/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for 
 * full list of contributors). Published under the Clear BSD license.  
 * See http://svn.openlayers.org/trunk/openlayers/license.txt for the
 * full text of the license. */
 
/**
 * @requires OpenLayers/Format/XML.js
 * @requires OpenLayers/Format/GML.js
 */
 
/**
 * Though required in the full build, if the GML format is excluded, we set
 * the namespace here.
 */
if(!OpenLayers.Format.GML) {
    OpenLayers.Format.GML = {};
}
 
/**
 * Class: OpenLayers.Format.GML.Base
 * Superclass for GML parsers.
 *
 * Inherits from:
 *  - <OpenLayers.Format.XML>
 */
OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
    
    /**
     * Property: namespaces
     * {Object} Mapping of namespace aliases to namespace URIs.
     */
    namespaces: {
        gml: "http://www.opengis.net/gml",
        xlink: "http://www.w3.org/1999/xlink",
        xsi: "http://www.w3.org/2001/XMLSchema-instance",
        wfs: "http://www.opengis.net/wfs" // this is a convenience for reading wfs:FeatureCollection
    },
    
    /**
     * Property: defaultPrefix
     */
    defaultPrefix: "gml",
 
    /**
     * Property: schemaLocation
     * {String} Schema location for a particular minor version.
     */
    schemaLocation: null,
    
    /**
     * APIProperty: featureType
     * {Array(String) or String} The local (without prefix) feature typeName(s).
     */
    featureType: null,
    
    /**
     * APIProperty: featureNS
     * {String} The feature namespace.  Must be set in the options at
     *     construction.
     */
    featureNS: null,
 
    /**
     * APIProperty: geometry
     * {String} Name of geometry element.  Defaults to "geometry".
     */
    geometryName: "geometry",
 
    /**
     * APIProperty: extractAttributes
     * {Boolean} Extract attributes from GML.  Default is true.
     */
    extractAttributes: true,
    
    /**
     * APIProperty: srsName
     * {String} URI for spatial reference system.  This is optional for
     *     single part geometries and mandatory for collections and multis.
     *     If set, the srsName attribute will be written for all geometries.
     *     Default is null.
     */
    srsName: null,
 
    /**
     * APIProperty: xy
     * {Boolean} Order of the GML coordinate true:(x,y) or false:(y,x)
     * Changing is not recommended, a new Format should be instantiated.
     */ 
    xy: true,
 
    /**
     * Property: geometryTypes
     * {Object} Maps OpenLayers geometry class names to GML element names.
     *     Use <setGeometryTypes> before accessing this property.
     */
    geometryTypes: null,
 
    /**
     * Property: singleFeatureType
     * {Boolean} True if there is only 1 featureType, and not an array
     *     of featuretypes.
     */
    singleFeatureType: null,
 
    /**
     * Property: regExes
     * Compiled regular expressions for manipulating strings.
     */
    regExes: {
        trimSpace: (/^\s*|\s*$/g),
        removeSpace: (/\s*/g),
        splitSpace: (/\s+/),
        trimComma: (/\s*,\s*/g)
    },
 
    /**
     * Constructor: OpenLayers.Format.GML.Base
     * Instances of this class are not created directly.  Use the
     *     <OpenLayers.Format.GML.v2> or <OpenLayers.Format.GML.v3> constructor
     *     instead.
     *
     * Parameters:
     * options - {Object} An optional object whose properties will be set on
     *     this instance.
     *
     * Valid options properties:
     * featureType - {Array(String) or String} Local (without prefix) feature 
     *     typeName(s) (required).
     * featureNS - {String} Feature namespace (required).
     * geometryName - {String} Geometry element name.
     */
    initialize: function(options) {
        OpenLayers.Format.XML.prototype.initialize.apply(this, [options]);
        this.setGeometryTypes();
        if(options && options.featureNS) {
            this.setNamespace("feature", options.featureNS);
        }
        this.singleFeatureType = !options || (typeof options.featureType === "string");
    },
    
    /**
     * Method: read
     *
     * Parameters:
     * data - {DOMElement} A gml:featureMember element, a gml:featureMembers
     *     element, or an element containing either of the above at any level.
     *
     * Returns:
     * {Array(<OpenLayers.Feature.Vector>)} An array of features.
     */
    read: function(data) {
        if(typeof data == "string") { 
            data = OpenLayers.Format.XML.prototype.read.apply(this, [data]);
        }
        if(data && data.nodeType == 9) {
            data = data.documentElement;
        }
        var features = [];
        this.readNode(data, {features: features});
        if(features.length == 0) {
            // look for gml:featureMember elements
            var elements = this.getElementsByTagNameNS(
                data, this.namespaces.gml, "featureMember"
            );
            if(elements.length) {
                for(var i=0, len=elements.length; i<len; ++i) {
                    this.readNode(elements[i], {features: features});
                }
            } else {
                // look for gml:featureMembers elements (this is v3, but does no harm here)
                var elements = this.getElementsByTagNameNS(
                    data, this.namespaces.gml, "featureMembers"
                );
                if(elements.length) {
                    // there can be only one
                    this.readNode(elements[0], {features: features});
                }
            }
        }
        return features;
    },
    
    /**
     * Property: readers
     * Contains public functions, grouped by namespace prefix, that will
     *     be applied when a namespaced node is found matching the function
     *     name.  The function will be applied in the scope of this parser
     *     with two arguments: the node being read and a context object passed
     *     from the parent.
     */
    readers: {
        "gml": {
            "featureMember": function(node, obj) {
                this.readChildNodes(node, obj);
            },
            "featureMembers": function(node, obj) {
                this.readChildNodes(node, obj);                
            },
            "name": function(node, obj) {
                obj.name = this.getChildValue(node);
            },
            "boundedBy": function(node, obj) {
                var container = {};
                this.readChildNodes(node, container);
                if(container.components && container.components.length > 0) {
                    obj.bounds = container.components[0];
                }
            },
            "Point": function(node, container) {
                var obj = {points: []};
                this.readChildNodes(node, obj);
                if(!container.components) {
                    container.components = [];
                }
                container.components.push(obj.points[0]);
            },
            "coordinates": function(node, obj) {
                var str = this.getChildValue(node).replace(
                    this.regExes.trimSpace, ""
                );
                str = str.replace(this.regExes.trimComma, ",");
                var pointList = str.split(this.regExes.splitSpace);
                var coords;
                var numPoints = pointList.length;
                var points = new Array(numPoints);
                for(var i=0; i<numPoints; ++i) {
                    coords = pointList[i].split(",");
                    if (this.xy) {
                        points[i] = new OpenLayers.Geometry.Point(
                            coords[0], coords[1], coords[2]
                        );
                    } else {
                        points[i] = new OpenLayers.Geometry.Point(
                            coords[1], coords[0], coords[2]
                        );
                    }
                }
                obj.points = points;
            },
            "coord": function(node, obj) {
                var coord = {};
                this.readChildNodes(node, coord);
                if(!obj.points) {
                    obj.points = [];
                }
                obj.points.push(new OpenLayers.Geometry.Point(
                    coord.x, coord.y, coord.z
                ));
            },
            "X": function(node, coord) {
                coord.x = this.getChildValue(node);
            },
            "Y": function(node, coord) {
                coord.y = this.getChildValue(node);
            },
            "Z": function(node, coord) {
                coord.z = this.getChildValue(node);
            },
            "MultiPoint": function(node, container) {
                var obj = {components: []};
                this.readChildNodes(node, obj);
                container.components = [
                    new OpenLayers.Geometry.MultiPoint(obj.components)
                ];
            },
            "pointMember": function(node, obj) {
                this.readChildNodes(node, obj);
            },
            "LineString": function(node, container) {
                var obj = {};
                this.readChildNodes(node, obj);
                if(!container.components) {
                    container.components = [];
                }
                container.components.push(
                    new OpenLayers.Geometry.LineString(obj.points)
                );
            },
            "MultiLineString": function(node, container) {
                var obj = {components: []};
                this.readChildNodes(node, obj);
                container.components = [
                    new OpenLayers.Geometry.MultiLineString(obj.components)
                ];
            },
            "lineStringMember": function(node, obj) {
                this.readChildNodes(node, obj);
            },
            "Polygon": function(node, container) {
                var obj = {outer: null, inner: []};
                this.readChildNodes(node, obj);
                obj.inner.unshift(obj.outer);
                if(!container.components) {
                    container.components = [];
                }
                container.components.push(
                    new OpenLayers.Geometry.Polygon(obj.inner)
                );
            },
            "LinearRing": function(node, obj) {
                var container = {};
                this.readChildNodes(node, container);
                obj.components = [new OpenLayers.Geometry.LinearRing(
                    container.points
                )];
            },
            "MultiPolygon": function(node, container) {
                var obj = {components: []};
                this.readChildNodes(node, obj);
                container.components = [
                    new OpenLayers.Geometry.MultiPolygon(obj.components)
                ];
            },
            "polygonMember": function(node, obj) {
                this.readChildNodes(node, obj);
            },
            "GeometryCollection": function(node, container) {
                var obj = {components: []};
                this.readChildNodes(node, obj);
                container.components = [
                    new OpenLayers.Geometry.Collection(obj.components)
                ];
            },
            "geometryMember": function(node, obj) {
                this.readChildNodes(node, obj);
            }
        },
        "feature": {
            "*": function(node, obj) {
                // The node can either be named like the featureType, or it
                // can be a child of the feature:featureType.  Children can be
                // geometry or attributes.
                var name;
                var local = node.localName || node.nodeName.split(":").pop();
                // Since an attribute can have the same name as the feature type
                // we only want to read the node as a feature if the parent
                // node can have feature nodes as children.  In this case, the
                // obj.features property is set.
                if (obj.features) {
                    if (!this.singleFeatureType &&
                        (OpenLayers.Util.indexOf(this.featureType, local) !== -1)) {
                        name = "_typeName";
                    } else if(local === this.featureType) {
                        name = "_typeName";
                    }
                } else {
                    // Assume attribute elements have one child node and that the child
                    // is a text node.  Otherwise assume it is a geometry node.
                    if(node.childNodes.length == 0 ||
                       (node.childNodes.length == 1 && node.firstChild.nodeType == 3)) {
                        if(this.extractAttributes) {
                            name = "_attribute";
                        }
                    } else {
                        name = "_geometry";
                    }
                }
                if(name) {
                    this.readers.feature[name].