import {CADElementTS, CADElement} from '../core/element'
import {SVGURI} from '../constant/Element'
import {ProcessingTS} from './processing/index'

export type Screen = {x: number, y: number}

interface RendererProps {
  layer: HTMLElement,
  width?: number,
  height?: number,
  processing: ProcessingTS
}

class Renderer {
  svg: SVGSVGElement
  g: SVGGElement
  layer: HTMLElement
  elements: Array<CADElementTS>
  processing: ProcessingTS
  props: {
    left: number;
    top: number;
    width: number;
    height: number,
    multiple: number,
    scale: number
  }
  realWidth: number
  realHeight: number

  constructor({layer, width = layer.offsetWidth, height = layer.offsetHeight, processing}: RendererProps) {
    CADElement.init(this)

    this.props = {left: 0, top: 0, width, height, multiple: 1, scale: 1}
    this.elements = []
    this.processing = processing
    this.init(layer)
  }

  private clickHandle = () => {
    this.elements.forEach(e => e.changeSelect(false))
  }
  
  private init(layer) {
    this.svg = document.createElementNS(SVGURI, 'svg')
    this.g = document.createElementNS(SVGURI, 'g')
    this.svg.appendChild(this.g)
    this.layer = layer

    this.layer.style.position = 'relative'
    this.svg.style.position = 'absolute'
    this.svg.style.left = '0'
    this.svg.style.top = '0'
    this.svg.style.right = '0'
    this.svg.style.bottom = '0'
    this.svg.setAttribute('version', '1.0')
    this.svg.setAttribute('xmlns', 'http://www.w3.org/2000/svg')
    this.svg.setAttribute('xmlns:xlink', 'http://www.w3.org/1999/xlink')
    this.svg.addEventListener('click', this.clickHandle, false)
    this.layer.appendChild(this.svg)
  }

  adaptLayer(width = this.layer.offsetWidth, height = this.layer.offsetHeight) {
    
    let centerStepX = this.props.width / 2 - this.props.left
    let centerStepY = this.props.height / 2 - this.props.top

    this.g.setAttribute('transform', `
      translate(${this.props.left},${this.props.top})
      translate(${centerStepX},${centerStepY})
      scale(${this.props.scale},${this.props.scale})
      translate(${-centerStepX},${-centerStepY})
    `)
    this.svg.setAttribute('width', width.toString())
    this.svg.setAttribute('height', height.toString())
    this.svg.setAttribute('viewBox', `0 0 ${this.props.width} ${this.props.height}`)
    this.realWidth = width
    this.realHeight = height

    CADElement.update(this)
  }

  render() {
    CADElement.update(this)
  }
  
  // dom坐标转换为真实坐标
  screenToRealPoint({x, y}: Screen) {
    let centerStepX = this.props.width / 2 - this.props.left
    let centerStepY = this.props.height / 2 - this.props.top
    let width = this.props.width / this.props.multiple
    let height = this.props.height / this.props.multiple
    if(width == 0 || height == 0){
      return{
        x:centerStepX,
        y:centerStepY
      };
    }
    else{
      return {
        x: ((x * this.props.width) / width - this.props.left - centerStepX)  / this.props.scale + centerStepX,
        y: ((y * this.props.height) / height - this.props.top - centerStepY) / this.props.scale + centerStepY
      }
    }
  }

  // 点坐标转换真实坐标
  realPointToScreen({x, y}: Screen) {
    let centerStepX = this.props.width / 2 - this.props.left
    let centerStepY = this.props.height / 2 - this.props.top
    let width = this.props.width / this.props.multiple
    let height = this.props.height / this.props.multiple

    return {
      x: ((x - centerStepX) * this.props.scale + centerStepX + this.props.left) * width / this.props.width,
      y: ((y - centerStepY) * this.props.scale + centerStepY + this.props.top) * height / this.props.height
    }
  }

  push (...elements: Array<CADElementTS>) {
    elements.forEach(element => {
      let prevEle = this.elements.find(ele => ele.zIndex > element.zIndex)
      
      if (prevEle) {
        try {
          this.g.insertBefore(element.real, prevEle.real)
        } catch(e) {
          this.g.appendChild(element.real)  
        }
        this.elements.splice(this.elements.indexOf(prevEle), 0, element)
      } else {
        this.g.appendChild(element.real)
        this.elements.push(element)
      }
    })
  }

  remove (...elements: Array<CADElementTS>) {
    elements.forEach(element => {
      try {
        this.g.removeChild(element.real)
      } catch(e) {
      }
      ~this.elements.indexOf(element) && this.elements.splice(this.elements.indexOf(element), 1)
    })
  }

  destroy() {
    this.svg.removeEventListener('click', this.clickHandle, false)
    this.layer.removeChild(this.svg)
  }
}

export default Renderer