package mdb

type BTreeIterator[T any] struct {
	out     chan *T
	close   chan struct{}
	current *T
}

func newBTreeIterator[T any]() *BTreeIterator[T] {
	return &BTreeIterator[T]{
		out:   make(chan *T),
		close: make(chan struct{}, 1),
	}
}

func (iter *BTreeIterator[T]) each(i *T) bool {
	select {
	case iter.out <- i:
		return true
	case <-iter.close:
		return false
	}
}

func (iter *BTreeIterator[T]) done() {
	close(iter.out)
}

func (iter *BTreeIterator[T]) Next() bool {
	val, ok := <-iter.out
	if ok {
		iter.current = val
		return true
	}
	return false
}

func (iter *BTreeIterator[T]) Close() {
	iter.close <- struct{}{}
}

func (iter *BTreeIterator[T]) Value() T {
	return *iter.current
}