"use client";

import type {
  AccessControlProvider,
  AuthProvider,
  BaseRecord,
  CrudFilter,
  DataProvider,
  HttpError,
  CreateParams,
  DeleteOneParams,
  GetListParams,
  GetOneParams,
  UpdateParams,
} from "@refinedev/core";

export type AdminIdentity = {
  id: string;
  email: string;
  name: string;
  roles: string[];
  permissions: string[];
  requiresMfa: boolean;
};

const apiBase = "/api/admin";
let identityCache: AdminIdentity | null = null;

function logicalFilters(filters: CrudFilter[] | undefined) {
  return (filters ?? []).filter(
    (filter): filter is Extract<CrudFilter, { field: string }> =>
      "field" in filter,
  );
}

export async function adminRequestJson<T>(
  url: string,
  init?: RequestInit,
): Promise<T> {
  const response = await fetch(url, {
    cache: "no-store",
    credentials: "same-origin",
    ...init,
    headers: {
      ...(init?.body ? { "content-type": "application/json" } : {}),
      ...init?.headers,
    },
  });
  const payload = await response.json().catch(() => null);
  if (!response.ok) {
    const message =
      payload && typeof payload.error === "string"
        ? payload.error
        : "后台请求失败";
    throw Object.assign(new Error(message), {
      statusCode: response.status,
    } satisfies Partial<HttpError>);
  }
  return payload as T;
}

function listParams(
  pagination: { currentPage?: number; pageSize?: number } | undefined,
  sorters: { field: string; order: "asc" | "desc" }[] | undefined,
  filters: CrudFilter[] | undefined,
) {
  const search = new URLSearchParams({
    page: String(pagination?.currentPage ?? 1),
    pageSize: String(pagination?.pageSize ?? 20),
  });
  const sorter = sorters?.[0];
  if (sorter) {
    search.set("sort", sorter.field);
    search.set("order", sorter.order);
  }
  for (const filter of logicalFilters(filters)) {
    if (
      filter.value === undefined ||
      filter.value === null ||
      filter.value === ""
    )
      continue;
    if (filter.field === "q" || filter.field === "status") {
      search.set(filter.field, String(filter.value));
    }
  }
  return search;
}

export const adminDataProvider: DataProvider = {
  async getList<TData extends BaseRecord>({
    resource,
    pagination,
    sorters,
    filters,
  }: GetListParams) {
    const search = listParams(pagination, sorters, filters);
    return adminRequestJson<{ data: TData[]; total: number }>(
      `${apiBase}/${resource}?${search}`,
    );
  },
  async getOne<TData extends BaseRecord>({ resource, id }: GetOneParams) {
    return adminRequestJson<{ data: TData }>(`${apiBase}/${resource}/${id}`);
  },
  async create<TData extends BaseRecord, TVariables>({
    resource,
    variables,
  }: CreateParams<TVariables>) {
    return adminRequestJson<{ data: TData }>(`${apiBase}/${resource}`, {
      method: "POST",
      body: JSON.stringify(variables),
    });
  },
  async update<TData extends BaseRecord, TVariables>({
    resource,
    id,
    variables,
  }: UpdateParams<TVariables>) {
    return adminRequestJson<{ data: TData }>(`${apiBase}/${resource}/${id}`, {
      method: "PATCH",
      body: JSON.stringify(variables),
    });
  },
  async deleteOne<TData extends BaseRecord, TVariables>({
    resource,
    id,
  }: DeleteOneParams<TVariables>) {
    return adminRequestJson<{ data: TData }>(`${apiBase}/${resource}/${id}`, {
      method: "DELETE",
    });
  },
  getApiUrl: () => apiBase,
};

async function loadIdentity(): Promise<AdminIdentity> {
  if (identityCache) return identityCache;
  const payload = await adminRequestJson<{ user: AdminIdentity }>(
    `${apiBase}/session`,
  );
  identityCache = payload.user;
  return identityCache;
}

export const adminAuthProvider: AuthProvider = {
  async login() {
    return { success: false, redirectTo: "/login" };
  },
  async logout() {
    identityCache = null;
    await fetch("/api/auth/sign-out", {
      method: "POST",
      credentials: "same-origin",
    });
    return { success: true, redirectTo: "/login" };
  },
  async check() {
    try {
      await loadIdentity();
      return { authenticated: true };
    } catch (error) {
      const status = (error as HttpError).statusCode;
      return {
        authenticated: false,
        redirectTo: status === 401 ? "/login" : "/",
        error: error as HttpError,
      };
    }
  },
  async onError(error) {
    const status = (error as HttpError)?.statusCode;
    if (status === 401) return { redirectTo: "/login", logout: true };
    if (status === 403) return { error: error as HttpError };
    return { error: error as HttpError };
  },
  async getPermissions() {
    return (await loadIdentity()).permissions;
  },
  async getIdentity() {
    return loadIdentity();
  },
};

const resourcePermissions: Record<string, { read: string; write?: string }> = {
  administrators: {
    read: "admin.users.read",
    write: "admin.users.manage_roles",
  },
  roles: { read: "admin.users.read" },
  customers: { read: "admin.customers.read" },
  "account-deletions": { read: "admin.customers.read" },
  codes: { read: "admin.access", write: "admin.access" },
  "credit-transactions": { read: "billing.orders.read" },
  consultations: { read: "billing.orders.read" },
  "audit-logs": { read: "audit.read" },
  "moderation-events": { read: "audit.read" },
  payments: { read: "billing.orders.read" },
  packages: { read: "billing.products.read", write: "billing.products.write" },
  products: { read: "billing.products.read", write: "billing.products.write" },
  "feature-pricing": { read: "billing.products.read", write: "billing.products.write" },
  "pricing-simulator": { read: "billing.products.read" },
  subscriptions: {
    read: "billing.orders.read",
    write: "billing.adjustments.write",
  },
  orders: { read: "billing.orders.read", write: "billing.adjustments.write" },
  usage: { read: "billing.orders.read" },
  "rectification-telemetry": { read: "admin.customers.read" },
  feedback: { read: "support.feedback.read", write: "support.feedback.write" },
  models: { read: "models.read", write: "models.write" },
  "model-releases": { read: "models.read", write: "models.publish" },
  "feature-flags": { read: "admin.access", write: "ops.flags.write" },
  security: { read: "admin.access", write: "admin.access" },
};

export const adminAccessControlProvider: AccessControlProvider = {
  async can({ resource, action }) {
    const identity = await loadIdentity();
    const required = resourcePermissions[resource ?? ""];
    if (!required) return { can: false, reason: "未知管理资源" };
    const permission =
      action === "list" || action === "show" ? required.read : required.write;
    return permission && identity.permissions.includes(permission)
      ? { can: true }
      : { can: false, reason: "无此操作权限" };
  },
  options: {
    buttons: { enableAccessControl: true, hideIfUnauthorized: true },
  },
};