package stacks

import (
	"git.vezzani.net/ben/games/common/elements/v1"
	"git.vezzani.net/ben/games/common/elements/v1/mouse"

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

func New(ops ...OptFunc) elements.InitFunc {
	return func() elements.Element {
		s := Stack{}
		for op := range ops {
			ops[op](&s)
		}

		s.children = make([]elements.Element, len(s.childrenInit))
		var cw, ch int
		anchor := s.anchor
		for i := range s.childrenInit {
			s.children[i] = s.childrenInit[i]()
			s.children[i].SetAnchor(anchor)
			cw, ch = s.children[i].Size()
			if s.horizontal {
				anchor.X += cw
			} else {
				anchor.Y += ch
			}
		}

		return &s
	}
}

type Stack struct {
	mouse.NopHandler
	anchor       elements.Point
	horizontal   bool
	childrenInit []elements.InitFunc
	children     []elements.Element
}

func (s *Stack) SetAnchor(a elements.Point) {
	d := s.anchor.Delta(a)
	for i := range s.Children() {
		s.Children()[i].SetAnchor(s.Children()[i].Anchor().Add(d))
	}
	s.anchor = a
}

func (s *Stack) Anchor() elements.Point {
	return s.anchor
}

func (s *Stack) Size() (w, h int) {
	var cw, ch int
	for i := range s.children {
		cw, ch = s.children[i].Size()
		if s.horizontal {
			w += cw
			if h < ch {
				h = ch
			}
		} else {
			h += ch
			if w < cw {
				w = cw
			}
		}
	}

	return
}

func (s *Stack) Draw(image *ebiten.Image) {
	for i := range s.children {
		s.children[i].Draw(image)
	}
}

func (s *Stack) Children() []elements.Element {
	return s.children
}