"use client";

import { createContext, PropsWithChildren, useCallback, useContext, useMemo, useState } from "react";

type DevFlags = {
  opsPopup: boolean;
  eventDebug: boolean;
  abBanner: boolean;
};

type DevFlagsContextValue = {
  flags: DevFlags;
  setFlag: (key: keyof DevFlags, value: boolean) => void;
};

const STORAGE_KEY = "download_nova_dev_flags";

const defaultFlags: DevFlags = {
  opsPopup: false,
  eventDebug: false,
  abBanner: false,
};

const DevFlagsContext = createContext<DevFlagsContextValue | null>(null);

function readFlags(): DevFlags {
  if (typeof window === "undefined") return defaultFlags;
  const raw = localStorage.getItem(STORAGE_KEY);
  if (!raw) return defaultFlags;
  try {
    return { ...defaultFlags, ...(JSON.parse(raw) as Partial<DevFlags>) };
  } catch {
    return defaultFlags;
  }
}

export function DeveloperFlagsProvider({ children }: PropsWithChildren) {
  const [flags, setFlags] = useState<DevFlags>(() => readFlags());

  const setFlag = useCallback((key: keyof DevFlags, value: boolean) => {
    const next = { ...flags, [key]: value };
    setFlags(next);
    if (typeof window !== "undefined") localStorage.setItem(STORAGE_KEY, JSON.stringify(next));
  }, [flags]);

  const value = useMemo(() => ({ flags, setFlag }), [flags, setFlag]);
  return <DevFlagsContext.Provider value={value}>{children}</DevFlagsContext.Provider>;
}

export function useDeveloperFlags() {
  const ctx = useContext(DevFlagsContext);
  if (!ctx) throw new Error("useDeveloperFlags must be used within DeveloperFlagsProvider");
  return ctx;
}