package main

import (
	"fmt"
	"image/color"
	"os"
	"strconv"
	"strings"
	g "github.com/AllenDang/giu"
)

const (
	MasterWidth int = 378
	Version string = "0.2.0"
	FullStack int = iota
	TopThree
	TopOfStack
	Dsc
	Asc
)


type Input struct {
	buf      strings.Builder
	decimal  bool
	negative bool
}

func (i *Input) String() string {
	return i.buf.String()
}

func (i *Input) Append(value rune) {
	switch value {
	case '.':
		if i.decimal {
			return
		}
		if i.buf.Len() == 0 {
			i.buf.WriteRune('0')
		}
		i.decimal = true
		i.buf.WriteRune(value)
	case '-':
		if i.buf.Len() > 0 {
			return
		}
		i.negative = true
		i.buf.WriteRune(value)
	default:
		i.buf.WriteRune(value) 
	}

	inputDisplay = i.String()
	SetComboOut()
}

func (i *Input) Store() {
	if i.buf.Len() == 0 {
		return
	}

	if i.buf.Len() == 1 && (i.negative || i.decimal) {
		i.Reset()
		return
	}
	num, err := strconv.ParseFloat(i.buf.String(), 64)
	if err != nil {
		panic("Bad input")
	}
	s.Push(num)
	i.Reset()
	inputDisplay = ""
}

func (i *Input) Reset() {
	i.buf.Reset()
	i.decimal = false
	i.negative = false
}

func (i *Input) Delete() {
	if i.buf.Len() == 0 {
		return
	}
	val := i.buf.String()
	popped := val[len(val)-1]
	i.buf.Reset()
	i.buf.WriteString(val[:len(val)-1])
	if popped == '.' {
		i.decimal = false
	} else if popped == '-' {
		i.negative = false
	}
	inputDisplay = i.String()
	SetComboOut()
}

var (
	wnd           *g.MasterWindow
	inputBuffer   *Input                      = &Input{}
	s             *stack                      = &stack{-1, [100]float64{}}
	stackStyle    int                         = FullStack
	inputDisplay  string                      = inputBuffer.String()
	outputDisplay string                      = s.String()
	comboDisplay  string                      = inputBuffer.String()
	Display       *g.InputTextWidget          = g.InputText("", &inputDisplay)
	Output        *g.InputTextMultilineWidget = g.InputTextMultiline("", &outputDisplay)
	ComboView     *g.InputTextWidget          = g.InputText("", &comboDisplay)
	ShowStack     bool                        = true
	stackSort     int                         = Dsc
	stackLabel    *g.LabelWidget              = g.Label("Stack Output\n[d]{TOS ...}")
)

func callStackWord(f func()) {
	inputBuffer.Store()
	f()
	outputDisplay = s.String()
	SetComboOut()
}

func SetComboOut() {
	if inputBuffer.buf.Len() > 0 {
		comboDisplay = inputBuffer.String()
	} else {
		comboDisplay = strconv.FormatFloat(s.Peek(), 'f', -1, 64)
	}
}

func SetStackLabelWithSort() {
	sort := "TOS ..."
	if stackSort == Asc {
		sort = "... TOS"
	}

	stackLabel = g.Label(fmt.Sprintf("Stack Output\n[d]{%s}", sort))
	outputDisplay = s.String()
}

func ToggleScreenSize() {
	width := MasterWidth
	if ShowStack {
		width = MasterWidth + MasterWidth / 2
	}
	wnd.SetSize(width,400)
}

func loop() {
	g.SingleWindowWithMenuBar("gnums - " + Version).Layout(
		g.MenuBar().Layout(
			g.Menu("gnums").Layout(
				g.Label("v"+Version),
				g.Checkbox("Show Stack Window", &ShowStack).OnChange(ToggleScreenSize),
				g.Menu("Output Style").Layout(
					g.RadioButton("Full Stack", stackStyle == FullStack).OnChange(func(){stackStyle = FullStack; outputDisplay = s.String()}),
					g.RadioButton("Top Three", stackStyle == TopThree).OnChange(func(){stackStyle = TopThree; outputDisplay = s.String()}),
					g.RadioButton("Top Of Stack", stackStyle == TopOfStack).OnChange(func(){stackStyle = TopOfStack; outputDisplay = s.String()}),
				),
				g.Menu("Stack Sort").Layout(
					g.RadioButton("TOS ...", stackSort == Dsc).OnChange(func(){stackSort = Dsc; SetStackLabelWithSort()}),
					g.RadioButton("... TOS", stackSort == Asc).OnChange(func(){stackSort = Asc; SetStackLabelWithSort()}),
				),
				g.MenuItem("Exit").OnClick(Exit),
			),
		),
		g.Dummy(-1, 8),
		ComboView.Size(-1).Flags(1 << 14),
		g.Dummy(-1, 8),
		g.Row(
			g.Condition(ShowStack, g.Layout{
				g.Row(
					g.Child("Left").Layout(
						stackLabel,
						g.Tooltip("Stack display is\nnewest on top"),
						Output.Size(-1, -1).Flags(1 << 14),
					).Size(
						float32(MasterWidth/2), -1,
					),
					g.Child("Section").Layout(
						g.Row(
							g.Style().SetColor(g.StyleColorButton, color.RGBA{150, 55, 55, 255}).To(
								g.Button("Clear").Size(50,50).OnClick(func(){callStackWord(s.Clear)}),
							),
							g.Button("Delete").Size(50,50).OnClick(func(){inputBuffer.Delete()}),
							g.Button("Round").Size(50,50).OnClick(func(){callStackWord(s.Round)}),
							g.Button("^").Size(50,50).OnClick(func(){callStackWord(s.Pow)}),
							g.Button("÷").Size(50,50).OnClick(func(){callStackWord(s.Div)}),
							g.Button("Sqrt").Size(50,50).OnClick(func(){callStackWord(s.Sqt)}),
						),
						g.Row(
							g.Button("Over").Size(50,50).OnClick(func(){callStackWord(s.Ovr)}),
							g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
								g.Row(
									g.Button("7").Size(50,50).OnClick(func(){inputBuffer.Append('7')}),
									g.Button("8").Size(50,50).OnClick(func(){inputBuffer.Append('8')}),
									g.Button("9").Size(50,50).OnClick(func(){inputBuffer.Append('9')}),
								),
							),
							g.Button("×").Size(50,50).OnClick(func(){callStackWord(s.Mul)}),
							g.Button("Floor").Size(50,50).OnClick(func(){callStackWord(s.Floor)}),
						),
						g.Row(
							g.Button("Swap").Size(50,50).OnClick(func(){callStackWord(s.Swp)}),
							g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
								g.Row(
									g.Button("4").Size(50,50).OnClick(func(){inputBuffer.Append('4')}),
									g.Button("5").Size(50,50).OnClick(func(){inputBuffer.Append('5')}),
									g.Button("6").Size(50,50).OnClick(func(){inputBuffer.Append('6')}),
								),
							),
							g.Button("-").Size(50,50).OnClick(func(){callStackWord(s.Sub)}),
							g.Button("Ceil").Size(50,50).OnClick(func(){callStackWord(s.Ceil)}),
						),
						g.Row(
							g.Button("Dup").Size(50,50).OnClick(func(){callStackWord(s.Dup)}),
							g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
								g.Row(
									g.Button("1").Size(50,50).OnClick(func(){inputBuffer.Append('1')}),
									g.Button("2").Size(50,50).OnClick(func(){inputBuffer.Append('2')}),
									g.Button("3").Size(50,50).OnClick(func(){inputBuffer.Append('3')}),
								),
							),
							g.Button("+").Size(50,50).OnClick(func(){callStackWord(s.Add)}),
							g.Button("+/-").Size(50,50).OnClick(func(){callStackWord(s.Inv)}),
						),
						g.Row(
							g.Button("Drop").Size(50,50).OnClick(func(){callStackWord(s.Drp)}),
							g.Button(".").Size(50,50).OnClick(func(){inputBuffer.Append('.')}),
							g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
								g.Button("0").Size(50,50).OnClick(func(){inputBuffer.Append('0')}),
							),
							g.Style().SetColor(g.StyleColorButton, color.RGBA{51, 102, 55, 255}).To(
								g.Button("Enter").Size(165,50).OnClick(func(){inputBuffer.Store(); outputDisplay = s.String()}),
							),
						),
					),
				),
			}, g.Layout{
				g.Child("Button Section").Layout(
					g.Row(
						g.Style().SetColor(g.StyleColorButton, color.RGBA{150, 55, 55, 255}).To(
							g.Button("Clear").Size(50,50).OnClick(func(){callStackWord(s.Clear)}),
						),
						g.Button("Delete").Size(50,50).OnClick(func(){inputBuffer.Delete()}),
						g.Button("Round").Size(50,50).OnClick(func(){callStackWord(s.Round)}),
						g.Button("^").Size(50,50).OnClick(func(){callStackWord(s.Pow)}),
						g.Button("÷").Size(50,50).OnClick(func(){callStackWord(s.Div)}),
						g.Button("Sqrt").Size(50,50).OnClick(func(){callStackWord(s.Sqt)}),
					),
					g.Row(
						g.Button("Over").Size(50,50).OnClick(func(){callStackWord(s.Ovr)}),
						g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
							g.Row(
								g.Button("7").Size(50,50).OnClick(func(){inputBuffer.Append('7')}),
								g.Button("8").Size(50,50).OnClick(func(){inputBuffer.Append('8')}),
								g.Button("9").Size(50,50).OnClick(func(){inputBuffer.Append('9')}),
							),
						),
						g.Button("×").Size(50,50).OnClick(func(){callStackWord(s.Mul)}),
						g.Button("Floor").Size(50,50).OnClick(func(){callStackWord(s.Floor)}),
					),
					g.Row(
						g.Button("Swap").Size(50,50).OnClick(func(){callStackWord(s.Swp)}),
						g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
							g.Row(
								g.Button("4").Size(50,50).OnClick(func(){inputBuffer.Append('4')}),
								g.Button("5").Size(50,50).OnClick(func(){inputBuffer.Append('5')}),
								g.Button("6").Size(50,50).OnClick(func(){inputBuffer.Append('6')}),
							),
						),
						g.Button("-").Size(50,50).OnClick(func(){callStackWord(s.Sub)}),
						g.Button("Ceil").Size(50,50).OnClick(func(){callStackWord(s.Ceil)}),
					),
					g.Row(
						g.Button("Dup").Size(50,50).OnClick(func(){callStackWord(s.Dup)}),
						g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
							g.Row(
								g.Button("1").Size(50,50).OnClick(func(){inputBuffer.Append('1')}),
								g.Button("2").Size(50,50).OnClick(func(){inputBuffer.Append('2')}),
								g.Button("3").Size(50,50).OnClick(func(){inputBuffer.Append('3')}),
							),
						),
						g.Button("+").Size(50,50).OnClick(func(){callStackWord(s.Add)}),
						g.Button("+/-").Size(50,50).OnClick(func(){callStackWord(s.Inv)}),
					),
					g.Row(
						g.Button("Drop").Size(50,50).OnClick(func(){callStackWord(s.Drp)}),
						g.Button(".").Size(50,50).OnClick(func(){inputBuffer.Append('.')}),
						g.Style().SetColor(g.StyleColorButton, color.RGBA{205, 150, 30, 200}).To(
							g.Button("0").Size(50,50).OnClick(func(){inputBuffer.Append('0')}),
						),
						g.Style().SetColor(g.StyleColorButton, color.RGBA{51, 102, 55, 255}).To(
							g.Button("Enter").Size(165,50).OnClick(func(){inputBuffer.Store(); outputDisplay = s.String()}),
						),
					),
				),
			}),
		),
	)
}

func Exit() {
	os.Exit(0)
}

func main() {
	wnd = g.NewMasterWindow("gnums", MasterWidth+MasterWidth/2, 385, g.MasterWindowFlagsNotResizable).RegisterKeyboardShortcuts(
		g.WindowShortcut{Key: g.KeyQ, Modifier: g.ModControl, Callback: Exit},
		g.WindowShortcut{Key: g.Key0, Callback: func(){inputBuffer.Append('0')}},
		g.WindowShortcut{Key: g.Key1, Callback: func(){inputBuffer.Append('1')}},
		g.WindowShortcut{Key: g.Key2, Callback: func(){inputBuffer.Append('2')}},
		g.WindowShortcut{Key: g.Key3, Callback: func(){inputBuffer.Append('3')}},
		g.WindowShortcut{Key: g.Key4, Callback: func(){inputBuffer.Append('4')}},
		g.WindowShortcut{Key: g.Key5, Callback: func(){inputBuffer.Append('5')}},
		g.WindowShortcut{Key: g.Key6, Callback: func(){inputBuffer.Append('6')}},
		g.WindowShortcut{Key: g.Key7, Callback: func(){inputBuffer.Append('7')}},
		g.WindowShortcut{Key: g.Key8, Callback: func(){inputBuffer.Append('8')}},
		g.WindowShortcut{Key: g.Key9, Callback: func(){inputBuffer.Append('9')}},
		g.WindowShortcut{Key: g.KeyPeriod, Callback: func(){inputBuffer.Append('.')}},
		g.WindowShortcut{Key: g.KeyMinus, Callback: func(){callStackWord(s.Sub)}},
		g.WindowShortcut{Key: g.KeyR, Callback: func(){callStackWord(s.Round)}},
		g.WindowShortcut{Key: g.KeyC, Callback: func(){callStackWord(s.Ceil)}},
		g.WindowShortcut{Key: g.KeyF, Callback: func(){callStackWord(s.Floor)}},
		g.WindowShortcut{Key: g.KeyQ, Callback: func(){callStackWord(s.Sqt)}},
		g.WindowShortcut{Key: g.KeyS, Callback: func(){callStackWord(s.Swp)}},
		g.WindowShortcut{Key: g.KeyO, Callback: func(){callStackWord(s.Ovr)}},
		g.WindowShortcut{Key: g.KeyD, Callback: func(){callStackWord(s.Drp)}},
		g.WindowShortcut{Key: g.KeyU, Callback: func(){callStackWord(s.Dup)}},
		g.WindowShortcut{Key: g.KeyEqual, Modifier: g.ModShift, Callback: func(){callStackWord(s.Add)}},
		g.WindowShortcut{Key: g.Key8, Modifier: g.ModShift, Callback: func(){callStackWord(s.Mul)}},
		g.WindowShortcut{Key: g.KeySlash, Callback: func(){callStackWord(s.Div)}},
		g.WindowShortcut{Key: g.Key6, Modifier: g.ModShift, Callback: func(){callStackWord(s.Pow)}},
		g.WindowShortcut{Key: g.KeyEnter, Callback: func(){inputBuffer.Store(); outputDisplay = s.String()}},
		g.WindowShortcut{Key: g.KeyTab, Callback: func(){ShowStack = !ShowStack; ToggleScreenSize()}},
		g.WindowShortcut{Key: g.KeyEscape, Callback: func(){callStackWord(s.Clear)}},
		g.WindowShortcut{Key: g.Key1, Modifier: g.ModShift, Callback: func(){callStackWord(s.Inv)}},
		g.WindowShortcut{Key: g.KeyBackspace, Callback: func(){inputBuffer.Delete()}},
	)
	wnd.Run(loop)
}