/**
 * @module ol/style/Style
 */

/**
 * Feature styles.
 *
 * If no style is defined, the following default style is used:
 * ```js
 *  import {Fill, Stroke, Circle, Style} from 'ol/style';
 *
 *  var fill = new Fill({
 *    color: 'rgba(255,255,255,0.4)'
 *  });
 *  var stroke = new Stroke({
 *    color: '#3399CC',
 *    width: 1.25
 *  });
 *  var styles = [
 *    new Style({
 *      image: new Circle({
 *        fill: fill,
 *        stroke: stroke,
 *        radius: 5
 *      }),
 *      fill: fill,
 *      stroke: stroke
 *    })
 *  ];
 * ```
 *
 * A separate editing style has the following defaults:
 * ```js
 *  import {Fill, Stroke, Circle, Style} from 'ol/style';
 *  import GeometryType from 'ol/geom/GeometryType';
 *
 *  var white = [255, 255, 255, 1];
 *  var blue = [0, 153, 255, 1];
 *  var width = 3;
 *  styles[GeometryType.POLYGON] = [
 *    new Style({
 *      fill: new Fill({
 *        color: [255, 255, 255, 0.5]
 *      })
 *    })
 *  ];
 *  styles[GeometryType.MULTI_POLYGON] =
 *      styles[GeometryType.POLYGON];
 *  styles[GeometryType.LINE_STRING] = [
 *    new Style({
 *      stroke: new Stroke({
 *        color: white,
 *        width: width + 2
 *      })
 *    }),
 *    new Style({
 *      stroke: new Stroke({
 *        color: blue,
 *        width: width
 *      })
 *    })
 *  ];
 *  styles[GeometryType.MULTI_LINE_STRING] =
 *      styles[GeometryType.LINE_STRING];
 *  styles[GeometryType.POINT] = [
 *    new Style({
 *      image: new Circle({
 *        radius: width * 2,
 *        fill: new Fill({
 *          color: blue
 *        }),
 *        stroke: new Stroke({
 *          color: white,
 *          width: width / 2
 *        })
 *      }),
 *      zIndex: Infinity
 *    })
 *  ];
 *  styles[GeometryType.MULTI_POINT] =
 *      styles[GeometryType.POINT];
 *  styles[GeometryType.GEOMETRY_COLLECTION] =
 *      styles[GeometryType.POLYGON].concat(
 *          styles[GeometryType.LINE_STRING],
 *          styles[GeometryType.POINT]
 *      );
 * ```
 */
import {assert} from '../asserts.js';
import GeometryType from '../geom/GeometryType.js';
import CircleStyle from '../style/Circle.js';
import Fill from '../style/Fill.js';
import Stroke from '../style/Stroke.js';


/**
 * A function that takes an {@link module:ol/Feature} and a `{number}`
 * representing the view's resolution. The function should return a
 * {@link module:ol/style/Style} or an array of them. This way e.g. a
 * vector layer can be styled.
 *
 * @typedef {function((import("../Feature.js").default|import("../render/Feature.js").default), number):
 *     (import("./Style.js").default|Array<import("./Style.js").default>)} StyleFunction
 */


/**
 * A function that takes an {@link module:ol/Feature} as argument and returns an
 * {@link module:ol/geom/Geometry} that will be rendered and styled for the feature.
 *
 * @typedef {function((import("../Feature.js").default|import("../render/Feature.js").default)):
 *     (import("../geom/Geometry.js").default|import("../render/Feature.js").default|undefined)} GeometryFunction
 */


/**
 * Custom renderer function. Takes two arguments:
 *
 * 1. The pixel coordinates of the geometry in GeoJSON notation.
 * 2. The {@link module:ol/render~State} of the layer renderer.
 *
 * @typedef {function((import("../coordinate.js").Coordinate|Array<import("../coordinate.js").Coordinate>|Array<Array<import("../coordinate.js").Coordinate>>),import("../render.js").State)}
 * RenderFunction
 */


/**
 * @typedef {Object} Options
 * @property {string|import("../geom/Geometry.js").default|GeometryFunction} [geometry] Feature property or geometry
 * or function returning a geometry to render for this style.
 * @property {import("./Fill.js").default} [fill] Fill style.
 * @property {import("./Image.js").default} [image] Image style.
 * @property {RenderFunction} [renderer] Custom renderer. When configured, `fill`, `stroke` and `image` will be
 * ignored, and the provided function will be called with each render frame for each geometry.
 * @property {import("./Stroke.js").default} [stroke] Stroke style.
 * @property {import("./Text.js").default} [text] Text style.
 * @property {number} [zIndex] Z index.
 */


/**
 * @classdesc
 * Container for vector feature rendering styles. Any changes made to the style
 * or its children through `set*()` methods will not take effect until the
 * feature or layer that uses the style is re-rendered.
 * @api
 */
class Style {
  /**
   * @param {Options=} opt_options Style options.
   */
  constructor(opt_options) {

    const options = opt_options || {};

    /**
     * @private
     * @type {string|import("../geom/Geometry.js").default|GeometryFunction}
     */
    this.geometry_ = null;

    /**
     * @private
     * @type {!GeometryFunction}
     */
    this.geometryFunction_ = defaultGeometryFunction;

    if (options.geometry !== undefined) {
      this.setGeometry(options.geometry);
    }

    /**
     * @private
     * @type {import("./Fill.js").default}
     */
    this.fill_ = options.fill !== undefined ? options.fill : null;

    /**
       * @private
       * @type {import("./Image.js").default}
       */
    this.image_ = options.image !== undefined ? options.image : null;

    /**
     * @private
     * @type {RenderFunction|null}
     */
    this.renderer_ = options.renderer !== undefined ? options.renderer : null;

    /**
     * @private
     * @type {import("./Stroke.js").default}
     */
    this.stroke_ = options.stroke !== undefined ? options.stroke : null;

    /**
     * @private
     * @type {import("./Text.js").default}
     */
    this.text_ = options.text !== undefined ? options.text : null;

    /**
     * @private
     * @type {number|undefined}
     */
    this.zIndex_ = options.zIndex;

  }

  /**
   * Clones the style.
   * @return {import("./Style.js").default} The cloned style.
   * @api
   */
  clone() {
    let geometry = this.getGeometry();
    if (geometry && geometry.clone) {
      geometry = geometry.clone();
    }
    return new Style({
      geometry: geometry,
      fill: this.getFill() ? this.getFill().clone() : undefined,
      image: this.getImage() ? this.getImage().clone() : undefined,
      stroke: this.getStroke() ? this.getStroke().clone() : undefined,
      text: this.getText() ? this.getText().clone() : undefined,
      zIndex: this.getZIndex()
    });
  }

  /**
   * Get the custom renderer function that was configured with
   * {@link #setRenderer} or the `renderer` constructor option.
   * @return {RenderFunction|null} Custom renderer function.
   * @api
   */
  getRenderer() {
    return this.renderer_;
  }

  /**
   * Sets a custom renderer function for this style. When set, `fill`, `stroke`
   * and `image` options of the style will be ignored.
   * @param {RenderFunction|null} renderer Custom renderer function.
   * @api
   */
  setRenderer(renderer) {
    this.renderer_ = renderer;
  }

  /**
   * Get the geometry to be rendered.
   * @return {string|import("../geom/Geometry.js").default|GeometryFunction}
   * Feature property or geometry or function that returns the geometry that will
   * be rendered with this style.
   * @api
   */
  getGeometry() {
    return this.geometry_;
  }

  /**
   * Get the function used to generate a geometry for rendering.
   * @return {!GeometryFunction} Function that is called with a feature
   * and returns the geometry to render instead of the feature's geometry.
   * @api
   */
  getGeometryFunction() {
    return this.geometryFunction_;
  }

  /**
   * Get the fill style.
   * @return {import("./Fill.js").default} Fill style.
   * @api
   */
  getFill() {
    return this.fill_;
  }

  /**
   * Set the fill style.
   * @param {import("./Fill.js").default} fill Fill style.
   * @api
   */
  setFill(fill) {
    this.fill_ = fill;
  }

  /**
   * Get the image style.
   * @return {import("./Image.js").default} Image style.
   * @api
   */
  getImage() {
    return this.image_;
  }

  /**
   * Set the image style.
   * @param {import("./Image.js").default} image Image style.
   * @api
   */
  setImage(image) {
    this.image_ = image;
  }

  /**
   * Get the stroke style.
   * @return {import("./Stroke.js").default} Stroke style.
   * @api
   */
  getStroke() {
    return this.stroke_;
  }

  /**
   * Set the stroke style.
   * @param {import("./Stroke.js").default} stroke Stroke style.
   * @api
   */
  setStroke(stroke) {
    this.stroke_ = stroke;
  }

  /**
   * Get the text style.
   * @return {import("./Text.js").default} Text style.
   * @api
   */
  getText() {
    return this.text_;
  }

  /**
   * Set the text style.
   * @param {import("./Text.js").default} text Text style.
   * @api
   */
  setText(text) {
    this.text_ = text;
  }

  /**
   * Get the z-index for the style.
   * @return {number|undefined} ZIndex.
   * @api
   */
  getZIndex() {
    return this.zIndex_;
  }

  /**
   * Set a geometry that is rendered instead of the feature's geometry.
   *
   * @param {string|import("../geom/Geometry.js").default|GeometryFunction} geometry
   *     Feature property or geometry or function returning a geometry to render
   *     for this style.
   * @api
   */
  setGeometry(geometry) {
    if (typeof geometry === 'function') {
      this.geometryFunction_ = geometry;
    } else if (typeof geometry === 'string') {
      this.geometryFunction_ = function(feature) {
        return (
          /** @type {import("../geom/Geometry.js").default} */ (feature.get(geometry))
        );
      };
    } else if (!geometry) {
      this.geometryFunction_ = defaultGeometryFunction;
    } else if (geometry !== undefined) {
      this.geometryFunction_ = function() {
        return (
          /** @type {import("../geom/Geometry.js").default} */ (geometry)
        );
      };
    }
    this.geometry_ = geometry;
  }

  /**
   * Set the z-index.
   *
   * @param {number|undefined} zIndex ZIndex.
   * @api
   */
  setZIndex(zIndex) {
    this.zIndex_ = zIndex;
  }
}


/**
 * Convert the provided object into a style function.  Functions passed through
 * unchanged.  Arrays of import("./Style.js").default or single style objects wrapped in a
 * new style function.
 * @param {StyleFunction|Array<import("./Style.js").default>|import("./Style.js").default} obj
 *     A style function, a single style, or an array of styles.
 * @return {StyleFunction} A style function.
 */
export function toFunction(obj) {
  let styleFunction;

  if (typeof obj === 'function') {
    styleFunction = obj;
  } else {
    /**
     * @type {Array<import("./Style.js").default>}
     */
    let styles;
    if (Array.isArray(obj)) {
      styles = obj;
    } else {
      assert(obj instanceof Style,
        41); // Expected an `Style` or an array of `Style`
      styles = [obj];
    }
    styleFunction = function() {
      return styles;
    };
  }
  return styleFunction;
}


/**
 * @type {Array<import("./Style.js").default>}
 */
let defaultStyles = null;


/**
 * @param {import("../Feature.js").default|import("../render/Feature.js").default} feature Feature.
 * @param {number} resolution Resolution.
 * @return {Array<import("./Style.js").default>} Style.
 */
export function createDefaultStyle(feature, resolution) {
  // We don't use an immediately-invoked function
  // and a closure so we don't get an error at script evaluation time in
  // browsers that do not support Canvas. (import("./Circle.js").CircleStyle does
  // canvas.getContext('2d') at construction time, which will cause an.error
  // in such browsers.)
  if (!defaultStyles) {
    const fill = new Fill({
      color: 'rgba(255,255,255,0.4)'
    });
    const stroke = new Stroke({
      color: '#3399CC',
      width: 1.25
    });
    defaultStyles = [
      new Style({
        image: new CircleStyle({
          fill: fill,
          stroke: stroke,
          radius: 5
        }),
        fill: fill,
        stroke: stroke
      })
    ];
  }
  return defaultStyles;
}


/**
 * Default styles for editing features.
 * @return {Object<import("../geom/GeometryType.js").default, Array<import("./Style.js").default>>} Styles
 */
export function createEditingStyle() {
  /** @type {Object<import("../geom/GeometryType.js").default, Array<import("./Style.js").default>>} */
  const styles = {};
  const white = [255, 255, 255, 1];
  const blue = [0, 153, 255, 1];
  const width = 3;
  styles[GeometryType.POLYGON] = [
    new Style({
      fill: new Fill({
        color: [255, 255, 255, 0.5]
      })
    })
  ];
  styles[GeometryType.MULTI_POLYGON] =
      styles[GeometryType.POLYGON];

  styles[GeometryType.LINE_STRING] = [
    new Style({
      stroke: new Stroke({
        color: white,
        width: width + 2
      })
    }),
    new Style({
      stroke: new Stroke({
        color: blue,
        width: width
      })
    })
  ];
  styles[GeometryType.MULTI_LINE_STRING] =
      styles[GeometryType.LINE_STRING];

  styles[GeometryType.CIRCLE] =
      styles[GeometryType.POLYGON].concat(
        styles[GeometryType.LINE_STRING]
      );


  styles[GeometryType.POINT] = [
    new Style({
      image: new CircleStyle({
        radius: width * 2,
        fill: new Fill({
          color: blue
        }),
        stroke: new Stroke({
          color: white,
          width: width / 2
        })
      }),
      zIndex: Infinity
    })
  ];
  styles[GeometryType.MULTI_POINT] =
      styles[GeometryType.POINT];

  styles[GeometryType.GEOMETRY_COLLECTION] =
      styles[GeometryType.POLYGON].concat(
        styles[GeometryType.LINE_STRING],
        styles[GeometryType.POINT]
      );

  return styles;
}


/**
 * Function that is called with a feature and returns its default geometry.
 * @param {import("../Feature.js").default|import("../render/Feature.js").default} feature Feature to get the geometry for.
 * @return {import("../geom/Geometry.js").default|import("../render/Feature.js").default|undefined} Geometry to render.
 */
function defaultGeometryFunction(feature) {
  return feature.getGeometry();
}

export default Style;