/**
 * Copyright 2013, 2014 IBM Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

//Simple node to introduce a pause into a flow
module.exports = function(RED) {
    "use strict";

    var MILLIS_TO_NANOS = 1000000;
    var SECONDS_TO_NANOS = 1000000000;

    function DelayNode(n) {
        RED.nodes.createNode(this,n);

        this.pauseType = n.pauseType;
        this.timeoutUnits = n.timeoutUnits;
        this.randomUnits = n.randomUnits;
        this.rateUnits = n.rateUnits;

        if (n.timeoutUnits === "milliseconds") {
            this.timeout = n.timeout;
        } else if (n.timeoutUnits === "seconds") {
            this.timeout = n.timeout * 1000;
        } else if (n.timeoutUnits === "minutes") {
            this.timeout = n.timeout * (60 * 1000);
        } else if (n.timeoutUnits === "hours") {
            this.timeout = n.timeout * (60 * 60 * 1000);
        } else if (n.timeoutUnits === "days") {
            this.timeout = n.timeout * (24 * 60 * 60 * 1000);
        }

        if (n.rateUnits === "second") {
            this.rate = 1000/n.rate;
        } else if (n.rateUnits === "minute") {
            this.rate = (60 * 1000)/n.rate;
        } else if (n.rateUnits === "hour") {
            this.rate = (60 * 60 * 1000)/n.rate;
        } else if (n.rateUnits === "day") {
            this.rate = (24 * 60 * 60 * 1000)/n.rate;
        }

        if (n.randomUnits === "milliseconds") {
            this.randomFirst = n.randomFirst * 1;
            this.randomLast = n.randomLast * 1;
        } else if (n.randomUnits === "seconds") {
            this.randomFirst = n.randomFirst * 1000;
            this.randomLast = n.randomLast * 1000;
        } else if (n.randomUnits === "minutes") {
            this.randomFirst = n.randomFirst * (60 * 1000);
            this.randomLast = n.randomLast * (60 * 1000);
        } else if (n.randomUnits === "hours") {
            this.randomFirst = n.randomFirst * (60 * 60 * 1000);
            this.randomLast = n.randomLast * (60 * 60 * 1000);
        } else if (n.randomUnits === "days") {
            this.randomFirst = n.randomFirst * (24 * 60 * 60 * 1000);
            this.randomLast = n.randomLast * (24 * 60 * 60 * 1000);
        }

        this.diff = this.randomLast - this.randomFirst;
        this.name = n.name;
        this.idList = [];
        this.buffer = [];
        this.intervalID = -1;
        this.randomID = -1;
        this.lastSent = null;
        this.drop = n.drop;
        var node = this;

        if (this.pauseType === "delay") {
            this.on("input", function(msg) {
                var id;
                id = setTimeout(function(){
                    node.idList.splice(node.idList.indexOf(id),1);
                    node.send(msg);
                }, node.timeout);
                this.idList.push(id);
            });

            this.on("close", function() {
                for (var i=0; i<this.idList.length; i++ ) {
                    clearTimeout(this.idList[i]);
                }
                this.idList = [];
            });

        } else if (this.pauseType === "rate") {
            this.on("input", function(msg) {
                if (!node.drop) {
                    if ( node.intervalID !== -1) {
                        node.buffer.push(msg);
                        if (node.buffer.length > 0) {
                            node.status({text:node.buffer.length});
                        }
                        if (node.buffer.length > 1000) {
                            node.warn(this.name + " buffer exceeded 1000 messages");
                        }
                    } else {
                        node.send(msg);
                        node.intervalID = setInterval(function() {
                            if (node.buffer.length === 0) {
                                clearInterval(node.intervalID);
                                node.intervalID = -1;
                                node.status({text:""});
                            }

                            if (node.buffer.length > 0) {
                                node.send(node.buffer.shift());
                                node.status({text:node.buffer.length});
                            }
                        },node.rate);
                    }
                } else {
                    var timeSinceLast;
                    if (node.lastSent) {
                        timeSinceLast = process.hrtime(node.lastSent);
                    }
                    if (!node.lastSent) { // ensuring that we always send the first message
                        node.lastSent = process.hrtime();
                        node.send(msg);
                    } else if ( ( (timeSinceLast[0] * SECONDS_TO_NANOS) + timeSinceLast[1] ) > (node.rate * MILLIS_TO_NANOS) ) {
                        node.lastSent = process.hrtime();
                        node.send(msg);
                    }
                }
            });

            this.on("close", function() {
                clearInterval(this.intervalID);
                this.buffer = [];
            });

        } else if (this.pauseType === "queue") {
            this.intervalID = setInterval(function() {
                if (node.buffer.length > 0) {
                    node.send(node.buffer.shift()); // send the first on the queue
                }
                node.status({text:node.buffer.length});
            },node.rate);

            this.on("input", function(msg) {
                if (!msg.hasOwnProperty("topic")) { msg.topic = "_none_"; }
                var hit = false;
                for (var b in node.buffer) { // check if already in queue
                    if (msg.topic === node.buffer[b].topic) {
                        node.buffer[b] = msg; // if so - replace existing entry
                        hit = true;
                    }
                }
                if (!hit) { node.buffer.push(msg); } // if not add to end of queue
                node.status({text:node.buffer.length});
            });

            this.on("close", function() {
                clearInterval(this.intervalID);
                this.buffer = [];
                node.status({text:node.buffer.length});
            });

        } else if (this.pauseType === "random") {
            this.on("input", function(msg) {
                var wait = node.randomFirst + (node.diff * Math.random());
                var id = setTimeout(function(){
                    node.idList.splice(node.idList.indexOf(id),1);
                    node.send(msg);
                }, wait);
                this.idList.push(id);
            });

            this.on("close", function() {
                for (var i=0; i<this.idList.length; i++ ) {
                    clearTimeout(this.idList[i]);
                }
                this.idList = [];
            });

        }
    }
    RED.nodes.registerType("delay",DelayNode);
}