'use strict';

const _ = require( 'lodash' );

const mixins = {
    /**
     * Return a new array containing only the unique objects inside the provided
     * array. Unlike _.uniq, this will check _every_ key/value in the array
     *
     * @param   {Array}     arr     Array of structurally identical objects
     * @return  {Array}
     * @example
     *
     * const objs = [ { x: 1, y: 2 }, { a: 1, b: 2 }, { x: 1, y: 2 }];
     *
     * console.log( _( objs ).uniqObjs().value() )
     * console.log( _.uniqObjs( objs ) )
     *
     * // => [ { x: 1, y: 2 }, { a: 1, b: 2 } ]
     */
    uniqObjs: arr => {
        // Make sure that the arr parameter is a defined & populated array of objects
        if( _.isUndefined( arr ) || ! _.isArray( arr ) || ! arr.length || ! _.isObject( arr[0] ) )
            return false;

        const uniqs = [];

        // Filter out the duplicate objects within the array by checking if
        // the stringified object value already exist in the temporary uniqs
        // array (while adding them to the variable)
        return _.filter( arr, ( obj ) => {
            // Use _.sortObj to sort the contents of the object by the keys, since stringify
            // will use the current order (which means identical objects in different orders
            // will be seen as discrepancies)
            if( _.indexOf( uniqs, JSON.stringify( mixins.sortObj( obj ) ) ) === -1 ){
                uniqs.push( JSON.stringify( mixins.sortObj( obj ) ) );
                return true;
            }

            return false;
        });
    },

    /**
     * Return a copy of the object with the content sorted by the keys
     *
     * @param   {Object}    obj         Object to sort by keys
     * @param   {Function}  comparator  Function to compare/sort the elements
     * @return  {Object}
     * @example
     *
     * const obj = {b: 3, c: 2, a: 1};
     *
     * console.log( _.sortObj( obj ) );
     * console.log( _( obj ).sortObj().value() );
     *
     * // => {a: 1, b: 3, c: 2}
     *
     * _.sortObj(obj, (value, key) => {
     *      return value;
     * });
     *
     * // => {a: 1, c: 2, b: 3}
     *
     *
     */
    sortObj: ( obj, comparator ) => {
        const keys = _.sortBy( _.keys( obj ), key => {
            return _.isFunction( comparator ) ? comparator(obj[key], key) : key;
        });

        return _.object(keys, _.map(keys, key => {
            return obj[key];
        }));
    }
};

_.mixin( mixins );

module.exports = _;