import { useControllableState } from '@fluentui/react-utilities';
import { ImmutableMap } from '../../utils/ImmutableMap';
import * as React from 'react';
import { createCheckedItems } from '../../utils/createCheckedItems';
export function useFlatControllableCheckedItems(props, headlessTree) {
    return useControllableState({
        initialState: ImmutableMap.empty,
        state: React.useMemo(()=>props.selectionMode ? props.checkedItems && createCheckedItems(props.checkedItems) : undefined, [
            props.checkedItems,
            props.selectionMode
        ]),
        defaultState: props.defaultCheckedItems ? ()=>initializeCheckedItems(props, headlessTree) : undefined
    });
}
export function createNextFlatCheckedItems(data, previousCheckedItems, headlessTree) {
    if (data.selectionMode === 'single') {
        return ImmutableMap.from([
            [
                data.value,
                data.checked
            ]
        ]);
    }
    const treeItem = headlessTree.get(data.value);
    if (!treeItem) {
        if (process.env.NODE_ENV !== 'production') {
            // eslint-disable-next-line no-console
            console.error(`@fluentui/react-tree [useHeadlessFlatTree]:
Tree item ${data.value} not found.`);
        }
        return previousCheckedItems;
    }
    let nextCheckedItems = previousCheckedItems;
    for (const children of headlessTree.subtree(data.value)){
        nextCheckedItems = nextCheckedItems.set(children.value, data.checked);
    }
    nextCheckedItems = nextCheckedItems.set(data.value, data.checked);
    let isAncestorsMixed = false;
    for (const parent of headlessTree.ancestors(treeItem.value)){
        // if one parent is mixed, all ancestors are mixed
        if (isAncestorsMixed) {
            nextCheckedItems = nextCheckedItems.set(parent.value, 'mixed');
            continue;
        }
        let checkedChildrenAmount = 0;
        for (const child of headlessTree.children(parent.value)){
            if ((nextCheckedItems.get(child.value) || false) === data.checked) {
                checkedChildrenAmount++;
            }
        }
        // if all children are checked, parent is checked
        if (checkedChildrenAmount === parent.childrenValues.length) {
            nextCheckedItems = nextCheckedItems.set(parent.value, data.checked);
        } else {
            // if one parent is mixed, all ancestors are mixed
            isAncestorsMixed = true;
            nextCheckedItems = nextCheckedItems.set(parent.value, 'mixed');
        }
    }
    return nextCheckedItems;
}
function initializeCheckedItems(props, headlessTree) {
    if (!props.selectionMode) {
        return ImmutableMap.empty;
    }
    let state = createCheckedItems(props.defaultCheckedItems);
    // if selectionMode is multiselect, we need to calculate the checked state of all children
    // and ancestors of the defaultCheckedItems
    if (props.selectionMode === 'multiselect') {
        for (const [value, checked] of state){
            state = createNextFlatCheckedItems({
                value,
                checked,
                selectionMode: props.selectionMode
            }, state, headlessTree);
        }
    }
    return state;
}