type GraphQLResponse<T> = {
  data?: T;
  errors?: Array<{
    message: string;
    locations?: { line: number; column: number }[];
    path?: string[];
  }>;
};

export type Dataset = {
  id: number;
  name: string;
  description: string;
};

export async function list_datasets(): Promise<Dataset[]> {
  const query = `
    query {
      datasets {
        id
        name
        description
      }
    }
  `;
  return (await query_graphql<{datasets: Dataset[]}>(query)).datasets;
}

async function query_graphql<T>(query: string): Promise<T> {
  const response = await fetch('http://host.containers.internal:3000/graphql', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ query }),
  });

  if (!response.ok) {
    throw new Error(`Error - status ${response.status}`);
  }

  const result = await response.json() as GraphQLResponse<T>;

  if (result.errors) {
    throw new Error(result.errors.map(e => e.message).join(', '));
  }

  return result.data!;
}