/**
 * 正多边形
 * @module zrender/shape/Isogon
 * @author sushuang (宿爽, sushuang0322@gmail.com)
 */

/**
 * @typedef {Object} IIsogonStyle
 * @property {number} x 正n边形外接圆心x坐标
 * @property {number} y 正n边形外接圆心y坐标
 * @property {number} r 正n边形外接圆半径
 * @property {number} n 指明正几边形
 * @property {string} [brushType='fill']
 * @property {string} [color='#000000'] 填充颜色
 * @property {string} [strokeColor='#000000'] 描边颜色
 * @property {string} [lineCape='butt'] 线帽样式，可以是 butt, round, square
 * @property {number} [lineWidth=1] 描边宽度
 * @property {number} [opacity=1] 绘制透明度
 * @property {number} [shadowBlur=0] 阴影模糊度，大于0有效
 * @property {string} [shadowColor='#000000'] 阴影颜色
 * @property {number} [shadowOffsetX=0] 阴影横向偏移
 * @property {number} [shadowOffsetY=0] 阴影纵向偏移
 * @property {string} [text] 图形中的附加文本
 * @property {string} [textColor='#000000'] 文本颜色
 * @property {string} [textFont] 附加文本样式，eg:'bold 18px verdana'
 * @property {string} [textPosition='end'] 附加文本位置, 可以是 inside, left, right, top, bottom
 * @property {string} [textAlign] 默认根据textPosition自动设置，附加文本水平对齐。
 *                                可以是start, end, left, right, center
 * @property {string} [textBaseline] 默认根据textPosition自动设置，附加文本垂直对齐。
 *                                可以是top, bottom, middle, alphabetic, hanging, ideographic
 */
module.exports = function (require) {
  var math = require('../tool/math');

  var sin = math.sin;
  var cos = math.cos;
  var PI = Math.PI;

  var Base = require('./Base');
  /**
   * @constructor
   * @alias module:zrender/shape/Isogon
   * @param {Object} options
   */


  function Isogon(options) {
    Base.call(this, options);
    /**
     * 多边形绘制样式
     * @name module:zrender/shape/Isogon#style
     * @type {module:zrender/shape/Isogon~IIsogonStyle}
     */

    /**
     * 多边形高亮绘制样式
     * @name module:zrender/shape/Isogon#highlightStyle
     * @type {module:zrender/shape/Isogon~IIsogonStyle}
     */
  }

  Isogon.prototype = {
    type: 'isogon',

    /**
     * 创建n角星（n>=3）路径
     * @param {CanvasRenderingContext2D} ctx
     * @param {module:zrender/shape/Isogon~IIsogonStyle} style
     */
    buildPath: function (ctx, style) {
      var n = style.n;

      if (!n || n < 2) {
        return;
      }

      var x = style.x;
      var y = style.y;
      var r = style.r;
      var dStep = 2 * PI / n;
      var deg = -PI / 2;
      var xStart = x + r * cos(deg);
      var yStart = y + r * sin(deg);
      deg += dStep; // 记录边界点，用于判断insight

      var pointList = style.pointList = [];
      pointList.push([xStart, yStart]);

      for (var i = 0, end = n - 1; i < end; i++) {
        pointList.push([x + r * cos(deg), y + r * sin(deg)]);
        deg += dStep;
      }

      pointList.push([xStart, yStart]); // 绘制

      ctx.moveTo(pointList[0][0], pointList[0][1]);

      for (var i = 0; i < pointList.length; i++) {
        ctx.lineTo(pointList[i][0], pointList[i][1]);
      }

      ctx.closePath();
      return;
    },

    /**
     * 计算返回正多边形的包围盒矩形
     * @param {module:zrender/shape/Isogon~IIsogonStyle} style
     * @return {module:zrender/shape/Base~IBoundingRect}
     */
    getRect: function (style) {
      if (style.__rect) {
        return style.__rect;
      }

      var lineWidth;

      if (style.brushType == 'stroke' || style.brushType == 'fill') {
        lineWidth = style.lineWidth || 1;
      } else {
        lineWidth = 0;
      }

      style.__rect = {
        x: Math.round(style.x - style.r - lineWidth / 2),
        y: Math.round(style.y - style.r - lineWidth / 2),
        width: style.r * 2 + lineWidth,
        height: style.r * 2 + lineWidth
      };
      return style.__rect;
    }
  };

  require('../tool/util').inherits(Isogon, Base);

  return Isogon;
}(require);