
                  })}
                </div>
              </div>
            ))}
          </nav>
        </aside>

        <div className="flex h-screen min-w-0 flex-col">
          <header className="sticky top-0 z-20 flex h-16 items-center justify-between border-b border-border bg-background/90 px-4 backdrop-blur-xl md:px-6">
            <div className="flex min-w-0 items-center gap-3">
              <Button variant="outline" className="lg:hidden">
                <Menu className="size-4" />
              </Button>
              <div className="relative hidden w-80 md:block">
                <Search className="pointer-events-none absolute left-3 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
                <input
                  className="h-9 w-full rounded-md border border-input bg-background pl-9 pr-3 text-sm outline-none placeholder:text-muted-foreground focus:ring-2 focus:ring-ring"
                  placeholder="메뉴 검색"
                  value={menuSearch}
                  onChange={(event) => setMenuSearch(event.target.value)}
                />
              </div>
            </div>
            <div className="flex items-center gap-2">
              <Button variant="ghost" className="size-9 px-0">
                <Bell className="size-4" />
              </Button>
              <Button variant="outline" className="gap-2">
                <span className="flex size-6 items-center justify-center rounded bg-muted text-xs font-semibold">
                  <UserRound className="size-3.5" />
                </span>
                <span className="hidden md:inline">관리자</span>
                <ChevronDown className="size-4 text-muted-foreground" />
              </Button>
            </div>
          </header>

          <main className="scrollbar-stable min-h-0 flex-1 overflow-y-auto">
            <div className="mx-auto w-full max-w-[1520px] px-6 pb-16 pt-6 md:px-10 md:pb-20 xl:px-14">
              {children}
            </div>
          </main>
        </div>
      </div>
    </div>
  );
}

export function PageTitle({
  eyebrow,
  title,
  description,
  actions
}: {
  eyebrow: string;
  title: string;
  description?: string;
  actions?: ReactNode;
}) {
  return (
    <div className="mb-6 flex flex-col gap-4 lg:flex-row lg:items-end lg:justify-between">
      <div>
        <p className="text-sm text-muted-foreground">{eyebrow}</p>
        <h1 className="mt-1 text-2xl font-semibold tracking-tight md:text-3xl">{title}</h1>
        {description ? <p className="mt-2 max-w-3xl text-sm leading-6 text-muted-foreground">{description}</p> : null}
      </div>
      {actions ? <div className="flex flex-wrap gap-2">{actions}</div> : null}
    </div>
  );
}