/*global define, esri, i18n, console, $, RAMP, proj4, window */
 
/**
*
* A RAMP Map module with ESRI and Dojo AMD Modules
* This module provides function to create an ESRI web map control. A global config object is
* required to initialize the map.
*
* @module RAMP
* @submodule Map
* @main Map
*/
 
/**
* Map class represents the ESRI map object. The map is generated based on the application configuration and templates.
*
* ####Imports RAMP Modules:
* {{#crossLink "GlobalStorage"}}{{/crossLink}}  
* {{#crossLink "RAMP"}}{{/crossLink}}  
* {{#crossLink "FeatureClickHandler"}}{{/crossLink}}  
* {{#crossLink "MapClickHandler"}}{{/crossLink}}  
* {{#crossLink "Navigation"}}{{/crossLink}}  
* {{#crossLink "EventManager"}}{{/crossLink}}  
* {{#crossLink "Util"}}{{/crossLink}}  
* {{#crossLink "Array"}}{{/crossLink}}  
* 
* @class Map
* @static
* @uses dojo/_base/declare
* @uses dojo/_base/array
* @uses dojo/dom
* @uses dojo/dom-construct
* @uses dojo/number
* @uses dojo/query
* @uses dojo/topic
* @uses dojo/on
* @uses esri/map
* @uses esri/layers/FeatureLayer
* @uses esri/layers/ArcGISTiledMapServiceLayer
* @uses esri/layers/ArcGISDynamicMapServiceLayer
* @uses esri/layers/WMSLayer
* @uses esri/SpatialReference
* @uses esri/dijit/Scalebar
* @uses esri/geometry/Extent
* @uses esri/tasks/GeometryService
* @uses esri/tasks/ProjectParameters
*/
 
define([
/* Dojo */
"dojo/_base/declare", "dojo/_base/array", "dojo/dom",
        "dojo/dom-construct", "dojo/number", "dojo/query", "dojo/topic", "dojo/on",
 
/* Esri */
"esri/map", "esri/layers/FeatureLayer", "esri/layers/ArcGISTiledMapServiceLayer", "esri/layers/ArcGISDynamicMapServiceLayer",
"esri/SpatialReference", "esri/dijit/Scalebar", "esri/geometry/Extent", "esri/layers/WMSLayer", "esri/tasks/GeometryService", "esri/tasks/ProjectParameters",
 
/* Ramp */
"ramp/globalStorage", "ramp/ramp", "ramp/featureClickHandler", "ramp/mapClickHandler", "ramp/navigation", "ramp/eventManager",
 
/* Util */
"utils/util", "utils/array", "utils/dictionary"],
 
    function (
    /* Dojo */
    declare, dojoArray, dom, domConstruct, number, query, topic, dojoOn,
 
    /* Esri */
    EsriMap, FeatureLayer, ArcGISTiledMapServiceLayer, ArcGISDynamicMapServiceLayer,
    SpatialReference, EsriScalebar, EsriExtent, WMSLayer, GeometryService, ProjectParameters,
 
    /* Ramp */
    GlobalStorage, Ramp, FeatureClickHandler, MapClickHandler, Navigation, EventManager,
 
    /* Util */
    UtilMisc, UtilArray, UtilDict) {
        "use strict";
 
        /**
        * An Array of {{#crossLink "Esri/layers/FeatureLayer"}}{{/crossLink}} objects.
        *
        * @private
        * @property featureLayers {Array}
        */
        var featureLayers,
 
            /**
            * An Array of {{#crossLink "Esri/layer/WMSLayer"}}{{/crossLink}} objects.
            *
            * @private
            * @property wmsLayers {Array}
            */
            wmsLayers = [],
 
            /**
            * Maps the id of a graphic layer to the GraphicsLayer Object that represents its extent bounding box.
            * A dictionary of String, {{#crossLink "Esri/layers/GraphicsLayer"}}{{/crossLink}} pairs.
            *
            * @private
            * @property boundingBoxMapping {Object}
            */
            boundingBoxMapping = {},
 
            /**
            * The map not only contains feature layers, but also other layers such as the
            * basemap layer, highlight layer, bounding box layer, etc. This variable is
            * used to store the starting index of the feature layers in the map.
            *
            * @private
            * @property featureLayerStartIndex {Integer}
            */
            featureLayerStartIndex,
 
            map,
 
            fullExtent,
            maxExtent,
            initExtent;
 
        /**
        * Shows the loading image.
        *
        * @private
        * @method _showLoadingImg
        */
        function _showLoadingImg() {
            $("#map-load-indicator").removeClass("hidden");
        }
 
        /**
        * Hides the loading image.
        *
        * @private
        * @method _hideLoadingImg
        */
        function _hideLoadingImg() {
            $("#map-load-indicator").addClass("hidden");
        }
 
        /**
        * Update Map Scale when zoom level changes
        *
        * @private
        * @method _updateScale
        * @param {Object} event
        */
        function _updateScale(event) {
            if (event.levelChange) {
                var currentScale = number.format(event.lod.scale),
                    scaleLabelText = "1 : " + currentScale;
 
                domConstruct.empty('scaleLabel');
                $("#scaleLabel").text(scaleLabelText);
            }
        }
 
        /**
        * Initialize Map Scale
        *
        * @private
        * @method _initScale
        * @param {Object} event
        */
        function _initScale(event) {
            var map = event.map,
                scaleDiv = domConstruct.create("div", {
                    id: "scaleDiv",
                    class: "esriScalebarLabel"
                }),
                currentScale,
                scaleLabelText;
            $(scaleDiv).html("<span>" + i18n.t('map.scale') + "</span><br><span id='scaleLabel'><span/>");
            currentScale = number.format(map.getScale());
            scaleLabelText = "1 : " + currentScale;
 
            domConstruct.place(scaleDiv, query(".esriScalebarRuler")[0], "before");
            domConstruct.empty('scaleLabel');
            $("#scaleLabel").text(scaleLabelText);
 
            // Change the css class of the scale bar so it shows up against
            // the map
            topic.subscribe(EventManager.BasemapSelector.BASEMAP_CHANGED, function (attr) {
                $(".esriScalebar > div").removeClass().addClass(attr.cssStyle);
            });
        }
 
        /**
        * Republishes map events to the outside using topic.publish
        *
        * @method _initRepublishers
        * @param {Object} map object
        * @private
        */
        function _initRepublishers(map) {
            var prefix = "map";
 
            /**
            * Republish map events using topic.publish
            *
            * @method republish
            * @param {String} name
            * @private
            */
            function republish(name) {
                map.on(name, function (event) {
                    topic.publish(prefix + "/" + name, event);
                });
            }
 
            republish("update-end");
            republish("extent-change");
            republish("zoom-start");
            republish("zoom-end");
            republish("pan-start");
            republish("pan-end");
        }
 
        /**
        * Subscribe to external events (published using topic.publish)
        * and react accordingly
        *
        * @method _initListeners
        * @param {Object} map map object
        * @private
        */
        function _initListeners(map) {
            /* SUBSCRIBED EVENTS */
            topic.subscribe(EventManager.Map.CENTER_AT, function (event) {
                map.centerAt(event.point);
            });
 
            topic.subscribe(EventManager.Map.CENTER_AND_ZOOM, function (event) {
                var point = new esri.geometry.Point(event.graphic.geometry.x, event.graphic.geometry.y, map.spatialReference),
                    d = map.centerAndZoom(point, event.level); // Last parameter is the level
 
                if (event.callback) {
                    d.then(event.callback);
                }
            });
 
            topic.subscribe(EventManager.Map.SET_EXTENT, function (event) {
                event.extent.spatialReference = map.spatialReference;
                var d = map.setExtent(event.extent);
 
                if (event.callback) {
                    d.then(event.callback);
                }
            });
 
            /* NAVIGATION EVENTS */
            topic.subscribe(EventManager.Navigation.PAN, function (event) {
                // event.direction panUp, panDown, panLeft, panRight
                // this same as calling map.panUp(), map.panDown(), map.panLeft(), map.panRight()
                map[event.direction]();
            });
 
            topic.subscribe(EventManager.Navigation.ZOOM_STEP, function (event) {
                map.setLevel(map.getLevel() + event.level);
            });
 
            topic.subscribe(EventManager.Navigation.ZOOM, function (event) {
                map.setLevel(event.level);
            });
 
            topic.subscribe(EventManager.Navigation.FULL_EXTENT, function () {
                map.setExtent(fullExtent);
            });
 
            /* GUI EVENTS */
            topic.subscribe(EventManager.GUI.LAYOUT_CHANGE, function () {
                map.resize(true);
            });
 
            // Unhighlight the point when the subpanel is collapsed
            topic.subscribe(EventManager.GUI.SUBPANEL_CHANGE, function (eventArg) {
                // unhighlight only if the panel closing is the details panel
                if (!eventArg.visible &&
                    eventArg.isComplete &&
                    (eventArg.origin === ("rampPopup" || "datagrid"))) {
                    topic.publish(EventManager.FeatureHighlighter.HIGHLIGHT_HIDE, {});
                }
            });
 
            /* START BOUNDING BOX TOGGLE */
 
            topic.subscribe(EventManager.FilterManager.LAYER_VISIBILITY_TOGGLED, function (evt) {
                var setTo = evt.state,
                    layerId = evt.id,
                    // either take url (would need mapping to layer on map),
                    // map id in config, graphic layer id
                    layer = map.getLayer(layerId);
 
                layer.setVisibility(setTo);
                //loops through any static layers that are mapped to the feature layer being toggled
                try {
                    dojoArray.forEach(GlobalStorage.LayerMap[layerId], function (staticLayer) {
                        var layer = map.getLayer(staticLayer);
                        layer.setVisibility(setTo);
                    });
                }
                catch (err) {
                }
            });
 
            topic.subscribe(EventManager.FilterManager.LAYER_TRANSPARENCY_CHANGED, function (evt) {
                var layer = map.getLayer(evt.layerId);
 
                if (layer !== undefined) {
                    layer.setOpacity(evt.value);
                    //loops through any static layers that are mapped to the feature layer being toggled
                    try {
                        dojoArray.forEach(GlobalStorage.LayerMap[evt.layerId], function (staticLayer) {
                            var layer = map.getLayer(staticLayer);
                            layer.setOpacity(evt.value);
                        });
                    }
                    catch (err) {
                    }
                }
            });
 
            topic.subscribe(EventManager.FilterManager.BOX_VISIBILITY_TOGGLED, function (evt) {
                setBoundingBoxVisibility(evt.id, evt.state);
            });
            /* END BOUNDING BOX TOGGLE */
 
            topic.subscribe(EventManager.FilterManager.SELECTION_CHANGED, function (evt) {
                // this is handling the user trying to re-order the layers
                // graphical and feature layers must be handled separately from
                // all other layers as ESRI separates the two internally
 
                var newIndex = evt.index,
                    featureLayers;
 
                if (map.layerIds.contains(evt.id)) {
                    featureLayers = dojoArray.map(map.graphicsLayerIds, function (x) {
                        return map.getLayer(x).type === 'Feature Layer' ? 1 : 0;
                    }).sum();
                    newIndex += 1 - featureLayers; // offset by 1 basemap not accounted for
                    console.log('newIndex ' + newIndex);
                    console.log(map.layerIds);
                } else {
                    if (!featureLayerStartIndex) {
                        // Find the index of the first feature layer
                        featureLayerStartIndex = UtilArray.indexOf(map.graphicsLayerIds, function (layerId) {
                            var layer = map.getLayer(layerId);
                            return layer.type && layer.type === "Feature Layer";
                        });
                    }
                    newIndex += featureLayerStartIndex;
                }
                map.reorderLayer(map.getLayer(evt.id), newIndex);
                topic.publish(EventManager.Map.REORDER_END);
            });
 
            //TODO this will likely get removed or amended by aly
            /* Add Layer subscription*/
            topic.subscribe(EventManager.Map.ADD_LAYER, function () {
                var type = dom.byId("addLayer-select-type").value,
                    URL = dom.byId("addLayer-URL-input").value,
                    opacity = dom.byId("addLayer-Opacity").value;
 
                console.log(type + " | " + URL + " | " + opacity);
                addStaticLayer(type, URL, opacity);
            });
 
            topic.subscribe(EventManager.Map.ADD_LAYER_READY, function (temp_layer) {
                map.addLayer(temp_layer);
            });
        }
        /**
        * Creates event handlers for the map control: click, mouse-over, load, extent change, and update events.
        *
        * @private
        * @method _initEventHandlers
        * @param {Object} map A ESRI map object
        */
        function _initEventHandlers(map) {
            map.on("load", _initScale);
            map.on("extent-change", function (event) {
                _updateScale(event);
 
                console.log("map - >> extent-change", event);
                dojoOn.once(map, "update-end", function () {
                    console.log("map - >> update-end - >> Apply extent Filter");
                    topic.publish(EventManager.Datagrid.APPLY_EXTENT_FILTER);
                });
            });
 
            // Deselect all highlighted points if the map is clicked
            map.on("click", function (evt) {
                FeatureClickHandler.onFeatureDeselect(evt);
                topic.publish(EventManager.Map.CLICK, evt);
            });
 
            // Show/Hide spinner for map loading
            map.on("update-start", _showLoadingImg);
            map.on("update-end", _hideLoadingImg);
 
            // code that would wait until all layers were loaded.  not used anymore, but could be useful to keep around to steal later
            /*
            var handle = map.on("update-end", function () {
                var isAllLoaded = dojoArray.every(
                        map.graphicsLayerIds.concat(map.layerIds),
                        function (layerId) {
                            var layer = map.getLayer(layerId);
                            console.log(layer.loaded, layerId, layer);
                            return layer.loaded;
                        }
                    );
 
                console.log("map -> is all layers loaded: ", isAllLoaded);
 
                if (isAllLoaded) {
                    handle.remove();
                    console.log("map ->", EventManager.Map.ALL_LAYERS_LOADED);
                    topic.publish(EventManager.Map.ALL_LAYERS_LOADED);
                }
            });
            */
        }
 
        /**
        * Will project an extent to a desired spatial reference, using client side projection library.
        * Avoids the need for Esri Geometry Service
        *
        * @method localProjectExtent
        * @private
        * @param  {Esri/Extent} extent extent to be projected
        * @param {Esri/SpatialReference} sr {{#crossLink "Esri/SpatialReference"}}{{/crossLink}} to project to
        * @return {Esri/Extent} extent in the desired projection
        */
        function localProjectExtent(extent, sr) {
            //TODO can we handle WKT?
            // we can now
 
            // interpolates two points by splitting the line in half recursively
            function interpolate(p0, p1, steps) {
                var mid, i0, i1;
 
                if (steps === 0) { return [p0, p1]; }
 
                mid = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
                if (steps === 1) {
                    return [p0, mid, p1];
                }
                if (steps > 1) {
                    i0 = interpolate(p0, mid, steps - 1);
                    i1 = interpolate(mid, p1, steps - 1);
                    return i0.concat(i1.slice(1));
                }
            }
 
            var points = [[extent.xmin, extent.ymin], [extent.xmax, extent.ymin], [extent.xmax, extent.ymax], [extent.xmin, extent.ymax], [extent.xmin, extent.ymin]],
                projConvert, transformed, projExtent, x0, y0, x1, y1, xvals, yvals, interpolatedPoly = [], srcProj;
 
            // interpolate each edge by splitting it in half 3 times (since lines are not guaranteed to project to lines we need to consider
            // max / min points in the middle of line segments)
            [0, 1, 2, 3].map(function (i) { return interpolate(points[i], points[i + 1], 3).slice(1); }).forEach(function (seg) { interpolatedPoly = interpolatedPoly.concat(seg); });
 
            //reproject the extent
            if (extent.spatialReference.wkid) {
                srcProj = 'EPSG:' + extent.spatialReference.wkid;
            } else if (extent.spatialReference.wkt) {
                srcProj = extent.spatialReference.wkt;
            } else {
                throw new Error('No WKT or WKID specified on extent.spatialReference');
            }
            projConvert = proj4(srcProj, 'EPSG:' + sr.wkid);
            transformed = interpolatedPoly.map(function (x) { return projConvert.forward(x); });
 
            xvals = transformed.map(function (x) { return x[0]; });
            yvals = transformed.map(function (x) { return x[1]; });
 
            x0 = Math.min.apply(null, xvals);
            x1 = Math.max.apply(null, xvals);
 
            y0 = Math.min.apply(null, yvals);
            y1 = Math.max.apply(null, yvals);
 
            projExtent = new EsriExtent(x0, y0, x1, y1, sr);
            console.log('localProjectExtent complete: ' + JSON.stringify(projExtent));
 
            return projExtent;
        }
 
        /**
        * project an extent to a new spatial reference, if required
        * when projection is finished, call another function and pass the result to it.
        *
        * @method projectExtent
        * @private
        * @param {Object} extent an extent object from the configuration
        * @param {Esri/SpatialReference} sr {{#crossLink "Esri/SpatialReference"}}{{/crossLink}} to project to
        * @param {Function} callWhenDone function to call when extent is projected.  expects geometry parameter
        */
        function projectExtent(extent, sr, callWhenDone) {
            var realExtent;
 
            //convert configuration extent to proper esri extent object
            realExtent = new EsriExtent(extent);
 
            if (UtilMisc.isSpatialRefEqual(realExtent.spatialReference, sr)) {
                //the extent is already in the correct projection.
                //go to the next step
                callWhenDone([realExtent]);
            } else {
                //need to re-project the extent
 
                var projectedExtent = localProjectExtent(realExtent, sr);
                callWhenDone([projectedExtent]);
 
                //Geometry Service Version.  Makes a more accurate bounding box, but requires an arcserver
                /*
                var geomSrv, geomParams;
                geomSrv = new GeometryService(RAMP.config.geometryServiceUrl);
                geomParams = new ProjectParameters();
                geomParams.geometries = [realExtent];
                geomParams.outSR = sr;
 
                geomSrv.project(geomParams, function (projectedExtents) {
                    //after service returns, continue to next step
                    callWhenDone(projectedExtents);
                });
                */
            }
        }
 
        /**
        * process the projected default extent, begin projection of full extent.
        * used as an asynchronous gate for the projection.
        *
        * @method projectFullExtent
        * @private
        * @param {Array} projectedDefaultExtent an array containing the default extent object in the map's projection
        */
        function projectFullExtent(projectedDefaultExtent) {
            //store projected result
            RAMP.config.extents.defaultExtent = projectedDefaultExtent[0];
 
            //project the full extent.  when finished, process max extent
            projectExtent(RAMP.config.extents.fullExtent, projectedDefaultExtent[0].spatialReference, projectMaxExtent);
        }
 
        /**
        * process the projected full extent, begin projection of maximum extent.
        * used as an asynchronous gate for the projection.
        *
        * @method projectMaxExtent
        * @private
        * @param {Array} projectedFullExtent an array containing the full extent object in the map's projection
        */
        function projectMaxExtent(projectedFullExtent) {
            //store projected result
            RAMP.config.extents.fullExtent = projectedFullExtent[0];
 
            //project the max extent.  when finished, tell map to continue loading
            projectExtent(RAMP.config.extents.maximumExtent, projectedFullExtent[0].spatialReference, finishExtentProjection);
        }
 
        /**
        * process the projected maximum extent, then alert app to continue loading the map.
        * used as an asynchronous gate for the projection.
        *
        * @method finishExtentProjection
        * @private
        * @param {Array} projectedMaxExtent an array containing the maximum extent object in the map's projection
        */
        function finishExtentProjection(projectedMaxExtent) {
            //store projected result
            RAMP.config.extents.maximumExtent = projectedMaxExtent[0];
 
            //throw event
            topic.publish(EventManager.Map.EXTENTS_REPROJECTED);
        }
 
        /**
        * Add a static, non-interactive Layer to the map
        * NOTE: this function is currently not being used.
        *
        * @private
        * @method AddStaticLayer
        * @param {String} layer_type A value which controls how the layer is going to be added to the map
        * @param {String} layer_url A URL pointing to a valid map service endpoint
        * @param {Number} layer_op A value between 0.0 and 1.0 which determines the transparency of the layer
        */
        function addStaticLayer(layer_type, layer_url, layer_op) {
            //TODO: consider removing this?
            layer_op = layer_op / 100; // change percentage to decimal
            var tempLayer;
            switch (layer_type) {
                case "feature":
                    tempLayer = new FeatureLayer(layer_url, {
                        opacity: layer_op,
                        mode: FeatureLayer.MODE_SNAPSHOT
                    });
                    break;
 
                case "tile":
                    tempLayer = new ArcGISTiledMapServiceLayer(layer_url, {
                        opacity: layer_op
                    });
                    break;
 
                case "dynamic":
                    tempLayer = new ArcGISDynamicMapServiceLayer(layer_url, {
                        opacity: layer_op
                    });
                    break;
 
                default:
 
                    break;
            }
 
            topic.publish(EventManager.Map.ADD_LAYER_READY, tempLayer);
            topic.publish(EventManager.GUI.ADD_LAYER_PANEL_CHANGE, {
                visible: false
            });
        }
 
        /**
        * Sets the visibility of the bounding box that belongs to the layer with the given layerId.
        * Note: the layerId needs to be the ID of the featurelayer, not the ID of the actual bounding
        * box layer.
        *
        * @private
        * @method setBoundingBoxVisibility
        * @param {String} layerId the id of the layer whose bounding box visibility should be set
        */
        function setBoundingBoxVisibility(layerId, visibility) {
            var boxLayer = boundingBoxMapping[layerId];
 
            //if (boxLayer.graphics.isEmpty() && visibility) {
            //    // get bounding box info from config object
            //    var boundingBoxExtent;
            //    var layerConfig = dojoArray.find(config.featureLayers, function (layerConfig) {
            //        return layerConfig.id === layerId;
            //    });
 
            //    boundingBoxExtent.xmin = layerConfig.boundingBox.extent.xmin;
            //    boundingBoxExtent.ymin = layerConfig.boundingBox.extent.ymin;
            //    boundingBoxExtent.xmax = layerConfig.boundingBox.extent.xmax;
            //    boundingBoxExtent.ymax = layerConfig.boundingBox.extent.ymax;
 
            //    var extentGraphic = new esri.Graphic({
            //        geometry: boundingBoxExtent,
            //        symbol: {
            //            color: [255, 0, 0, 64],
            //            outline: {
            //                color: [240, 128, 128, 255],
            //                width: 1,
            //                type: "esriSLS",
            //                style: "esriSLSSolid"
            //            },
            //            type: "esriSFS",
            //            style: "esriSFSSolid"
            //        }
            //    });
            //    boxLayer.add(extentGraphic);
            //}
 
            boxLayer.setVisibility(visibility);
        }
 
        function resolveLayerOpacity(layerOpacity) {
            return layerOpacity.default || 1;
        }
 
        /**
        * Sets up loading event handlers and initializes the .ramp object of a layer
        * Circular reference errors prevent us from calling LayerLoader directly from this module
        *
        * @private
        * @method prepLayer
        * @param  {Object} layer layer to be prepped
        * @param  {Object} config config object for the layer
        * @param  {Boolean} userLayer optional.  indicates if layer was added by a user.  default value is false
        */
        function prepLayer(layer, config, userLayer) {
            layer.ramp = {
                config: config,
                user: typeof userLayer === 'boolean' ? userLayer : false,
                load: {
                    state: "loading",
                    inLS: false,  //layer has entry in layer selector
                    inCount: false  //layer is included in the layer counts
                }
            };
 
            layer.on('load', function (evt) {
                //console.log("PREP LOAD OK " + evt.layer.url);
                topic.publish(EventManager.LayerLoader.LAYER_LOADED, { layer: evt.layer });
            });
 
            layer.on('error', function (evt) {
                //console.log("PREP LOAD FAIL " + evt.target.url);
                evt.target.ramp.loadOk = false;
                console.log('layer failed to load');
                console.log(evt);
                topic.publish(EventManager.LayerLoader.LAYER_ERROR, {
                    layer: evt.target,
                    error: evt.error
                });
            });
 
            //since the update-start event doesn't let you know who threw it (supposed to but doesn't), we need to tack the handler
            //function onto the actual layer object so we can use the "this" keyword to grab the sending layer
            layer.ramp.load.onUpdateStart = function () {
                topic.publish(EventManager.LayerLoader.LAYER_UPDATING, { layer: this });
            };
 
            layer.on('update-start', layer.ramp.load.onUpdateStart);
 
            //add update end handler for layer
            layer.on('update-end', function (evt) {
                topic.publish(EventManager.LayerLoader.LAYER_UPDATED, { layer: evt.target });
            });
        }
 
        return {
            /**
            * For a specified layer, zooms to the closest level that has some visible data.
            * @param {String} layerId a layer id to zoom to.
            * @method zoomToLayerScale
            */
            zoomToLayerScale: function (layerId) {
                var layer = map.getLayer(layerId),
                    lods = map._params.lods,
                    currentLevel = map.getLevel(),
                    topLod,
                    bottomLod,
                    lod,
                    i;
 
                //gis lesson.
                //min scale means dont show the layer if zoomed out beyond the min scale
                //max scale means dont show the layer if zoomed in beyond the max scale
                //from a numerical perspective, min > max (as the scale number represents 1/number )
 
                for (i = 0; i < lods.length; i += 1) {
                    lod = lods[i];
                    //console.log("lod", lod, lod.scale > layer.minScale);
                    if (!topLod && lod.scale <= layer.minScale) {
                        topLod = lod;
                    }
 
                    if (!bottomLod && lod.scale <= layer.maxScale) {
                        bottomLod = lods[Math.max(0, i - 1)];
                    }
                }
 
                //assign defaults for open-ended ranges
                //we will never have the case where both values are 0, as in that case the layer is visible everywhere, and this
                //function will not be called (it's only used when layer is out-of-scale range).
 
                if (layer.minScale === 0) {
                    //no ceiling.  top = bottom
                    topLod = bottomLod;
                }
 
                if (layer.maxScale === 0) {
                    //no floor.  bottom = top
                    bottomLod = topLod;
                }
 
                //console.log(topLod, bottomLod, map.getLevel(), map.getZoom(), Math.abs(topLod.level - currentLevel) <= Math.abs(bottomLod.level - currentLevel));
 
                if (Math.abs(topLod.level - currentLevel) <= Math.abs(bottomLod.level - currentLevel)) {
                    map.setZoom(topLod.level);
                } else {
                    map.setZoom(bottomLod.level);
                }
            },
 
            /**
            * For a specified layer, determine if the layer's scale fit into map LOD range.
            * Return ture if in range
            * @param { number } maxScale maximum scale.
            * @param { number } minScale minimum scale
            * @method layerInLODRange
            * @type { boolean }
            */
            layerInLODRange: function (maxScale, minScale) {
                var lods = map._params.lods,                    
                    topLod = -1,
                    bottomLod = -1,
                    lod,
                    i,
                    inRange = false;
 
                //gis lesson.
                //min scale means dont show the layer if zoomed out beyond the min scale
                //max scale means dont show the layer if zoomed in beyond the max scale
                //from a numerical perspective, min > max (as the scale number represents 1/number )
                
                if (maxScale === 0) {
                    bottomLod = 0; 
                }
 
                if (minScale === 0) {
                    topLod = 0;
                }
 
                for (i = 0; i < lods.length; i += 1) {
                    lod = lods[i];
 
                    if (topLod === -1 && lod.scale <= minScale) {
                        topLod = lod;
                    }
 
                    if (bottomLod === -1 && lod.scale <= maxScale) {
                        bottomLod = lods[Math.max(0, i - 1)];
                    } 
                }
 
                if (maxScale === 0 && minScale === 0) {                    
                    inRange = true;
                } else if (minScale === 0) {
                    // check only maxScale (bottomLod)
                    inRange = (bottomLod === -1) ? false : true; 
                } else if (maxScale === 0) {
                    // check only minScale (topLod)
                    inRange = (topLod === -1) ? false : true; 
                } else {
                    inRange = (topLod !== -1 && bottomLod !== -1);
                }
 
                return inRange;
                
            },
 
            /**
            * The maximum extent of the map control is allowed to go to
            * @property getMaxExtent
            * @type {Object}
            *
            */
            getMaxExtent: function () {
                return maxExtent;
            },
            /**
            * Return the map control object
            * @property getMap
            * @type {Object}
            *
            */
            getMap: function () {
                if (!map) {
                    console.log("trying to get map before it is available!");
                }
                return map;
            },
 
            /**
            * Returns a list of feature layers that are currently visible on the map.
            * @method getVisibleFeatureLayers
            * @return {Array} an array of {{#crossLink "Esri/layers/FeatureLayer"}}{{/crossLink}} objects
            *
            */
            getVisibleFeatureLayers: function () {
                // Return only the feature layers
                //TODO do we need to consider static layers here?
                return dojoArray.filter(map.getLayersVisibleAtScale(), function (layer) {
                    return layer.type && (layer.type === "Feature Layer") && layer.visible;
                });
            },
 
            getVisibleLayers: function () {
                return map.getLayersVisibleAtScale();
            },
 
            getInvisibleLayers: function () {
                var visibleLayers,
                    allLayers,
                    invisibleLayers;
 
                visibleLayers = this.getVisibleLayers();
                allLayers = map._layers;
                invisibleLayers = [];
 
                UtilDict.forEachEntry(allLayers, function (key, value) {
                    var index = UtilArray.indexOf(visibleLayers, function (vl) {
                        return key === vl.id;
                    });
 
                    if (index === -1) {
                        invisibleLayers.push(value);
                    }
                });
 
                return invisibleLayers;
            },
 
            /**
            * Returns the mapping of feature layer ids to assocciated bounding box layers.
            * @method getBoundingBoxMapping
            * @return {Object} A dictionary of String, {{#crossLink "Esri/layers/GraphicsLayer"}}{{/crossLink}} pairs.
            *
            */
            getBoundingBoxMapping: function () {
                return boundingBoxMapping;
            },
 
            /**
            * Return the feature layer corresponding to the given id.
            *
            * @method getFeatureLayer
            * @private
            * @param {String} featureId the id of the feature layer
            * @return {Esri/layers/FeatureLayer} feature layer
            */
            getFeatureLayer: function (featureId) {
                return map.getLayer(featureId);
            },
 
            /**
            * Apply extent defaulting prior to URL overrides.
            *
            * @method applyExtentDefaulting
            * @private
            */
            applyExtentDefaulting: function () {
                //if full extent is missing, set to default extent.
                if (!(RAMP.config.extents.fullExtent)) {
                    //need to deserialize/reserialize to avoid pointing to actual defaultExtent, which may be changed later by the Bookmark Link module
                    RAMP.config.extents.fullExtent = JSON.parse(JSON.stringify(RAMP.config.extents.defaultExtent));
                }
 
                //if maximum extent is missing, set to full extent.
                if (!(RAMP.config.extents.maximumExtent)) {
                    RAMP.config.extents.maximumExtent = JSON.parse(JSON.stringify(RAMP.config.extents.fullExtent));
                }
            },
 
            /**
            * initiate the projection of the config extents to basemap extents
            *
            * @method projectConfigExtents
            */
            projectConfigExtents: function () {
                //extract default basemap projection
                var mapSR = new SpatialReference(RAMP.config.basemaps[RAMP.config.initialBasemapIndex].spatialReference);
 
                //project the default extent.  when finished, process full extent
                projectExtent(RAMP.config.extents.defaultExtent, mapSR, projectFullExtent);
            },
 
            /**
            * Given an ESRI Extent Object, returns a new ESRI Extent Object that
            * contains the extent adjusted according to this map's maximum extent
            *
            * NOTE: this method is currently unused!
            *
            * @param {esri/geometry/Extent} e the extent Object
            * @param {esri/geometry/Extent} maxExtent the maximum extent
            * @return {esri/geometry/Extent} An adjusted extent, if the target extent is outside the boundary
            * @method checkBoundary
            */
            checkBoundary: function (e, maxExtent) {
                var extent = e,
                width = extent.width(),
                height = extent.height(),
                centerX = extent.centerX(),
                centerY = extent.centerY(),
                flag, adjustedEx;
 
                adjustedEx = extent.clone();
 
                var maxHeight = maxExtent.height();
                if (height > maxHeight) {
                    height = maxHeight;
                }
 
                if (centerY > maxExtent.ymax) {
                    adjustedEx.ymax = maxExtent.ymax;
                    adjustedEx.ymin = maxExtent.ymax - height;
                    flag = true;
                    //} else if (extent.ymin < maxExtent.ymin) {
                } else if (centerY < maxExtent.ymin) {
                    adjustedEx.ymin = maxExtent.ymin;
                    adjustedEx.ymax = maxExtent.ymin + height;
                    flag = true;
                }
 
                var maxWidth = maxExtent.width();
                if (width > maxWidth) {
                    width = maxWidth;
                }
 
                if (centerX > maxExtent.xmax) {
                    adjustedEx.xmax = maxExtent.xmax;
                    adjustedEx.xmin = maxExtent.xmax - width;
                    flag = true;
                } else if (centerX < maxExtent.xmin) {
                    adjustedEx.xmin = maxExtent.xmin;
                    adjustedEx.xmax = maxExtent.xmin + width;
                    flag = true;
                }
 
                if (flag) {
                    return adjustedEx;
                }
            },
 
            /**
           * Create a new FeatureLayer object based on the config input
           *
           * @method makeFeatureLayer
           * @param {Object} layerConfig config object for the layer to create
           * @param {Boolean} userLayer optional specifies if layer was added by a user
           * @return {Esri/layers/FeatureLayer} feature layer object (unloaded)
           */
            makeFeatureLayer: function (layerConfig, userLayer) {
                // TODO: source of possible errors; add error handling
                var fl = new FeatureLayer(layerConfig.url, {
                    id: layerConfig.id,
                    mode: FeatureLayer.MODE_SNAPSHOT,
                    outFields: [layerConfig.layerAttributes],
                    visible: layerConfig.settings.visible,
                    opacity: resolveLayerOpacity(layerConfig.settings.opacity),
                    maxAllowableOffset: layerConfig.maxAllowableOffset
                });
 
                prepLayer(fl, layerConfig, userLayer);
 
                fl.ramp.type = GlobalStorage.layerType.feature;
 
                return fl;
            },
 
            /**
           * Return the feature layer corresponding to the given url.
           *
           * @method makeWmsLayer
           * @param {Object} layerConfig config object for the layer to create
           * @param {Boolean} userLayer optional specifies if layer was added by a user
           * @return {Esri/layers/WMSLayer} WMS layer
           */
 
            makeWmsLayer: function (layerConfig, userLayer) {
                var wmsl = new WMSLayer(layerConfig.url, {
                    id: layerConfig.id,
                    format: layerConfig.format,
                    opacity: resolveLayerOpacity(layerConfig.settings.opacity),
                    visibleLayers: [layerConfig.layerName]
                    //resourceInfo: {
                    //    extent: new EsriExtent(layer.extent),
                    //    layerInfos: [new WMSLayerInfo({name:layer.layerName,title:layer.displayName})]
                    //}
                });
 
                prepLayer(wmsl, layerConfig, userLayer);
 
                wmsl.ramp.type = GlobalStorage.layerType.wms;
 
                wmsl.setVisibility(layerConfig.settings.visible);
 
                return wmsl;
            },
 
            /**
            * Return the static layer corresponding to the given url.
            *
            * @method makeStaticLayer
            * @private
            * @param {Object} layerConfig config object for the layer to create
            * @param {Boolean} userLayer optional specifies if layer was added by a user
            * @return {Object} layer object of the appropriate type
            */
 
            makeStaticLayer: function (layerConfig, userLayer) {
                var tempLayer,
                    layerType = layerConfig.layerType || "feature";
                //determine layer type and process
                switch (layerType) {
                    case "feature":
                        tempLayer = new FeatureLayer(layerConfig.url, {
                            opacity: resolveLayerOpacity(layerConfig.settings.opacity),
                            mode: FeatureLayer.MODE_SNAPSHOT,
                            visible: layerConfig.settings.visible,
                            id: layerConfig.id,
                            maxAllowableOffset: layerConfig.maxAllowableOffset
                        });
 
                        prepLayer(tempLayer, layerConfig, userLayer);
 
                        tempLayer.ramp.type = GlobalStorage.layerType.Static;
 
                        break;
 
                        //We are currently not supporting other static layer types at the moment.
                        //Future versions should re-implement these cases
                        /*
                    case "tile":
                        tempLayer = new ArcGISTiledMapServiceLayer(staticLayer.url, {
                            opacity: resolveLayerOpacity(staticLayer.settings.opacity),
                            id: staticLayer.id
                        });
                        console.log("tile layer added. " + staticLayer.id);
                        break;
 
                    case "dynamic":
                        tempLayer = new ArcGISDynamicMapServiceLayer(staticLayer.url, {
                            opacity: resolveLayerOpacity(staticLayer.settings.opacity),
                            id: staticLayer.id
                        });
                        console.log("dynamic layer added. " + staticLayer.id);
                        break;
                        */
 
                    default:
                        console.log("unknown static layer type encountered: " + layerType);
                        break;
                }
                return tempLayer;
            },
 
            /**
            * Adds custom ramp properties to layer.  Adds handlers to loading events.
            *
            * @method enhanceLayer
            * @param  {Object} layer layer to be prepped
            * @param  {Object} config config object for the layer
            * @param  {Boolean} userLayer optional.  indicates if layer was added by a user.  default value is false
            */
            enhanceLayer: function (layer, config, userLayer) {
                //call the private function
                prepLayer(layer, config, userLayer);
            },
 
            /**
            * Will project an extent to a desired spatial reference, using client side projection library.
            * Avoids the need for Esri Geometry Service
            *
            * @method localProjectExtent
            * @param  {Esri/Extent} extent extent to be projected
            * @param {Esri/SpatialReference} sr {{#crossLink "Esri/SpatialReference"}}{{/crossLink}} to project to
            * @return {Esri/Extent} extent in the desired projection
            */
            localProjectExtent: localProjectExtent,
 
            /*
            * Initialize map control with configuration objects provided in the bootstrapper.js file.
            *
            * Initialize extent
            * Generate and load initial base map
            * Generate map layer objects
            * Show scalebar
            * Publish events to outside for other modules to use
            * Subscribe events to update map control
            *
            * @method init
            * @param {Object} mapDiv the HTML div that will store the map control
            * @constructor
            *
            */
            init: function () {
                var that = this,
 
                schemaBasemap = RAMP.config.basemaps[RAMP.config.initialBasemapIndex],
 
                /**
                * The URL of the first layer of the basemap that is on by default.
                *
                * @property url
                * @private
                * @type {String}
                */
                url = schemaBasemap.layers[0].url,
 
                /**
                * The basemap layer
                *
                * @property baseLayer
                * @private
                * @type {Esri/layers/ArcGISTiledMapServiceLayer}
                */
                baseLayer = new ArcGISTiledMapServiceLayer(url, {
                    id: "basemapLayer"
                }),
 
                loadListener = baseLayer.on('update-end', function () {
                    //only load things once, pls!
                    loadListener.remove();
 
                    //basemap has loaded.  continue on with the map loading
                    topic.publish(EventManager.Map.INITIAL_BASEMAP_LOADED);
                });
 
                baseLayer.on('error', function (evt) {
                    //basemap has died.  long live the basemap.
                    //TODO some proper error handling here.  error page?  message to user of catastrophic failure?
                    console.log('initial basemap failed to load: ' + evt.error.message);
                    window.location.href = RAMP.config.mapInitFailUrl;
                });
 
                /**
                * The initial extent of the map
                *
                * @property InitExtent
                * @private
                * @type {esri/geometry/Extent}
                */
                initExtent = new EsriExtent(RAMP.config.extents.defaultExtent);
 
                /**
                * Used for full extent in nav widget
                *
                * @property fullExtent
                * @private
                * @type {esri/geometry/Extent}
                */
                fullExtent = new EsriExtent(RAMP.config.extents.fullExtent);
 
                /**
                * The maximum extent of the map
                *
                * @property maxExtent
                * @private
                * @type {esri/geometry/Extent}
                */
                maxExtent = new EsriExtent(RAMP.config.extents.maximumExtent);
 
                //generate WMS layers array
                wmsLayers = dojoArray.map(RAMP.config.layers.wms, function (layer) {
                    return that.makeWmsLayer(layer);
                });
 
                //generate feature layers array
                featureLayers = dojoArray.map(RAMP.config.layers.feature, function (layerConfig) {
                    var fl;
 
                    if (layerConfig.isStatic) {
                        fl = that.makeStaticLayer(layerConfig);
                    } else {
                        fl = that.makeFeatureLayer(layerConfig);
                    }
 
                    return fl;
                });
 
                // determine the basmap wkid from config
                var tileSchema = schemaBasemap.tileSchema;
 
                // add custom level of details if lod exists in config.json
                if (tileSchema) {
                    var levelOfDetails = UtilArray.find(RAMP.config.LODs, function (configLOD) {
                        return configLOD.tileSchema === tileSchema;
                    });
 
                    //the map!
                    map = new EsriMap(RAMP.config.divNames.map, {
                        extent: initExtent,
                        logo: false,
                        minZoom: RAMP.config.zoomLevels.min,
                        maxZoom: RAMP.config.zoomLevels.max,
                        slider: false,
                        lods: levelOfDetails.lod
                    });
                } else {
                    //the map!
                    map = new EsriMap(RAMP.config.divNames.map, {
                        extent: initExtent,
                        logo: false,
                        minZoom: RAMP.config.zoomLevels.min,
                        maxZoom: RAMP.config.zoomLevels.max,
                        slider: false
                    });
                }
 
                RAMP.map = map;
                MapClickHandler.init(map);
 
                /*  START - Add static layers   */
                //NOTE: this type of thing is not currenlty supported by the config schema.  Need to revisit and determine if we want to keep this code or not.
                // this only deals with static layers that are bound to a feature layer.  stand alone static layers are handled like normal feature layers
 
                //if this does get implemented, this code should be moved to the layerLoader.js onLayerLoaded function.  After a feature layer successfully loads,
                //we should then load any of it's static layers.  Extra tricky because these static layers do not appear in the layer selector (their state is bound
                //to the feature layer.
                //may want to consider another layerType .BoundStatic
 
                var staticLayers = [],
                    perLayerStaticMaps = [],
                    staticLayerMap = [];
 
                dojoArray.forEach(RAMP.config.layers.feature, function (layer) {
                    perLayerStaticMaps = [];
                    dojoArray.forEach(layer.staticLayers, function (staticLayer, i) {
                        var tempLayer = that.makeStaticLayer(staticLayer);
 
                        staticLayers.push(tempLayer);
                        //creates an array of all static layers defined for the current, single feature layer
                        perLayerStaticMaps[i] = staticLayer.id;
                    });
                    //adds the static layer id array as a value to an array indexed by feature layer id
                    staticLayerMap[layer.id] = perLayerStaticMaps;
                });
 
                RAMP.staticLayerMap = staticLayerMap;
 
                /*  End - Add static layers   */
 
                //This was intended to be used to distinguish layers from each other when crawling; Looks like we are not using it. Commenting out for now. SZ
                baseLayer.ramp = {
                    type: GlobalStorage.layerType.Basemap
                };
 
                //save layer objects to load after basemap.
                //static layers is currently empty always
                RAMP.startupLayers = wmsLayers.concat(staticLayers, featureLayers);
 
                //add the basemap
                map.addLayer(baseLayer);
 
                /* Start - Show scalebar */
                var scalebar = new EsriScalebar({
                    map: map,
                    attachTo: "bottom-left",
                    scalebarUnit: "metric"
                });
 
                scalebar.show();
 
                /* End - Show scalebar */
 
                _initRepublishers(map);
                _initListeners(map);
                _initEventHandlers(map);
            }
        };
    });