import React, { Component } from 'react'
// import { Link } from 'react-router-dom'
// import { bindActionCreators } from 'redux'
import { connect } from 'react-redux'

import actions from 'app/actions'

import {
  WAVEFORM_SIZE, INNER_HEIGHT,
  ZOOM_STEPS, ZOOM_LABEL_STEPS, ZOOM_TICK_STEPS,
} from 'app/constants'

class Waveform extends Component {
  constructor(props){
    super(props)
    this.canvasRef = React.createRef()
  }
  componentDidMount() {
    this.resize()
    this.draw()
  }
  componentDidUpdate() {
    this.draw()
  }
  resize() {
    const canvas = this.canvasRef.current
    canvas.width = WAVEFORM_SIZE
    canvas.height = INNER_HEIGHT
  }
  draw() {
    const canvas = this.canvasRef.current
    const ctx = canvas.getContext('2d')
    const h = INNER_HEIGHT
    this.clearCanvas(ctx, h)
    this.drawCurve(ctx, h)
  }
  clearCanvas(ctx, h) {  
    const w = WAVEFORM_SIZE
    ctx.clearRect(0, 0, w, h)
    ctx.fillStyle = 'rgba(0,0,0,0.5)'
    ctx.fillRect(0, 0, w, h)
    ctx.fillStyle = 'rgba(64,128,192,0.5)'
  }
  drawCurve(ctx, h) {
    let { peaks, timeline } = this.props
    let { start_ts, zoom, duration } = timeline

    let secondsPerPixel = ZOOM_STEPS[zoom] * 0.1 // 0.1 sec / step
    let stepsPerPixel = ZOOM_STEPS[zoom] // 0.1 sec / step

    let widthTimeDuration = h * secondsPerPixel // secs per pixel

    let timeMin = Math.round(start_ts / secondsPerPixel) * secondsPerPixel
    let timeMax = Math.min(timeMin + widthTimeDuration, duration)
    let timeWidth = timeMax - timeMin

    let stepMin = Math.floor(timeMin * 10)
    let pixelWidth = Math.ceil(timeWidth / secondsPerPixel)

    let i = 0
    let step = stepMin
    let waveformPeak = WAVEFORM_SIZE / 2
    let origin = (1 - peaks[step]) * waveformPeak
    let y
    let peak
    // console.log(stepMin, pixelWidth * stepsPerPixel + stepMin)
    ctx.beginPath()
    ctx.moveTo(origin, 0)
    for (i = 0; i < pixelWidth; i++) {
      step = i * stepsPerPixel + stepMin
      peak = peaks[step]
      y = (1 - peak) * waveformPeak
      ctx.lineTo(y, i)
    }
    for (i = pixelWidth - 1; i > 0; i--) {
      step = i * stepsPerPixel + stepMin
      peak = peaks[step]
      y = (1 + peak) * waveformPeak
      ctx.lineTo(y, i)
    }
    ctx.lineTo(origin, 0)
    ctx.fillStyle = 'rgba(255,255,255,0.8)'
    ctx.fill()
  }
  render() {
    return (
      <canvas
        ref={this.canvasRef}
        onMouseDown={this.props.onMouseDown}
        onMouseUp={this.props.onMouseUp}
      />
    )
  }
}

const mapStateToProps = state => ({
  timeline: state.align.timeline,
  peaks: state.site.peaks,
})

const mapDispatchToProps = dispatch => ({
  // uploadActions: bindActionCreators({ ...uploadActions }, dispatch),
})

export default connect(mapStateToProps, mapDispatchToProps)(Waveform)