import { Chart, Tooltip, Axis, Legend, Line, Point } from 'viser-react';
import * as React from 'react';
const DataSet = require('@antv/data-set');

const sourceData = [
  { month: 'Jan', Tokyo: 7.0, London: 3.9 },
  { month: 'Feb', Tokyo: 6.9, London: 4.2 },
  { month: 'Mar', Tokyo: 9.5, London: 5.7 },
  { month: 'Apr', Tokyo: 14.5, London: 8.5 },
  { month: 'May', Tokyo: 18.4, London: 11.9 },
  { month: 'Jun', Tokyo: 21.5, London: 15.2 },
  { month: 'Jul', Tokyo: 25.2, London: 17.0 },
  { month: 'Aug', Tokyo: 26.5, London: 16.6 },
  { month: 'Sep', Tokyo: 23.3, London: 14.2 },
  { month: 'Oct', Tokyo: 18.3, London: 10.3 },
  { month: 'Nov', Tokyo: 13.9, London: 6.6 },
  { month: 'Dec', Tokyo: 9.6, London: 4.8 },
];

const dv = new DataSet.View().source(sourceData);
dv.transform({
  type: 'fold',
  fields: ['Tokyo', 'London'],
  key: 'city',
  value: 'temperature',
});
const data = dv.rows;

const scale = [{
  dataKey: 'month',
  min: 0,
  max: 1,
}];

export default class App extends React.Component {
  render() {
    return (
      <Chart forceFit height={400} data={data} scale={scale}>
        <Tooltip />
        <Axis />
        <Legend />
        <Line position="month*temperature" color="city" />
        <Point position="month*temperature" color="city" size={4} style={{ stroke: '#fff', lineWidth: 1 }} shape="circle"/>
      </Chart>
    );
  }
}