// middleware.ts
import { NextResponse, NextRequest } from "next/server";

const PUBLIC_PATHS = new Set<string>([
    "/auth/sign-in",
    "/auth/sign-up",
]);

export function middleware(req: NextRequest) {
    const url = req.nextUrl.clone();
    const { pathname } = url;

    // ── 1) Legacy → Portal mapping (runs before auth gating)
    const mapped = legacyMap(pathname);
    if (mapped) {
        url.pathname = mapped.pathname;
        // keep existing query, add/override provided params (e.g., ?t=fiber)
        if (mapped.query) {
            for (const [k, v] of Object.entries(mapped.query)) {
                url.searchParams.set(k, v);
            }
        }
        return NextResponse.redirect(url);
    }

    // ── 2) Auth gating
    const token = req.cookies.get("ma_at")?.value ?? "";
    const isAuthRoute = pathname.startsWith("/auth/");

    // Authed users on any /auth/* route → /portal
    if (token && isAuthRoute) {
        url.pathname = "/portal";
        url.search = "";
        return NextResponse.redirect(url);
    }

    // Unauthed users on protected paths → sign-in (no ?next=)
    if (!token && !isPublicPath(pathname)) {
        url.pathname = "/auth/sign-in";
        url.search = "";
        return NextResponse.redirect(url);
    }

    return NextResponse.next();
}

type MapResult = { pathname: string; query?: Record<string, string> };

function legacyMap(pathname: string): MapResult | null {
    switch (pathname) {
        // Laser settings (old links)
        case "/fiber-settings":
            return { pathname: "/portal/laser-settings", query: { t: "fiber" } };
        case "/uv-settings":
            return { pathname: "/portal/laser-settings", query: { t: "uv" } };
        case "/co2-galvo-settings":
            return { pathname: "/portal/laser-settings", query: { t: "co2-galvo" } };
        case "/co2-gantry-settings":
            return { pathname: "/portal/laser-settings", query: { t: "co2-gantry" } };

            // Materials (both legacy structures)
        case "/materials":
            return { pathname: "/portal/materials", query: { t: "materials" } };
        case "/materials/materials":
            return { pathname: "/portal/materials", query: { t: "materials" } };
        case "/materials/materials-coatings":
            return { pathname: "/portal/materials", query: { t: "materials-coatings" } };
        case "/materials-coatings":
            return { pathname: "/portal/materials", query: { t: "materials-coatings" } };

            // Lasers / Projects / Rigs (legacy)
        case "/lasers":
            return { pathname: "/portal/laser-sources" };
        case "/projects":
            return { pathname: "/portal/projects" };
        case "/my/rigs":
            return { pathname: "/portal/rigs", query: { t: "my" } };

        default:
            return null;
    }
}

function isPublicPath(pathname: string): boolean {
    if (PUBLIC_PATHS.has(pathname)) return true;

    // Static assets / internals
    if (
        pathname.startsWith("/_next/") ||
        pathname.startsWith("/static/") ||
        pathname.startsWith("/images/") ||
        pathname === "/favicon.ico" ||
        pathname === "/robots.txt" ||
        pathname === "/sitemap.xml"
    ) return true;

    // API routes aren't gated here; each route should enforce auth as needed
    if (pathname.startsWith("/api/")) return true;

    // Everything else is protected
    return false;
}

export const config = {
    matcher: [
        "/((?!_next/static|_next/image|favicon.ico|robots.txt|sitemap.xml|images|static).*)",
    ],
};