felixgirault/essence.js

import {Map} from 'immutable';
import {set, reduce} from 'lodash';



/**
 *
 */
export default function createResponse(props = Map()) {

    /**
     *    Tells if the response is empty.
     *
     *    @return bool
     */
    const isEmpty = () =>
        !props.size;

    /**
     *    Tells if the response has any data for the given key.
     *
     *    @param string key Key.
     *    @return bool
     */
    const hasProp = (key) =>
        props.has(key);

    /**
     *    Returns the first data available for the given key.
     *
     *    @param string key Key.
     *    @param string missing Value to be returned if the key
     *        does not exists.
     *    @return mixed Data.
     */
    const firstProp = (key, missing) => {
        const all = allProps(key);

        return all.length
            ? all[0]
            : missing;
    };

    /**
     *    Returns all data available for the given key.
     *
     *    @param string key Key.
     *    @return array Data.
     */
    const allProps = (key) =>
        props.get(key, []);

    /**
     *    Returns all keys that has any associated data.
     *
     * @return array Data.
     */
    const allKeys = () =>
        props.keySeq().toArray();

    /**
     *    Returns number of data associated to the given key.
     *
     *    @param string key Key.
     *    @return int Count.
     */
    const propCount = (key) =>
        allProps(key).length;

    /**
     *
     */
    const propGroups = (keys) => {
        const groups = [];

        keys.forEach((key) => {
            allProps(key).forEach((value, i) => {
                set(groups, [i, key], value);
            });
        });

        return groups;
    };

    const allPropGroups = () =>
        propGroups(allKeys());

    /**
     *    Returns a new response with the given prop.
     *
     *    @param string key Key.
     *    @param mixed value Value.
     *    @return Response Response.
     */
    const withProp = (key, value) => {
        const all = allProps(key);
        const values = all.concat(value);

        return createResponse(
            props.set(key, values)
        );
    };

    /**
     *    Returns a new response with the given props.
     *
     *    @param object newProps New Props.
     *    @return Response Response.
     */
    const withProps = (newProps) =>
        reduce(
            newProps,
            (res, value, key) =>
                res.withProp(key, value),
            createResponse(props)
        );

    /**
     *    Returns a JSON representation of the response.
     *
     *    @param int spaces Number of spaces used for indentation.
     */
    const toJson = (spaces) =>
        JSON.stringify(
            allPropGroups(),
            null,
            spaces
        );

    return {
        isEmpty,
        withProp,
        withProps,
        toJson,
        has: hasProp,
        first: firstProp,
        get: firstProp,
        all: allProps,
        keys: allKeys,
        count: propCount,
        groups: propGroups,
        allGroups: allPropGroups
    };
};