middleware.ts

import { createServerClient } from '@supabase/ssr'
import { type CookieOptions } from '@supabase/ssr'
import { NextResponse, type NextRequest } from 'next/server'

export async function middleware(request: NextRequest) {
  let response = NextResponse.next({
    request: { headers: request.headers },
  })

  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        get(name: string) {
          return request.cookies.get(name)?.value
        },
        set(name: string, value: string, options: CookieOptions) {
          request.cookies.set({ name, value, ...options })
          response = NextResponse.next({ request: { headers: request.headers } })
          response.cookies.set({ name, value, ...options })
        },
        remove(name: string, options: CookieOptions) {
          request.cookies.set({ name, value: '', ...options })
          response = NextResponse.next({ request: { headers: request.headers } })
          response.cookies.set({ name, value: '', ...options })
        },
      },
    }
  )

  // ✅ getUser() validates JWT server-side — never trust getSession() in middleware
  const { data: { user } } = await supabase.auth.getUser()

  // Protect /dashboard — redirect to login if not authenticated
  if (!user && request.nextUrl.pathname.startsWith('/dashboard')) {
    const loginUrl = request.nextUrl.clone()
    loginUrl.pathname = '/login'
    return NextResponse.redirect(loginUrl)
  }

  // Redirect authenticated users away from /login and /signup
  if (
    user &&
    (request.nextUrl.pathname === '/login' ||
      request.nextUrl.pathname === '/signup')
  ) {
    const dashUrl = request.nextUrl.clone()
    dashUrl.pathname = '/dashboard'
    return NextResponse.redirect(dashUrl)
  }

  return response
}

export const config = {
  // Exclude static files, images, and favicon to prevent edge runtime errors
  matcher: [
    '/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
  ],
}