import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import {
  DEFAULT_SETTINGS,
  type GlobalSettings,
  type GlobalSettingsUpdate,
  mergeSettings,
  type WebSearchTestResult,
} from "@umt/contracts";
import { apiData } from "~/lib/api.ts";
import { qk } from "~/lib/query-keys.ts";

export function useSettings() {
  return useQuery({
    queryKey: qk.settings,
    queryFn: ({ signal }) => apiData<GlobalSettings>("/settings", { signal }).then(withSettingsDefaults),
  });
}

/**
 * 后端比前端旧时(滚动升级、回滚)响应里会缺新加的 key;按 key 用默认值补齐,
 * 避免设置页读 `settings.<新key>.x` 直接崩掉。只补缺的,不覆盖已有值。
 */
export function withSettingsDefaults(s: GlobalSettings): GlobalSettings {
  const out: Record<string, unknown> = { ...s };
  for (const [k, def] of Object.entries(DEFAULT_SETTINGS)) {
    const cur = out[k];
    if (cur === undefined || cur === null) out[k] = def;
    else if (typeof def === "object" && !Array.isArray(def) && typeof cur === "object") out[k] = { ...def, ...cur };
  }
  return out as GlobalSettings;
}

/** PATCH /settings,乐观更新(失败回滚) */
export function useUpdateSettings() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (patch: GlobalSettingsUpdate) =>
      apiData<GlobalSettings>("/settings", { method: "PATCH", body: patch }).then(withSettingsDefaults),
    onMutate: async (patch) => {
      await qc.cancelQueries({ queryKey: qk.settings });
      const prev = qc.getQueryData<GlobalSettings>(qk.settings);
      if (prev) qc.setQueryData(qk.settings, mergeSettings(prev, patch));
      return { prev };
    },
    onError: (_e, _p, ctx) => {
      if (ctx?.prev) qc.setQueryData(qk.settings, ctx.prev);
    },
    onSuccess: (data) => {
      qc.setQueryData(qk.settings, data);
      qc.invalidateQueries({ queryKey: qk.dashboard });
    },
  });
}

/** POST /websearch/test:用已保存的搜索服务 Key 实际查一次 */
export function useTestWebSearch() {
  return useMutation({
    mutationFn: (body: { query?: string } = {}) =>
      apiData<WebSearchTestResult>("/websearch/test", { method: "POST", body }),
  });
}