/**
 * 多边形
 * @module zrender/shape/Polygon
 * @author Kener (@Kener-林峰, kener.linfeng@gmail.com)
 * @example
 *     var Polygon = require('zrender/shape/Polygon');
 *     var shape = new Polygon({
 *         style: {
 *             // 100x100的正方形
 *             pointList: [[0, 0], [100, 0], [100, 100], [0, 100]],
 *             color: 'blue'
 *         }
 *     });
 *     zr.addShape(shape);
 */

/**
 * @typedef {Object} IPolygonStyle
 * @property {string} pointList 多边形顶点数组
 * @property {string} [smooth=''] 是否做平滑插值, 平滑算法可以选择 bezier, spline
 * @property {number} [smoothConstraint] 平滑约束
 * @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 Base = require('./Base');

  var smoothSpline = require('./util/smoothSpline');

  var smoothBezier = require('./util/smoothBezier');

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


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

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

  Polygon.prototype = {
    type: 'polygon',

    /**
     * 创建多边形路径
     * @param {CanvasRenderingContext2D} ctx
     * @param {module:zrender/shape/Polygon~IPolygonStyle} style
     */
    buildPath: function (ctx, style) {
      // 虽然能重用brokenLine，但底层图形基于性能考虑，重复代码减少调用吧
      var pointList = style.pointList; // 开始点和结束点重复

      /*
      var start = pointList[0];
      var end = pointList[pointList.length-1];
       if (start && end) {
          if (start[0] == end[0] &&
              start[1] == end[1]) {
              // 移除最后一个点
              pointList.pop();
          }
      }
      */

      if (pointList.length < 2) {
        // 少于2个点就不画了~
        return;
      }

      if (style.smooth && style.smooth !== 'spline') {
        var controlPoints = smoothBezier(pointList, style.smooth, true, style.smoothConstraint);
        ctx.moveTo(pointList[0][0], pointList[0][1]);
        var cp1;
        var cp2;
        var p;
        var len = pointList.length;

        for (var i = 0; i < len; i++) {
          cp1 = controlPoints[i * 2];
          cp2 = controlPoints[i * 2 + 1];
          p = pointList[(i + 1) % len];
          ctx.bezierCurveTo(cp1[0], cp1[1], cp2[0], cp2[1], p[0], p[1]);
        }
      } else {
        if (style.smooth === 'spline') {
          pointList = smoothSpline(pointList, true);
        }

        if (!style.lineType || style.lineType == 'solid') {
          // 默认为实线
          ctx.moveTo(pointList[0][0], pointList[0][1]);

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

          ctx.lineTo(pointList[0][0], pointList[0][1]);
        } else if (style.lineType == 'dashed' || style.lineType == 'dotted') {
          var dashLength = style._dashLength || (style.lineWidth || 1) * (style.lineType == 'dashed' ? 5 : 1);
          style._dashLength = dashLength;
          ctx.moveTo(pointList[0][0], pointList[0][1]);

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

          dashedLineTo(ctx, pointList[pointList.length - 1][0], pointList[pointList.length - 1][1], pointList[0][0], pointList[0][1], dashLength);
        }
      }

      ctx.closePath();
      return;
    },

    /**
     * 计算返回多边形包围盒矩阵
     * @param {module:zrender/shape/Polygon~IPolygonStyle} style
     * @return {module:zrender/shape/Base~IBoundingRect}
     */
    getRect: function (style) {
      if (style.__rect) {
        return style.__rect;
      }

      var minX = Number.MAX_VALUE;
      var maxX = Number.MIN_VALUE;
      var minY = Number.MAX_VALUE;
      var maxY = Number.MIN_VALUE;
      var pointList = style.pointList;

      for (var i = 0, l = pointList.length; i < l; i++) {
        if (pointList[i][0] < minX) {
          minX = pointList[i][0];
        }

        if (pointList[i][0] > maxX) {
          maxX = pointList[i][0];
        }

        if (pointList[i][1] < minY) {
          minY = pointList[i][1];
        }

        if (pointList[i][1] > maxY) {
          maxY = pointList[i][1];
        }
      }

      var lineWidth;

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

      style.__rect = {
        x: Math.round(minX - lineWidth / 2),
        y: Math.round(minY - lineWidth / 2),
        width: maxX - minX + lineWidth,
        height: maxY - minY + lineWidth
      };
      return style.__rect;
    }
  };

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

  return Polygon;
}(require);