package main

import (
	"golang.org/x/exp/slices"
	"log"
	"os"

	"gioui.org/app"
	"gioui.org/font/gofont"
	"gioui.org/io/system"
	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"
)

const (
	gasConstant  = 8.314472
	airMolarMass = 0.0289647 // kg/mol
)

func main() {
	state, err := NewApp()
	if err != nil {
		log.Fatal(err)
	}

	go func() {
		w := app.NewWindow(
			app.Title("Volute"),
		)
		if err := run(state, w); err != nil {
			log.Fatal(err)
		}
		os.Exit(0)
	}()
	app.Main()
}

func run(s App, w *app.Window) error {
	var ops op.Ops

	th := material.NewTheme(gofont.Collection())
	inset := layout.UniformInset(unit.Dp(2))

	displacement := NewFloat(th)
	displacement.Set(2000.0)

	var rpm []Int
	rpm = append(rpm, NewInt(th))
	rpm[0].Set(2000)
	var rpmList = layout.List{Axis: layout.Horizontal}

	var duplicateButton []widget.Clickable
	duplicateButton = append(duplicateButton, widget.Clickable{})
	var duplicateButtonList = layout.List{Axis: layout.Horizontal}

	var deleteButton []widget.Clickable
	deleteButton = append(deleteButton, widget.Clickable{})
	var deleteButtonList = layout.List{Axis: layout.Horizontal}

	for {
		e := <-w.Events()
		switch e := e.(type) {
		case system.DestroyEvent:
			return e.Err
		case system.FrameEvent:
			gtx := layout.NewContext(&ops, e)

			for i := range rpm {
				if duplicateButton[i].Clicked() {
					rpm = slices.Insert(rpm, i, rpm[i])
					duplicateButton = slices.Insert(
						duplicateButton,
						i,
						duplicateButton[i],
					)
					deleteButton = slices.Insert(
						deleteButton,
						i,
						deleteButton[i],
					)
					break
				}
				if deleteButton[i].Clicked() && len(rpm) > 1 {
					rpm = slices.Delete(rpm, i, i+1)
					duplicateButton = slices.Delete(duplicateButton, i, i+1)
					deleteButton = slices.Delete(deleteButton, i, i+1)
					break
				}
			}

			layout.Flex{
				Axis: layout.Vertical,
			}.Layout(gtx,
				// Displacement
				layout.Rigid(
					func(gtx layout.Context) layout.Dimensions {
						return inset.Layout(gtx,
							func(gtx layout.Context) layout.Dimensions {
								return displacement.Layout(gtx)
							},
						)
					},
				),
				// Rpm
				layout.Rigid(
					func(gtx layout.Context) layout.Dimensions {
						return rpmList.Layout(gtx,
							len(rpm),
							func(gtx layout.Context, index int) layout.Dimensions {
								return inset.Layout(gtx,
									func(gtx layout.Context) layout.Dimensions {
										return rpm[index].Layout(gtx)
									},
								)
							},
						)
					},
				),
				// Duplicate
				layout.Rigid(
					func(gtx layout.Context) layout.Dimensions {
						return duplicateButtonList.Layout(gtx,
							len(duplicateButton),
							func(gtx layout.Context, i int) layout.Dimensions {
								return material.Button(th, &duplicateButton[i], "Duplicate").
									Layout(gtx)
							},
						)
					},
				),
				// Delete
				layout.Rigid(
					func(gtx layout.Context) layout.Dimensions {
						return deleteButtonList.Layout(gtx,
							len(deleteButton),
							func(gtx layout.Context, i int) layout.Dimensions {
								return material.Button(th, &deleteButton[i], "Delete").
									Layout(gtx)
							},
						)
					},
				),
			)

			e.Frame(gtx.Ops)
		}
	}
}