// Plot implements the plot.Plotter interface.
func (b *BarChart) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)

	for i, ht := range b.Values {
		x := b.XMin + float64(i)
		xmin := trX(float64(x))
		if !da.ContainsX(xmin) {
			continue
		}
		xmin = xmin - b.Width/2 + b.Offset
		xmax := xmin + b.Width
		bottom := b.stackedOn.BarHeight(i)
		ymin := trY(bottom)
		ymax := trY(bottom + ht)

		pts := []plot.Point{
			{xmin, ymin},
			{xmin, ymax},
			{xmax, ymax},
			{xmax, ymin},
		}
		poly := da.ClipPolygonY(pts)
		da.FillPolygon(b.Color, poly)

		pts = append(pts, plot.Pt(xmin, ymin))
		outline := da.ClipLinesY(pts)
		da.StrokeLines(b.LineStyle, outline...)
	}
}

func (pt *Dots) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)

	da.SetColor(pt.Color)

	for i := range pt.Y {
		// Transform the data x, y coordinate of this bubble
		// to the corresponding drawing coordinate.
		x := trX(pt.X[i])
		y := trY(pt.Y[i])

		// Get the radius of this bubble.  The radius
		// is specified in drawing units (i.e., its size
		// is given as the final size at which it will
		// be drawn) so it does not need to be transformed.
		rad := vg.Length(2)

		// Fill a circle centered at x,y on the draw area.
		var p vg.Path
		p.Move(x+rad, y)
		p.Arc(x, y, rad, 0, 2*math.Pi)
		p.Close()
		da.Fill(p)
	}
}

// Plot implements the plot.Plotter interface.
func (g *Grid) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)

	if g.Vertical.Color == nil {
		goto horiz
	}
	for _, tk := range plt.X.Tick.Marker(plt.X.Min, plt.X.Max) {
		if tk.IsMinor() {
			continue
		}
		x := trX(tk.Value)
		da.StrokeLine2(g.Vertical, x, da.Min.Y, x, da.Min.Y+da.Size.Y)
	}

horiz:
	if g.Horizontal.Color == nil {
		return
	}
	for _, tk := range plt.Y.Tick.Marker(plt.Y.Min, plt.Y.Max) {
		if tk.IsMinor() {
			continue
		}
		y := trY(tk.Value)
		da.StrokeLine2(g.Horizontal, da.Min.X, y, da.Min.X+da.Size.X, y)
	}
}

func (s *SparkLines) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)

	w := vg.Length(1)

	da.SetLineWidth(w)

	_, _, ymin, ymax := s.DataRange()

	for _, d := range s.XYs {
		perc := float64(d.Y-ymin) / float64(ymax-ymin)
		c := BrightColorGradient.GetInterpolatedColorFor((perc*-1+1)*0.5 + 0.6)
		da.SetColor(c)

		// Transform the data x, y coordinate of this bubble
		// to the corresponding drawing coordinate.
		x := trX(d.X)
		y := trY(d.Y * 0.9)

		//rad := vg.Length(10)
		var p vg.Path
		p.Move(x-w, y)
		p.Line(x-w, 0)
		//p.Close()
		da.Stroke(p)

		//da.StrokeLine2(*sty, x, 0, x, y)
	}
}

// AddLines adds Line plotters to a plot.
// The variadic arguments must be either strings
// or plotter.XYers.  Each plotter.XYer is added to
// the plot using the next color and dashes
// shape via the Color and Dashes functions.
// If a plotter.XYer is immediately preceeded by
// a string then a legend entry is added to the plot
// using the string as the name.
//
// If an error occurs then none of the plotters are added
// to the plot, and the error is returned.
func AddLines(plt *plot.Plot, vs ...interface{}) error {
	var ps []plot.Plotter
	names := make(map[*plotter.Line]string)
	name := ""
	var i int
	for _, v := range vs {
		switch t := v.(type) {
		case string:
			name = t

		case plotter.XYer:
			l, err := plotter.NewLine(t)
			if err != nil {
				return err
			}
			l.Color = Color(i)
			l.Dashes = Dashes(i)
			i++
			ps = append(ps, l)
			if name != "" {
				names[l] = name
				name = ""
			}

		default:
			panic(fmt.Sprintf("AddLines handles strings and plotter.XYers, got %T", t))
		}
	}
	plt.Add(ps...)
	for p, n := range names {
		plt.Legend.Add(n, p)
	}
	return nil
}

// AddBoxPlots adds box plot plotters to a plot and
// sets the X axis of the plot to be nominal.
// The variadic arguments must be either strings
// or plotter.Valuers.  Each valuer adds a box plot
// to the plot at the X location corresponding to
// the number of box plots added before it.  If a
// plotter.Valuer is immediately preceeded by a
// string then the string value is used to label the
// tick mark for the box plot's X location.
//
// If an error occurs then none of the plotters are added
// to the plot, and the error is returned.
func AddBoxPlots(plt *plot.Plot, width vg.Length, vs ...interface{}) error {
	var ps []plot.Plotter
	var names []string
	name := ""
	for _, v := range vs {
		switch t := v.(type) {
		case string:
			name = t

		case plotter.Valuer:
			b, err := plotter.NewBoxPlot(width, float64(len(names)), t)
			if err != nil {
				return err
			}
			ps = append(ps, b)
			names = append(names, name)
			name = ""

		default:
			panic(fmt.Sprintf("AddScatters handles strings and plotter.XYers, got %T", t))
		}
	}
	plt.Add(ps...)
	plt.NominalX(names...)
	return nil
}

func (b *QuartPlot) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)
	x := trX(b.Location)
	if !da.ContainsX(x) {
		return
	}
	x += b.Offset

	med := plot.Pt(x, trY(b.Median))
	q1 := trY(b.Quartile1)
	q3 := trY(b.Quartile3)
	aLow := trY(b.AdjLow)
	aHigh := trY(b.AdjHigh)

	da.StrokeLine2(b.WhiskerStyle, x, aHigh, x, q3)
	if da.ContainsY(med.Y) {
		da.DrawGlyphNoClip(b.MedianStyle, med)
	}
	da.StrokeLine2(b.WhiskerStyle, x, aLow, x, q1)

	ostyle := b.MedianStyle
	ostyle.Radius = b.MedianStyle.Radius / 2
	for _, out := range b.Outside {
		y := trY(b.Value(out))
		if da.ContainsY(y) {
			da.DrawGlyphNoClip(ostyle, plot.Pt(x, y))
		}
	}
}

// AddScatters adds Scatter plotters to a plot.
// The variadic arguments must be either strings
// or plotter.XYers.  Each plotter.XYer is added to
// the plot using the next color, and glyph shape
// via the Color and Shape functions. If a
// plotter.XYer is immediately preceeded by
// a string then a legend entry is added to the plot
// using the string as the name.
//
// If an error occurs then none of the plotters are added
// to the plot, and the error is returned.
func AddScatters(plt *plot.Plot, vs ...interface{}) error {
	var ps []plot.Plotter
	names := make(map[*plotter.Scatter]string)
	name := ""
	var i int
	for _, v := range vs {
		switch t := v.(type) {
		case string:
			name = t

		case plotter.XYer:
			s, err := plotter.NewScatter(t)
			if err != nil {
				return err
			}
			s.Color = Color(i)
			s.Shape = Shape(i)
			i++
			ps = append(ps, s)
			if name != "" {
				names[s] = name
				name = ""
			}

		default:
			panic(fmt.Sprintf("AddScatters handles strings and plotter.XYers, got %T", t))
		}
	}
	plt.Add(ps...)
	for p, n := range names {
		plt.Legend.Add(n, p)
	}
	return nil
}

// AddLinePoints adds Line and Scatter plotters to a
// plot.  The variadic arguments must be either strings
// or plotter.XYers.  Each plotter.XYer is added to
// the plot using the next color, dashes, and glyph
// shape via the Color, Dashes, and Shape functions.
// If a plotter.XYer is immediately preceeded by
// a string then a legend entry is added to the plot
// using the string as the name.
func AddLinePoints(plt *plot.Plot, vs ...interface{}) {
	name := ""
	var i int
	for _, v := range vs {
		switch t := v.(type) {
		case string:
			name = t

		case plotter.XYer:
			l, s := plotter.NewLinePoints(t)
			l.Color = Color(i)
			l.Dashes = Dashes(i)
			s.Color = Color(i)
			s.Shape = Shape(i)
			i++
			plt.Add(l, s)
			if name != "" {
				plt.Legend.Add(name, l, s)
				name = ""
			}

		default:
			panic(fmt.Sprintf("AddLinePoints handles strings and plotter.XYers, got %T", t))
		}
	}
}

// AddErrorBars adds XErrorBars and YErrorBars
// to a plot.  The variadic arguments must be
// of type plotter.XYer, and must be either a
// plotter.XErrorer, plotter.YErrorer, or both.
// Each errorer is added to the plot the color from
// the Colors function corresponding to its position
// in the argument list.
func AddErrorBars(plt *plot.Plot, vs ...interface{}) {
	for i, v := range vs {
		added := false

		if xerr, ok := v.(interface {
			plotter.XYer
			plotter.XErrorer
		}); ok {
			e := plotter.NewXErrorBars(xerr)
			e.Color = Color(i)
			plt.Add(e)
			added = true
		}

		if yerr, ok := v.(interface {
			plotter.XYer
			plotter.YErrorer
		}); ok {
			e := plotter.NewYErrorBars(yerr)
			e.Color = Color(i)
			plt.Add(e)
			added = true
		}

		if added {
			continue
		}
		panic(fmt.Sprintf("AddErrorBars expects plotter.XErrorer or plotter.YErrorer, got %T", v))
	}
}

// Plot draws the Line, implementing the plot.Plotter interface.
func (rp *ResponsePlotter) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)

	start := float64(rp.Response.GetStartTime())
	step := float64(rp.Response.GetStepTime())
	absent := rp.Response.IsAbsent

	lines := make([][]plot.Point, 1)
	lines[0] = make([]plot.Point, 0, len(rp.Response.Values))

	/* ikruglov
	 * swithing between lineMode and looping inside
	 * is more branch-prediction friendly i.e. potentially faster */
	switch rp.lineMode {
	case "slope":
		currentLine := 0
		lastAbsent := false
		for i, v := range rp.Response.Values {
			if absent[i] {
				lastAbsent = true
			} else if lastAbsent {
				currentLine++
				lines = append(lines, make([]plot.Point, 1))
				lines[currentLine][0] = plot.Point{X: trX(start + float64(i)*step), Y: trY(v)}
				lastAbsent = false
			} else {
				lines[currentLine] = append(lines[currentLine], plot.Point{X: trX(start + float64(i)*step), Y: trY(v)})
			}
		}

	case "connected":
		for i, v := range rp.Response.Values {
			if absent[i] {
				continue
			}

			lines[0] = append(lines[0], plot.Point{X: trX(start + float64(i)*step), Y: trY(v)})
		}

	case "drawAsInfinite":
		for i, v := range rp.Response.Values {
			if !absent[i] && v > 0 {
				infiniteLine := []plot.Point{
					plot.Point{X: trX(start + float64(i)*step), Y: da.Y(1)},
					plot.Point{X: trX(start + float64(i)*step), Y: da.Y(0)},
				}
				lines = append(lines, infiniteLine)
			}
		}

	//case "staircase": // TODO
	default:
		panic("Unimplemented " + rp.lineMode)
	}

	da.StrokeLines(rp.LineStyle, lines...)
}

// Plot draws the Line, implementing the plot.Plotter
// interface.
func (pts *Line) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)
	ps := make([]plot.Point, len(pts.XYs))
	for i, p := range pts.XYs {
		ps[i].X = trX(p.X)
		ps[i].Y = trY(p.Y)
	}
	da.StrokeLines(pts.LineStyle, da.ClipLinesXY(ps)...)
}

// AddYErrorBars adds YErrorBars to a plot.
// The variadic arguments must be
// of type plotter.XYer, and plotter.YErrorer.
// Each errorer is added to the plot the color from
// the Colors function corresponding to its position
// in the argument list.
func AddYErrorBars(plt *plot.Plot, es ...interface {
	plotter.XYer
	plotter.YErrorer
}) {
	for i, e := range es {
		bars := plotter.NewYErrorBars(e)
		bars.Color = Color(i)
		plt.Add(bars)
	}
}

func (pts *VerticalLine) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, _ := plt.Transforms(&da)
	ps := make([]plot.Point, 2)
	ps[0].X = trX(pts.X)
	ps[1].X = ps[0].X

	ps[0].Y = da.Min.Y
	ps[1].Y = da.Max().Y

	da.StrokeLines(pts.LineStyle, da.ClipLinesXY(ps)...)
}

// Plot implements the Plotter interface, drawing a line
// that connects each point in the Line.
func (f *Function) Plot(da plot.DrawArea, p *plot.Plot) {
	trX, trY := p.Transforms(&da)

	d := (p.X.Max - p.X.Min) / float64(f.Samples-1)
	line := make([]plot.Point, f.Samples)
	for i := range line {
		x := p.X.Min + float64(i)*d
		line[i].X = trX(x)
		line[i].Y = trY(f.F(x))
	}
	da.StrokeLines(f.LineStyle, da.ClipLinesXY(line)...)
}

func (pts *HorizontalLine) Plot(da plot.DrawArea, plt *plot.Plot) {
	_, trY := plt.Transforms(&da)
	ps := make([]plot.Point, 2)

	ps[0].X = da.Min.X
	ps[1].X = da.Max().X

	ps[0].Y = trY(pts.Y)
	ps[1].Y = ps[0].Y

	da.StrokeLines(pts.LineStyle, da.ClipLinesXY(ps)...)
}

func (g GlyphBoxes) Plot(da plot.DrawArea, plt *plot.Plot) {
	for _, b := range plt.GlyphBoxes(plt) {
		x := da.X(b.X) + b.Rect.Min.X
		y := da.Y(b.Y) + b.Rect.Min.Y
		da.StrokeLines(g.LineStyle, []plot.Point{
			{x, y},
			{x + b.Rect.Size.X, y},
			{x + b.Rect.Size.X, y + b.Rect.Size.Y},
			{x, y + b.Rect.Size.Y},
			{x, y},
		})
	}
}

// Plot implements the Plotter interface, drawing labels.
func (e *XErrorBars) Plot(da plot.DrawArea, p *plot.Plot) {
	trX, trY := p.Transforms(&da)
	for i, err := range e.XErrors {
		y := trY(e.XYs[i].Y)
		xlow := trX(e.XYs[i].X - math.Abs(err.Low))
		xhigh := trX(e.XYs[i].X + math.Abs(err.High))

		bar := da.ClipLinesX([]plot.Point{{xlow, y}, {xhigh, y}})
		da.StrokeLines(e.LineStyle, bar...)
		e.drawCap(&da, xlow, y)
		e.drawCap(&da, xhigh, y)
	}
}

// Plot implements the Plotter interface, drawing labels.
func (l *Labels) Plot(da plot.DrawArea, p *plot.Plot) {
	trX, trY := p.Transforms(&da)
	for i, label := range l.Labels {
		x := trX(l.XYs[i].X)
		y := trY(l.XYs[i].Y)
		if !da.Contains(plot.Pt(x, y)) {
			continue
		}
		x += l.XOffset
		y += l.YOffset
		da.FillText(l.TextStyle, x, y, l.XAlign, l.YAlign, label)
	}
}

// Plot implements the plot.Plotter interface.
func (cg *ColorGrid) Plot(da plot.DrawArea, plt *plot.Plot) {
	trX, trY := plt.Transforms(&da)
	for i, d := range cg.XYZs {
		if i%cg.Ny != cg.Ny-1 && i < cg.Nx*cg.Ny-cg.Ny {
			pts := []plot.Point{
				{trX(d.X), trY(d.Y)},
				{trX(cg.XYZs[i+cg.Ny].X), trY(cg.XYZs[i+cg.Ny].Y)},
				{trX(cg.XYZs[i+cg.Ny+1].X), trY(cg.XYZs[i+cg.Ny+1].Y)},
				{trX(cg.XYZs[i+1].X), trY(cg.XYZs[i+1].Y)},
			}
			da.FillPolygon(color.Gray{uint8((d.Z - cg.MinZ) / math.Abs(cg.MaxZ-cg.MinZ) * 255.0)}, pts)
		}
	}
}