package main

import "fmt"

type Sprite struct {
	node        *Node
	Img         string
	Animated    bool
	FrameRate   int
	Delay       int
	RandomStart bool
}

func (s *Sprite) Parse(node *Node) error {
	if node.Key() != "sprite" {
		return fmt.Errorf("expected 'sprite' node, invalid node")
	}
	s.Img = node.Value()
	s.node = node
	if node.Len() != 0 {
		s.Animated = true
		for _, kid := range node.Children {
			switch kid.Key() {
			case "frame rate", "frame time":
				s.FrameRate = kid.ValueInt()
			case "delay":
				s.Delay = kid.ValueInt()
			case "random start frame":
				s.RandomStart = true
			}
		}
	}
	return nil
}

func (s *Sprite) Update() error {
	if s.node == nil {
		return fmt.Errorf("no node, sprite")
	}
	s.node.RmAllChildren()
	s.node.SetValue(s.Img)
	if s.Animated {
		n := s.node.NewChild()
		n.Set("frame rate", s.FrameRate)
		n = s.node.NewChild()
		n.Set("delay", s.Delay)
		if s.RandomStart {
			n := s.node.NewChild()
			n.Line = n.Format("random start frame")
		}
	}
	return nil
}