'use client'

import { useState, useEffect } from 'react'
import Link from 'next/link'
import { usePathname } from 'next/navigation'
import { signOut, useSession } from 'next-auth/react'
import { cn } from '@/lib/utils'
import { Button } from '@/components/ui/button'
import { UserAvatar } from '@/components/shared/user-avatar'
import { trpc } from '@/lib/trpc/client'
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuSeparator,
  DropdownMenuTrigger,
} from '@/components/ui/dropdown-menu'
import type { Route } from 'next'
import type { LucideIcon } from 'lucide-react'
import { LogOut, Menu, Moon, Settings, Sun, User, X } from 'lucide-react'
import { useTheme } from 'next-themes'
import { Logo } from '@/components/shared/logo'
import { NotificationBell } from '@/components/shared/notification-bell'

export type NavItem = {
  name: string
  href: string
  icon: LucideIcon
}

export type RoleNavUser = {
  name?: string | null
  email?: string | null
}

type RoleNavProps = {
  navigation: NavItem[]
  roleName: string
  user: RoleNavUser
  /** The base path for the role (e.g., '/jury', '/mentor', '/observer'). Used for active state detection on the dashboard link. */
  basePath: string
  /** Optional status badge displayed next to the logo (e.g., remaining evaluations count) */
  statusBadge?: React.ReactNode
}

function isNavItemActive(pathname: string, href: string, basePath: string): boolean {
  return pathname === href || (href !== basePath && pathname.startsWith(href))
}

export function RoleNav({ navigation, roleName, user, basePath, statusBadge }: RoleNavProps) {
  const pathname = usePathname()
  const [isMobileMenuOpen, setIsMobileMenuOpen] = useState(false)
  const { status: sessionStatus } = useSession()
  const isAuthenticated = sessionStatus === 'authenticated'
  const { data: avatarUrl } = trpc.avatar.getUrl.useQuery(undefined, {
    enabled: isAuthenticated,
  })
  const { theme, setTheme } = useTheme()
  const [mounted, setMounted] = useState(false)
  useEffect(() => setMounted(true), [])

  return (
    <header className="sticky top-0 z-40 border-b bg-card">
      <div className="container-app">
        <div className="flex h-16 items-center justify-between">
          {/* Logo */}
          <div className="flex items-center gap-3">
            <Logo showText textSuffix={roleName} />
            {statusBadge}
          </div>

          {/* Desktop nav */}
          <nav className="hidden md:flex items-center gap-1">
            {navigation.map((item) => {
              const isActive = isNavItemActive(pathname, item.href, basePath)
              return (
                <Link
                  key={item.name}
                  href={item.href as Route}
                  className={cn(
                    'flex items-center gap-2 rounded-md px-3 py-2 text-sm font-medium transition-colors',
                    isActive
                      ? 'bg-primary/10 text-primary'
                      : 'text-muted-foreground hover:bg-muted hover:text-foreground'
                  )}
                >
                  <item.icon className="h-4 w-4" />
                  {item.name}
                </Link>
              )
            })}
          </nav>

          {/* User menu & mobile toggle */}
          <div className="flex items-center gap-2">
            {mounted && (
              <Button
                variant="ghost"
                size="icon"
                onClick={() => setTheme(theme === 'dark' ? 'light' : 'dark')}
                aria-label="Toggle theme"
              >
                {theme === 'dark' ? (
                  <Sun className="h-5 w-5" />
                ) : (
                  <Moon className="h-5 w-5" />
                )}
              </Button>
            )}
            <NotificationBell />
            <DropdownMenu>
              <DropdownMenuTrigger asChild>
                <Button
                  variant="ghost"
                  className="gap-2 hidden sm:flex"
                  size="sm"
                >
                  <UserAvatar user={user} avatarUrl={avatarUrl} size="xs" />
                  <span className="max-w-[120px] truncate">
                    {user.name || user.email}
                  </span>
                </Button>
              </DropdownMenuTrigger>
              <DropdownMenuContent align="end" className="w-48">
                <DropdownMenuItem disabled>
                  <User className="mr-2 h-4 w-4" />
                  {user.email}
                </DropdownMenuItem>
                <DropdownMenuSeparator />
                <DropdownMenuItem asChild>
                  <Link href={"/settings/profile" as Route} className="flex cursor-pointer items-center">
                    <Settings className="mr-2 h-4 w-4" />
                    Settings
                  </Link>
                </DropdownMenuItem>
                <DropdownMenuSeparator />
                <DropdownMenuItem
                  onClick={() => signOut({ callbackUrl: '/login' })}
                  className="text-destructive focus:text-destructive"
                >
                  <LogOut className="mr-2 h-4 w-4" />
                  Sign Out
                </DropdownMenuItem>
              </DropdownMenuContent>
            </DropdownMenu>

            <Button
              variant="ghost"
              size="icon"
              className="md:hidden"
              aria-label={isMobileMenuOpen ? 'Close menu' : 'Open menu'}
              onClick={() => setIsMobileMenuOpen(!isMobileMenuOpen)}
            >
              {isMobileMenuOpen ? (
                <X className="h-5 w-5" />
              ) : (
                <Menu className="h-5 w-5" />
              )}
            </Button>
          </div>
        </div>
      </div>

      {/* Mobile menu */}
      {isMobileMenuOpen && (
        <div className="border-t md:hidden">
          <nav className="container-app py-4 space-y-1">
            {navigation.map((item) => {
              const isActive = isNavItemActive(pathname, item.href, basePath)
              return (
                <Link
                  key={item.name}
                  href={item.href as Route}
                  onClick={() => setIsMobileMenuOpen(false)}
                  className={cn(
                    'flex items-center gap-3 rounded-md px-3 py-2 text-sm font-medium transition-colors',
                    isActive
                      ? 'bg-primary/10 text-primary'
                      : 'text-muted-foreground hover:bg-muted hover:text-foreground'
                  )}
                >
                  <item.icon className="h-4 w-4" />
                  {item.name}
                </Link>
              )
            })}
            <div className="border-t pt-4 mt-4">
              <Button
                variant="ghost"
                className="w-full justify-start text-destructive hover:text-destructive"
                onClick={() => signOut({ callbackUrl: '/login' })}
              >
                <LogOut className="mr-2 h-4 w-4" />
                Sign Out
              </Button>
            </div>
          </nav>
        </div>
      )}
    </header>
  )
}
