// @flow
import React from "react";
import RadarAxis from "./RadarAxis";
import RadarRings from "./RadarRings";
import type { RadarVariable } from "./types";
import { radiusScales, forEachArray } from "./utils";

type Props = {
  width: number,
  height: number,
  padding: number,
  variables: Array<RadarVariable>,
  domainMax: number,
  style?: {}
};

const defaultRadarStyle = {
  numRings: 4,
  axisColor: "#cdcdcd",
  ringColor: "#cdcdcd"
};

export default function EmptyRadar(props: Props) {
  const { width, height, padding, variables, domainMax, style } = props;
  const { axisColor, ringColor, numRings } = { ...defaultRadarStyle, ...style };
  const innerHeight = height - padding * 2;
  const innerWidth = width - padding * 2;

  const radius = Math.min(innerWidth / 2, innerHeight / 2);
  const diameter = radius * 2;

  const scales = radiusScales(variables, domainMax, radius);

  const angleSliceRadians = (Math.PI * 2) / variables.length;
  const offsetAngles = {};
  forEachArray(variables, ({ key }, i) => {
    offsetAngles[key] = angleSliceRadians * i;
  });

  const backgroundScale = scales[variables[0].key];
  const ticks = backgroundScale.ticks(numRings).slice(1);
  const tickFormat = backgroundScale.tickFormat(numRings);

  return (
    <svg width={width} height={height}>
      <g transform={`translate(${padding}, ${padding})`}>
        <rect
          width={diameter}
          height={diameter}
          fill={"transparent"}
          transform={`translate(${(innerWidth - diameter) / 2}, ${(innerHeight -
            diameter) /
            2})`}
        />
        <g transform={`translate(${innerWidth / 2}, ${innerHeight / 2})`}>
          <RadarRings
            ticks={ticks}
            scale={backgroundScale}
            color={ringColor}
            format={tickFormat}
          />
          {variables.map(({ key, label }) => {
            return (
              <RadarAxis
                variableKey={key}
                key={key}
                scale={scales[key]}
                offsetAngle={offsetAngles[key]}
                label={label}
                domainMax={domainMax}
                color={axisColor}
                textStyle={{}}
              />
            );
          })}
        </g>
      </g>
    </svg>
  );
}