/***********************************************************************************

    Abstractor | JSON module | MIT License | ©2016 Hexagon <github.com/hexagon>

    JSON parser and stringifier. When feeded with an object, payload is 
    stringified to JSON and vice versa.

    ----------------------------------------------------------------------------


    I/O

    -------------------------------+----------------------+---------------------
    Incoming property              |  Possible triggers   |  Sets property
    -------------------------------+----------------------+---------------------
                                   |  success             |  payload
    payload: <json string>         +----------------------+---------------------
                                   |  error               |  error
    -------------------------------+----------------------+---------------------
                                   |  success             |  payload
    payload: <object>              +----------------------+---------------------
                                   |  error               |  error
    -------------------------------+----------------------+---------------------


***********************************************************************************/

"use strict";

const
    Node = require("../node.js");

class Json extends Node {

    invoke(msg) {
        
        let self = this,
            result;

        // ToDo, headers should have a default, and be passed to this.getConfig

        // Parse if we got a string
        if ( typeof msg.payload == "string" ) {

            try {
                result = JSON.parse(msg.payload);
                self.success( msg, result );
            } catch ( e ) {
                self.error( msg, "Could not parse string as JSON: " + e);
            }

        // Stringify if we got an object
        } else if ( typeof msg.payload == "object" ) {

            try {
                result = JSON.stringify(msg.payload);
                self.success( msg, result );
            } catch ( e ) {
                self.error( msg, "Could not stringify object to JSON: " + e);
            }

        } else {
            return self.error(msg, "JSON node could not determine what to do with payload of type " + typeof msg.payload);

        }
        

    }

}

module.exports = Json;