import { create } from "zustand";
import type { PlayerSession } from "../app/types";
import { requestOnlineJson } from "../app/onlineAccountClient";
import { DEFAULT_PARTY_BUFF_POLICY, normalizePartyBuffPolicy, type PartyBuffPolicy } from "./partyBuffPolicy";

interface PublishedPolicy {
  readonly revision: number;
  readonly updatedAt: number | null;
  readonly updatedBy?: string | null;
  readonly config: PartyBuffPolicy;
}
interface PolicyState extends PublishedPolicy {
  readonly draft: PartyBuffPolicy;
  readonly loading: boolean;
  readonly saving: boolean;
  readonly dirty: boolean;
  readonly error: string | null;
  refresh: (session?: PlayerSession | null) => Promise<void>;
  replaceDraft: (draft: PartyBuffPolicy) => void;
  resetDraft: () => void;
  publish: (session: PlayerSession | null) => Promise<boolean>;
}

const CACHE_KEY = "healer-man.party-buff-policy.v1";
function cached(): PublishedPolicy {
  try {
    const value = JSON.parse(window.localStorage.getItem(CACHE_KEY) ?? "null") as PublishedPolicy;
    if (!Number.isInteger(value.revision)) throw new Error("missing");
    return { ...value, config: normalizePartyBuffPolicy(value.config) };
  } catch {
    return { revision: 0, updatedAt: null, config: DEFAULT_PARTY_BUFF_POLICY };
  }
}
function cache(payload: PublishedPolicy): void {
  try { window.localStorage.setItem(CACHE_KEY, JSON.stringify(payload)); } catch { /* optional cache */ }
}

const initial = cached();
export const usePartyBuffPolicyStore = create<PolicyState>((set, get) => ({
  ...initial,
  draft: initial.config,
  loading: false,
  saving: false,
  dirty: false,
  error: null,
  refresh: async (session = null) => {
    set({ loading: true, error: null });
    try {
      const gm = Boolean(session?.accessToken && session.roles?.includes("gm"));
      const payload = await requestOnlineJson<PublishedPolicy>(
        gm ? "/api/gm/party-buff-policy" : "/api/party-buff-policy", {}, gm ? session?.accessToken : undefined,
      );
      const normalized = { ...payload, config: normalizePartyBuffPolicy(payload.config) };
      cache(normalized);
      set({ ...normalized, draft: normalized.config, loading: false, dirty: false });
    } catch (error) {
      set({ loading: false, error: error instanceof Error ? error.message : "Could not load party buff policy." });
    }
  },
  replaceDraft: (draft) => set({ draft: normalizePartyBuffPolicy(draft), dirty: true, error: null }),
  resetDraft: () => set((state) => ({ draft: state.config, dirty: false, error: null })),
  publish: async (session) => {
    if (!session?.accessToken || !session.roles?.includes("gm")) {
      set({ error: "Game Master access is required." });
      return false;
    }
    set({ saving: true, error: null });
    try {
      const payload = await requestOnlineJson<PublishedPolicy>("/api/gm/party-buff-policy", {
        method: "PUT", body: JSON.stringify({ expectedRevision: get().revision, config: get().draft }),
      }, session.accessToken);
      const normalized = { ...payload, config: normalizePartyBuffPolicy(payload.config) };
      cache(normalized);
      set({ ...normalized, draft: normalized.config, saving: false, dirty: false });
      return true;
    } catch (error) {
      set({ saving: false, error: error instanceof Error ? error.message : "Could not publish party buff policy." });
      return false;
    }
  },
}));