goog.provide('ol.Feature');
goog.provide('ol.feature');

goog.require('goog.asserts');
goog.require('goog.events');
goog.require('goog.events.EventType');
goog.require('goog.functions');
goog.require('ol.Object');
goog.require('ol.geom.Geometry');
goog.require('ol.style.Circle');
goog.require('ol.style.Fill');
goog.require('ol.style.Stroke');
goog.require('ol.style.Style');



/**
 * @constructor
 * @extends {ol.Object}
 * @param {ol.geom.Geometry|Object.<string, *>=} opt_geometryOrValues
 *     Values or geometry.
 * @todo stability experimental
 */
ol.Feature = function(opt_geometryOrValues) {

  goog.base(this);

  /**
   * @private
   * @type {number|string|undefined}
   */
  this.id_ = undefined;

  /**
   * @type {string}
   * @private
   */
  this.geometryName_ = 'geometry';

  /**
   * User provided style.
   * @private
   * @type {ol.style.Style|Array.<ol.style.Style>|
   *     ol.feature.FeatureStyleFunction}
   */
  this.style_ = null;

  /**
   * @private
   * @type {ol.feature.FeatureStyleFunction|undefined}
   */
  this.styleFunction_ = undefined;

  /**
   * @private
   * @type {goog.events.Key}
   */
  this.geometryChangeKey_ = null;

  goog.events.listen(
      this, ol.Object.getChangeEventType(this.geometryName_),
      this.handleGeometryChanged_, false, this);

  if (goog.isDefAndNotNull(opt_geometryOrValues)) {
    if (opt_geometryOrValues instanceof ol.geom.Geometry) {
      var geometry = /** @type {ol.geom.Geometry} */ (opt_geometryOrValues);
      this.setGeometry(geometry);
    } else {
      goog.asserts.assert(goog.isObject(opt_geometryOrValues));
      var values = /** @type {Object.<string, *>} */ (opt_geometryOrValues);
      this.setValues(values);
    }
  } else {
    this.setGeometry(null);
  }
};
goog.inherits(ol.Feature, ol.Object);


/**
 * @return {ol.geom.Geometry|undefined} Geometry.
 * @todo stability experimental
 */
ol.Feature.prototype.getGeometry = function() {
  return /** @type {ol.geom.Geometry|undefined} */ (
      this.get(this.geometryName_));
};
goog.exportProperty(
    ol.Feature.prototype,
    'getGeometry',
    ol.Feature.prototype.getGeometry);


/**
 * @return {number|string|undefined} Id.
 * @todo stability experimental
 */
ol.Feature.prototype.getId = function() {
  return this.id_;
};


/**
 * @return {string} Geometry property name.
 * @todo stability experimental
 */
ol.Feature.prototype.getGeometryName = function() {
  return this.geometryName_;
};


/**
 * @return {ol.style.Style|Array.<ol.style.Style>|
 *     ol.feature.FeatureStyleFunction} User provided style.
 * @todo stability experimental
 */
ol.Feature.prototype.getStyle = function() {
  return this.style_;
};


/**
 * @return {ol.feature.FeatureStyleFunction|undefined} Style function.
 * @todo stability experimental
 */
ol.Feature.prototype.getStyleFunction = function() {
  return this.styleFunction_;
};


/**
 * @private
 */
ol.Feature.prototype.handleGeometryChange_ = function() {
  this.dispatchChangeEvent();
};


/**
 * @private
 */
ol.Feature.prototype.handleGeometryChanged_ = function() {
  if (!goog.isNull(this.geometryChangeKey_)) {
    goog.events.unlistenByKey(this.geometryChangeKey_);
    this.geometryChangeKey_ = null;
  }
  var geometry = this.getGeometry();
  if (goog.isDefAndNotNull(geometry)) {
    this.geometryChangeKey_ = goog.events.listen(geometry,
        goog.events.EventType.CHANGE, this.handleGeometryChange_, false, this);
  }
};


/**
 * @param {ol.geom.Geometry|undefined} geometry Geometry.
 * @todo stability experimental
 */
ol.Feature.prototype.setGeometry = function(geometry) {
  this.set(this.geometryName_, geometry);
};
goog.exportProperty(
    ol.Feature.prototype,
    'setGeometry',
    ol.Feature.prototype.setGeometry);


/**
 * @param {ol.style.Style|Array.<ol.style.Style>|
 *     ol.feature.FeatureStyleFunction} style Feature style.
 * @todo stability experimental
 */
ol.Feature.prototype.setStyle = function(style) {
  this.style_ = style;
  this.styleFunction_ = ol.feature.createFeatureStyleFunction(style);
  this.dispatchChangeEvent();
};


/**
 * @param {number|string|undefined} id Id.
 * @todo stability experimental
 */
ol.Feature.prototype.setId = function(id) {
  this.id_ = id;
};


/**
 * @param {string} name Geometry property name.
 * @todo stability experimental
 */
ol.Feature.prototype.setGeometryName = function(name) {
  goog.events.unlisten(
      this, ol.Object.getChangeEventType(this.geometryName_),
      this.handleGeometryChanged_, false, this);
  this.geometryName_ = name;
  goog.events.listen(
      this, ol.Object.getChangeEventType(this.geometryName_),
      this.handleGeometryChanged_, false, this);
  this.handleGeometryChanged_();
};


/**
 * A function that takes a `{number}` representing the view's resolution. It
 * returns an Array of {@link ol.style.Style}. This way individual features
 * can be styled. The this keyword inside the function references the
 * {@link ol.Feature} to be styled.
 *
 * @typedef {function(this: ol.Feature, number): Array.<ol.style.Style>}
 * @todo stability experimental
 */
ol.feature.FeatureStyleFunction;


/**
 * Default style function for features.
 * @param {number} resolution Resolution.
 * @return {Array.<ol.style.Style>} Style.
 * @this {ol.Feature}
 * @todo stability experimental
 */
ol.feature.defaultFeatureStyleFunction = function(resolution) {
  var fill = new ol.style.Fill({
    color: 'rgba(255,255,255,0.4)'
  });
  var stroke = new ol.style.Stroke({
    color: '#3399CC',
    width: 1.25
  });
  var styles = [
    new ol.style.Style({
      image: new ol.style.Circle({
        fill: fill,
        stroke: stroke,
        radius: 5
      }),
      fill: fill,
      stroke: stroke
    })
  ];

  // now that we've run it the first time,
  // replace the function with a constant version
  ol.feature.defaultFeatureStyleFunction =
      /** @type {function(this:ol.Feature):Array.<ol.style.Style>} */(
      function(resolution) {
        return styles;
      });

  return styles;
};


/**
 * A function that takes an {@link ol.Feature} and a `{number}` representing
 * the view's resolution. The function should return an array of
 * {@link ol.style.Style}. This way e.g. a vector layer can be styled.
 *
 * @typedef {function(ol.Feature, number): Array.<ol.style.Style>}
 * @todo stability experimental
 */
ol.feature.StyleFunction;


/**
 * @param {ol.Feature} feature Feature.
 * @param {number} resolution Resolution.
 * @return {Array.<ol.style.Style>} Style.
 * @todo stability experimental
 */
ol.feature.defaultStyleFunction = function(feature, resolution) {
  var featureStyleFunction = feature.getStyleFunction();
  if (!goog.isDef(featureStyleFunction)) {
    featureStyleFunction = ol.feature.defaultFeatureStyleFunction;
  }
  return featureStyleFunction.call(feature, resolution);
};


/**
 * Convert the provided object into a feature style function.  Functions passed
 * through unchanged.  Arrays of ol.style.Style or single style objects wrapped
 * in a new feature style function.
 * @param {ol.feature.FeatureStyleFunction|Array.<ol.style.Style>|
 *     ol.style.Style} obj A feature style function, a single style, or an array
 *     of styles.
 * @return {ol.feature.FeatureStyleFunction} A style function.
 */
ol.feature.createFeatureStyleFunction = function(obj) {
  /**
   * @type {ol.feature.FeatureStyleFunction}
   */
  var styleFunction;

  if (goog.isFunction(obj)) {
    styleFunction = /** @type {ol.feature.FeatureStyleFunction} */ (obj);
  } else {
    /**
     * @type {Array.<ol.style.Style>}
     */
    var styles;
    if (goog.isArray(obj)) {
      styles = obj;
    } else {
      goog.asserts.assertInstanceof(obj, ol.style.Style);
      styles = [obj];
    }
    styleFunction = goog.functions.constant(styles);
  }
  return styleFunction;
};


/**
 * Convert the provided object into a style function.  Functions passed through
 * unchanged.  Arrays of ol.style.Style or single style objects wrapped in a
 * new style function.
 * @param {ol.feature.StyleFunction|Array.<ol.style.Style>|ol.style.Style} obj
 *     A style function, a single style, or an array of styles.
 * @return {ol.feature.StyleFunction} A style function.
 */
ol.feature.createStyleFunction = function(obj) {
  /**
   * @type {ol.feature.StyleFunction}
   */
  var styleFunction;

  if (goog.isFunction(obj)) {
    styleFunction = /** @type {ol.feature.StyleFunction} */ (obj);
  } else {
    /**
     * @type {Array.<ol.style.Style>}
     */
    var styles;
    if (goog.isArray(obj)) {
      styles = obj;
    } else {
      goog.asserts.assertInstanceof(obj, ol.style.Style);
      styles = [obj];
    }
    styleFunction = goog.functions.constant(styles);
  }
  return styleFunction;
};