package elements

import (
	"context"

	"github.com/hajimehoshi/ebiten/v2"
)

type MouseState struct {
	X, Y                      int32
	LeftDown, RightDown       bool
	LeftChanged, RightChanged bool
}

const (
	ContainerSizeKey = "container_size"
	ZeroKey          = "zero"
)

type Clickable interface {
	Element
	HandleClick(ctx context.Context, s MouseState) error
}

type Mouseable interface {
	Element
	HandleMouseEnter(ctx context.Context, s MouseState) error
	HandleMouseLeave(ctx context.Context, s MouseState) error
	HandleMouseMove(ctx context.Context, s MouseState) error
	HandleMouseDown(ctx context.Context, s MouseState) error
	HandleMouseUp(ctx context.Context, s MouseState) error
}

type Element interface {
	Draw(ctx context.Context, image *ebiten.Image) error
}

func SetZero(ctx context.Context, x, y float32) context.Context {
	return context.WithValue(ctx, ZeroKey, [2]float32{x, y})
}

func SetContainerSize(ctx context.Context, w, h float32) context.Context {
	return context.WithValue(ctx, ContainerSizeKey, [2]float32{w, h})
}

func GetZero(ctx context.Context) (x, y float32) {
	if v, ok := ctx.Value(ZeroKey).([2]float32); ok {
		return v[0], v[1]
	}
	return 0, 0
}

func GetContainerSize(ctx context.Context) (w, h float32) {
	if s, ok := ctx.Value(ContainerSizeKey).([2]float32); ok {
		return s[0], s[1]
	}
	return 0, 0
}

type mouseHandler struct {
	mouseState     MouseState
	prevMouseState MouseState
}

func (b *mouseHandler) HandleMouseEnter(s MouseState) error {
	b.mouseState = s
	return nil
}

func (b *mouseHandler) HandleMouseLeave(s MouseState) error {
	b.prevMouseState = b.mouseState
	b.mouseState = MouseState{}
	return nil
}

func (b *mouseHandler) HandleMouseMove(s MouseState) error {
	b.prevMouseState = b.mouseState
	b.mouseState = s
	return nil
}

func (b *mouseHandler) HandleMouseDown(s MouseState) error {
	b.prevMouseState = b.mouseState
	b.mouseState = s
	return nil
}

func (b *mouseHandler) HandleMouseUp(s MouseState) error {
	b.prevMouseState = b.mouseState
	b.mouseState = s
	return nil
}