const {
  datacenter,
  portal,
  deploymentGroups,
  services,
  instances
} = require('./data.json');

const find = (query = {}) => item =>
  Object.keys(query).every(key => item[key] === query[key]);

const cleanQuery = (q = {}) => JSON.parse(JSON.stringify(q));

const getInstances = query =>
  Promise.resolve(instances.filter(find(cleanQuery(query))));

const getServices = query => {
  const instancesResolver = ({ id }) => query =>
    getInstances(
      Object.assign({}, query, {
        serviceId: id
      })
    );

  const addNestedResolvers = service =>
    Object.assign({}, service, {
      instances: instancesResolver(service)
    });

  return Promise.resolve(
    services.filter(find(cleanQuery(query))).map(addNestedResolvers)
  );
};

const getDeploymentGroups = query => {
  const servicesResolver = ({ id }) => query =>
    getServices(
      Object.assign({}, query, {
        deploymentGroupId: id
      })
    );

  const addNestedResolvers = dg =>
    Object.assign({}, dg, {
      services: servicesResolver(dg)
    });

  return Promise.resolve(
    deploymentGroups.filter(find(cleanQuery(query))).map(addNestedResolvers)
  );
};

const getPortal = () =>
  Promise.resolve(
    Object.assign({}, portal, {
      datacenter,
      deploymentGroups: getDeploymentGroups
    })
  );

module.exports = {
  portal: getPortal,
  deploymentGroups: getDeploymentGroups,
  deploymentGroup: query => getDeploymentGroups(query),
  services: getServices,
  service: query => getServices(query).then(services => services.shift()),
  instances: getInstances,
  instance: query => getInstances(query).then(instances => instances.shift())
};