package tracker

import (
	"fmt"
	"image"
	"image/color"

	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"
	"github.com/vsariola/sointu"
	"golang.org/x/exp/shiny/materialdesign/icons"
)

func (t *Tracker) layoutUnitEditor(gtx C) D {
	editorFunc := t.layoutUnitSliders
	if t.song.Patch.Instruments[t.CurrentInstrument].Units[t.CurrentUnit].Type == "" {
		editorFunc = t.layoutUnitTypeChooser
	}
	paint.FillShape(gtx.Ops, unitSurfaceColor, clip.Rect{Max: image.Pt(gtx.Constraints.Max.X, gtx.Constraints.Max.Y)}.Op())
	return layout.Flex{Axis: layout.Vertical}.Layout(gtx,
		layout.Flexed(1, editorFunc),
		layout.Rigid(t.layoutUnitFooter()),
	)
}

func (t *Tracker) layoutUnitSliders(gtx C) D {
	ut, ok := sointu.UnitTypes[t.song.Patch.Instruments[t.CurrentInstrument].Units[t.CurrentUnit].Type]
	if !ok {
		return layout.Dimensions{}
	}
	listElements := func(gtx C, index int) D {
		if ut[index].MaxValue < ut[index].MinValue {
			return layout.Dimensions{}
		}
		for len(t.ParameterSliders) <= index {
			t.ParameterSliders = append(t.ParameterSliders, new(widget.Float))
		}
		params := t.song.Patch.Instruments[t.CurrentInstrument].Units[t.CurrentUnit].Parameters
		for t.ParameterSliders[index].Changed() {
			params[ut[index].Name] = int(t.ParameterSliders[index].Value)
			// TODO: tracker should have functions to update parameters and
			// to do this efficiently i.e. not compile the whole patch again
			t.LoadSong(t.song)
		}
		t.ParameterSliders[index].Value = float32(params[ut[index].Name])
		sliderStyle := material.Slider(t.Theme, t.ParameterSliders[index], float32(ut[index].MinValue), float32(ut[index].MaxValue))
		sliderStyle.Color = t.Theme.Fg
		var valueText string
		value := params[ut[index].Name]
		if ut[index].ToString != nil {
			valueText = fmt.Sprintf("%v / %v", value, ut[index].ToString(value))
		} else {
			valueText = fmt.Sprintf("%v", value)
		}
		return layout.Flex{Axis: layout.Horizontal, Alignment: layout.Middle}.Layout(gtx,
			layout.Rigid(func(gtx C) D {
				gtx.Constraints.Min.X = gtx.Px(unit.Dp(110))
				return layout.E.Layout(gtx, Label(ut[index].Name, white))
			}),
			layout.Rigid(func(gtx C) D {
				gtx.Constraints.Min.X = gtx.Px(unit.Dp(200))
				return sliderStyle.Layout(gtx)
			}),
			layout.Rigid(Label(valueText, white)),
		)
	}
	return t.ParameterList.Layout(gtx, len(ut), listElements)
}

func (t *Tracker) layoutUnitFooter() layout.Widget {
	return func(gtx C) D {
		for t.ClearUnitBtn.Clicked() {
			t.ClearUnit()
			op.InvalidateOp{}.Add(gtx.Ops)
		}
		for t.DeleteUnitBtn.Clicked() {
			t.DeleteUnit()
			op.InvalidateOp{}.Add(gtx.Ops)
		}
		deleteUnitBtnStyle := material.IconButton(t.Theme, t.DeleteUnitBtn, widgetForIcon(icons.ActionDelete))
		deleteUnitBtnStyle.Background = transparent
		deleteUnitBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
		if len(t.song.Patch.Instruments[t.CurrentInstrument].Units) > 1 {
			deleteUnitBtnStyle.Color = primaryColor
		} else {
			deleteUnitBtnStyle.Color = disabledTextColor
		}
		if t.song.Patch.Instruments[t.CurrentInstrument].Units[t.CurrentUnit].Type == "" {
			return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
				layout.Flexed(1, func(gtx C) D { return layout.Dimensions{Size: gtx.Constraints.Min} }),
				layout.Rigid(deleteUnitBtnStyle.Layout))
		}
		clearUnitBtnStyle := material.IconButton(t.Theme, t.ClearUnitBtn, widgetForIcon(icons.ContentClear))
		clearUnitBtnStyle.Color = primaryColor
		clearUnitBtnStyle.Background = transparent
		clearUnitBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
		return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
			layout.Flexed(1, func(gtx C) D { return layout.Dimensions{Size: gtx.Constraints.Min} }),
			layout.Rigid(clearUnitBtnStyle.Layout),
			layout.Rigid(deleteUnitBtnStyle.Layout))
	}
}

func (t *Tracker) layoutUnitTypeChooser(gtx C) D {
	paint.FillShape(gtx.Ops, unitSurfaceColor, clip.Rect{Max: image.Pt(gtx.Constraints.Max.X, gtx.Constraints.Max.Y)}.Op())
	listElem := func(gtx C, i int) D {
		for t.ChooseUnitTypeBtns[i].Clicked() {
			t.SetUnit(allUnits[i])
		}
		labelStyle := LabelStyle{Text: allUnits[i], ShadeColor: black, Color: white, Font: labelDefaultFont, FontSize: unit.Sp(12)}
		bg := func(gtx C) D {
			gtx.Constraints = layout.Exact(image.Pt(120, 20))
			var color color.NRGBA
			if t.ChooseUnitTypeBtns[i].Hovered() {
				color = unitTypeListHighlightColor
			}
			paint.FillShape(gtx.Ops, color, clip.Rect{Max: image.Pt(gtx.Constraints.Min.X, gtx.Constraints.Min.Y)}.Op())
			return D{Size: gtx.Constraints.Min}
		}
		return layout.Stack{Alignment: layout.W}.Layout(gtx,
			layout.Stacked(bg),
			layout.Expanded(labelStyle.Layout),
			layout.Expanded(t.ChooseUnitTypeBtns[i].Layout))
	}
	return t.ChooseUnitTypeList.Layout(gtx, len(allUnits), listElem)
}