// router.jsx — URL ↔ screen for Grant4Me (History API).
// Paths live under /app/* so they never collide with /graphql, /healthz, /download.

const G4M_ROUTER = (() => {
  const WIZARD = ["company", "reference", "upload", "run", "confirm", "result"];

  function pathFromNav(nav) {
    if (!nav || !nav.screen) return "/app";
    const s = nav.screen;
    const id = nav.runId ? encodeURIComponent(String(nav.runId)) : null;
    if (s === "login") return "/app/login";
    if (s === "register") return "/app/register";
    if (s === "dashboard") return "/app";
    if (s === "team") return "/app/team";
    if (s === "settings") return "/app/settings";
    if (s === "pickProject") return "/app/new/select";
    if (s === "company") return "/app/new";
    if (s === "reference") {
      const q = nav.refStage === "review" ? "?stage=review" : "";
      return "/app/new/project" + q;
    }
    if (s === "upload") return "/app/new/upload";
    if (s === "run") return id ? `/app/runs/${id}` : "/app/new/run";
    if (s === "confirm") return id ? `/app/runs/${id}/review` : "/app/new/review";
    if (s === "result") return id ? `/app/runs/${id}/result` : "/app/new/result";
    return "/app";
  }

  function navFromLocation(loc) {
    const raw = (loc && loc.pathname) || "/";
    let path = raw;
    // Legacy entry: / or /Grant4me.html → treat as app root (caller may replaceState).
    if (path === "/" || path === "/Grant4me.html" || path.endsWith("/Grant4me.html")) {
      return { screen: "dashboard", refStage: "intro" };
    }
    // Strip trailing slash (except root)
    if (path.length > 1 && path.endsWith("/")) path = path.slice(0, -1);

    const params = new URLSearchParams((loc && loc.search) || "");
    const stage = params.get("stage");

    if (path === "/app/login") return { screen: "login", refStage: "intro" };
    if (path === "/app/register") return { screen: "register", refStage: "intro" };
    if (path === "/app" || path === "/app/") return { screen: "dashboard", refStage: "intro" };
    if (path === "/app/team") return { screen: "team", refStage: "intro" };
    if (path === "/app/settings") return { screen: "settings", refStage: "intro" };
    if (path === "/app/new/select") return { screen: "pickProject", refStage: "intro" };
    if (path === "/app/new") return { screen: "company", refStage: "intro" };
    if (path === "/app/new/project") {
      return { screen: "reference", refStage: stage === "review" ? "review" : "intro" };
    }
    if (path === "/app/new/upload") return { screen: "upload", refStage: "intro" };
    if (path === "/app/new/run") return { screen: "run", refStage: "intro" };
    if (path === "/app/new/review") return { screen: "confirm", refStage: "intro" };
    if (path === "/app/new/result") return { screen: "result", refStage: "intro" };

    let m = path.match(/^\/app\/runs\/([^/]+)\/review$/);
    if (m) return { screen: "confirm", runId: decodeURIComponent(m[1]), refStage: "intro" };
    m = path.match(/^\/app\/runs\/([^/]+)\/result$/);
    if (m) return { screen: "result", runId: decodeURIComponent(m[1]), refStage: "intro" };
    m = path.match(/^\/app\/runs\/([^/]+)$/);
    if (m) return { screen: "run", runId: decodeURIComponent(m[1]), refStage: "intro" };

    return { screen: "dashboard", refStage: "intro" };
  }

  function isWizardScreen(screen) {
    return WIZARD.indexOf(screen) >= 0;
  }

  /** Mid-flow wizard (not finished result): warn before abandoning. */
  function shouldConfirmLeave(screen) {
    return isWizardScreen(screen) && screen !== "result";
  }

  function samePath(a, b) {
    const norm = (p) => {
      if (!p) return "/";
      const [path, qs] = String(p).split("?");
      let x = path;
      if (x.length > 1 && x.endsWith("/")) x = x.slice(0, -1);
      return x + (qs ? "?" + qs : "");
    };
    return norm(a) === norm(b);
  }

  return { pathFromNav, navFromLocation, isWizardScreen, shouldConfirmLeave, samePath, WIZARD };
})();

Object.assign(window, { G4M_ROUTER });