'use strict';
/* global <%= globalID %> */

/**
 * <%= filename %> service
 *
 * @description: A set of functions similar to controller's actions to avoid code duplication.
 */

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

module.exports = {

  /**
   * Promise to fetch all <%= humanizeIdPluralized %>.
   *
   * @return {Promise}
   */

  fetchAll: (params) => {
    // Convert `params` object to filters compatible with Mongo.
    const filters = strapi.utils.models.convertParams('<%= globalID.toLowerCase() %>', params);

    // Select field to populate.
    const populate = <%= globalID %>.associations
      .filter(ast => ast.autoPopulate)
      .reduce((acc, ast) => {
        // Strapi Model
        const model = ast.plugin
          ? strapi.plugins[ast.plugin].models[ast.collection || ast.model]
          : strapi.models[ast.collection || ast.model];

        const from = model.collectionName;
        const as = ast.alias;
        const localField = ast.dominant ? '_id' : ast.via === <%= globalID %>.collectionName || ast.via === 'related' ? '_id' : ast.alias;
        const foreignField = ast.filter ? `${ast.via}.ref` :
          ast.dominant ?
            (ast.via === <%= globalID %>.collectionName ? ast.via : '_id') :
            (ast.via === <%= globalID %>.collectionName ? '_id' : ast.via);

        // Add the juncture like the `.populate()` function
        acc.push({
          $lookup: {
            from,
            localField,
            foreignField,
            as,
          }
        });

        // Unwind the relation's result if only one is expected
        if (ast.type === 'model') {
          acc.push({
            $unwind: {
              path: `$${ast.alias}`,
              preserveNullAndEmptyArrays: true
            }
          });
        }

        // Preserve relation field if it is empty
        acc.push({
          $addFields: {
            [ast.alias]: {
              $ifNull: [`$${ast.alias}`, null]
            }
          }
        });

        // Filtrate the result depending of params
        if (filters.relations) {
          Object.keys(filters.relations).forEach(
            (relationName) => {
              if (ast.alias === relationName) {
                const association = <%= globalID %>.associations.find(a => a.alias === relationName);
                if (association) {
                  const relation = filters.relations[relationName];

                  Object.keys(relation).forEach(
                    (filter) => {
                      acc.push({
                        $match: { [`${relationName}.${filter}`]: relation[filter] }
                      });
                    }
                  );
                }
              }
            }
          );
        }

        return acc;
      }, []);

    const result = <%= globalID %>
      .aggregate([
        {
          $match: filters.where
        },
        ...populate,
      ])
      .skip(filters.start)
      .limit(filters.limit);

    if (filters.sort) result.sort(filters.sort);

    return result;
  },

  /**
   * Promise to fetch a/an <%= id %>.
   *
   * @return {Promise}
   */

  fetch: (params) => {
    // Select field to populate.
    const populate = <%= globalID %>.associations
      .filter(ast => ast.autoPopulate !== false)
      .map(ast => ast.alias)
      .join(' ');

    return <%= globalID %>
      .findOne(_.pick(params, _.keys(<%= globalID %>.schema.paths)))
      .populate(populate);
  },

  /**
   * Promise to count <%= humanizeIdPluralized %>.
   *
   * @return {Promise}
   */

  count: (params) => {
    // Convert `params` object to filters compatible with Mongo.
    const filters = strapi.utils.models.convertParams('<%= globalID.toLowerCase() %>', params);

    return <%= globalID %>
      .count()
      .where(filters.where);
  },

  /**
   * Promise to add a/an <%= id %>.
   *
   * @return {Promise}
   */

  add: async (values) => {
    // Extract values related to relational data.
    const relations = _.pick(values, <%= globalID %>.associations.map(ast => ast.alias));
    const data = _.omit(values, <%= globalID %>.associations.map(ast => ast.alias));

    // Create entry with no-relational data.
    const entry = await <%= globalID %>.create(data);

    // Create relational data and return the entry.
    return <%= globalID %>.updateRelations({ _id: entry.id, values: relations });
  },

  /**
   * Promise to edit a/an <%= id %>.
   *
   * @return {Promise}
   */

  edit: async (params, values) => {
    // Extract values related to relational data.
    const relations = _.pick(values, <%= globalID %>.associations.map(a => a.alias));
    const data = _.omit(values, <%= globalID %>.associations.map(a => a.alias));

    // Update entry with no-relational data.
    const entry = await <%= globalID %>.update(params, data, { multi: true });

    // Update relational data and return the entry.
    return <%= globalID %>.updateRelations(Object.assign(params, { values: relations }));
  },

  /**
   * Promise to remove a/an <%= id %>.
   *
   * @return {Promise}
   */

  remove: async params => {
    // Select field to populate.
    const populate = <%= globalID %>.associations
      .filter(ast => ast.autoPopulate !== false)
      .map(ast => ast.alias)
      .join(' ');

    // Note: To get the full response of Mongo, use the `remove()` method
    // or add spent the parameter `{ passRawResult: true }` as second argument.
    const data = await <%= globalID %>
      .findOneAndRemove(params, {})
      .populate(populate);

    if (!data) {
      return data;
    }

    await Promise.all(
      <%= globalID %>.associations.map(async association => {
        if (!association.via || !data._id) {
          return true;
        }

        const search = _.endsWith(association.nature, 'One') || association.nature === 'oneToMany' ? { [association.via]: data._id } : { [association.via]: { $in: [data._id] } };
        const update = _.endsWith(association.nature, 'One') || association.nature === 'oneToMany' ? { [association.via]: null } : { $pull: { [association.via]: data._id } };

        // Retrieve model.
        const model = association.plugin ?
          strapi.plugins[association.plugin].models[association.model || association.collection] :
          strapi.models[association.model || association.collection];

        return model.update(search, update, { multi: true });
      })
    );

    return data;
    },

  /**
   * Promise to search a/an <%= id %>.
   *
   * @return {Promise}
   */

  search: async (params) => {
    // Convert `params` object to filters compatible with Mongo.
    const filters = strapi.utils.models.convertParams('<%= globalID.toLowerCase() %>', params);
    // Select field to populate.
    const populate = <%= globalID %>.associations
      .filter(ast => ast.autoPopulate !== false)
      .map(ast => ast.alias)
      .join(' ');

    const $or = Object.keys(<%= globalID %>.attributes).reduce((acc, curr) => {
      switch (<%= globalID %>.attributes[curr].type) {
        case 'integer':
        case 'float':
        case 'decimal':
          if (!_.isNaN(_.toNumber(params._q))) {
            return acc.concat({ [curr]: params._q });
          }

          return acc;
        case 'string':
        case 'text':
        case 'password':
          return acc.concat({ [curr]: { $regex: params._q, $options: 'i' } });
        case 'boolean':
          if (params._q === 'true' || params._q === 'false') {
            return acc.concat({ [curr]: params._q === 'true' });
          }

          return acc;
        default:
          return acc;
      }
    }, []);

    return <%= globalID %>
      .find({ $or })
      .sort(filters.sort)
      .skip(filters.start)
      .limit(filters.limit)
      .populate(populate);
  }
};