import { DataProvider, fetchUtils } from 'react-admin';
import { getValidAccessToken } from './auth/keycloak';
import { env } from './config/env';

const apiUrl = env.apiUrl;

const httpClient = async (url: string, options: fetchUtils.Options = {}) => {
  const token = await getValidAccessToken();
  const headers = new Headers(options.headers ?? { Accept: 'application/json' });
  headers.set('Authorization', `Bearer ${token}`);

  return fetchUtils.fetchJson(url, {
    ...options,
    headers,
  });
};

const dataProvider: DataProvider = {
  getList: async (resource, params) => {
    const { page, perPage } = params.pagination!;
    const { field, order } = params.sort!;
    const start = (page - 1) * perPage;
    const end = page * perPage;

    const query: Record<string, string> = {
      _start: String(start),
      _end: String(end),
      _sort: field,
      _order: order,
    };

    if (params.filter) {
      Object.keys(params.filter).forEach((key) => {
        const val = params.filter[key];
        if (val !== undefined && val !== null && val !== '') {
          query[key] = String(val);
        }
      });
    }

    const queryString = new URLSearchParams(query).toString();
    const url = `${apiUrl}/${resource}?${queryString}`;
    const { json, headers } = await httpClient(url);

    const contentRange = headers.get('Content-Range');
    const total = contentRange
      ? parseInt(contentRange.split('/').pop() || '0', 10)
      : json.length;

    return { data: json, total };
  },

  getOne: async (resource, params) => {
    const { json } = await httpClient(`${apiUrl}/${resource}/${params.id}`);
    return { data: json };
  },

  getMany: async (resource, params) => {
    const query = params.ids.map((id) => `id=${id}`).join('&');
    const { json } = await httpClient(`${apiUrl}/${resource}?${query}`);
    return { data: json };
  },

  getManyReference: async (resource, params) => {
    const { page, perPage } = params.pagination!;
    const { field, order } = params.sort!;
    const start = (page - 1) * perPage;
    const end = page * perPage;

    const query: Record<string, string> = {
      _start: String(start),
      _end: String(end),
      _sort: field,
      _order: order,
      [params.target]: String(params.id),
    };

    const queryString = new URLSearchParams(query).toString();
    const url = `${apiUrl}/${resource}?${queryString}`;
    const { json, headers } = await httpClient(url);

    const contentRange = headers.get('Content-Range');
    const total = contentRange
      ? parseInt(contentRange.split('/').pop() || '0', 10)
      : json.length;

    return { data: json, total };
  },

  create: async (resource, params) => {
    const { json } = await httpClient(`${apiUrl}/${resource}`, {
      method: 'POST',
      body: JSON.stringify(params.data),
    });
    return { data: json };
  },

  update: async (resource, params) => {
    const { json } = await httpClient(`${apiUrl}/${resource}/${params.id}`, {
      method: 'PATCH',
      body: JSON.stringify(params.data),
    });
    return { data: json };
  },

  updateMany: async (resource, params) => {
    const responses = await Promise.all(
      params.ids.map((id) =>
        httpClient(`${apiUrl}/${resource}/${id}`, {
          method: 'PATCH',
          body: JSON.stringify(params.data),
        })
      )
    );
    return { data: responses.map(({ json }) => json.id) };
  },

  delete: async (resource, params) => {
    const { json } = await httpClient(`${apiUrl}/${resource}/${params.id}`, {
      method: 'DELETE',
    });
    return { data: json };
  },

  deleteMany: async (resource, params) => {
    const responses = await Promise.all(
      params.ids.map((id) =>
        httpClient(`${apiUrl}/${resource}/${id}`, {
          method: 'DELETE',
        })
      )
    );
    return { data: responses.map(({ json }) => json.id) };
  },
};

export default dataProvider;