package d2ui

import (
	"fmt"
	"image"
	"log"

	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2enum"
	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2interface"
	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2resource"
	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2util"
	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2gui"
)

// ButtonType defines the type of button
type ButtonType int

// ButtonType constants
const (
	ButtonTypeWide     ButtonType = 1
	ButtonTypeMedium   ButtonType = 2
	ButtonTypeNarrow   ButtonType = 3
	ButtonTypeCancel   ButtonType = 4
	ButtonTypeTall     ButtonType = 5
	ButtonTypeShort    ButtonType = 6
	ButtonTypeOkCancel ButtonType = 7

	// Game UI

	ButtonTypeSkill              ButtonType = 7
	ButtonTypeRun                ButtonType = 8
	ButtonTypeMenu               ButtonType = 9
	ButtonTypeGoldCoin           ButtonType = 10
	ButtonTypeClose              ButtonType = 11
	ButtonTypeSecondaryInvHand   ButtonType = 12
	ButtonTypeMinipanelCharacter ButtonType = 13
	ButtonTypeMinipanelInventory ButtonType = 14
	ButtonTypeMinipanelSkill     ButtonType = 15
	ButtonTypeMinipanelAutomap   ButtonType = 16
	ButtonTypeMinipanelMessage   ButtonType = 17
	ButtonTypeMinipanelQuest     ButtonType = 18
	ButtonTypeMinipanelMen       ButtonType = 19
	ButtonTypeSquareClose        ButtonType = 20
)

const (
	greyAlpha100     = 0x646464ff
	lightGreyAlpha75 = 0x808080c3
)

// ButtonLayout defines the type of buttons
type ButtonLayout struct {
	ResourceName     string
	PaletteName      string
	FontPath         string
	XSegments        int
	YSegments        int
	BaseFrame        int
	DisabledFrame    int
	ClickableRect    *image.Rectangle
	TextOffset       int
	Toggleable       bool
	AllowFrameChange bool
}

const (
	buttonWideSegmentsX     = 2
	buttonWideSegmentsY     = 1
	buttonWideDisabledFrame = -1
	buttonWideTextOffset    = 1

	buttonShortSegmentsX     = 1
	buttonShortSegmentsY     = 1
	buttonShortDisabledFrame = -1
	buttonShortTextOffset    = -1

	buttonMediumSegmentsX = 1
	buttonMediumSegmentsY = 1

	buttonTallSegmentsX  = 1
	buttonTallSegmentsY  = 1
	buttonTallTextOffset = 5

	buttonOkCancelSegmentsX     = 1
	buttonOkCancelSegmentsY     = 1
	buttonOkCancelDisabledFrame = -1

	buttonBuySellSegmentsX     = 1
	buttonBuySellSegmentsY     = 1
	buttonBuySellDisabledFrame = 1

	buttonRunSegmentsX     = 1
	buttonRunSegmentsY     = 1
	buttonRunDisabledFrame = -1

	pressedButtonOffset = 2
)

func getButtonLayouts() map[ButtonType]ButtonLayout {
	return map[ButtonType]ButtonLayout{
		ButtonTypeWide: {
			XSegments:        buttonWideSegmentsX,
			YSegments:        buttonWideSegmentsY,
			DisabledFrame:    buttonWideDisabledFrame,
			TextOffset:       buttonWideTextOffset,
			ResourceName:     d2resource.WideButtonBlank,
			PaletteName:      d2resource.PaletteUnits,
			FontPath:         d2resource.FontExocet10,
			AllowFrameChange: true,
		},
		ButtonTypeShort: {
			XSegments:        buttonShortSegmentsX,
			YSegments:        buttonShortSegmentsY,
			DisabledFrame:    buttonShortDisabledFrame,
			TextOffset:       buttonShortTextOffset,
			ResourceName:     d2resource.ShortButtonBlank,
			PaletteName:      d2resource.PaletteUnits,
			FontPath:         d2resource.FontRediculous,
			AllowFrameChange: true,
		},
		ButtonTypeMedium: {
			XSegments:        buttonMediumSegmentsX,
			YSegments:        buttonMediumSegmentsY,
			ResourceName:     d2resource.MediumButtonBlank,
			PaletteName:      d2resource.PaletteUnits,
			FontPath:         d2resource.FontExocet10,
			AllowFrameChange: true,
		},
		ButtonTypeTall: {
			XSegments:        buttonTallSegmentsX,
			YSegments:        buttonTallSegmentsY,
			TextOffset:       buttonTallTextOffset,
			ResourceName:     d2resource.TallButtonBlank,
			PaletteName:      d2resource.PaletteUnits,
			FontPath:         d2resource.FontExocet10,
			AllowFrameChange: true,
		},
		ButtonTypeOkCancel: {
			XSegments:        buttonOkCancelSegmentsX,
			YSegments:        buttonOkCancelSegmentsY,
			DisabledFrame:    buttonOkCancelDisabledFrame,
			ResourceName:     d2resource.CancelButton,
			PaletteName:      d2resource.PaletteUnits,
			FontPath:         d2resource.FontRediculous,
			AllowFrameChange: true,
		},
		ButtonTypeRun: {
			XSegments:        buttonRunSegmentsX,
			YSegments:        buttonRunSegmentsY,
			DisabledFrame:    buttonRunDisabledFrame,
			ResourceName:     d2resource.RunButton,
			PaletteName:      d2resource.PaletteSky,
			Toggleable:       true,
			FontPath:         d2resource.FontRediculous,
			AllowFrameChange: true,
		},
		ButtonTypeSquareClose: {
			XSegments:        buttonBuySellSegmentsX,
			YSegments:        buttonBuySellSegmentsY,
			DisabledFrame:    buttonBuySellDisabledFrame,
			ResourceName:     d2resource.BuySellButton,
			PaletteName:      d2resource.PaletteUnits,
			Toggleable:       true,
			FontPath:         d2resource.Font30,
			AllowFrameChange: true,
			BaseFrame:        10,
		},
	}
}

var _ Widget = &Button{} // static check to ensure button implements widget

// Button defines a standard wide UI button
type Button struct {
	manager               *UIManager
	buttonLayout          ButtonLayout
	normalSurface         d2interface.Surface
	pressedSurface        d2interface.Surface
	toggledSurface        d2interface.Surface
	pressedToggledSurface d2interface.Surface
	disabledSurface       d2interface.Surface
	x                     int
	y                     int
	width                 int
	height                int
	onClick               func()
	enabled               bool
	visible               bool
	pressed               bool
	toggled               bool
}

// NewButton creates an instance of Button
func (ui *UIManager) NewButton(buttonType ButtonType, text string) *Button {
	btn := &Button{
		width:   0,
		height:  0,
		visible: true,
		enabled: true,
		pressed: false,
	}

	buttonLayout := getButtonLayouts()[buttonType]
	btn.buttonLayout = buttonLayout
	lbl := ui.NewLabel(buttonLayout.FontPath, d2resource.PaletteUnits)

	lbl.SetText(text)
	lbl.Color[0] = d2util.Color(greyAlpha100)
	lbl.Alignment = d2gui.HorizontalAlignCenter

	buttonSprite, err := ui.NewSprite(buttonLayout.ResourceName, buttonLayout.PaletteName)
	if err != nil {
		log.Print(err)
		return nil
	}

	for i := 0; i < buttonLayout.XSegments; i++ {
		w, _, err := buttonSprite.GetFrameSize(i)
		if err != nil {
			log.Print(err)
			return nil
		}

		btn.width += w
	}

	for i := 0; i < buttonLayout.YSegments; i++ {
		_, h, err := buttonSprite.GetFrameSize(i * buttonLayout.YSegments)
		if err != nil {
			log.Print(err)
			return nil
		}

		btn.height += h
	}

	btn.normalSurface, err = ui.renderer.NewSurface(btn.width, btn.height, d2enum.FilterNearest)
	if err != nil {
		log.Print(err)
		return nil
	}

	buttonSprite.SetPosition(0, 0)
	buttonSprite.SetEffect(d2enum.DrawEffectModulate)

	ui.addWidget(btn) // important that this comes before renderFrames!

	btn.renderFrames(buttonSprite, &buttonLayout, lbl)

	return btn
}

func (v *Button) renderFrames(btnSprite *Sprite, btnLayout *ButtonLayout, label *Label) {
	var err error

	totalButtonTypes := btnSprite.GetFrameCount() / (btnLayout.XSegments * btnLayout.YSegments)

	err = btnSprite.RenderSegmented(v.normalSurface, btnLayout.XSegments, btnLayout.YSegments, btnLayout.BaseFrame)

	if err != nil {
		fmt.Printf("failed to render button normalSurface, err: %v\n", err)
	}

	_, labelHeight := label.GetSize()
	textY := half(v.height - labelHeight)
	xOffset := half(v.width)

	label.SetPosition(xOffset, textY)
	label.Render(v.normalSurface)

	if btnLayout.AllowFrameChange {
		frameOffset := 0
		xSeg, ySeg, baseFrame := btnLayout.XSegments, btnLayout.YSegments, btnLayout.BaseFrame

		totalButtonTypes--
		if totalButtonTypes > 0 { // button has more than one type
			frameOffset++

			v.pressedSurface, err = v.manager.renderer.NewSurface(v.width, v.height,
				d2enum.FilterNearest)
			if err != nil {
				log.Print(err)
			}

			err = btnSprite.RenderSegmented(v.pressedSurface, xSeg, ySeg, baseFrame+frameOffset)
			if err != nil {
				fmt.Printf("failed to render button pressedSurface, err: %v\n", err)
			}

			label.SetPosition(xOffset-pressedButtonOffset, textY+pressedButtonOffset)
			label.Render(v.pressedSurface)
		}

		if btnLayout.ResourceName == d2resource.BuySellButton {
			// Without returning early, the button UI gets all subsequent (unrelated) frames stacked on top
			// Only 2 frames from this sprite are applicable to the button in question
			// The presentation is incorrect without this hack
			return
		}

		totalButtonTypes--
		if totalButtonTypes > 0 { // button has more than two types
			frameOffset++

			v.toggledSurface, err = v.manager.renderer.NewSurface(v.width, v.height,
				d2enum.FilterNearest)
			if err != nil {
				log.Print(err)
			}

			err = btnSprite.RenderSegmented(v.pressedSurface, xSeg, ySeg, baseFrame+frameOffset)
			if err != nil {
				fmt.Printf("failed to render button toggledSurface, err: %v\n", err)
			}

			label.SetPosition(xOffset, textY)
			label.Render(v.toggledSurface)
		}

		totalButtonTypes--
		if totalButtonTypes > 0 { // button has more than three types
			frameOffset++

			v.pressedToggledSurface, err = v.manager.renderer.NewSurface(v.width, v.height,
				d2enum.FilterNearest)
			if err != nil {
				log.Print(err)
			}

			err = btnSprite.RenderSegmented(v.pressedSurface, xSeg, ySeg, baseFrame+frameOffset)
			if err != nil {
				fmt.Printf("failed to render button pressedToggledSurface, err: %v\n", err)
			}

			label.SetPosition(xOffset, textY)
			label.Render(v.pressedToggledSurface)
		}

		if btnLayout.DisabledFrame != -1 {
			v.disabledSurface, err = v.manager.renderer.NewSurface(v.width, v.height,
				d2enum.FilterNearest)
			if err != nil {
				log.Print(err)
			}

			err = btnSprite.RenderSegmented(v.disabledSurface, xSeg, ySeg, btnLayout.DisabledFrame)
			if err != nil {
				fmt.Printf("failed to render button disabledSurface, err: %v\n", err)
			}

			label.SetPosition(xOffset, textY)
			label.Render(v.disabledSurface)
		}
	}
}

// bindManager binds the button to the UI manager
func (v *Button) bindManager(manager *UIManager) {
	v.manager = manager
}

// OnActivated defines the callback handler for the activate event
func (v *Button) OnActivated(callback func()) {
	v.onClick = callback
}

// Activate calls the on activated callback handler, if any
func (v *Button) Activate() {
	if v.onClick == nil {
		return
	}

	v.onClick()
}

// Render renders the button
func (v *Button) Render(target d2interface.Surface) error {
	target.PushFilter(d2enum.FilterNearest)
	defer target.Pop()

	target.PushTranslation(v.x, v.y)
	defer target.Pop()

	var err error

	switch {
	case !v.enabled:
		target.PushColor(d2util.Color(lightGreyAlpha75))
		defer target.Pop()
		err = target.Render(v.disabledSurface)
	case v.toggled && v.pressed:
		err = target.Render(v.pressedToggledSurface)
	case v.pressed:
		err = target.Render(v.pressedSurface)
	case v.toggled:
		err = target.Render(v.toggledSurface)
	default:
		err = target.Render(v.normalSurface)
	}

	if err != nil {
		fmt.Printf("failed to render button surface, err: %v\n", err)
	}

	return nil
}

// Toggle negates the toggled state of the button
func (v *Button) Toggle() {
	v.toggled = !v.toggled
}

// Advance advances the button state
func (v *Button) Advance(_ float64) error {
	return nil
}

// GetEnabled returns the enabled state
func (v *Button) GetEnabled() bool {
	return v.enabled
}

// SetEnabled sets the enabled state
func (v *Button) SetEnabled(enabled bool) {
	v.enabled = enabled
}

// GetSize returns the size of the button
func (v *Button) GetSize() (width, height int) {
	return v.width, v.height
}

// SetPosition moves the button
func (v *Button) SetPosition(x, y int) {
	v.x = x
	v.y = y
}

// GetPosition returns the location of the button
func (v *Button) GetPosition() (x, y int) {
	return v.x, v.y
}

// GetVisible returns the visibility of the button
func (v *Button) GetVisible() bool {
	return v.visible
}

// SetVisible sets the visibility of the button
func (v *Button) SetVisible(visible bool) {
	v.visible = visible
}

// GetPressed returns the pressed state of the button
func (v *Button) GetPressed() bool {
	return v.pressed
}

// SetPressed sets the pressed state of the button
func (v *Button) SetPressed(pressed bool) {
	v.pressed = pressed
}

func half(n int) int {
	return n / 2
}