'use strict';

/**
 * Module dependencies
 */

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

// Utils
const {
  models: { getValuePrimaryKey },
} = require('strapi-utils');

const transformToArrayID = (array, association) => {
  if (_.isArray(array)) {
    array = array.map(value => {
      if (_.isPlainObject(value)) {
        return value._id || value.id || false;
      }

      return value;
    });

    return array.filter(n => n);
  }

  if (
    association.type === 'model' ||
    (association.type === 'collection' && _.isObject(array))
  ) {
    return _.isEmpty(_.toString(array)) ? [] : transformToArrayID([array]);
  }

  return [];
};

const getModel = (model, plugin) => {
  return (
    _.get(strapi.plugins, [plugin, 'models', model]) ||
    _.get(strapi, ['models', model]) ||
    undefined
  );
};

const removeUndefinedKeys = obj => _.pickBy(obj, _.negate(_.isUndefined));

module.exports = {
  async findOne(params, populate, { transacting } = {}) {
    const record = await this.forge({
      [this.primaryKey]: getValuePrimaryKey(params, this.primaryKey),
    }).fetch({
      transacting,
      withRelated: populate,
    });

    const data = record ? record.toJSON() : record;

    // Retrieve data manually.
    if (_.isEmpty(populate)) {
      const arrayOfPromises = this.associations
        .filter(association =>
          ['manyMorphToOne', 'manyMorphToMany'].includes(association.nature)
        )
        .map(() => {
          return this.morph
            .forge()
            .where({
              [`${this.collectionName}_id`]: getValuePrimaryKey(
                params,
                this.primaryKey
              ),
            })
            .fetchAll({
              transacting,
            });
        });

      const related = await Promise.all(arrayOfPromises);

      related.forEach((value, index) => {
        data[this.associations[index].alias] = value ? value.toJSON() : value;
      });
    }

    return data;
  },

  async update(params, { transacting } = {}) {
    const relationUpdates = [];
    const primaryKeyValue = getValuePrimaryKey(params, this.primaryKey);
    const response = await module.exports.findOne.call(this, params, null, {
      transacting,
    });

    // Only update fields which are on this document.
    const values =
      params.parseRelationships === false
        ? params.values
        : Object.keys(removeUndefinedKeys(params.values)).reduce(
            (acc, current) => {
              const property = params.values[current];
              const association = this.associations.filter(
                x => x.alias === current
              )[0];
              const details = this._attributes[current];

              if (!association && _.get(details, 'isVirtual') !== true) {
                return _.set(acc, current, property);
              }

              const assocModel = getModel(
                details.model || details.collection,
                details.plugin
              );
              switch (association.nature) {
                case 'oneWay': {
                  return _.set(
                    acc,
                    current,
                    _.get(property, assocModel.primaryKey, property)
                  );
                }
                case 'oneToOne': {
                  if (response[current] === property) return acc;

                  if (_.isNull(property)) {
                    const updatePromise = assocModel
                      .where({
                        [assocModel.primaryKey]: getValuePrimaryKey(
                          response[current],
                          assocModel.primaryKey
                        ),
                      })
                      .save(
                        { [details.via]: null },
                        {
                          method: 'update',
                          patch: true,
                          require: false,
                          transacting,
                        }
                      );

                    relationUpdates.push(updatePromise);
                    return _.set(acc, current, null);
                  }

                  // set old relations to null
                  const updateLink = this.where({ [current]: property })
                    .save(
                      { [current]: null },
                      {
                        method: 'update',
                        patch: true,
                        require: false,
                        transacting,
                      }
                    )
                    .then(() => {
                      return assocModel
                        .where({ [this.primaryKey]: property })
                        .save(
                          { [details.via]: primaryKeyValue },
                          {
                            method: 'update',
                            patch: true,
                            require: false,
                            transacting,
                          }
                        );
                    });

                  // set new relation
                  relationUpdates.push(updateLink);
                  return _.set(acc, current, property);
                }
                case 'oneToMany': {
                  // receive array of ids or array of objects with ids

                  // set relation to null for all the ids not in the list
                  const currentIds = response[current];
                  const toRemove = _.differenceWith(
                    currentIds,
                    property,
                    (a, b) => {
                      return (
                        `${a[assocModel.primaryKey] || a}` ===
                        `${b[assocModel.primaryKey] || b}`
                      );
                    }
                  );

                  const updatePromise = assocModel
                    .where(
                      assocModel.primaryKey,
                      'in',
                      toRemove.map(val => val[assocModel.primaryKey] || val)
                    )
                    .save(
                      { [details.via]: null },
                      {
                        method: 'update',
                        patch: true,
                        require: false,
                        transacting,
                      }
                    )
                    .then(() => {
                      return assocModel
                        .where(
                          assocModel.primaryKey,
                          'in',
                          property.map(val => val[assocModel.primaryKey] || val)
                        )
                        .save(
                          { [details.via]: primaryKeyValue },
                          {
                            method: 'update',
                            patch: true,
                            require: false,
                            transacting,
                          }
                        );
                    });

                  relationUpdates.push(updatePromise);
                  return acc;
                }
                case 'manyToOne': {
                  return _.set(
                    acc,
                    current,
                    _.get(property, assocModel.primaryKey, property)
                  );
                }
                case 'manyWay':
                case 'manyToMany': {
                  const currentValue = transformToArrayID(
                    response[current],
                    association
                  ).map(id => id.toString());
                  const storedValue = transformToArrayID(
                    params.values[current],
                    association
                  ).map(id => id.toString());

                  const toAdd = _.difference(storedValue, currentValue);
                  const toRemove = _.difference(currentValue, storedValue);

                  const collection = this.forge({
                    [this.primaryKey]: primaryKeyValue,
                  })[association.alias]();

                  const updatePromise = collection
                    .detach(toRemove, { transacting })
                    .then(() => collection.attach(toAdd, { transacting }));

                  relationUpdates.push(updatePromise);
                  return acc;
                }
                case 'manyMorphToMany':
                case 'manyMorphToOne':
                  // Update the relational array.
                  params.values[current].forEach(obj => {
                    const model = strapi.getModel(
                      obj.ref,
                      obj.source && obj.source !== 'content-manager'
                        ? obj.source
                        : null
                    );

                    // Remove existing relationship because only one file
                    // can be related to this field.
                    if (association.nature === 'manyMorphToOne') {
                      relationUpdates.push(
                        module.exports.removeRelationMorph
                          .call(
                            this,
                            {
                              alias: association.alias,
                              ref: model.collectionName,
                              refId: obj.refId,
                              field: obj.field,
                            },
                            { transacting }
                          )
                          .then(() =>
                            module.exports.addRelationMorph.call(
                              this,
                              {
                                id: response[this.primaryKey],
                                alias: association.alias,
                                ref: model.collectionName,
                                refId: obj.refId,
                                field: obj.field,
                              },
                              { transacting }
                            )
                          )
                      );
                    } else {
                      relationUpdates.push(
                        module.exports.addRelationMorph.call(
                          this,
                          {
                            id: response[this.primaryKey],
                            alias: association.alias,
                            ref: model.collectionName,
                            refId: obj.refId,
                            field: obj.field,
                          },
                          { transacting }
                        )
                      );
                    }
                  });
                  break;
                case 'oneToManyMorph':
                case 'manyToManyMorph': {
                  // Compare array of ID to find deleted files.
                  const currentValue = transformToArrayID(
                    response[current],
                    association
                  ).map(id => id.toString());
                  const storedValue = transformToArrayID(
                    params.values[current],
                    association
                  ).map(id => id.toString());

                  const toAdd = _.difference(storedValue, currentValue);
                  const toRemove = _.difference(currentValue, storedValue);

                  const model = getModel(
                    details.collection || details.model,
                    details.plugin
                  );

                  toAdd.forEach(id => {
                    relationUpdates.push(
                      module.exports.addRelationMorph.call(
                        model,
                        {
                          id,
                          alias: association.via,
                          ref: this.collectionName,
                          refId: response.id,
                          field: association.alias,
                        },
                        { transacting }
                      )
                    );
                  });

                  // Update the relational array.
                  toRemove.forEach(id => {
                    relationUpdates.push(
                      module.exports.removeRelationMorph.call(
                        model,
                        {
                          id,
                          alias: association.via,
                          ref: this.collectionName,
                          refId: response.id,
                          field: association.alias,
                        },
                        { transacting }
                      )
                    );
                  });
                  break;
                }
                case 'oneMorphToOne':
                case 'oneMorphToMany': {
                  break;
                }
                default:
              }

              return acc;
            },
            {}
          );

    await Promise.all(relationUpdates);

    delete values[this.primaryKey];
    if (!_.isEmpty(values)) {
      await this.forge({
        [this.primaryKey]: getValuePrimaryKey(params, this.primaryKey),
      }).save(values, {
        patch: true,
        transacting,
      });
    }

    const result = await this.forge({
      [this.primaryKey]: getValuePrimaryKey(params, this.primaryKey),
    }).fetch({
      transacting,
    });

    return result && result.toJSON ? result.toJSON() : result;
  },

  async addRelationMorph(params, { transacting } = {}) {
    const record = await this.morph
      .forge()
      .where({
        [`${this.collectionName}_id`]: params.id,
        [`${params.alias}_id`]: params.refId,
        [`${params.alias}_type`]: params.ref,
        field: params.field,
      })
      .fetch({
        transacting,
      });

    const entry = record ? record.toJSON() : record;

    if (entry) {
      return Promise.resolve();
    }

    return await this.morph
      .forge({
        [`${this.collectionName}_id`]: params.id,
        [`${params.alias}_id`]: params.refId,
        [`${params.alias}_type`]: params.ref,
        field: params.field,
      })
      .save(null, { transacting });
  },

  async removeRelationMorph(params, { transacting } = {}) {
    return await this.morph
      .forge()
      .where(
        _.omitBy(
          {
            [`${this.collectionName}_id`]: params.id,
            [`${params.alias}_id`]: params.refId,
            [`${params.alias}_type`]: params.ref,
            field: params.field,
          },
          _.isUndefined
        )
      )
      .destroy({
        require: false,
        transacting,
      });
  },
};