import { useState, useRef, useEffect } from "react";
import { useAuth } from "@/hooks/use-auth";
import {
  useGetMePreferences,
  useUpdateMePreferences,
  getGetMePreferencesQueryKey,
  type UserPreferences,
} from "@workspace/api-client-react";

export type ViewMode = "grid" | "table" | "rows";
export type Density = "cozy" | "compact";

const LS_KEY = "toolrate:browse-preferences";
const VIEWS = new Set<string>(["grid", "table", "rows"]);
const DENSITIES = new Set<string>(["cozy", "compact"]);

export function isViewMode(v: string | null): v is ViewMode {
  return v !== null && VIEWS.has(v);
}

export function isDensity(v: string | null): v is Density {
  return v !== null && DENSITIES.has(v);
}

function readLocal(): Partial<UserPreferences> {
  try {
    const raw = window.localStorage.getItem(LS_KEY);
    if (!raw) return {};
    const parsed = JSON.parse(raw) as Record<string, unknown>;
    return {
      ...(isViewMode(typeof parsed.view === "string" ? parsed.view : null) ? { view: parsed.view as ViewMode } : {}),
      ...(isDensity(typeof parsed.density === "string" ? parsed.density : null) ? { density: parsed.density as Density } : {}),
    };
  } catch {
    return {};
  }
}

function writeLocal(prefs: Partial<UserPreferences>) {
  try {
    window.localStorage.setItem(LS_KEY, JSON.stringify(prefs));
  } catch {
    /* ignore */
  }
}

export function useBrowsePreferences() {
  const { isAuthenticated } = useAuth();
  const [localPrefs, setLocalPrefs] = useState(readLocal);
  const syncTimer = useRef<ReturnType<typeof setTimeout> | null>(null);

  const { data: serverPrefs } = useGetMePreferences({
    query: {
      queryKey: getGetMePreferencesQueryKey(),
      enabled: isAuthenticated,
      retry: false,
      staleTime: 5 * 60 * 1000,
    },
  });
  const { mutate: updatePrefs } = useUpdateMePreferences();

  function persist(view: ViewMode, density: Density) {
    const prefs: Partial<UserPreferences> = { view, density };
    setLocalPrefs(prefs);
    writeLocal(prefs);
    if (isAuthenticated) {
      if (syncTimer.current) clearTimeout(syncTimer.current);
      syncTimer.current = setTimeout(() => updatePrefs({ data: prefs }), 400);
    }
  }

  useEffect(
    () => () => {
      if (syncTimer.current) clearTimeout(syncTimer.current);
    },
    [],
  );

  const serverView = isViewMode(serverPrefs?.view ?? null) ? serverPrefs!.view : undefined;
  const serverDensity = isDensity(serverPrefs?.density ?? null) ? serverPrefs!.density : undefined;

  return {
    serverView,
    serverDensity,
    localView: localPrefs.view,
    localDensity: localPrefs.density,
    persist,
  };
}