/*global OpenLayers*/
(function() {
    'use strict';
    /**
     * Transforms an array of features to a single feature with the merged
     * geometry of geom_type
     */
    OpenLayers.Util.properFeatures = function(features, geom_type) {
        if (features.constructor === Array) {
            var geoms = [];
            for (var i = 0; i < features.length; i++) {
                geoms.push(features[i].geometry);
            }
            var geom = new geom_type(geoms);
            features = new OpenLayers.Feature.Vector(geom);
        }
        return features;
    };

    /**
     * @requires OpenLayers/Format/WKT.js
     */

    /**
     * Class: OpenLayers.Format.DjangoWKT
     * Class for reading Well-Known Text, with workarounds to successfully parse
     * geometries and collections as returned by django.contrib.gis.geos.
     *
     * Inherits from:
     *  - <OpenLayers.Format.WKT>
     */

    OpenLayers.Format.DjangoWKT = OpenLayers.Class(OpenLayers.Format.WKT, {
        initialize: function(options) {
            OpenLayers.Format.WKT.prototype.initialize.apply(this, [options]);
            this.regExes.justComma = /\s*,\s*/;
        },

        parse: {
            'point': function(str) {
                var coords = OpenLayers.String.trim(str).split(this.regExes.spaces);
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.Point(coords[0], coords[1])
                );
            },

            'multipoint': function(str) {
                var point;
                var points = OpenLayers.String.trim(str).split(this.regExes.justComma);
                var components = [];
                for(var i = 0, len = points.length; i < len; ++i) {
                    point = points[i].replace(this.regExes.trimParens, '$1');
                    components.push(this.parse.point.apply(this, [point]).geometry);
                }
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.MultiPoint(components)
                );
            },

            'linestring': function(str) {
                var points = OpenLayers.String.trim(str).split(',');
                var components = [];
                for(var i = 0, len = points.length; i < len; ++i) {
                    components.push(this.parse.point.apply(this, [points[i]]).geometry);
                }
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.LineString(components)
                );
            },

            'multilinestring': function(str) {
                var line;
                var lines = OpenLayers.String.trim(str).split(this.regExes.parenComma);
                var components = [];
                for(var i = 0, len = lines.length; i < len; ++i) {
                    line = lines[i].replace(this.regExes.trimParens, '$1');
                    components.push(this.parse.linestring.apply(this, [line]).geometry);
                }
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.MultiLineString(components)
                );
            },

            'polygon': function(str) {
                var ring, linestring, linearring;
                var rings = OpenLayers.String.trim(str).split(this.regExes.parenComma);
                var components = [];
                for(var i = 0, len = rings.length; i < len; ++i) {
                    ring = rings[i].replace(this.regExes.trimParens, '$1');
                    linestring = this.parse.linestring.apply(this, [ring]).geometry;
                    linearring = new OpenLayers.Geometry.LinearRing(linestring.components);
                    components.push(linearring);
                }
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.Polygon(components)
                );
            },

            'multipolygon': function(str) {
                var polygon;
                var polygons = OpenLayers.String.trim(str).split(this.regExes.doubleParenComma);
                var components = [];
                for(var i = 0, len = polygons.length; i < len; ++i) {
                    polygon = polygons[i].replace(this.regExes.trimParens, '$1');
                    components.push(this.parse.polygon.apply(this, [polygon]).geometry);
                }
                return new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.MultiPolygon(components)
                );
            },

            'geometrycollection': function(str) {
                // separate components of the collection with |
                str = str.replace(/,\s*([A-Za-z])/g, '|$1');
                var wktArray = OpenLayers.String.trim(str).split('|');
                var components = [];
                for(var i = 0, len = wktArray.length; i < len; ++i) {
                    components.push(OpenLayers.Format.WKT.prototype.read.apply(this, [wktArray[i]]));
                }
                return components;
            }
        },

        extractGeometry: function(geometry) {
            var type = geometry.CLASS_NAME.split('.')[2].toLowerCase();
            if (!this.extract[type]) {
                return null;
            }
            if (this.internalProjection && this.externalProjection) {
                geometry = geometry.clone();
                geometry.transform(this.internalProjection, this.externalProjection);
            }
            var wktType = type === 'collection' ? 'GEOMETRYCOLLECTION' : type.toUpperCase();
            var data = wktType + '(' + this.extract[type].apply(this, [geometry]) + ')';
            return data;
        },

        /**
         * Patched write: successfully writes WKT for geometries and
         * geometrycollections.
         */
        write: function(features) {
            var collection, isCollection;
            isCollection = features.geometry.CLASS_NAME === "OpenLayers.Geometry.Collection";
            var pieces = [];
            if (isCollection) {
                collection = features.geometry.components;
                pieces.push('GEOMETRYCOLLECTION(');
                for (var i = 0, len = collection.length; i < len; ++i) {
                    if (i > 0) {
                        pieces.push(',');
                    }
                    pieces.push(this.extractGeometry(collection[i]));
                }
                pieces.push(')');
            } else {
                pieces.push(this.extractGeometry(features.geometry));
            }
            return pieces.join('');
        },

        CLASS_NAME: "OpenLayers.Format.DjangoWKT"
    });

    function MapWidget(options) {
        this.map = null;
        this.controls = null;
        this.panel = null;
        this.layers = {};
        this.wkt_f = new OpenLayers.Format.DjangoWKT();

        // Mapping from OGRGeomType name to OpenLayers.Geometry name
        if (options.geom_name === 'Unknown') {
            options.geom_type = OpenLayers.Geometry;
        } else if (options.geom_name === 'GeometryCollection') {
            options.geom_type = OpenLayers.Geometry.Collection;
        } else {
            options.geom_type = OpenLayers.Geometry[options.geom_name];
        }

        // Default options
        this.options = {
            color: 'ee9900',
            default_lat: 0,
            default_lon: 0,
            default_zoom: 4,
            is_collection: new options.geom_type() instanceof OpenLayers.Geometry.Collection,
            layerswitcher: false,
            map_options: {},
            map_srid: 4326,
            modifiable: true,
            mouse_position: false,
            opacity: 0.4,
            point_zoom: 12,
            scale_text: false,
            scrollable: true
        };

        // Altering using user-provided options
        for (var property in options) {
            if (options.hasOwnProperty(property)) {
                this.options[property] = options[property];
            }
        }

        this.map = this.create_map();

        var defaults_style = {
            'fillColor': '#' + this.options.color,
            'fillOpacity': this.options.opacity,
            'strokeColor': '#' + this.options.color
        };
        if (this.options.geom_name === 'LineString') {
            defaults_style.strokeWidth = 3;
        }
        var styleMap = new OpenLayers.StyleMap({'default': OpenLayers.Util.applyDefaults(defaults_style, OpenLayers.Feature.Vector.style.default)});
        this.layers.vector = new OpenLayers.Layer.Vector(" " + this.options.name, {styleMap: styleMap});
        this.map.addLayer(this.layers.vector);
        var wkt = document.getElementById(this.options.id).value;
        if (wkt) {
            var feat = OpenLayers.Util.properFeatures(this.read_wkt(wkt), this.options.geom_type);
            this.write_wkt(feat);
            if (this.options.is_collection) {
                for (var i = 0; i < this.num_geom; i++) {
                    this.layers.vector.addFeatures([new OpenLayers.Feature.Vector(feat.geometry.components[i].clone())]);
                }
            } else {
                this.layers.vector.addFeatures([feat]);
            }
            this.map.zoomToExtent(feat.geometry.getBounds());
            if (this.options.geom_name === 'Point') {
                this.map.zoomTo(this.options.point_zoom);
            }
        } else {
            this.map.setCenter(this.defaultCenter(), this.options.default_zoom);
        }
        this.layers.vector.events.on({'featuremodified': this.modify_wkt, scope: this});
        this.layers.vector.events.on({'featureadded': this.add_wkt, scope: this});

        this.getControls(this.layers.vector);
        this.panel.addControls(this.controls);
        this.map.addControl(this.panel);
        this.addSelectControl();

        if (this.options.mouse_position) {
            this.map.addControl(new OpenLayers.Control.MousePosition());
        }
        if (this.options.scale_text) {
            this.map.addControl(new OpenLayers.Control.Scale());
        }
        if (this.options.layerswitcher) {
            this.map.addControl(new OpenLayers.Control.LayerSwitcher());
        }
        if (!this.options.scrollable) {
            this.map.getControlsByClass('OpenLayers.Control.Navigation')[0].disableZoomWheel();
        }
        if (wkt) {
            if (this.options.modifiable) {
                this.enableEditing();
            }
        } else {
            this.enableDrawing();
        }
    }

    MapWidget.prototype.create_map = function() {
        var map = new OpenLayers.Map(this.options.map_id, this.options.map_options);
        if (this.options.base_layer) {
            this.layers.base = this.options.base_layer;
        } else {
            this.layers.base = new OpenLayers.Layer.WMS('OpenLayers WMS', 'http://vmap0.tiles.osgeo.org/wms/vmap0', {layers: 'basic'});
        }
        map.addLayer(this.layers.base);
        return map;
    };

    MapWidget.prototype.get_ewkt = function(feat) {
        return "SRID=" + this.options.map_srid + ";" + this.wkt_f.write(feat);
    };

    MapWidget.prototype.read_wkt = function(wkt) {
        var prefix = 'SRID=' + this.options.map_srid + ';';
        if (wkt.indexOf(prefix) === 0) {
            wkt = wkt.slice(prefix.length);
        }
        return this.wkt_f.read(wkt);
    };

    MapWidget.prototype.write_wkt = function(feat) {
        feat = OpenLayers.Util.properFeatures(feat, this.options.geom_type);
        if (this.options.is_collection) {
            this.num_geom = feat.geometry.components.length;
        } else {
            this.num_geom = 1;
        }
        document.getElementById(this.options.id).value = this.get_ewkt(feat);
    };

    MapWidget.prototype.add_wkt = function(event) {
        if (this.options.is_collection) {
            var feat = new OpenLayers.Feature.Vector(new this.options.geom_type());
            for (var i = 0; i < this.layers.vector.features.length; i++) {
                feat.geometry.addComponents([this.layers.vector.features[i].geometry]);
            }
            this.write_wkt(feat);
        } else {
            if (this.layers.vector.features.length > 1) {
                var old_feats = [this.layers.vector.features[0]];
                this.layers.vector.removeFeatures(old_feats);
                this.layers.vector.destroyFeatures(old_feats);
            }
            this.write_wkt(event.feature);
        }
    };

    MapWidget.prototype.modify_wkt = function(event) {
        if (this.options.is_collection) {
            if (this.options.geom_name === 'MultiPoint') {
                this.add_wkt(event);
                return;
            } else {
                var feat = new OpenLayers.Feature.Vector(new this.options.geom_type());
                for (var i = 0; i < this.num_geom; i++) {
                    feat.geometry.addComponents([this.layers.vector.features[i].geometry]);
                }
                this.write_wkt(feat);
            }
        } else {
            this.write_wkt(event.feature);
        }
    };

    MapWidget.prototype.deleteFeatures = function() {
        this.layers.vector.removeFeatures(this.layers.vector.features);
        this.layers.vector.destroyFeatures();
    };

    MapWidget.prototype.clearFeatures = function() {
        this.deleteFeatures();
        document.getElementById(this.options.id).value = '';
        this.map.setCenter(this.defaultCenter(), this.options.default_zoom);
    };

    MapWidget.prototype.defaultCenter = function() {
        var center = new OpenLayers.LonLat(this.options.default_lon, this.options.default_lat);
        if (this.options.map_srid) {
            return center.transform(new OpenLayers.Projection("EPSG:4326"), this.map.getProjectionObject());
        }
        return center;
    };

    MapWidget.prototype.addSelectControl = function() {
        var select = new OpenLayers.Control.SelectFeature(this.layers.vector, {'toggle': true, 'clickout': true});
        this.map.addControl(select);
        select.activate();
    };

    MapWidget.prototype.enableDrawing = function() {
        this.map.getControlsByClass('OpenLayers.Control.DrawFeature')[0].activate();
    };

    MapWidget.prototype.enableEditing = function() {
        this.map.getControlsByClass('OpenLayers.Control.ModifyFeature')[0].activate();
    };

    MapWidget.prototype.getControls = function(layer) {
        this.panel = new OpenLayers.Control.Panel({'displayClass': 'olControlEditingToolbar'});
        this.controls = [new OpenLayers.Control.Navigation()];
        if (!this.options.modifiable && layer.features.length) {
            return;
        }
        if (this.options.geom_name.indexOf('LineString') >= 0 || this.options.geom_name === 'GeometryCollection' || this.options.geom_name === 'Unknown') {
            this.controls.push(new OpenLayers.Control.DrawFeature(layer, OpenLayers.Handler.Path, {'displayClass': 'olControlDrawFeaturePath'}));
        }
        if (this.options.geom_name.indexOf('Polygon') >= 0 || this.options.geom_name === 'GeometryCollection' || this.options.geom_name === 'Unknown') {
            this.controls.push(new OpenLayers.Control.DrawFeature(layer, OpenLayers.Handler.Polygon, {'displayClass': 'olControlDrawFeaturePolygon'}));
        }
        if (this.options.geom_name.indexOf('Point') >= 0 || this.options.geom_name === 'GeometryCollection' || this.options.geom_name === 'Unknown') {
            this.controls.push(new OpenLayers.Control.DrawFeature(layer, OpenLayers.Handler.Point, {'displayClass': 'olControlDrawFeaturePoint'}));
        }
        if (this.options.modifiable) {
            this.controls.push(new OpenLayers.Control.ModifyFeature(layer, {'displayClass': 'olControlModifyFeature'}));
        }
    };
    window.MapWidget = MapWidget;
})();