import type { GridRowId } from '../types'
import type { Collection } from './types'

const getAllParents = (
    parentLookup: Map<GridRowId, GridRowId>,
    id: null | GridRowId
) => {
    const parentIds: GridRowId[] = []

    if (id === null) {
        return parentIds
    }

    let parentId: null | GridRowId = parentLookup.get(id) ?? null

    while (parentId !== null) {
        parentIds.push(parentId)
        parentId = parentLookup.get(parentId) ?? null
    }
    return parentIds
}

export const buildParentLookup = (collection: Collection) => {
    const parentLookup = new Map<GridRowId, GridRowId>()

    const collect = (nodeId: GridRowId, parentId: GridRowId | null) => {
        if (parentId) {
            parentLookup.set(nodeId, parentId)
        }

        const meta = collection.meta.get(nodeId)

        if (meta?.children?.length) {
            meta.children.forEach((childId) => collect(childId, nodeId))
        }
    }

    collection.ids.forEach((id) => collect(id, null))

    return {
        parentLookup,
        getAllParents(id: null | GridRowId) {
            return getAllParents(parentLookup, id)
        },
    }
}