package gioui

import (
	"image"

	"gioui.org/layout"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/unit"
	"github.com/vsariola/sointu/tracker"
)

type (
	SpectrumState struct {
		resolutionNumber *NumericUpDownState
		smoothingBtn     *Clickable
		chnModeBtn       *Clickable
	}
)

func NewSpectrumState() *SpectrumState {
	return &SpectrumState{
		resolutionNumber: NewNumericUpDownState(),
		smoothingBtn:     new(Clickable),
		chnModeBtn:       new(Clickable),
	}
}

func (s *SpectrumState) Layout(gtx C) D {
	s.Update(gtx)
	t := TrackerFromContext(gtx)
	leftSpacer := layout.Spacer{Width: unit.Dp(6), Height: unit.Dp(24)}.Layout
	rightSpacer := layout.Spacer{Width: unit.Dp(6)}.Layout

	var chnModeTxt string = "???"
	switch tracker.SpecChnMode(t.Model.SpecAnChannelsInt().Value()) {
	case tracker.SpecChnModeCombine:
		chnModeTxt = "Combine"
	case tracker.SpecChnModeSeparate:
		chnModeTxt = "Separate"
	case tracker.SpecChnModeLeft:
		chnModeTxt = "Left"
	case tracker.SpecChnModeRight:
		chnModeTxt = "Right"
	case tracker.SpecChnModeOff:
		chnModeTxt = "Off"
	}

	var smoothTxt string = "???"
	switch tracker.SpecSmoothing(t.Model.SpecAnSmoothing().Value()) {
	case tracker.SpecSmoothingSlow:
		smoothTxt = "Slow"
	case tracker.SpecSmoothingMedium:
		smoothTxt = "Medium"
	case tracker.SpecSmoothingFast:
		smoothTxt = "Fast"
	}

	resolution := NumUpDown(t.Model.SpecAnResolution(), t.Theme, s.resolutionNumber, "Resolution")
	chnModeBtn := Btn(t.Theme, &t.Theme.Button.Filled, s.chnModeBtn, chnModeTxt, "Channel mode")
	smoothBtn := Btn(t.Theme, &t.Theme.Button.Filled, s.smoothingBtn, smoothTxt, "Smoothing")

	return layout.Flex{Axis: layout.Vertical}.Layout(gtx,
		layout.Flexed(1, s.drawSpectrum),
		layout.Rigid(func(gtx C) D {
			return layout.Flex{Axis: layout.Horizontal, Alignment: layout.Middle}.Layout(gtx,
				layout.Rigid(leftSpacer),
				layout.Flexed(1, func(gtx C) D { return D{Size: gtx.Constraints.Min} }),
				layout.Rigid(chnModeBtn.Layout),
				layout.Rigid(smoothBtn.Layout),
				layout.Rigid(resolution.Layout),
				layout.Rigid(rightSpacer),
			)
		}),
	)
}

func (s *SpectrumState) Update(gtx C) {
	t := TrackerFromContext(gtx)
	for s.chnModeBtn.Clicked(gtx) {
		t.Model.SpecAnChannelsInt().SetValue((t.SpecAnChannelsInt().Value() + 1) % int(tracker.NumSpecChnModes))
	}
	for s.smoothingBtn.Clicked(gtx) {
		r := t.Model.SpecAnSmoothing().Range()
		t.Model.SpecAnSmoothing().SetValue((t.SpecAnSmoothing().Value()+1)%(r.Max-r.Min+1) + r.Min)
	}
}

func (s *SpectrumState) drawSpectrum(gtx C) D {
	t := TrackerFromContext(gtx)
	for chn := range 2 {
		paint.ColorOp{Color: t.Theme.Oscilloscope.CurveColors[chn]}.Add(gtx.Ops)
		p := t.Spectrum()[chn]
		if len(p) <= 0 {
			continue
		}
		fillRect(gtx, clip.Rect{Min: image.Pt(0, 0), Max: image.Pt(gtx.Constraints.Max.X, 1)})
		fillRect(gtx, clip.Rect{Min: image.Pt(0, gtx.Constraints.Min.Y-1), Max: image.Pt(gtx.Constraints.Max.X, gtx.Constraints.Max.Y)})
		for px := range gtx.Constraints.Max.X {
			y2 := gtx.Constraints.Max.Y - 1
			y1 := int(-p[px*len(p)/gtx.Constraints.Max.X] / 80 * float32(y2))
			fillRect(gtx, clip.Rect{Min: image.Pt(px, y1), Max: image.Pt(px+1, y2+1)})
		}
	}
	return D{Size: image.Pt(gtx.Constraints.Max.X, gtx.Constraints.Max.Y)}
}