// <UserMenu> — the profile affordance in the header's top-right corner:
// an initials avatar button opening a popover with the signed-in name,
// a link to Authelia's own account settings, and a sign-out link. Same
// icon-button + popover chrome as `SettingsMenu`/`LinksMenu` (own
// stylesheet — see `SettingsMenu.css`'s note on why these stay separate).
//
// Identity: `auth_request` only ever answers yes/no, never *who*. This
// learns "who" from authelia's own `GET /api/user/info`, proxied
// same-origin at `/api/whoami` (see `swarm-ui.nix`) — no
// swarm-controller code, a pure pass-through.
//
// Avatar: authelia has no photo field. Ships as a generated initials
// avatar (self-contained, no third-party CDN call — gravatar was the
// other option, rejected for leaking a hashed email on every load); a
// real uploaded photo is a follow-up, not blocking this. Colour is a
// deterministic pick from the same seven base16 chromatic slots the nav
// accent cycles through (`AVATAR_ACCENTS`).
//
// "Authelia settings" / "log out" both build off the *same* base URL
// `LinksMenu` already shows for "Authelia" (`GET /api/links`), not a
// second source of the domain — `/settings` and `/logout` are appended
// client-side, both real authelia routes (mara confirmed `/settings` is
// the real path after the plain domain-root link landed short of it).
import { useEffect, useRef, useState } from "preact/hooks";
import "./UserMenu.css";

interface WhoAmI {
  displayName: string | null;
  email: string | null;
}

interface ServiceLink {
  label: string;
  icon: string;
  url: string;
}

// Same seven chromatic slots `Shell.tsx`'s `NAV_ITEMS` cycle through —
// not imported from there directly: that list is route accents, this is
// a name→colour pick, different domains that happen to share a palette.
const AVATAR_ACCENTS = [
  "var(--red)",
  "var(--yellow)",
  "var(--green)",
  "var(--cyan)",
  "var(--blue)",
  "var(--purple)",
  "var(--pink)",
];

function pickAccent(seed: string): string {
  let hash = 0;
  for (let i = 0; i < seed.length; i++)
    hash = (hash * 31 + seed.charCodeAt(i)) | 0;
  return AVATAR_ACCENTS[Math.abs(hash) % AVATAR_ACCENTS.length];
}

// Lenient parse — authelia wraps its API responses in a `{status, data}`
// envelope; this is a cosmetic-only display (same "a fetch failure just
// falls back" rule `Shell.tsx`'s own swarm-name fetch follows), so an
// unexpected shape degrades to no name rather than a thrown error.
function parseWhoAmI(body: unknown): WhoAmI {
  const record = (body ?? {}) as Record<string, unknown>;
  const data = (record.data ?? record) as Record<string, unknown>;
  const displayName =
    typeof data.display_name === "string" ? data.display_name : null;
  const emails = Array.isArray(data.emails) ? data.emails : null;
  const email =
    emails && typeof emails[0] === "string" ? (emails[0] as string) : null;
  return { displayName, email };
}

export function UserMenu() {
  const [who, setWho] = useState<WhoAmI | null>(null);
  const [autheliaUrl, setAutheliaUrl] = useState<string | null>(null);
  const [open, setOpen] = useState(false);
  const rootRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    fetch("/api/whoami")
      .then((r) =>
        r.ok ? r.json() : Promise.reject(new Error(`http ${r.status}`)),
      )
      .then((body) => setWho(parseWhoAmI(body)))
      .catch(() => setWho(null)); // cosmetic only — see file-top comment
  }, []);

  // Reuses `LinksMenu`'s own data source rather than a second endpoint —
  // see file-top comment.
  useEffect(() => {
    fetch("/api/links")
      .then((r) =>
        r.ok
          ? (r.json() as Promise<ServiceLink[]>)
          : Promise.reject(new Error(`http ${r.status}`)),
      )
      .then((links) => {
        const authelia = links.find((l) => l.label === "Authelia");
        if (authelia) setAutheliaUrl(authelia.url);
      })
      .catch(() => {
        /* cosmetic only — the menu just renders with no links */
      });
  }, []);

  // Close on an outside click or Escape — identical pattern to
  // `LinksMenu`/`SettingsMenu`.
  useEffect(() => {
    if (!open) return;
    function onPointerDown(e: MouseEvent) {
      if (rootRef.current && !rootRef.current.contains(e.target as Node))
        setOpen(false);
    }
    function onKeyDown(e: KeyboardEvent) {
      if (e.key === "Escape") setOpen(false);
    }
    document.addEventListener("pointerdown", onPointerDown);
    document.addEventListener("keydown", onKeyDown);
    return () => {
      document.removeEventListener("pointerdown", onPointerDown);
      document.removeEventListener("keydown", onKeyDown);
    };
  }, [open]);

  const label = who?.displayName || who?.email || null;
  const initial = label ? label.trim().charAt(0).toUpperCase() : "?";
  const accent = pickAccent(label ?? "operator");
  // Trailing slash normalised off so `/logout` appends cleanly
  // regardless of whether the contributed link kept one (the `Authelia`
  // entry does — see `swarm-authelia.nix` — but this isn't the only
  // conceivable shape a future contributor's own URL could take).
  const base = autheliaUrl?.replace(/\/+$/, "") ?? null;

  return (
    <div class="user-menu" ref={rootRef}>
      <button
        type="button"
        class="user-menu-button"
        style={{ background: accent }}
        aria-haspopup="true"
        aria-expanded={open}
        aria-label={label ? `signed in as ${label}` : "account"}
        onClick={() => setOpen((v) => !v)}
      >
        {initial}
      </button>
      {open ? (
        <div class="user-menu-popover" role="menu">
          {label ? <div class="user-menu-name">{label}</div> : null}
          {base ? (
            <>
              <a
                class="user-menu-item"
                href={`${base}/settings`}
                target="_blank"
                rel="noreferrer"
                role="menuitem"
                onClick={() => setOpen(false)}
              >
                authelia settings
              </a>
              <a
                class="user-menu-item"
                href={`${base}/logout`}
                role="menuitem"
                onClick={() => setOpen(false)}
              >
                log out
              </a>
            </>
          ) : null}
        </div>
      ) : null}
    </div>
  );
}