'use strict';

/**
 * Module dependencies
 */

// Public node modules.
const _ = require('lodash');

// Local utils.
const actionUtil = require('../actionUtil');
const associationUtil = require('../associationUtil');

/**
 * Destroy an entry
 */

module.exports = function destroy(_ctx) {
  const deferred = Promise.defer();

  // Return the model used.
  const Model = actionUtil.parseModel(_ctx);

  // Locate and validate the required `id` parameter.
  const pk = actionUtil.requirePk(_ctx);

  // First, check if the record exists.
  const query = Model.findOne(pk);
  query.exec(function foundRecord(err, record) {
    if (err) {
      _ctx.status = 500;
      deferred.reject(err);
    }

    // Record not found.
    if (!record) {
      _ctx.status = 404;
      deferred.reject({
        message: 'No record found with the specified `id`.'
      });
    }

    // Destroy the record.
    Model.destroy(pk).exec(function destroyedRecord(err, deletedRecords) {
      if (err) {
        _ctx.status = 500;
        return deferred.reject(err);
      }

      // Select the first object of the updated records.
      const deletedRecord = deletedRecords[0];

      // Update the `oneToOne` relations.
      const relationPromises = [];
      _.forEach(_.where(Model.associations, {nature: 'oneToOne'}), function (relation) {
        relationPromises.push(associationUtil.removeRelationsOut(_ctx.model || _ctx.params.model, deletedRecord.id, relation.model));
      });

      // Update the `oneToMany` relations.
      _.forEach(_.where(Model.associations, {nature: 'oneToMany'}), function (relation) {
        relationPromises.push(associationUtil.removeRelationsOut(_ctx.model || _ctx.params.model, deletedRecord.id, relation.collection));
      });

      Promise.all(relationPromises)

        // Related records updated.
        .then(function () {
          deferred.resolve(deletedRecord);
        })

        // Error during related records update.
        .catch(function (err) {
          _ctx.status = 500;
          deferred.reject(err);
        });
    });
  });

  return deferred.promise;
};