// 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 / Canonical 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 {
    // 1) DETAIL PAGES: legacy [id] → existing canonical [id] pages
    //    (keeps working now; we can later switch these to open inside /portal once wrappers exist)
    const detailRules: Array<[RegExp, (m: RegExpExecArray) => MapResult]> = [
        [/^\/fiber-settings\/([^/]+)\/?$/i,         (m) => ({ pathname: `/settings/fiber/${m[1]}` })],
        [/^\/uv-settings\/([^/]+)\/?$/i,            (m) => ({ pathname: `/settings/uv/${m[1]}` })],
        [/^\/co2-galvo-settings\/([^/]+)\/?$/i,     (m) => ({ pathname: `/settings/co2-galvo/${m[1]}` })],
        [/^\/co2-gantry-settings\/([^/]+)\/?$/i,    (m) => ({ pathname: `/settings/co2-gantry/${m[1]}` })],
        [/^\/co2gantry-settings\/([^/]+)\/?$/i,     (m) => ({ pathname: `/settings/co2-gantry/${m[1]}` })], // old alias
        [/^\/materials\/([^/]+)\/?$/i,              (m) => ({ pathname: `/materials/materials/${m[1]}` })],
        [/^\/materials-coatings\/([^/]+)\/?$/i,     (m) => ({ pathname: `/materials/materials-coatings/${m[1]}` })],
        // Lasers / Projects detail already live under their canonical routes
        // (keep as-is; no redirect needed). If you still want to map legacy, uncomment:
        // [/^\/lasers\/([^/]+)\/?$/i,                (m) => ({ pathname: `/lasers/${m[1]}` })],
        // [/^\/projects\/([^/]+)\/?$/i,              (m) => ({ pathname: `/projects/${m[1]}` })],
    ];
    for (const [re, to] of detailRules) {
        const m = re.exec(pathname);
        if (m) return to(m);
    }

    // 2) LIST PAGES: legacy lists → portal lists (with tab param) or portal sections
    //    Accept optional trailing slash variants.
    const listRules: Array<[RegExp, MapResult]> = [
        [/^\/fiber-settings\/?$/i,          { pathname: "/portal/laser-settings", query: { t: "fiber" } }],
        [/^\/uv-settings\/?$/i,             { pathname: "/portal/laser-settings", query: { t: "uv" } }],
        [/^\/co2-galvo-settings\/?$/i,      { pathname: "/portal/laser-settings", query: { t: "co2-galvo" } }],
        [/^\/co2-ganry-settings\/?$/i,      { pathname: "/portal/laser-settings", query: { t: "co2-gantry" } }], // just in case of typos
        [/^\/co2-gantry-settings\/?$/i,     { pathname: "/portal/laser-settings", query: { t: "co2-gantry" } }],
        [/^\/co2gantry-settings\/?$/i,      { pathname: "/portal/laser-settings", query: { t: "co2-gantry" } }], // old alias

        [/^\/materials\/?$/i,               { pathname: "/portal/materials",      query: { t: "materials" } }],
        [/^\/materials\/materials\/?$/i,    { pathname: "/portal/materials",      query: { t: "materials" } }],
        [/^\/materials\/materials-coatings\/?$/i,
        { pathname: "/portal/materials",      query: { t: "materials-coatings" } }],
        [/^\/materials-coatings\/?$/i,      { pathname: "/portal/materials",      query: { t: "materials-coatings" } }],

        [/^\/lasers\/?$/i,                  { pathname: "/portal/laser-sources" }],
        [/^\/projects\/?$/i,                { pathname: "/portal/projects" }],
        [/^\/my\/rigs\/?$/i,                { pathname: "/portal/rigs",           query: { t: "my" } }],
    ];
    for (const [re, dest] of listRules) {
        if (re.test(pathname)) return dest;
    }

    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).*)",
    ],
};