import { useEffect, useState } from "react";
import { NavLink, Outlet, useLocation } from "react-router-dom";

import { NAVIGATION_ROUTES, routePath } from "../../contracts/routes.js";
import { useSession } from "../providers/session-provider.jsx";
import { useTheme } from "../providers/theme-provider.jsx";

const SESSION_LABELS = Object.freeze({
  authenticated: "인증됨",
  unauthenticated: "로그인 전",
  "recovery-pending": "복구 대기",
  "integration-failed": "연동 필요",
});

export function AppShell() {
  const location = useLocation();
  const { sessionState, beginSignIn, signOut, recover } = useSession();
  const { preference, setPreference } = useTheme();
  const [navigationOpen, setNavigationOpen] = useState(false);
  const [sessionActionPending, setSessionActionPending] = useState(false);
  const [sessionActionFailed, setSessionActionFailed] = useState(false);

  useEffect(() => {
    setNavigationOpen(false);
  }, [location.pathname]);

  useEffect(() => {
    if (!navigationOpen) return undefined;
    /** @param {KeyboardEvent} event */
    const closeOnEscape = (event) => {
      if (event.key === "Escape") setNavigationOpen(false);
    };
    window.addEventListener("keydown", closeOnEscape);
    return () => window.removeEventListener("keydown", closeOnEscape);
  }, [navigationOpen]);

  async function runSessionAction() {
    setSessionActionPending(true);
    setSessionActionFailed(false);
    try {
      if (sessionState === "authenticated") {
        await signOut();
      } else if (sessionState === "recovery-pending") {
        await recover();
      } else {
        await beginSignIn(
          `${location.pathname}${location.search}${location.hash}`,
        );
      }
    } catch {
      setSessionActionFailed(true);
    } finally {
      setSessionActionPending(false);
    }
  }

  const sessionActionLabel =
    sessionState === "authenticated"
      ? "로그아웃"
      : sessionState === "recovery-pending"
        ? "세션 복구"
        : "로그인";
  const integrationAvailable = sessionState !== "integration-failed";

  return (
    <div className="app-shell">
      <a className="skip-link" href="#main-content">
        본문으로 건너뛰기
      </a>
      <header className="app-shell__header">
        <button
          className="app-shell__menu-button"
          type="button"
          aria-controls="primary-navigation"
          aria-expanded={navigationOpen}
          onClick={() => setNavigationOpen((open) => !open)}
        >
          <span aria-hidden="true">☰</span>
          <span>메뉴</span>
        </button>
        <NavLink className="app-shell__brand" to={routePath("APP_HOME")}>
          Frontend Skeleton
        </NavLink>
        <div className="app-shell__session">
          <label className="visually-hidden" htmlFor="theme-preference">
            색상 테마
          </label>
          <select
            className="theme-selector"
            id="theme-preference"
            value={preference}
            onChange={(event) =>
              setPreference(
                /** @type {"system" | "light" | "dark"} */ (
                  event.currentTarget.value
                ),
              )
            }
          >
            <option value="system">시스템 테마</option>
            <option value="light">라이트 테마</option>
            <option value="dark">다크 테마</option>
          </select>
          <span className="session-status" data-state={sessionState}>
            {SESSION_LABELS[sessionState]}
          </span>
          {integrationAvailable ? (
            <button
              className="ui-button ui-button--compact"
              type="button"
              disabled={sessionActionPending}
              onClick={() => void runSessionAction()}
            >
              {sessionActionPending ? "처리 중…" : sessionActionLabel}
            </button>
          ) : null}
        </div>
        {sessionActionFailed ? (
          <p className="app-shell__session-error" role="alert">
            세션 작업을 완료하지 못했습니다.
          </p>
        ) : null}
      </header>
      <aside
        className="app-shell__sidebar"
        data-open={navigationOpen}
        aria-label="사이드바"
      >
        <nav id="primary-navigation" aria-label="주요 탐색">
          <ul className="app-navigation">
            {NAVIGATION_ROUTES.map((definition) => (
              <li key={definition.routeId}>
                <NavLink
                  className={({ isActive }) =>
                    `app-navigation__link${isActive ? " is-active" : ""}`
                  }
                  end={definition.path === "/"}
                  to={definition.path}
                >
                  {definition.navigationLabel}
                </NavLink>
              </li>
            ))}
          </ul>
        </nav>
      </aside>
      {navigationOpen ? (
        <button
          className="app-shell__scrim"
          type="button"
          aria-label="메뉴 닫기"
          onClick={() => setNavigationOpen(false)}
        />
      ) : null}
      <main className="app-shell__content" id="main-content" tabIndex={-1}>
        <Outlet />
      </main>
    </div>
  );
}