function Guide () {
  Layer.call(this)

  this.el.id = 'guide'
  this.inspect = true

  this.update = function () {
    this.clear()

    var units = this.find_units()

    if (this.inspect) {
      this.draw_inspector()
    }

    if (ronin.commander.input_el.value == '~') {
      this.toggle_color_picker(true)
    }

    // Brush mirrors
    for (id in ronin.brush.pointers) {
      var pointer = ronin.brush.pointers[id]
      if (!pointer.options.mirror) { continue }
      units.push({ x1: pointer.options.mirror.x, y1: 0, x2: pointer.options.mirror.x, y2: ronin.frame.height })
    }

    if (units.length == 0) { return }

    for (i in units) {
      this.draw(units[i])
    }
  }

  this.toggle = function () {
    this.el.style.opacity = this.el.style.opacity == 0 ? 1 : 0
  }

  this.toggle_color_picker = function (show) {
    if (!show) { return }
    var originalData = ronin.cursor.target.context().getImageData(0, 0, ronin.frame.width * 2, ronin.frame.height * 2)
    var data = originalData.data
    for (var i = 0; i < data.length; i += 4) {
      var x = i % (ronin.frame.width * 8)
      var y = i / (ronin.frame.width * 32)
      data[i] = x / 32
      data[i + 1] = 255 - (x / 32)
      data[i + 2] = y
      data[i + 3] = 255
    }
    ronin.layers.guide.context().putImageData(originalData, 0, 0)
  }

  this.draw = function (u = null) {
    if (u && u.x1 != null && u.y1 != null && u.x2 != null && u.y2 != null) {
      this.draw_line({ x: u.x1, y: u.y1 }, { x: u.x2, y: u.y2 })
    }

    if (u && u.x && u.y) {
      this.draw_pos(u)
    }
    if (u && u.width && u.height) {
      this.draw_rect(u)
      this.draw_pos({ x: u.x + (u.width / 2), y: u.y + (u.height / 2) })
    }
  }

  this.draw_rect = function (u) {
    var ctx = this.context()

    u.x = !u.x ? 0 : u.x
    u.y = !u.y ? 0 : u.y

    var offset = { x: u.x * 2, y: u.y * 2 }
    var rect = { width: u.width * 2, height: u.height * 2 }

    // Outline

    ctx.beginPath()
    ctx.globalCompositeOperation = 'source-over'
    ctx.moveTo(offset.x, offset.y)
    ctx.lineTo(offset.x + rect.width, offset.y)
    ctx.lineTo(offset.x + rect.width, offset.y + rect.height)
    ctx.lineTo(offset.x, offset.y + rect.height)
    ctx.lineTo(offset.x, offset.y)
    ctx.lineCap = 'round'
    ctx.lineWidth = 2
    ctx.strokeStyle = '#000'
    ctx.stroke()
    ctx.closePath()
  }

  this.draw_line = function (u1, u2, color = '#000') {
    var ctx = this.context()

    ctx.beginPath()
    ctx.globalCompositeOperation = 'source-over'
    ctx.moveTo(u1.x * 2, u1.y * 2)
    ctx.lineTo(u2.x * 2, u2.y * 2)
    ctx.lineCap = 'round'
    ctx.lineWidth = 0.5
    ctx.strokeStyle = color
    ctx.stroke()
    ctx.closePath()
  }

  this.draw_pos = function (u) {
    var ctx = this.context()

    var offset = 2
    var radius = 5

    var pos = { x: u.x * 2, y: u.y * 2 }

    ctx.beginPath()
    ctx.globalCompositeOperation = 'source-over'
    ctx.moveTo(pos.x + offset, pos.y)
    ctx.lineTo(pos.x + radius, pos.y)
    ctx.moveTo(pos.x, pos.y + offset)
    ctx.lineTo(pos.x, pos.y + radius)
    ctx.moveTo(pos.x - offset, pos.y)
    ctx.lineTo(pos.x - radius, pos.y)
    ctx.moveTo(pos.x, pos.y - offset)
    ctx.lineTo(pos.x, pos.y - radius)
    ctx.lineCap = 'round'
    ctx.lineWidth = 4
    ctx.strokeStyle = '#000'
    ctx.stroke()
    ctx.lineWidth = 2
    ctx.strokeStyle = '#fff'
    ctx.stroke()
    ctx.closePath()
  }

  this.find_units = function (q = ronin.commander.getQuery()) {
    var a = []

    // for (method_id in q.methods) {
    //   var params = q.methods[method_id]
    //   if (params.from && params.to) {
    //     a = a.concat(params.from)
    //     a = a.concat(params.to)
    //   } else {
    //     a = a.concat(params)
    //   }
    // }
    return a
  }

  this.draw_inspector = function () {
    var color = 'black'

    // Center
    this.draw_line({ x: 0, y: ronin.frame.height / 2 }, { x: 10, y: ronin.frame.height / 2 }, color)
    this.draw_line({ x: ronin.frame.width - 10, y: ronin.frame.height / 2 }, { x: ronin.frame.width, y: ronin.frame.height / 2 }, color)
    this.draw_line({ x: (ronin.frame.width / 2) - 10, y: ronin.frame.height / 2 }, { x: (ronin.frame.width / 2) + 10, y: ronin.frame.height / 2 }, color)
    this.draw_line({ x: ronin.frame.width / 2, y: 0 }, { x: ronin.frame.width / 2, y: 10 }, color)
    this.draw_line({ x: ronin.frame.width / 2, y: ronin.frame.height - 10 }, { x: ronin.frame.width / 2, y: ronin.frame.height }, color)
    this.draw_line({ x: ronin.frame.width / 2, y: (ronin.frame.height / 2) - 10 }, { x: ronin.frame.width / 2, y: (ronin.frame.height / 2) + 10 }, color)

    var ctx = this.context()

    var w = ronin.frame.width * 2
    var h = ronin.frame.height * 2
    var angle = 45

    ctx.translate(w / 2, h / 2)

    ctx.rotate(angle * Math.PI / 180)

    this.line(ctx, -w, 0, w, 0, color)

    this.line(ctx, w * 0.4, -h, w * 0.4, h, color)
    this.line(ctx, -w * 0.4, -h, -w * 0.4, h, color)

    this.line(ctx, -w, h * 0.25, w, h * 0.25, color)
    this.line(ctx, -w, -h * 0.25, w, -h * 0.25, color)

    this.line(ctx, w * 0.1, 0, w * 0.1, h, color)
    this.line(ctx, -w * 0.1, 0, -w * 0.1, -h, color)

    this.circle(ctx, w * 0.4, -h * 0.25, w * 0.05, 1, 1.5, color)
    this.circle(ctx, -w * 0.4, h * 0.25, w * 0.05, 0, 0.5, color)

    ctx.font = '5px Arial'
    ctx.fillStyle = color
    ctx.fillText(angle + "'", (w * 0.4) + 10, 10)

    ctx.font = '5px Arial'
    ctx.fillStyle = color
    ctx.fillText(angle + "'", (-w * 0.4) - 20, -10)

    ctx.rotate(-angle * Math.PI / 180)
    ctx.translate(-w / 2, -h / 2)
  }

  this.line = function (context, x1, x2, y1, y2, color) {
    context.beginPath()
    context.moveTo(x1, x2)
    context.lineTo(y1, y2)
    context.lineCap = 'round'
    context.lineWidth = 0.5
    context.strokeStyle = color
    context.stroke()
    context.closePath()
  }

  this.circle = function (context, x, y, r, c1, c2, color) {
    context.beginPath()
    context.arc(x, y, r, c1 * Math.PI, c2 * Math.PI)
    context.lineCap = 'round'
    context.lineWidth = 0.5
    context.strokeStyle = color
    context.stroke()
    context.closePath()
  }
}