package day22

type Space struct {
	MaxZ           uint
	SettledOnZ     [][]*Block
	MaxSettledOnXY map[XY]*Block
	UnsettledByZ   [][]*Block
}

func NewSpace(blocksByZ [][]*Block) Space {
	return Space{
		UnsettledByZ:   blocksByZ,
		MaxZ:           uint(len(blocksByZ)),
		MaxSettledOnXY: make(map[XY]*Block),
		SettledOnZ:     make([][]*Block, len(blocksByZ)),
	}
}

// settle all blocks in Z, remove Z from UnsettledByZ
func (s *Space)SettleZ(z uint) {

}

// for the block:
// check all XY in MaxSettledOnXY
// if there are any settled blocks on these XY, find max of their Z
// for all blocks with that Z - add block to their 'supports'
// set Z for block to Z+1, settled to true
// add block as highest settled for all the XY
// add block to MaxSettledOnXY
func (s *Space)SettleBlock(block *Block) {
	underZMax := uint(0)
	underZBlocks := make([]*Block, 0)
	for _, xy := range block.getXY() {
		underBlock, found := s.MaxSettledOnXY[xy]
		// if block.NameNum
		if found {
			if underBlock.Z > underZMax {
				underZBlocks = []*Block{underBlock}
				underZMax = underBlock.Z
			} else if underBlock.Z == underZMax {
				underZBlocks = append(underZBlocks, underBlock)
			}
		}
		s.MaxSettledOnXY[xy] = block
	}

	for _, settledUnderblock := range underZBlocks {
		settledUnderblock.Supports = append(settledUnderblock.Supports, block)
	}

	block.Z = underZMax + 1
	block.IsSettled = true

	s.SettledOnZ[block.Z] = append(s.SettledOnZ[block.Z], block)
}