import { NextResponse, type NextRequest } from "next/server"
import { getSessionCookie } from "better-auth/cookies"

const PROTECTED_PATHS = [
  "/admin",
  "/dashboard",
  "/properties",
  "/tenants",
  "/rent",
  "/maintenance",
  "/leases",
  "/expenses",
  "/settings",
  "/onboarding",
  "/calendar",
  "/inspections",
  "/vendors",
  "/reports",
  "/activity",
  "/ai",
  "/ai-dashboard",
  "/predictions",
  "/recommendations",
  "/impact",
  "/follow-ups",
  "/team",
]

const AUTH_PATHS = ["/login", "/signup", "/forgot-password"]

// Build the per-request Content-Security-Policy. `script-src` carries a
// per-request nonce instead of 'unsafe-inline'. `style-src` keeps
// 'unsafe-inline' because Radix / Tailwind / framer-motion inject inline
// styles and removing it would break the UI. Next.js reads the nonce from the
// `content-security-policy` request header and applies it to its own inline
// scripts automatically.
function buildCsp(nonce: string): string {
  const isDev = process.env.NODE_ENV !== "production"

  // In development, Next.js/React and Turbopack HMR require eval() for hot
  // reloading and debugging features, and open a dev websocket. These are NOT
  // added in production, where the nonce-based policy stays strict.
  const scriptSrc = isDev
    ? `script-src 'self' 'nonce-${nonce}' 'unsafe-eval' https://challenges.cloudflare.com`
    : `script-src 'self' 'nonce-${nonce}' https://challenges.cloudflare.com`
  const connectSrc = isDev
    ? "connect-src 'self' ws: wss: https://api.stripe.com https://api.openai.com https://challenges.cloudflare.com"
    : "connect-src 'self' https://api.stripe.com https://api.openai.com https://challenges.cloudflare.com"

  return [
    "default-src 'self'",
    "img-src 'self' data: blob: https:",
    "style-src 'self' 'unsafe-inline'",
    scriptSrc,
    "font-src 'self' data:",
    connectSrc,
    "frame-src https://js.stripe.com https://hooks.stripe.com https://challenges.cloudflare.com",
    "frame-ancestors 'none'",
    "base-uri 'self'",
    "form-action 'self'",
  ].join("; ")
}

export async function proxy(request: NextRequest) {
  const pathname = request.nextUrl.pathname

  // Optimistic check based on the presence of the session cookie. Real
  // enforcement happens in routes / server components via getSessionUser().
  const sessionCookie = getSessionCookie(request)

  const isProtected = PROTECTED_PATHS.some((p) => pathname.startsWith(p))
  if (isProtected && !sessionCookie) {
    const url = request.nextUrl.clone()
    url.pathname = "/login"
    return NextResponse.redirect(url)
  }

  const isAuthPage = AUTH_PATHS.some((p) => pathname.startsWith(p))
  if (isAuthPage && sessionCookie) {
    const url = request.nextUrl.clone()
    url.pathname = "/dashboard"
    return NextResponse.redirect(url)
  }

  // Per-request CSP nonce. UUID contains only hex + dashes, so it never
  // includes HTML-escape characters (which Next rejects in nonces).
  const nonce = crypto.randomUUID()
  const csp = buildCsp(nonce)

  // Forward the nonce + CSP on the request headers so Next.js can pick up the
  // nonce and apply it to its own inline scripts during render.
  const requestHeaders = new Headers(request.headers)
  requestHeaders.set("x-nonce", nonce)
  requestHeaders.set("Content-Security-Policy", csp)

  const response = NextResponse.next({ request: { headers: requestHeaders } })
  // Also set the CSP on the outgoing response so the browser enforces it.
  response.headers.set("Content-Security-Policy", csp)
  return response
}

export const config = {
  matcher: [
    "/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)",
  ],
}