var inited = false;

module.exports = function(RED) {
    if (!inited) {
        inited = true;
        init(RED.server, RED.httpNode || RED.httpAdmin, RED.log, RED.settings);
    }
    return {
        add: add,
        addLink: addLink,
        addBaseConfig: addBaseConfig,
        emit: emit,
        emitSocket: emitSocket,
        toNumber: toNumber.bind(null, false),
        toFloat: toNumber.bind(null, true),
        updateUi: updateUi,
        ev: ev,
        getTheme: getTheme,
        getSizes: getSizes,
        isDark: isDark
    };
};

var fs = require('fs');
var path = require('path');
var events = require('events');
var socketio = require('socket.io');
var serveStatic = require('serve-static');
var compression = require('compression')
var dashboardVersion = require('./package.json').version;

var baseConfiguration = {};
var io;
var menu = [];
var globals = [];
var settings = {};
var updateValueEventName = 'update-value';
var currentValues = {};
var replayMessages = {};
var removeStateTimers = {};
var removeStateTimeout = 1000;
var ev = new events.EventEmitter();
var params = {};
ev.setMaxListeners(0);

// default manifest.json to be returned as required.
var mani = {
    "name": "Node-RED Dashboard",
    "short_name": "Dashboard",
    "description": "A dashboard for Node-RED",
    "start_url": "./#/0",
    "background_color": "#910000",
    "theme_color": "#910000",
    "display": "standalone",
    "icons": [
        {"src":"icon192x192.png", "sizes":"192x192", "type":"image/png"},
        {"src":"icon120x120.png", "sizes":"120x120", "type":"image/png"},
        {"src":"icon64x64.png", "sizes":"64x64", "type":"image/png"}
    ]
}

function toNumber(keepDecimals, config, input, old, m, s) {
    if (input === undefined) { return; }
    if (typeof input !== "number") {
        var inputString = input.toString();
        input = keepDecimals ? parseFloat(inputString) : parseInt(inputString);
    }
    if (s) { input = Math.round(Math.round(input/s)*s*10000)/10000; }
    return isNaN(input) ? config.min : input;
}

function emit(event, data) {
    io.emit(event, data);
}

function emitSocket(event, data) {
    if (data.hasOwnProperty("msg") && data.msg.hasOwnProperty("socketid") && (data.msg.socketid !== undefined)) {
        io.to(data.msg.socketid).emit(event, data);
    }
    else if (data.hasOwnProperty("socketid") && (data.socketid !== undefined)) {
        io.to(data.socketid).emit(event, data);
    }
    else {
        io.emit(event, data);
    }
}

function noConvert(value) {
    return value;
}

function beforeEmit(msg, value) {
    return { value:value };
}

function beforeSend(msg) {
    //do nothing
}

/* This is the handler for inbound msg from previous nodes...
options:
    node - the node that represents the control on a flow
    control - the control to be added
    tab - tab config node that this control belongs to
    group - group name
    [emitOnlyNewValues] - boolean (default true).
        If true, it checks if the payload changed before sending it
        to the front-end. If the payload is the same no message is sent.
    [forwardInputMessages] - boolean (default true).
        If true, forwards input messages to the output
    [storeFrontEndInputAsState] - boolean (default true).
        If true, any message received from front-end is stored as state

    [convert] - callback to convert the value before sending it to the front-end
    [beforeEmit] - callback to prepare the message that is emitted to the front-end

    [convertBack] - callback to convert the message from front-end before sending it to the next connected node
    [beforeSend] - callback to prepare the message that is sent to the output
*/
function add(opt) {
    clearTimeout(removeStateTimers[opt.node.id]);
    delete removeStateTimers[opt.node.id];

    if (typeof opt.emitOnlyNewValues === 'undefined') {
        opt.emitOnlyNewValues = true;
    }
    if (typeof opt.forwardInputMessages === 'undefined') {
        opt.forwardInputMessages = true;
    }
    if (typeof opt.storeFrontEndInputAsState === 'undefined') {
        opt.storeFrontEndInputAsState = true;
    }
    opt.convert = opt.convert || noConvert;
    opt.beforeEmit = opt.beforeEmit || beforeEmit;
    opt.convertBack = opt.convertBack || noConvert;
    opt.beforeSend = opt.beforeSend || beforeSend;
    opt.control.id = opt.node.id;
    var remove = addControl(opt.tab, opt.group, opt.control);

    opt.node.on("input", function(msg) {
        if (typeof msg.enabled === 'boolean') {
            var state = replayMessages[opt.node.id];
            if (!state) { replayMessages[opt.node.id] = state = {id: opt.node.id}; }
            state.disabled = !msg.enabled;
            io.emit(updateValueEventName, state);
        }

        // remove res and req as they are often circular
        if (msg.hasOwnProperty("res")) { delete msg.res; }
        if (msg.hasOwnProperty("req")) { delete msg.req; }

        // Retrieve the dataset for this node
        var oldValue = currentValues[opt.node.id];

        // let any arriving msg.ui_control message mess with control parameters
        if (msg.ui_control && (typeof msg.ui_control === "object") && (!Array.isArray(msg.ui_control)) && (!Buffer.isBuffer(msg.ui_control) )) {
            var changed = {};
            for (var property in msg.ui_control) {
                if (msg.ui_control.hasOwnProperty(property) && opt.control.hasOwnProperty(property)) {
                    if ((property !== "id")&&(property !== "type")&&(property !== "order")&&(property !== "name")&&(property !== "value")&&(property !== "label")&&(property !== "width")&&(property !== "height")) {
                        opt.control[property] = msg.ui_control[property];
                        changed[property] = msg.ui_control[property];
                    }
                }
            }
            if (Object.keys(changed).length !== 0) {
                io.emit('ui-control', {control:changed, id:opt.node.id});
            }
            if (!msg.hasOwnProperty("payload")) { return; }
        }

        // Call the convert function in the node to get the new value
        // as well as the full dataset.
        var conversion = opt.convert(msg.payload, oldValue, msg, opt.control.step);

        // If the update flag is set, emit the newPoint, and store the full dataset
        var fullDataset;
        var newPoint;
        if ((typeof(conversion) === 'object') && (conversion.update !== undefined)) {
            newPoint = conversion.newPoint;
            fullDataset = conversion.updatedValues;
        }
        else if (conversion === undefined) {
            fullDataset = oldValue;
            newPoint = true;
        }
        else {
            // If no update flag is set, this means the conversion contains
            // the full dataset or the new value (e.g. gauges)
            fullDataset = conversion;
        }

        // If we have something new to emit
        if (newPoint !== undefined || !opt.emitOnlyNewValues || oldValue != fullDataset) {
            currentValues[opt.node.id] = fullDataset;

            // Determine what to emit over the websocket
            // (the new point or the full dataset).

            // Always store the full dataset.
            var toStore = opt.beforeEmit(msg, fullDataset);
            var toEmit;
            if ((newPoint !== undefined) && (typeof newPoint !== "boolean")) { toEmit = opt.beforeEmit(msg, newPoint); }
            else { toEmit = toStore; }

            var addField = function(m) {
                if (opt.control.hasOwnProperty(m) && opt.control[m] && opt.control[m].indexOf("{{") !== -1) {
                    var a = opt.control[m].split("{{");
                    a.shift();
                    for (var i = 0; i < a.length; i++) {
                        var b = a[i].split("}}")[0].trim();
                        b.replace(/\"/g,'').replace(/\'/g,'');
                        if (b.indexOf("|") !== -1) { b = b.split("|")[0]; }
                        if (b.indexOf(" ") !== -1) { b = b.split(" ")[0]; }
                        if (b.indexOf("?") !== -1) { b = b.split("?")[0]; }
                        b.replace(/\(/g,'').replace(/\)/g,'');
                        if (b.indexOf("msg.") >= 0) {
                            b = b.split("msg.")[1];
                            if (b.indexOf(".") !== -1) { b = b.split(".")[0]; }
                            if (b.indexOf("[") !== -1) { b = b.split("[")[0]; }
                            if (!toEmit.hasOwnProperty("msg")) { toEmit.msg = {}; }
                            if (!toEmit.msg.hasOwnProperty(b) && msg.hasOwnProperty(b) && (msg[b] !== undefined)) {
                                if (Buffer.isBuffer(msg[b])) { toEmit.msg[b] = msg[b].toString("binary"); }
                                else { toEmit.msg[b] = JSON.parse(JSON.stringify(msg[b])); }
                            }
                        }
                        else {
                            if (b.indexOf(".") !== -1) { b = b.split(".")[0]; }
                            if (b.indexOf("[") !== -1) { b = b.split("[")[0]; }
                            if (!toEmit.hasOwnProperty(b) && msg.hasOwnProperty(b)) {
                                if (Buffer.isBuffer(msg[b])) { toEmit[b] = msg[b].toString("binary"); }
                                else { toEmit[b] = JSON.parse(JSON.stringify(msg[b])); }
                            }
                        }
                    }
                }
            }

            // if label, format or color field is set to a msg property, emit that as well
            addField("label");
            addField("format");
            addField("color");
            addField("units");
            if (msg.hasOwnProperty("enabled")) { toEmit.disabled = !msg.enabled; }
            toEmit.id = toStore.id = opt.node.id;
            // Emit and Store the data
            //if (settings.verbose) { console.log("UI-EMIT",JSON.stringify(toEmit)); }
            emitSocket(updateValueEventName, toEmit);
            replayMessages[opt.node.id] = toStore;

            // Handle the node output
            if (opt.forwardInputMessages && opt.node._wireCount) {
                msg.payload = opt.convertBack(fullDataset);
                msg = opt.beforeSend(msg) || msg;
                //if (settings.verbose) { console.log("UI-SEND",JSON.stringify(msg)); }
                opt.node.send(msg);
            }
        }
    });

    // This is the handler for messages coming back from the UI
    var handler = function (msg) {
        if (msg.id !== opt.node.id) { return; }  // ignore if not us
        if (settings.readOnly === true) {
            msg.value = currentValues[msg.id];
        } // don't accept input if we are in read only mode
        else {
            var converted = opt.convertBack(msg.value);
            if (opt.storeFrontEndInputAsState === true) {
                currentValues[msg.id] = converted;
                replayMessages[msg.id] = msg;
            }
            var toSend = {payload:converted};
            toSend = opt.beforeSend(toSend, msg) || toSend;
            toSend.socketid = toSend.socketid || msg.socketid;
            if (toSend.hasOwnProperty("topic") && (toSend.topic === undefined)) { delete toSend.topic; }
            if (!msg.hasOwnProperty("_fromInput")) {   // TODO: too specific
                opt.node.send(toSend);      // send to following nodes
            }
        }
        if (opt.storeFrontEndInputAsState === true) {
            //fwd to all UI clients
            io.emit(updateValueEventName, msg);
        }
    };

    ev.on(updateValueEventName, handler);

    return function() {
        ev.removeListener(updateValueEventName, handler);
        remove();
        removeStateTimers[opt.node.id] = setTimeout(function() {
            delete currentValues[opt.node.id];
            delete replayMessages[opt.node.id];
        }, removeStateTimeout);
    };
}

//from: https://stackoverflow.com/a/28592528/3016654
function join() {
    var trimRegex = new RegExp('^\\/|\\/$','g');
    var paths = Array.prototype.slice.call(arguments);
    return '/'+paths.map(function(e) {
        if (e) { return e.replace(trimRegex,""); }
    }).filter(function(e) {return e;}).join('/');
}

function init(server, app, log, redSettings) {
    var uiSettings = redSettings.ui || {};
    if ((uiSettings.hasOwnProperty("path")) && (typeof uiSettings.path === "string")) {
        settings.path = uiSettings.path;
    }
    else { settings.path = 'ui'; }
    if ((uiSettings.hasOwnProperty("readOnly")) && (typeof uiSettings.readOnly === "boolean")) {
        settings.readOnly = uiSettings.readOnly;
    }
    else { settings.readOnly = false; }
    settings.defaultGroupHeader = uiSettings.defaultGroup || 'Default';
    settings.verbose = redSettings.verbose || false;

    var fullPath = join(redSettings.httpNodeRoot, settings.path);
    var socketIoPath = join(fullPath, 'socket.io');

    io = socketio(server, {path: socketIoPath});

    var dashboardMiddleware = function(req, res, next) { next(); }

    if (uiSettings.middleware) {
        if (typeof uiSettings.middleware === "function") {
            dashboardMiddleware = uiSettings.middleware;
        }
    }

    fs.stat(path.join(__dirname, 'dist/index.html'), function(err, stat) {
        app.use(compression());
        if (!err) {
            app.use( join(settings.path, "manifest.json"), function(req, res) { res.send(mani); });
            app.use( join(settings.path), dashboardMiddleware, serveStatic(path.join(__dirname, "dist")) );
        }
        else {
            log.info("[Dashboard] Dashboard using development folder");
            app.use(join(settings.path), dashboardMiddleware, serveStatic(path.join(__dirname, "src")));
            var vendor_packages = [
                'angular', 'angular-sanitize', 'angular-animate', 'angular-aria', 'angular-material', 'angular-touch',
                'angular-material-icons', 'svg-morpheus', 'font-awesome', 'weather-icons-lite',
                'sprintf-js', 'jquery', 'jquery-ui', 'd3', 'raphael', 'justgage', 'angular-chart.js', 'chart.js',
                'moment', 'angularjs-color-picker', 'tinycolor2', 'less'
            ];
            vendor_packages.forEach(function (packageName) {
                app.use(join(settings.path, 'vendor', packageName), serveStatic(path.join(__dirname, 'node_modules', packageName)));
            });
        }
    });

    log.info("Dashboard version " + dashboardVersion + " started at " + fullPath);

    io.on('connection', function(socket) {
        ev.emit("newsocket", socket.client.id, socket.request.connection.remoteAddress);
        updateUi(socket);

        socket.on(updateValueEventName, ev.emit.bind(ev, updateValueEventName));
        socket.on('ui-replay-state', function() {
            var ids = Object.getOwnPropertyNames(replayMessages);
            setTimeout(function() {
                ids.forEach(function (id) {
                    socket.emit(updateValueEventName, replayMessages[id]);
                });
            }, 50);
            socket.emit('ui-replay-done');
        });
        socket.on('ui-change', function(index) {
            var name = "";
            if ((index != null) && !isNaN(index) && (menu.length > 0) && (index < menu.length) && menu[index]) {
                name = (menu[index].hasOwnProperty("header") && typeof menu[index].header !== 'undefined') ? menu[index].header : menu[index].name;
                ev.emit("changetab", index, name, socket.client.id, socket.request.connection.remoteAddress, params);
            }
        });
        socket.on('ui-refresh', function() {
            updateUi();
        });
        socket.on('disconnect', function() {
            ev.emit("endsocket", socket.client.id, socket.request.connection.remoteAddress);
        });
        socket.on('ui-audio', function(audioStatus) {
            ev.emit("audiostatus", audioStatus, socket.client.id, socket.request.connection.remoteAddress);
        });
        socket.on('ui-params', function(p) {
            delete p.socketid;
            params = p;
        });
    });
}

var updateUiPending = false;
function updateUi(to) {
    if (!to) {
        if (updateUiPending) { return; }
        updateUiPending = true;
        to = io;
    }
    process.nextTick(function() {
        menu.forEach(function(o) {
            o.theme = baseConfiguration.theme;
        });
        to.emit('ui-controls', {
            site: baseConfiguration.site,
            theme: baseConfiguration.theme,
            menu: menu,
            globals: globals
        });
        updateUiPending = false;
    });
}

function find(array, predicate) {
    for (var i=0; i<array.length; i++) {
        if (predicate(array[i])) {
            return array[i];
        }
    }
}

function itemSorter(item1, item2) {
    if (item1.order === 0 && item2.order !== 0) {
        return 1;
    }
    else if (item1.order !== 0 && item2.order === 0) {
        return -1;
    }
    return item1.order - item2.order;
}

function addControl(tab, groupHeader, control) {
    if (typeof control.type !== 'string') { return function() {}; }

    // global template?
    if (control.type === 'template' && control.templateScope === 'global') {
        // add content to globals
        globals.push(control);
        updateUi();

        // return remove function
        return function() {
            var index = globals.indexOf(control);
            if (index >= 0) {
                globals.splice(index, 1);
                updateUi();
            }
        }
    }
    else {
        groupHeader = groupHeader || settings.defaultGroupHeader;
        control.order = parseFloat(control.order);

        var foundTab = find(menu, function (t) {return t.id === tab.id });
        if (!foundTab) {
            foundTab = {
                id: tab.id,
                header: tab.config.name,
                order: parseFloat(tab.config.order),
                icon: tab.config.icon,
                //icon: tab.config.hidden ? "fa-ban" : tab.config.icon,
                disabled: tab.config.disabled,
                hidden: tab.config.hidden,
                items: []
            };
            menu.push(foundTab);
            menu.sort(itemSorter);
        }

        var foundGroup = find(foundTab.items, function (g) {return g.header === groupHeader;});
        if (!foundGroup) {
            foundGroup = {
                header: groupHeader,
                items: []
            };
            foundTab.items.push(foundGroup);
        }
        foundGroup.items.push(control);
        foundGroup.items.sort(itemSorter);
        foundGroup.order = groupHeader.config.order;
        foundTab.items.sort(itemSorter);

        updateUi();

        // Return the remove function for this control
        return function() {
            var index = foundGroup.items.indexOf(control);
            if (index >= 0) {
                // Remove the item from the group
                foundGroup.items.splice(index, 1);

                // If the group is now empty, remove it from the tab
                if (foundGroup.items.length === 0) {
                    index = foundTab.items.indexOf(foundGroup);
                    if (index >= 0) {
                        foundTab.items.splice(index, 1);

                        // If the tab is now empty, remove it as well
                        if (foundTab.items.length === 0) {
                            index = menu.indexOf(foundTab);
                            if (index >= 0) {
                                menu.splice(index, 1);
                            }
                        }
                    }
                }
                updateUi();
            }
        }
    }
}

function addLink(name, link, icon, order, target) {
    var newLink = {
        name: name,
        link: link,
        icon: icon,
        order: order || 1,
        target: target
    };

    menu.push(newLink);
    menu.sort(itemSorter);
    updateUi();

    return function() {
        var index = menu.indexOf(newLink);
        if (index < 0) { return; }
        menu.splice(index, 1);
        updateUi();
    }
}

function addBaseConfig(config) {
    if (config) { baseConfiguration = config; }
    mani.name = config.site ? config.site.name : "Node-RED Dashboard";
    mani.short_name = mani.name.replace("Node-RED","").trim();
    mani.background_color = config.theme.themeState["page-titlebar-backgroundColor"].value;
    mani.theme_color = config.theme.themeState["page-titlebar-backgroundColor"].value;
    updateUi();
}

function getTheme() {
    if (baseConfiguration && baseConfiguration.hasOwnProperty("theme") && (typeof baseConfiguration.theme !== "undefined") ) {
        return baseConfiguration.theme.themeState;
    }
    else {
        return undefined;
    }
}

function getSizes() {
    if (baseConfiguration && baseConfiguration.hasOwnProperty("site") && (typeof baseConfiguration.site !== "undefined") && baseConfiguration.site.hasOwnProperty("sizes")) {
        return baseConfiguration.site.sizes;
    }
    else {
        return { sx:48, sy:48, gx:6, gy:6, cx:6, cy:6, px:0, py:0 };
    }
}

function isDark() {
    if (baseConfiguration && baseConfiguration.hasOwnProperty("theme") && baseConfiguration.theme.hasOwnProperty("themeState")) {
        var rgb = parseInt(baseConfiguration.theme.themeState["page-sidebar-backgroundColor"].value.substring(1), 16);
        var luma = 0.2126 * ((rgb >> 16) & 0xff) + 0.7152 * ((rgb >> 8) & 0xff) + 0.0722 * ((rgb >> 0) & 0xff); // per ITU-R BT.709
        if (luma > 128) { return false; }
        else { return true; }
    }
    else { return false; } // if in doubt - let's say it's light.
}