'use strict';

const _ = require('lodash');

function checkNamingCollision(association) {
  if (association.source.rawAttributes.hasOwnProperty(association.as)) {
    throw new Error(
      'Naming collision between attribute \'' + association.as +
      '\' and association \'' + association.as + '\' on model ' + association.source.name +
      '. To remedy this, change either foreignKey or as in your association definition'
    );
  }
}
exports.checkNamingCollision = checkNamingCollision;

function addForeignKeyConstraints(newAttribute, source, target, options, key) {
  // FK constraints are opt-in: users must either set `foreignKeyConstraints`
  // on the association, or request an `onDelete` or `onUpdate` behaviour

  if (options.foreignKeyConstraint || options.onDelete || options.onUpdate) {

    // Find primary keys: composite keys not supported with this approach
    const primaryKeys = _.chain(source.rawAttributes).keys()
      .filter(key => source.rawAttributes[key].primaryKey)
      .map(key => source.rawAttributes[key].field || key).value();

    if (primaryKeys.length === 1) {
      if (source._schema) {
        newAttribute.references = {
          model: source.sequelize.getQueryInterface().QueryGenerator.addSchema({
            tableName: source.tableName,
            _schema: source._schema,
            _schemaDelimiter: source._schemaDelimiter
          })
        };
      } else {
        newAttribute.references = { model: source.tableName };
      }

      newAttribute.references.key = key || primaryKeys[0];
      newAttribute.onDelete = options.onDelete;
      newAttribute.onUpdate = options.onUpdate;
    }
  }
}
exports.addForeignKeyConstraints = addForeignKeyConstraints;

/**
 * Mixin (inject) association methods to model prototype
 *
 * @private
 * @param {Object} Association instance
 * @param {Object} Model prototype
 * @param {Array} Method names to inject
 * @param {Object} Mapping between model and association method names
 */
function mixinMethods(association, obj, methods, aliases) {
  aliases = aliases || {};

  for (const method of methods) {
    // don't override custom methods
    if (!obj[association.accessors[method]]) {
      const realMethod = aliases[method] || method;

      obj[association.accessors[method]] = function() {
        const instance = this;
        const args = [instance].concat(Array.from(arguments));

        return association[realMethod].apply(association, args);
      };
    }
  }
}
exports.mixinMethods = mixinMethods;
