/**
 * @file Sagi.tsx
 * @description Floating mascot companion shell. Mounts once (next to UpdateNotifier
 *   in Layout) so it persists across routes and shares the single WebSocket.
 *   Owns the open/closed panel state, the ⌘B / Esc shortcuts, reduced-motion
 *   detection, and route navigation. Reactive personality + status/Ask come
 *   from useSagiBrain; the avatar is draggable (AssistiveTouch-style) via
 *   useSagiPosition, and the bubble/panel render in a self-clamping flyout so
 *   they never spill off any screen edge regardless of where the mascot is docked.
 *
 *   The "do the job" path: an unmatched Ask query starts a claude session in
 *   the "Sagi" workspace carrying it as the first prompt, then opens that
 *   workspace's session view (`/workspace?lane=<id>&run=<runId>`) — no new LLM
 *   backend. ⌘B/Ctrl+B is taken only while the mascot is shown and focus is not
 *   in an editable field (a terminal's Ctrl+B is tmux's prefix).
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */
/* =============================================================================
 * MODULE_GUIDE — extended in-file reference (comments only; safe to read, never executed)
 * =============================================================================
 * **Purpose:** Sagi is the optional on-screen mascot assistant — quips, intents, and lightweight event reactions layered above the dashboard chrome.
 *
 * ## 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
 * - `./SagiAvatar`
 * - `./SpeechBubble`
 * - `./SagiPanel`
 * - `./useSagiBrain`
 * - `./useSagiPosition`
 * - `./intents`
 * - `./prefs`
 *
 * ## Public surface
 * - `Sagi` — 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).
 * -----------------------------------------------------------------------------
 * **Sagi**
 *   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 {
  useCallback,
  useEffect,
  useLayoutEffect,
  useRef,
  useState,
  type CSSProperties,
  type ReactNode,
} from "react";
import { useNavigate } from "react-router-dom";
import { useTranslation } from "react-i18next";
import { SagiAvatar } from "./SagiAvatar";
import { PetSprite } from "./PetSprite";
import { PetMenu } from "./PetMenu";
import { SpeechBubble } from "./SpeechBubble";
import { SagiPanel } from "./SagiPanel";
import { useSagiBrain } from "./useSagiBrain";
import { useSagiPosition } from "./useSagiPosition";
import { matchIntent } from "./intents";
import { sagiPrefs } from "./prefs";
import { api } from "../../lib/api";
import "./sagi.css";

const FLYOUT_GAP = 10; // px between avatar and flyout
const VIEWPORT_MARGIN = 12; // min gap from any screen edge

/** True while focus sits where typing happens (an input, a terminal's textarea). */
function isEditable(el: EventTarget | null): boolean {
  if (!(el instanceof HTMLElement)) return false;
  return (
    el.isContentEditable ||
    el.tagName === "INPUT" ||
    el.tagName === "TEXTAREA" ||
    el.tagName === "SELECT"
  );
}

interface Anchor {
  left: number;
  top: number;
  size: number;
  side: "left" | "right";
  openUp: boolean;
  dragging: boolean;
}

/** The OS "reduce motion" preference, followed live. */
export function usePrefersReducedMotion(): boolean {
  const [reduced, setReduced] = useState(
    () =>
      typeof window !== "undefined" &&
      window.matchMedia?.("(prefers-reduced-motion: reduce)").matches
  );
  useEffect(() => {
    const mq = window.matchMedia?.("(prefers-reduced-motion: reduce)");
    if (!mq) return;
    const onChange = () => setReduced(mq.matches);
    mq.addEventListener?.("change", onChange);
    return () => mq.removeEventListener?.("change", onChange);
  }, []);
  return reduced;
}

/**
 * Fixed-position wrapper that places its content next to the avatar and clamps
 * it inside the viewport. It measures itself (and re-measures on content/size
 * changes via ResizeObserver) so a tall panel near a screen edge slides fully
 * into view instead of being cropped.
 */
/** `front`: above the mascot itself — the pet menu, which may overlap it. */
function SagiFlyout({
  anchor,
  children,
  front = false,
}: {
  anchor: Anchor;
  children: ReactNode;
  front?: boolean;
}) {
  const ref = useRef<HTMLDivElement>(null);
  const [style, setStyle] = useState<CSSProperties>({ visibility: "hidden" });

  const place = useCallback(() => {
    const el = ref.current;
    if (!el) return;
    const w = el.offsetWidth;
    const h = el.offsetHeight;
    const vw = window.innerWidth;
    const vh = window.innerHeight;

    // Horizontal: hug the avatar's docked edge, then clamp on-screen.
    let left = anchor.side === "left" ? anchor.left : anchor.left + anchor.size - w;
    left = Math.min(vw - w - VIEWPORT_MARGIN, Math.max(VIEWPORT_MARGIN, left));

    // Vertical: prefer above the mascot (feels natural). Only drop below when
    // there isn't room above - i.e. the mascot is near the top edge.
    const above = anchor.top - h - FLYOUT_GAP;
    const below = anchor.top + anchor.size + FLYOUT_GAP;
    let top = above >= VIEWPORT_MARGIN ? above : below;
    top = Math.min(vh - h - VIEWPORT_MARGIN, Math.max(VIEWPORT_MARGIN, top));

    setStyle({ left, top, visibility: "visible" });
  }, [anchor.left, anchor.top, anchor.size, anchor.side, anchor.openUp]);

  useLayoutEffect(() => {
    place();
    const el = ref.current;
    if (!el || typeof ResizeObserver === "undefined") return;
    const ro = new ResizeObserver(() => place());
    ro.observe(el);
    window.addEventListener("resize", place);
    return () => {
      ro.disconnect();
      window.removeEventListener("resize", place);
    };
  }, [place]);

  return (
    <div
      ref={ref}
      className="sagi-flyout"
      // Mirrors the avatar button: eased left/top so the flyout glides along
      // with the mascot when it snaps to an edge, 1:1 (no easing) mid-drag.
      data-dragging={anchor.dragging ? "1" : "0"}
      data-front={front ? "1" : undefined}
      style={style}
    >
      {children}
    </div>
  );
}

export function Sagi() {
  const { t } = useTranslation("settings");
  const [enabled, setEnabled] = useState(() => sagiPrefs.getEnabled());
  const [pet, setPet] = useState(() => sagiPrefs.getPet());
  const [size, setSize] = useState(() => sagiPrefs.getSize());
  const [open, setOpen] = useState(false);
  // The right-click pet menu (`PetMenu.tsx`).
  const [menu, setMenu] = useState(false);
  const [hover, setHover] = useState(false);
  const reducedMotion = usePrefersReducedMotion();
  const navigate = useNavigate();
  const brain = useSagiBrain();
  const place = useSagiPosition(size);

  // Keep enabled, the pet and its size in sync with Settings / other tabs.
  useEffect(
    () =>
      sagiPrefs.subscribe(() => {
        setEnabled(sagiPrefs.getEnabled());
        setPet(sagiPrefs.getPet());
        setSize(sagiPrefs.getSize());
      }),
    []
  );

  // ⌘B / Ctrl+B toggles the panel; Esc closes it. Only while the mascot is
  // shown, and never from an editable field, where Ctrl+B belongs to the field.
  useEffect(() => {
    if (!enabled) return;
    const onKey = (e: KeyboardEvent) => {
      if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === "b") {
        if (isEditable(e.target) || isEditable(document.activeElement)) return;
        e.preventDefault();
        setOpen((v) => !v);
      } else if (e.key === "Escape") {
        setOpen(false);
      }
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  }, [enabled]);

  const onNavigate = useCallback(
    (route: string) => {
      navigate(route);
      setOpen(false);
    },
    [navigate]
  );

  const onAsk = useCallback(
    (query: string): string | null => {
      const result = matchIntent(query, brain.status);
      if (result.kind === "answer") return result.text;
      // Handoff: ensure the "Sagi" lane exists for this dashboard, spawn a
      // fresh claude session in it carrying the user's prompt as its first
      // message, then open that workspace's session view on the new pane.
      // Fire-and-forget — the panel already clears its composer on null and
      // closes; errors surface as an answer instead of silently swallowing.
      const prompt = result.prompt;
      brain.setThinking(true);
      (async () => {
        try {
          const { lane } = await api.lanes.ensure({ title: "Sagi" });
          const run = await api.run.start({
            laneId: lane.id,
            cwd: lane.cwd,
            initialPrompt: prompt,
            permissionMode: "acceptEdits",
          });
          navigate(`/workspace?lane=${lane.id}&run=${encodeURIComponent(run.id)}`);
          setOpen(false);
        } catch (err) {
          const msg = err instanceof Error ? err.message : String(err);
          brain.setBubble(t("sagi.startFailed", { error: msg }));
        } finally {
          brain.setThinking(false);
        }
      })();
      return null;
    },
    [brain, navigate, t]
  );

  if (!enabled) return null;

  const anchor: Anchor = {
    left: place.left,
    top: place.top,
    size: place.size,
    side: place.side,
    openUp: place.openUp,
    dragging: place.dragging,
  };

  return (
    <>
      {/* The panel is too big to drag around, so it hides mid-drag. The bubble
          does not - it is Sagi talking, and it has to stay by its mouth. */}
      {!place.dragging && open && (
        <SagiFlyout anchor={anchor}>
          <SagiPanel
            status={brain.status}
            muted={brain.muted}
            onToggleMute={brain.toggleMute}
            onClearAlerts={brain.clearAlerts}
            onNavigate={onNavigate}
            onAsk={onAsk}
            onClose={() => setOpen(false)}
          />
        </SagiFlyout>
      )}

      {!place.dragging && menu && (
        <SagiFlyout anchor={anchor} front>
          <PetMenu
            pet={pet}
            size={size}
            onClose={() => setMenu(false)}
            onSettings={() => {
              setMenu(false);
              navigate("/settings/appearance#pet");
            }}
          />
        </SagiFlyout>
      )}

      {!open && !menu && brain.bubble && (
        <SagiFlyout anchor={anchor}>
          <SpeechBubble text={brain.bubble} onDismiss={brain.dismissBubble} />
        </SagiFlyout>
      )}

      <button
        className="sagi-avatar-btn"
        data-dragging={place.dragging ? "1" : "0"}
        style={{ left: place.left, top: place.top, width: size, height: size }}
        onPointerEnter={() => setHover(true)}
        onPointerLeave={() => setHover(false)}
        onPointerDown={place.onPointerDown}
        onPointerMove={place.onPointerMove}
        onPointerUp={place.onPointerUp}
        onKeyDown={place.onKeyDown}
        onClick={() => {
          // A drag just ended - swallow the synthetic click so the panel
          // doesn't toggle when the user only repositioned the avatar.
          if (place.consumeDrag()) return;
          setOpen((v) => !v);
        }}
        // Right-click: the pet menu (hide, size, choose, upload, import).
        onContextMenu={(e) => {
          e.preventDefault();
          setOpen(false);
          setMenu(true);
        }}
        aria-label={open ? t("sagi.closeAvatar") : t("sagi.open")}
        aria-expanded={open}
        title={t("sagi.avatarTitle")}
      >
        {pet.id === "sagi" || !("kind" in pet) ? (
          <SagiAvatar mood={brain.mood} reducedMotion={reducedMotion} size={size} />
        ) : (
          <PetSprite
            id={pet.id}
            kind={pet.kind}
            mood={brain.mood}
            // Dragged → runs that way; hovered → waves (Codex's pet does both).
            action={place.moving ? `run-${place.moving}` : hover ? "wave" : null}
            size={size}
            reducedMotion={reducedMotion}
            // Deleted elsewhere, or unreadable: back to Sagi.
            onBroken={() => sagiPrefs.setPet({ id: "sagi" })}
          />
        )}
        {brain.status.errorCount > 0 && (
          <span className="sagi-error-dot" aria-hidden>
            {brain.status.errorCount > 9 ? "9+" : brain.status.errorCount}
          </span>
        )}
      </button>
    </>
  );
}