/*
 * Copyright 2015 Open Networking Laboratory
 *
 * 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.
 */

/*
 ONOS GUI -- Topology Selection Module.
 Defines behavior when selecting nodes.
 */

(function () {
    'use strict';

    // injected refs
    var $log, fs, wss, tov, tps, tts, ns;

    // api to topoForce
    var api;
    /*
       node()                         // get ref to D3 selection of nodes
       zoomingOrPanning( ev )
       updateDeviceColors( [dev] )
       deselectLink()
     */

    // internal state
    var hovered,                // the node over which the mouse is hovering
        selections = {},        // currently selected nodes (by id)
        selectOrder = [],       // the order in which we made selections
        consumeClick = false;   // used to coordinate with SVG click handler

    // ==========================

    function nSel() {
        return selectOrder.length;
    }
    function getSel(idx) {
        return selections[selectOrder[idx]];
    }
    function allSelectionsClass(cls) {
        for (var i=0, n=nSel(); i<n; i++) {
            if (getSel(i).obj.class !== cls) {
                return false;
            }
        }
        return true;
    }

    // ==========================

    function nodeMouseOver(m) {
        if (!m.dragStarted) {
            if (hovered != m) {
                hovered = m;
                tov.hooks.mouseOver({
                    id: m.id,
                    class: m.class,
                    type: m.type
                });
            }
        }
    }

    function nodeMouseOut(m) {
        if (!m.dragStarted) {
            if (hovered) {
                hovered = null;
                tov.hooks.mouseOut();
            }
        }
    }

    // ==========================

    function selectObject(obj) {
        var el = this,
            nodeEv = el && el.tagName === 'g',
            ev = d3.event.sourceEvent || {},
            n;

        if (api.zoomingOrPanning(ev)) {
            return;
        }

        if (nodeEv) {
            n = d3.select(el);
        } else {
            api.node().each(function (d) {
                if (d == obj) {
                    n = d3.select(el = this);
                }
            });
        }
        if (!n) return;

        if (nodeEv) {
            consumeClick = true;
        }
        api.deselectLink();

        if (ev.shiftKey && n.classed('selected')) {
            deselectObject(obj.id);
            updateDetail();
            return;
        }

        if (!ev.shiftKey) {
            deselectAll(true);
        }

        selections[obj.id] = { obj: obj, el: el };
        selectOrder.push(obj.id);

        n.classed('selected', true);
        api.updateDeviceColors(obj);
        updateDetail();
    }

    function deselectObject(id) {
        var obj = selections[id];
        if (obj) {
            d3.select(obj.el).classed('selected', false);
            delete selections[id];
            fs.removeFromArray(id, selectOrder);
            api.updateDeviceColors(obj.obj);
        }
    }

    function deselectAll(skipUpdate) {
        var something = (selectOrder.length > 0);

        // deselect all nodes in the network...
        api.node().classed('selected', false);
        selections = {};
        selectOrder = [];
        api.updateDeviceColors();
        if (!skipUpdate) {
            updateDetail();
        }

        // return true if something was selected
        return something;
    }

    // === -----------------------------------------------------

    function requestDetails(data) {
        wss.sendEvent('requestDetails', {
            id: data.id,
            class: data.class
        });
    }

    // === -----------------------------------------------------

    function updateDetail() {
        var nSel = selectOrder.length;
        if (!nSel) {
            emptySelect();
        } else if (nSel === 1) {
            singleSelect();
        } else {
            multiSelect();
        }
    }

    function emptySelect() {
        tov.hooks.emptySelect();
        tps.displayNothing();
    }

    function singleSelect() {
        var data = getSel(0).obj;
        requestDetails(data);
        // NOTE: detail panel is shown as a response to receiving
        //       a 'showDetails' event from the server. See 'showDetails'
        //       callback function below...
    }

    function multiSelect() {
        // display the selected nodes in the detail panel
        tps.displayMulti(selectOrder);
        addHostSelectionActions();
        tov.hooks.multiSelect(selectOrder);
        tps.displaySomething();
    }

    function addHostSelectionActions() {
        if (allSelectionsClass('host')) {
            if (nSel() === 2) {
                tps.addAction({
                    id: 'host-flow-btn',
                    gid: 'endstation',
                    cb: tts.addHostIntent,
                    tt: 'Create Host-to-Host Flow'
                });
            } else if (nSel() >= 2) {
                tps.addAction({
                    id: 'mult-src-flow-btn',
                    gid: 'flows',
                    cb: tts.addMultiSourceIntent,
                    tt: 'Create Multi-Source Flow'
                });
            }
        }
    }


    // === -----------------------------------------------------
    //  Event Handlers

    // display the data for the single selected node
    function showDetails(data) {
        var buttons = fs.isA(data.buttons) || [];
        tps.displaySingle(data);
        tov.installButtons(buttons, data, data.props['URI']);
        tov.hooks.singleSelect(data);
        tps.displaySomething();
    }

    // returns true if one or more nodes are selected.
    function somethingSelected() {
        return nSel();
    }

    function clickConsumed(x) {
        var cc = consumeClick;
        consumeClick = !!x;
        return cc;
    }

    // returns a selection context, providing info about what is selected
    function selectionContext() {
        var devices = [],
            hosts = [],
            types = {};

        angular.forEach(selections, function (d) {
            var o = d.obj,
                c = o.class;

            if (c === 'device') {
                devices.push(o.id);
                types[o.id] = o.type;
            }
            if (c === 'host') {
                hosts.push(o.id);
                types[o.id] = o.type;
            }
        });

        return {
            devices: devices,
            hosts: hosts,
            types: types
        };
    }

    // === -----------------------------------------------------
    // === MODULE DEFINITION ===

    angular.module('ovTopo')
    .factory('TopoSelectService',
        ['$log', 'FnService', 'WebSocketService', 'TopoOverlayService',
            'TopoPanelService', 'TopoTrafficService', 'NavService',

        function (_$log_, _fs_, _wss_, _tov_, _tps_, _tts_, _ns_) {
            $log = _$log_;
            fs = _fs_;
            wss = _wss_;
            tov = _tov_;
            tps = _tps_;
            tts = _tts_;
            ns = _ns_;

            function initSelect(_api_) {
                api = _api_;
            }

            function destroySelect() { }

            return {
                initSelect: initSelect,
                destroySelect: destroySelect,

                showDetails: showDetails,

                nodeMouseOver: nodeMouseOver,
                nodeMouseOut: nodeMouseOut,
                selectObject: selectObject,
                deselectObject: deselectObject,
                deselectAll: deselectAll,
                updateDetail: updateDetail,

                hovered: function () { return hovered; },
                selectOrder: function () { return selectOrder; },
                somethingSelected: somethingSelected,

                clickConsumed: clickConsumed,
                selectionContext: selectionContext
            };
        }]);
}());