export class DxfWritor
{
  layers: WeakSet<Layer>
  activeLayer: Layer
  lineTypes: WeakSet<LineType>
  offX = 0
  offY = 0 // 基点
  constructor()
  {
    this.layers = new WeakSet()
    this.activeLayer = null
    this.lineTypes = new WeakSet()

    for (let i = 0; i < DrawingType.LINE_TYPES.length; ++i)
    {
      this.addLineType(
        DrawingType.LINE_TYPES[i].name,
        DrawingType.LINE_TYPES[i].description,
        DrawingType.LINE_TYPES[i].elements,
      )
    }

    for (let i = 0; i < DrawingType.LAYERS.length; ++i)
    {
      this.addLayer(
        DrawingType.LAYERS[i].name,
        DrawingType.LAYERS[i].colorNumber,
        DrawingType.LAYERS[i].lineTypeName,
      )
    }

    this.setActiveLayer('0')
  }

  /**
   * @param {string} name
   * @param {string} description
   * @param {Array} elements - if elem > 0 it is a line, if elem < 0 it is gap, if elem == 0.0 it is a
   */
  addLineType(name, description, elements)
  {
    this.lineTypes[name] = new LineType(name, description, elements)
    return this
  }

  addLayer(name, colorNumber, lineTypeName)
  {
    this.layers[name] = new Layer(name, colorNumber, lineTypeName)
    return this
  }

  /** 设置当前图层 白=0, 红=1, 黄=2, 绿=3,CYAN=4,BLUE=5,MAGENTA=6 */
  setActiveLayer(name)
  {
    this.activeLayer = this.layers[name]
    return this
  }

  setOffset(x1, y1)
  {
    this.offX = x1
    this.offY = y1
  }

  clear()
  {

  }

  drawLine(x1, y1, x2, y2)
  {
    this.activeLayer.addShape(new Line(x1 + this.offX, y1 + this.offY, x2 + this.offX, y2 + this.offY))
    return this
  }

  drawRect(x1, y1, w, h)
  {
    x1 = x1 + this.offX
    y1 = y1 + this.offY
    this.activeLayer.addShape(new Line(x1, y1, x1 + w, y1))
    this.activeLayer.addShape(new Line(x1 + w, y1, x1 + w, y1 + h))
    this.activeLayer.addShape(new Line(x1 + w, y1 + h, x1, y1 + h))
    this.activeLayer.addShape(new Line(x1, y1 + h, x1, y1))
    return this
  }

  /**
   * @param {number} x1 - Center x
   * @param {number} y1 - Center y
   * @param {number} r - radius
   * @param {number} startAngle - degree
   * @param {number} endAngle - degree
   */
  drawArc(x1, y1, r, startAngle, endAngle)
  {
    this.activeLayer.addShape(new Arc(x1 + this.offX, y1 + this.offY, r, startAngle, endAngle))
    return this
  }

  /**
   * @param {number} x1 - Center x
   * @param {number} y1 - Center y
   * @param {number} r - radius
   */
  drawCircle(x1, y1, r)
  {
    this.activeLayer.addShape(new Circle(x1 + this.offX, y1 + this.offY, r))
    return this
  }

  /**
   * @param {number} x1 - x
   * @param {number} y1 - y
   * @param {number} height - Text height
   * @param {number} rotation - Text rotation
   * @param {string} value - the string itself
   */
  drawText(x1, y1, height, rotation, value)
  {
    this.activeLayer.addShape(new Text(x1 + this.offX, y1 + this.offY, height, rotation, value))
    return this
  }

  /**
   * @param {Array} points - Array of points like [ [x1, y1,r], [x2, y2,r]... ]
   */
  drawPolyline(points, isClose = false)
  {
    for (const p of points)
    {
      p.x += this.offX
      p.y += this.offY
    }
    this.activeLayer.addShape(new Polyline(points, isClose))
    return this
  }

  _getDxfLtypeTable()
  {
    let s = '0\nTABLE\n' // start table
    s += '2\nLTYPE\n' // name table as LTYPE table

    for (let lineTypeName in this.lineTypes)
    {
      s += this.lineTypes[lineTypeName].toDxfString()
    }

    s += '0\nENDTAB\n' // end table

    return s
  }

  _getDxfLayerTable()
  {
    let s = '0\nTABLE\n' // start table
    s += '2\nLAYER\n' // name table as LAYER table

    for (let layerName in this.layers)
    {
      s += this.layers[layerName].toDxfString()
    }

    s += '0\nENDTAB\n'

    return s
  }

  toDxfString()
  {
    let s = ''

    // start section
    s += '0\nSECTION\n'
    // name section as TABLES section
    s += '2\nTABLES\n'

    s += this._getDxfLtypeTable()
    s += this._getDxfLayerTable()

    // end section
    s += '0\nENDSEC\n'

    // ENTITES section
    s += '0\nSECTION\n'
    s += '2\nENTITIES\n'

    for (let layerName in this.layers)
    {
      let layer = this.layers[layerName]
      s += layer.shapesToDxf()
      // let shapes = layer.getShapes();
    }

    s += '0\nENDSEC\n'

    // close file
    s += '0\nEOF'

    return s
  }
}

namespace DrawingType
{
  // AutoCAD Color Index (ACI)
  // http://sub-atomic.com/~moses/acadcolors.html
  export const ACI = {
    LAYER: 0,
    RED: 1,
    YELLOW: 2,
    GREEN: 3,
    CYAN: 4,
    BLUE: 5,
    MAGENTA: 6,
    WHITE: 7,
  }
  export const LINE_TYPES = [
    { name: 'CONTINUOUS', description: '______', elements: [] },
    { name: 'DASHED', description: '_ _ _ ', elements: [5.0, -5.0] },
    { name: 'DOTTED', description: '. . . ', elements: [0.0, -5.0] },
  ]
  export const LAYERS = [
    { name: '0', colorNumber: ACI.WHITE, lineTypeName: 'CONTINUOUS' },
    { name: '1', colorNumber: ACI.RED, lineTypeName: 'CONTINUOUS' },
    { name: '2', colorNumber: ACI.YELLOW, lineTypeName: 'CONTINUOUS' },
    { name: '3', colorNumber: ACI.GREEN, lineTypeName: 'CONTINUOUS' },
    { name: '4', colorNumber: ACI.CYAN, lineTypeName: 'CONTINUOUS' },
    { name: '5', colorNumber: ACI.BLUE, lineTypeName: 'CONTINUOUS' },
    { name: '6', colorNumber: ACI.MAGENTA, lineTypeName: 'CONTINUOUS' },
  ]
}

export class LineType
{
  name: string
  description: string
  elements: any[]

  /**
   * @param {string} name
   * @param {string} description
   * @param {Array} elements - if elem > 0 it is a line, if elem < 0 it is gap, if elem == 0.0 it is a
   */
  constructor(name, description, elements)
  {
    this.name = name
    this.description = description
    this.elements = elements
  }

  /**
   * @link https://www.autodesk.com/techpubs/autocad/acadr14/dxf/ltype_al_u05_c.htm
   */
  toDxfString()
  {
    let s = '0\nLTYPE\n'
    s += '72\n65\n'
    s += '70\n64\n'
    s += `2\n${this.name}\n`
    s += `3\n${this.description}\n`
    s += `73\n${this.elements.length}\n`
    s += `40\n${this.getElementsSum()}\n`

    for (let i = 0; i < this.elements.length; ++i)
    {
      s += `49\n${this.elements[i]}\n`
    }

    return s
  }

  getElementsSum()
  {
    let sum = 0
    for (let i = 0; i < this.elements.length; ++i)
    {
      sum += Math.abs(this.elements[i])
    }

    return sum
  }
}

export class Layer
{
  name: string
  colorNumber: string
  lineTypeName: string
  shapes: any[]
  constructor(name, colorNumber, lineTypeName)
  {
    this.name = name
    this.colorNumber = colorNumber
    this.lineTypeName = lineTypeName
    this.shapes = []
  }

  toDxfString()
  {
    let s = '0\nLAYER\n'
    s += '70\n64\n'
    s += `2\n${this.name}\n`
    s += `62\n${this.colorNumber}\n`
    s += `6\n${this.lineTypeName}\n`
    return s
  }

  addShape(shape)
  {
    this.shapes.push(shape)
    shape.layer = this
  }

  getShapes()
  {
    return this.shapes
  }

  shapesToDxf()
  {
    let s = ''
    for (let i = 0; i < this.shapes.length; ++i)
    {
      s += this.shapes[i].toDxfString()
    }

    return s
  }
}

export class Arc
{
  x1: number
  y1: number
  r: number
  startAngle: number
  endAngle: number
  layer: Layer
  /**
   * @param {number} x1 - Center x
   * @param {number} y1 - Center y
   * @param {number} r - radius
   * @param {number} startAngle - degree
   * @param {number} endAngle - degree
   */
  constructor(x1, y1, r, startAngle, endAngle)
  {
    this.x1 = x1
    this.y1 = y1
    this.r = r
    this.startAngle = startAngle
    this.endAngle = endAngle
  }

  toDxfString()
  {
    // https://www.autodesk.com/techpubs/autocad/acadr14/dxf/line_al_u05_c.htm
    let s = `0\nARC\n`
    s += `8\n${this.layer.name}\n`
    s += `10\n${this.x1}\n20\n${this.y1}\n30\n0\n`
    s += `40\n${this.r}\n50\n${this.startAngle}\n51\n${this.endAngle}\n`
    return s
  }
}

export class Circle
{
  x1: number
  y1: number
  r: number
  layer: Layer
  /**
   * @param {number} x1 - Center x
   * @param {number} y1 - Center y
   * @param {number} r - radius
   */
  constructor(x1, y1, r)
  {
    this.x1 = x1
    this.y1 = y1
    this.r = r
  }

  toDxfString()
  {
    // https://www.autodesk.com/techpubs/autocad/acadr14/dxf/circle_al_u05_c.htm
    let s = `0\nCIRCLE\n`
    s += `8\n${this.layer.name}\n`
    s += `10\n${this.x1}\n20\n${this.y1}\n30\n0\n`
    s += `40\n${this.r}\n`
    return s
  }
}

export class Line
{
  x1: number
  y1: number
  x2: number
  y2: number
  layer: Layer
  constructor(x1: number, y1: number, x2: number, y2: number)
  {
    this.x1 = x1
    this.y1 = y1
    this.x2 = x2
    this.y2 = y2
  }

  toDxfString()
  {
    // https://www.autodesk.com/techpubs/autocad/acadr14/dxf/line_al_u05_c.htm
    let s = `0\nLINE\n`
    s += `8\n${this.layer.name}\n`
    s += `10\n${this.x1}\n20\n${this.y1}\n30\n0\n`
    s += `11\n${this.x2}\n21\n${this.y2}\n31\n0\n`
    return s
  }
}

export class Polyline
{
  points: any[]
  isClose = false
  layer: Layer
  /**
   * @param {Array} points - Array of points like [ [x1, y1,r], [x2, y2,r]... ]
   */
  constructor(points, isClose)
  {
    this.points = points
    this.isClose = isClose
  }

  toDxfString()
  {
    // https://www.autodesk.com/techpubs/autocad/acad2000/dxf/polyline_dxf_06.htm
    // https://www.autodesk.com/techpubs/autocad/acad2000/dxf/vertex_dxf_06.htm
    let s = `0\nPOLYLINE\n`
    s += `8\n${this.layer.name}\n`
    s += `66\n1\n70\n${this.isClose ? 1 : 0}\n`

    for (let i = 0; i < this.points.length; ++i)
    {
      s += `0\nVERTEX\n`
      s += `8\n${this.layer.name}\n`
      s += `70\n0\n`
      s += `10\n${this.points[i].x}\n20\n${this.points[i].y}\n42\n${this.points[i].r}\n`
    }

    s += `0\nSEQEND\n`
    return s
  }
}

export class Text
{
  x1: number
  y1: number
  height: number
  rotation: number
  value: string
  layer: Layer
  /**
   * @param {number} x1 - x
   * @param {number} y1 - y
   * @param {number} height - Text height
   * @param {number} rotation - Text rotation
   * @param {string} value - the string itself
   */
  constructor(x1, y1, height, rotation, value)
  {
    this.x1 = x1
    this.y1 = y1
    this.height = height
    this.rotation = rotation
    this.value = value
  }

  toDxfString()
  {
    // https://www.autodesk.com/techpubs/autocad/acadr14/dxf/text_al_u05_c.htm
    let s = `0\nTEXT\n`
    s += `8\n${this.layer.name}\n`
    s += `1\n${this.value}\n`
    s += `10\n${this.x1}\n20\n${this.y1}\n30\n0\n`
    s += `40\n${this.height}\n50\n${this.rotation}\n`
    return s
  }
}