import { useState, useMemo } from 'react'
import { Link, Outlet, useLocation, useNavigate } from 'react-router-dom'
import { useTheme } from '../hooks/useTheme'
import { useAuth } from '../contexts/AuthContext'

function NavLink({
  to,
  active,
  children,
  onClick,
  className = '',
}: {
  to: string
  active: boolean
  children: React.ReactNode
  onClick?: () => void
  className?: string
}) {
  return (
    <Link
      to={to}
      onClick={onClick}
      className={`${className} px-3 py-2 rounded-md text-sm font-medium transition-colors ${
        active
          ? 'bg-accent-600/20 text-accent-300'
          : 'text-text-secondary hover:text-text-primary hover:bg-surface-3'
      }`}
    >
      {children}
    </Link>
  )
}

function ThemeToggle() {
  const { theme, toggle } = useTheme()

  return (
    <button
      type="button"
      onClick={toggle}
      className="p-2 rounded-md text-text-secondary hover:text-text-primary hover:bg-surface-3 transition-colors"
      aria-label={`Switch to ${theme === 'dark' ? 'light' : 'dark'} mode`}
    >
      {theme === 'dark' ? (
        <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
          <path
            strokeLinecap="round"
            strokeLinejoin="round"
            strokeWidth={2}
            d="M12 3v1m0 16v1m8.66-13.66l-.71.71M4.05 19.95l-.71.71M21 12h-1M4 12H3m16.66 7.66l-.71-.71M4.05 4.05l-.71-.71M16 12a4 4 0 11-8 0 4 4 0 018 0z"
          />
        </svg>
      ) : (
        <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
          <path
            strokeLinecap="round"
            strokeLinejoin="round"
            strokeWidth={2}
            d="M20.354 15.354A9 9 0 018.646 3.646 9.003 9.003 0 0012 21a9.003 9.003 0 008.354-5.646z"
          />
        </svg>
      )}
    </button>
  )
}

function UserMenu({ onAction }: { onAction?: () => void }) {
  const { user, loading, signOut } = useAuth()
  const [open, setOpen] = useState(false)
  const navigate = useNavigate()

  if (loading) {
    return <div className="w-8 h-8 rounded-full bg-surface-3 animate-pulse" />
  }

  if (!user) {
    return (
      <Link
        to="/login"
        onClick={onAction}
        className="px-3 py-2 rounded-md text-sm font-medium text-text-secondary hover:text-text-primary hover:bg-surface-3 transition-colors"
      >
        Sign in
      </Link>
    )
  }

  const email = user.email ?? ''
  const initials = email.charAt(0).toUpperCase()

  return (
    <div className="relative">
      <button
        type="button"
        onClick={() => setOpen(!open)}
        className="flex items-center gap-2 p-1 rounded-full hover:bg-surface-3 transition-colors"
      >
        <div className="w-8 h-8 rounded-full bg-accent-600 flex items-center justify-center text-white text-sm font-medium">
          {initials}
        </div>
      </button>
      {open && (
        <>
          <div className="fixed inset-0 z-40" onClick={() => setOpen(false)} />
          <div className="absolute right-0 mt-2 w-48 bg-surface-2 border border-border-default rounded-lg shadow-lg z-50">
            <div className="px-4 py-3 border-b border-border-default">
              <p className="text-sm text-text-primary truncate">{email}</p>
            </div>
            <div className="py-1">
              <button
                type="button"
                onClick={() => {
                  setOpen(false)
                  onAction?.()
                  navigate('/settings')
                }}
                className="w-full text-left px-4 py-2 text-sm text-text-secondary hover:text-text-primary hover:bg-surface-3 transition-colors"
              >
                Settings
              </button>
              <button
                type="button"
                onClick={async () => {
                  setOpen(false)
                  onAction?.()
                  await signOut()
                }}
                className="w-full text-left px-4 py-2 text-sm text-text-secondary hover:text-text-primary hover:bg-surface-3 transition-colors"
              >
                Sign out
              </button>
            </div>
          </div>
        </>
      )}
    </div>
  )
}

export function Layout() {
  const [menuOpen, setMenuOpen] = useState(false)
  const location = useLocation()
  const { user, isAdmin } = useAuth()

  const navLinks = useMemo(() => {
    if (!user) {
      // Logged out: Home, Runs, Genlockes, Stats
      return [
        { to: '/', label: 'Home' },
        { to: '/runs', label: 'Runs' },
        { to: '/genlockes', label: 'Genlockes' },
        { to: '/stats', label: 'Stats' },
      ]
    }
    // Logged in: New Run, My Runs, Genlockes, Stats
    const links = [
      { to: '/runs/new', label: 'New Run' },
      { to: '/runs', label: 'My Runs' },
      { to: '/genlockes', label: 'Genlockes' },
      { to: '/stats', label: 'Stats' },
    ]
    // Admin gets Admin link
    if (isAdmin) {
      links.push({ to: '/admin', label: 'Admin' })
    }
    return links
  }, [user, isAdmin])

  function isActive(to: string) {
    if (to === '/' || to === '/runs/new') return location.pathname === to
    return location.pathname.startsWith(to)
  }

  return (
    <div className="min-h-screen flex flex-col bg-surface-0 text-text-primary">
      <nav className="sticky top-0 z-40 bg-surface-1/80 backdrop-blur-lg border-b border-border-default">
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
          <div className="flex justify-between h-14">
            <div className="flex items-center gap-2">
              <Link to="/" className="flex items-center gap-2 group">
                <img
                  src="/favicon.svg"
                  alt=""
                  className="w-7 h-7 transition-transform group-hover:scale-110"
                />
                <span className="text-lg font-bold tracking-tight text-text-primary">ANT</span>
              </Link>
            </div>
            {/* Desktop nav */}
            <div className="hidden sm:flex items-center gap-1">
              {navLinks.map((link) => (
                <NavLink key={link.to} to={link.to} active={isActive(link.to)}>
                  {link.label}
                </NavLink>
              ))}
              <ThemeToggle />
              <UserMenu />
            </div>
            {/* Mobile hamburger */}
            <div className="flex items-center gap-1 sm:hidden">
              <ThemeToggle />
              <button
                type="button"
                onClick={() => setMenuOpen(!menuOpen)}
                className="p-2 rounded-md text-text-secondary hover:text-text-primary hover:bg-surface-3 transition-colors"
                aria-label="Toggle menu"
              >
                <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  {menuOpen ? (
                    <path
                      strokeLinecap="round"
                      strokeLinejoin="round"
                      strokeWidth={2}
                      d="M6 18L18 6M6 6l12 12"
                    />
                  ) : (
                    <path
                      strokeLinecap="round"
                      strokeLinejoin="round"
                      strokeWidth={2}
                      d="M4 6h16M4 12h16M4 18h16"
                    />
                  )}
                </svg>
              </button>
            </div>
          </div>
        </div>
        {/* Mobile dropdown */}
        {menuOpen && (
          <div className="sm:hidden border-t border-border-default">
            <div className="px-2 pt-2 pb-3 space-y-1">
              {navLinks.map((link) => (
                <NavLink
                  key={link.to}
                  to={link.to}
                  active={isActive(link.to)}
                  onClick={() => setMenuOpen(false)}
                  className="block"
                >
                  {link.label}
                </NavLink>
              ))}
              <div className="pt-2 border-t border-border-default mt-2">
                <UserMenu onAction={() => setMenuOpen(false)} />
              </div>
            </div>
          </div>
        )}
      </nav>
      <main className="flex-1">
        <Outlet />
      </main>
      <footer className="border-t border-border-default bg-surface-1/50">
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-4 text-center text-xs text-text-tertiary">
          Encounter data from{' '}
          <a
            href="https://pokedb.org"
            className="underline hover:text-text-secondary transition-colors"
            target="_blank"
            rel="noopener noreferrer"
          >
            PokeDB.org
          </a>
        </div>
      </footer>
    </div>
  )
}