import React from 'react'
import { Line, Bar } from 'react-chartjs-2'
import debounceRender from 'react-debounce-render'

import { downloadAsJson } from '../../../lib/json-download/index.js'
import { datasetTemplates, genOptions, beautifyLabels } from './chartOptions.js'

export class Chart extends React.Component {
  render() {
    let { formState, stats, nodeData } = this.props
    let { tolRange, chart } = formState
    tolRange = tolRange || []

    let labels = beautifyLabels(tolRange)
    // let labels = tolRange.map(x => Math.round(x * 1000) / 1000)
    let datasets = Object.keys(stats).map(name => ({
      ...datasetTemplates[name],
      data: stats[name]
    }))
    datasets.push({ ...datasetTemplates.numberOfNodes, data: nodeData })
    let data = { datasets, labels }
    return (
      <div className="component">
        <h2>Chart</h2>
        {chart === 'wasmVsJs' && <WasmVsJsChart data={data} />}
        {chart === 'wasmStack' && <WasmStackChart data={data} />}
        {chart === 'simplifyJSStack' && <JsStackChart data={data} />}
      </div>
    )
  }
}

class WasmVsJsChart extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      scaleY: 'linear',
      values: 'mean'
    }
  }
  convertDataToHz(data) {
    let datasets = data.datasets
    for (let dataset of datasets.filter(d => d.label !== 'numberOfNodes')) {
      dataset.data = dataset.data.map(mean => 1000 / mean)
    }
  }

  render() {
    let data = JSON.parse(JSON.stringify(this.props.data)) // deep copy
    let options = genOptions('Wasm vs. JavaScript', false, this.state.scaleY)
    if (this.state.values === 'hz') this.convertDataToHz(data)
    return (
      <>
        <Line
          ref={ref => (this.ref = ref)}
          height={400}
          width={400}
          data={data}
          options={options}
        />
        <label>Scale Y-Axis</label>
        <select
          name="scaleY"
          value={this.state.scaleY}
          onChange={e => this.setState({ scaleY: e.target.value })}
        >
          <option value="linear">Linear</option>
          <option value="logarithmic">Logarithmic</option>
        </select>

        <label>Values: </label>
        <select
          name="values"
          value={this.state.values}
          onChange={e => this.setState({ values: e.target.value })}
        >
          <option value="mean">ms per operation (mean)</option>
          <option value="hz">Operations per second (hz)</option>
        </select>
        <button onClick={() => saveChart(this.ref)}>Save chart</button>
      </>
    )
  }
}

/**
 * Returns the dataset specified by label
 */
function getDataset(data, label) {
  return data.datasets.filter(d => d.label === label)[0]
}

/**
 * Takes three data arrays. Subtracts the values of arr1 and arr2 from whole.
 * This is used for calculating the time of execution in cases where the data
 * transformation is part of the whole operation.
 * Example: subtract storeCoords and loadResult from the whole simplifyWASM
 * operation to get execution time of wasm code.
 */
function calculateTimeDelta(whole, arr1, arr2) {
  const safeGet = (arr, idx) => (idx < arr.length ? arr[idx] : 0)
  return whole.map((val, i) => val - (safeGet(arr1, i) + safeGet(arr2, i)))
}

function modifyDataArrays(data, exec, pre, after) {
  if (getDataset(data, exec)) {
    getDataset(data, exec).data = calculateTimeDelta(
      getDataset(data, exec).data,
      getDataset(data, pre).data,
      getDataset(data, after).data
    )
  }
}

class WasmStackChart extends React.Component {
  render() {
    const data = this.props.data
    modifyDataArrays(data, 'simplifyWASM', 'storeCoords', 'loadResult')
    const options = genOptions('Wasm execution', true)
    return (
      <>
        <Bar
          ref={ref => (this.ref = ref)}
          height={400}
          width={400}
          data={data}
          options={options}
        />
        <button onClick={() => saveChart(this.ref)}>Save chart</button>
      </>
    )
  }
}

class JsStackChart extends React.Component {
  render() {
    const data = this.props.data
    const options = genOptions('SimplifyJS execution', true)
    modifyDataArrays(
      data,
      'origSimplifyWithTransformCase',
      'transformToObjectFormCase',
      'transformToArrayFormCase'
    )
    return (
      <>
        <Bar
          ref={ref => (this.ref = ref)}
          height={400}
          width={400}
          data={data}
          options={options}
        />
        <button onClick={() => saveChart(this.ref)}>Save chart</button>
      </>
    )
  }
}

export const DebouncedChart = debounceRender(Chart, 300)

/**
 * Downloads the chart config as json
 */
function saveChart(chartRef) {
  let myChart = chartRef.chartInstance.config
  let config = JSON.stringify(myChart, (key, val) =>
    key === '_meta' ? undefined : val
  )
  downloadAsJson(config, 'config.json')
}