import { createContext, useContext, useState, useCallback } from "react";
import api from "@/utils/api.util";
import { toast } from "sonner";

const StaffUserContext = createContext(null);

export const useStaffUsers = () => {
  const ctx = useContext(StaffUserContext);
  if (!ctx) throw new Error("useStaffUsers must be used inside StaffUserProvider");
  return ctx;
};

const PAGINATION_INIT = {
  page: 1,
  limit: 10,
  totalRecords: 0,
  totalPages: 0,
  hasPrevPage: false,
  hasNextPage: false,
};

const BASE = "/staff";

export const StaffUserProvider = ({ children }) => {
  const [users, setUsers]           = useState([]);
  const [user, setUser]             = useState(null);
  const [pagination, setPagination] = useState(PAGINATION_INIT);
  const [attributes, setAttributes] = useState([]);
  const [loading, setLoading]       = useState(false);
  const [error, setError]           = useState(null);

  const request = useCallback(async (fn) => {
    setLoading(true);
    setError(null);
    try {
      return await fn();
    } catch (err) {
      const message = err?.response?.data?.message || err.message || "Something went wrong.";
      setError(message);
      toast(message);
      return null;
    } finally {
      setLoading(false);
    }
  }, []);

  // ─── GET /api/staff/users ─────────────────────────────────────────────────
  // Returns users scoped to the logged-in staff member's groups.
  // Optional query: group_id or group_code to filter to one group.
  const fetchUsers = useCallback(
    ({ page = 1, limit = 10, group_id, group_code, filters = [], sort = [] } = {}) =>
      request(async () => {
        const { data } = await api.get(`${BASE}/users`, {
          params: {
            page, limit,
            ...(group_id   && { group_id }),
            ...(group_code && { group_code }),
            filters: filters.length ? JSON.stringify(filters) : undefined,
            sort:    sort.length    ? JSON.stringify(sort)    : undefined,
          },
        });
        const final_data = data?.data;
        setUsers(final_data?.data ?? []);
        setPagination(final_data?.pagination ?? PAGINATION_INIT);
        setAttributes(final_data?.attributes ?? []);
        return data?.data;
      }),
    [request]
  );

  // ─── GET /api/staff/users/:user_id ───────────────────────────────────────
  // Returns a single user profile — only if they share a group with the staff member.
  const fetchUser = useCallback(
    (userId) =>
      request(async () => {
        const res = await api.get(`${BASE}/users/${userId}`);
        setUser(res.data?.data ?? null);
        return res.data;
      }),
    [request]
  );

  return (
    <StaffUserContext.Provider value={{
      users, user, pagination, attributes, loading, error,
      setPagination,
      fetchUsers, fetchUser,
    }}>
      {children}
    </StaffUserContext.Provider>
  );
};