/**
 * @file Layout.tsx
 * @description Application shell that frames every authenticated route: persistent
 * sidebar, main content column, the bottom status bar, update notifier, and the
 * Sagi assistant overlay. The connection details modal's open state lives here
 * because both the sidebar's rail button and the status bar open it.
 * The layout is the single parent route in {@link App} — child pages render inside
 * React Router's `<Outlet />` so navigation never remounts chrome.
 *
 * ## Sidebar persistence
 * Collapsed state is read once from `localStorage` via {@link loadCollapsed} and
 * written back on every toggle. Failures to access storage are swallowed so a
 * private-browsing quota error never breaks the UI.
 *
 * ## Sidebar width
 * The expanded sidebar's right edge drags (or takes ←/→) between
 * {@link SIDEBAR_MIN} and {@link SIDEBAR_MAX} px — never past 40% of the
 * window — kept in `agenthub.sidebar.width`; a double-click resets it.
 *
 * ## Narrow viewports
 * With no stored preference the sidebar starts collapsed below `lg` (see
 * {@link loadCollapsed}). Below `md` it leaves the flow entirely: a menu
 * button in a slim top bar opens it as an off-canvas drawer (a modal dialog —
 * backdrop, Escape, focus trapped and restored), which closes on navigation.
 *
 * ## Sticky descendants
 * The inner content wrapper uses `overflow-x-clip` (not `hidden`) so horizontal
 * overflow is clipped without creating a scroll container. That keeps `position:
 * sticky` elements — e.g. the Settings page table-of-contents — pinned to the
 * viewport rather than a nested scroll box.
 *
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */
/* =============================================================================
 * MODULE_GUIDE — extended in-file reference (comments only; safe to read, never executed)
 * =============================================================================
 * **Purpose:** Dashboard module consumed by the React client, MCP tools, or desktop shell depending on deployment mode.
 *
 * ## Design constraints
 * - Local-first: no telemetry leaves the machine unless the user configures webhooks.
 * - Fail-safe hooks path on the server must never block Claude Code; UI mirrors that
 *   philosophy by degrading gracefully (empty states, stale badges, reconnect loops).
 * - Destructive flows stay behind explicit confirmation modals and server-side gates.
 * - Internationalization: user-visible strings belong in i18n JSON, not literals here.
 *
 * ## Remote data & SSH
 * Remote Data Sources let operators aggregate multiple machines. SSH entries describe
 * how to reach a peer dashboard; the global data scope (`dataScope.ts`) narrows every
 * scoped GET via `?sources=`. Health checks and import history surface in Settings.
 *
 * ## Internal dependencies
 * - `./Sidebar`
 * - `./UpdateNotifier`
 * - `./lanes/InterruptedSessionsPrompt` (the "resume interrupted sessions?" dialog)
 * - `./Sagi/SagiMount`
 *
 * ## Public surface
 * - `Layout` — exported API; see TSDoc on the symbol for behavior.
 *
 * ## Testing pointers
 * - Prefer colocated `__tests__` with Vitest + Testing Library for UI.
 * - Server contract changes require `npm run test:server` and OpenAPI sync.
 *
 * ## Related docs
 * - `ARCHITECTURE.md` — hooks → API → SQLite → WebSocket → UI pipeline.
 * - `docs/API.md` — REST reference.
 * - `skills/file-headers/` — mandatory `@author` header policy.
 * ============================================================================= */
/* -----------------------------------------------------------------------------
 * EXPORT CATALOG — quick index of symbols defined below (documentation only).
 * -----------------------------------------------------------------------------
 * **Layout**
 *   Part of this module's public contract. Downstream imports should treat
 *   the signature and return type as stable unless release notes say otherwise.
 *   When behavior changes, update the `@file` overview and relevant tests.
 *
 * ----------------------------------------------------------------------------- */

import { lazy, Suspense, useState, useCallback, useEffect, useSyncExternalStore } from "react";
import { Outlet, useLocation } from "react-router-dom";
import { Menu } from "lucide-react";
import { useTranslation } from "react-i18next";
import { Sidebar, SIDEBAR_STORAGE_KEY, loadCollapsed } from "./Sidebar";
import { UpdateNotifier } from "./UpdateNotifier";
import { InterruptedSessionsPrompt } from "./lanes/InterruptedSessionsPrompt";
import { SagiMount } from "./Sagi/SagiMount";
import { StatusBar } from "./StatusBar";
import { useOnboarding } from "../lib/userPrefs";
import { OnboardingTour } from "./onboarding/OnboardingTour";

// Loaded only for an account that has not finished onboarding: the wizard
// carries the appearance, pet and notification settings screens.
const OnboardingWizard = lazy(() =>
  import("./onboarding/OnboardingWizard").then((m) => ({ default: m.OnboardingWizard }))
);

const WIDTH_KEY = "agenthub.sidebar.width";
/** The default width, and the narrowest the edge drags to. */
export const SIDEBAR_MIN = 240;
/** Wide enough for long workspace names on a large screen, no wider. */
export const SIDEBAR_MAX = 480;

/** A width inside the bounds, and at most 40% of the window. */
export function clampSidebar(px: number): number {
  const max = Math.max(SIDEBAR_MIN, Math.min(SIDEBAR_MAX, window.innerWidth * 0.4));
  return Math.round(Math.min(max, Math.max(SIDEBAR_MIN, px)));
}

function loadWidth(): number {
  try {
    const n = Number(localStorage.getItem(WIDTH_KEY));
    if (n) return clampSidebar(n);
  } catch {}
  return SIDEBAR_MIN;
}

/** Below Tailwind's `md`: the sidebar becomes an off-canvas drawer. */
export const DRAWER_QUERY = "(max-width: 767.98px)";

function useMedia(query: string): boolean {
  return useSyncExternalStore(
    (cb) => {
      const mq = window.matchMedia?.(query);
      mq?.addEventListener?.("change", cb);
      return () => mq?.removeEventListener?.("change", cb);
    },
    () => window.matchMedia?.(query).matches ?? false
  );
}

/** Props for {@link Layout}. */
interface LayoutProps {
  /** Live WebSocket status forwarded to the sidebar connection indicator. */
  wsConnected: boolean;
}

/**
 * Root layout wrapping all dashboard routes.
 * @param props See {@link LayoutProps}.
 */
export function Layout({ wsConnected }: LayoutProps) {
  const { t } = useTranslation("nav");
  const [collapsed, setCollapsed] = useState(loadCollapsed);
  const [connectionOpen, setConnectionOpen] = useState(false);
  const onboarding = useOnboarding();
  const [updateAvailable, setUpdateAvailable] = useState(false);
  const drawer = useMedia(DRAWER_QUERY);
  const [drawerOpen, setDrawerOpen] = useState(false);
  const closeDrawer = useCallback(() => setDrawerOpen(false), []);
  const { pathname, search } = useLocation();
  const [width, setWidth] = useState(loadWidth);
  const [resizing, setResizing] = useState(false);
  const sidebarWidth = drawer ? "0rem" : collapsed ? "4.25rem" : `${width}px`;

  const saveWidth = useCallback((px: number) => {
    const next = clampSidebar(px);
    setWidth(next);
    try {
      localStorage.setItem(WIDTH_KEY, String(next));
    } catch {}
  }, []);

  // A pick in the drawer navigates; the drawer has done its job.
  useEffect(closeDrawer, [pathname, search, closeDrawer]);
  useEffect(() => {
    if (!drawer) setDrawerOpen(false);
  }, [drawer]);

  const toggle = useCallback(() => {
    setCollapsed((prev) => {
      const next = !prev;
      try {
        localStorage.setItem(SIDEBAR_STORAGE_KEY, String(next));
      } catch {}
      return next;
    });
  }, []);

  return (
    <div className="min-h-screen bg-surface-0">
      <a href="#main-content" className="skip-to-content">
        {t("skipToContent")}
      </a>
      <UpdateNotifier />
      <InterruptedSessionsPrompt />
      <SagiMount />
      {onboarding.loaded && !onboarding.onboardedAt && (
        <Suspense fallback={null}>
          <OnboardingWizard />
        </Suspense>
      )}
      <OnboardingTour />
      {drawer && drawerOpen && (
        <div
          aria-hidden
          data-testid="sidebar-backdrop"
          onClick={closeDrawer}
          className="fixed inset-0 z-40 bg-black/50 animate-fade-in"
        />
      )}
      <Sidebar
        wsConnected={wsConnected}
        collapsed={drawer ? false : collapsed}
        onToggle={drawer ? closeDrawer : toggle}
        drawer={drawer ? { open: drawerOpen, onClose: closeDrawer } : undefined}
        connectionOpen={connectionOpen}
        onConnectionOpenChange={setConnectionOpen}
        onUpdateAvailableChange={setUpdateAvailable}
        width={width}
        resizing={resizing}
      />
      {!drawer && !collapsed && (
        <div
          role="separator"
          tabIndex={0}
          aria-orientation="vertical"
          aria-valuenow={width}
          aria-valuemin={SIDEBAR_MIN}
          aria-valuemax={SIDEBAR_MAX}
          aria-label={t("resizeSidebar")}
          title={t("resizeSidebar")}
          data-testid="sidebar-resize"
          className={`fixed top-0 bottom-0 z-30 w-1.5 -translate-x-1/2 cursor-col-resize outline-none transition-colors hover:bg-accent/40 focus-visible:bg-accent/60 ${
            resizing ? "bg-accent/60" : ""
          }`}
          style={{ left: width }}
          onPointerDown={(e) => {
            e.preventDefault();
            e.currentTarget.setPointerCapture?.(e.pointerId);
            setResizing(true);
          }}
          onPointerMove={(e) => {
            if (resizing) setWidth(clampSidebar(e.clientX));
          }}
          onPointerUp={(e) => {
            if (!resizing) return;
            setResizing(false);
            saveWidth(e.clientX);
          }}
          onPointerCancel={() => setResizing(false)}
          onDoubleClick={() => saveWidth(SIDEBAR_MIN)}
          onKeyDown={(e) => {
            if (e.key !== "ArrowLeft" && e.key !== "ArrowRight") return;
            e.preventDefault();
            saveWidth(width + (e.key === "ArrowRight" ? 16 : -16));
          }}
        />
      )}
      <main
        id="main-content"
        tabIndex={-1}
        className={`min-h-screen min-w-0 pb-6 duration-200 outline-none ${
          resizing ? "" : "transition-[margin-left,width]"
        }`}
        style={{
          marginLeft: sidebarWidth,
          width: `calc(100% - ${sidebarWidth})`,
        }}
      >
        {drawer && (
          <div className="sticky top-0 z-20 flex h-11 items-center gap-2 border-b border-border bg-surface-1 px-2">
            <button
              type="button"
              data-testid="sidebar-open"
              onClick={() => setDrawerOpen(true)}
              aria-label={t("openMenu")}
              aria-expanded={drawerOpen}
              title={t("openMenu")}
              className="btn-icon"
            >
              <Menu className="h-5 w-5" aria-hidden />
            </button>
            <span className="text-sm font-semibold text-fg-primary">{t("brand")}</span>
          </div>
        )}
        {/* overflow-x-clip (not -hidden) clips horizontal overflow without
            creating a scroll container, so descendant `position: sticky`
            elements (e.g. the Settings page TOC) still pin to the window. */}
        <div className="p-5 lg:p-6 max-w-full overflow-x-clip">
          <Outlet />
        </div>
      </main>
      <StatusBar
        wsConnected={wsConnected}
        left={sidebarWidth}
        onConnectionClick={() => setConnectionOpen(true)}
        updateAvailable={updateAvailable}
      />
    </div>
  );
}