threedom/threedom/src/main/kotlin/me/eater/threedom/utils/MutableOrderedSetListIterator.kt

package me.eater.threedom.utils

class MutableOrderedSetListIterator<T>(private val collection: OrderedSet<T>, private var index: Int = 0) :
    MutableListIterator<T> {

    override fun hasPrevious() = collection.size > (index - 1) && index > 1

    override fun nextIndex() = index + 1
    override fun previous(): T {
        if (!hasPrevious()) {
            throw NoSuchElementException()
        }

        index = previousIndex()
        return collection[index]
    }

    override fun previousIndex() = index - 1
    override fun add(element: T) {
        collection.add(index, element)
    }

    override fun hasNext() = nextIndex() < collection.size

    override fun next(): T {
        if (!hasNext()) {
            throw NoSuchElementException()
        }

        index = nextIndex()
        return collection[index]
    }

    override fun remove() {
        collection.removeAt(index)

        if (index > 0) {
            index -= 1
        }
    }

    override fun set(element: T) {
        collection[index] = element
    }
}