package ui

import (
	"github.com/hajimehoshi/ebiten"

	"code.ur.gs/lupine/ordoor/internal/menus"
)

// Setup handlers know how to handle each type of widget.
// TODO: it might be better to have a Widget interface and different structs for
// each type of widget, but let's see how far we can push this model.
var setupHandlers = map[menus.MenuType]func(i *Interface, r *menus.Record) error{
	menus.TypeStatic:          handleStatic,
	menus.TypeMenu:            nil,
	menus.TypeButton:          handleButton,
	menus.TypeInvokeButton:    handleInvokeButton,
	menus.TypeOverlay:         nil, // FIXME: What's it for?
	menus.TypeHypertext:       handleHypertext,
	menus.TypeCheckbox:        handleCheckbox,
	menus.TypeAnimationSample: nil, // FIXME: handle this
	menus.TypeMainButton:      handleMainButton,
	menus.TypeSlider:          nil, // FIXME: handle this
}

func handleStatic(i *Interface, record *menus.Record) error {
	spriteId := record.Share

	// FIXME: SpriteID takes precedence over SHARE if present, but is that right?
	if len(record.SpriteId) > 0 && record.SpriteId[0] != -1 {
		spriteId = record.SpriteId[0]
	}

	sprite, err := i.menu.Sprite(spriteId)
	if err != nil {
		return err
	}

	static := &staticElement{
		bounds:  sprite.Rect,
		image:   sprite.Image,
		tooltip: record.Desc,
	}

	i.static = append(i.static, static)

	return nil
}

// A hypertext is static, but we should only take the bounds from "SHARE", not
// display anything.
func handleHypertext(i *Interface, record *menus.Record) error {
	sprite, err := i.menu.Sprite(record.Share)
	if err != nil {
		return err
	}

	static := &staticElement{
		bounds:  sprite.Rect,
		image:   nil,
		tooltip: record.Desc,
	}

	i.static = append(i.static, static)

	return nil
}

// A checkbox has 3 sprites, and 3 states: unchecked, checked, disabled.
func handleCheckbox(i *Interface, record *menus.Record) error {
	widget, err := i.widgetFromRecord(record, record.Share)
	if err != nil {
		return err
	}

	unchecked := widget.sprite
	disabled, err := i.menu.Sprite(record.Share + 1)
	if err != nil {
		return err
	}
	checked, err := i.menu.Sprite(record.Share + 2)
	if err != nil {
		return err
	}

	widget.Value = "0"

	widget.OnMouseClick = func() {
		if widget.Value == "1" { // Click disables
			widget.Value = "0"
		} else { // Click enables
			widget.Value = "1"
		}
	}

	widget.disabledImage = disabled.Image
	widget.valueToImage = func() *ebiten.Image {
		if widget.Value == "1" {
			return checked.Image
		}

		return unchecked.Image
	}

	i.widgets = append(i.widgets, widget)

	return nil
}

func handleButton(i *Interface, record *menus.Record) error {
	spriteId := record.SpriteId[0]
	widget, err := i.widgetFromRecord(record, spriteId)
	if err != nil {
		return err
	}

	pressed, err := i.menu.Sprite(spriteId + 1)
	if err != nil {
		return err
	}

	disabled, err := i.menu.Sprite(spriteId + 2)
	if err != nil {
		return err
	}

	widget.mouseButtonDownImage = pressed.Image
	widget.disabledImage = disabled.Image

	i.widgets = append(i.widgets, widget)

	return nil
}

func handleInvokeButton(i *Interface, record *menus.Record) error {
	widget, err := i.widgetFromRecord(record, record.Share)
	if err != nil {
		return err
	}

	pressed, err := i.menu.Sprite(record.Share + 1)
	if err != nil {
		return err
	}

	disabled, err := i.menu.Sprite(record.Share + 2)
	if err != nil {
		return err
	}

	widget.mouseButtonDownImage = pressed.Image
	widget.disabledImage = disabled.Image

	i.widgets = append(i.widgets, widget)

	return nil
}

// A main button is quite complex. It has 3 main sprites and a hover animation
func handleMainButton(i *Interface, record *menus.Record) error {
	widget, err := i.widgetFromRecord(record, record.Share)
	if err != nil {
		return err
	}

	pressed, err := i.menu.Sprite(record.Share + 1)
	if err != nil {
		return err
	}

	disabled, err := i.menu.Sprite(record.Share + 2)
	if err != nil {
		return err
	}

	hovers, err := i.menu.Images(record.SpriteId[0], record.DrawType)
	if err != nil {
		return err
	}

	widget.mouseButtonDownImage = pressed.Image
	widget.disabledImage = disabled.Image
	widget.hoverAnimation = hovers

	i.widgets = append(i.widgets, widget)

	return nil
}

// Widgets need a bounding box determined by a sprite. Different widgets specify
// their sprites in different attributes, so pass in the right sprite externally
func (i *Interface) widgetFromRecord(record *menus.Record, spriteId int) (*Widget, error) {
	sprite, err := i.menu.Sprite(spriteId)
	if err != nil {
		return nil, err
	}

	var path []int
	for r := record; r != nil; r = r.Parent {
		path = append([]int{r.Id}, path...)
	}

	widget := &Widget{
		Bounds:  sprite.Rect,
		Tooltip: record.Desc,
		path:    path,
		record:  record,
		sprite:  sprite,
	}

	return widget, nil
}