BlackDice/b3-chief

/**
 * @module Chief
 */

import { compose } from 'stampit'
import warning from 'warning'
import invariant from 'invariant'
import { oneLine } from 'common-tags'

import Store from './Store'
import BehaviorList from './BehaviorList'
import setupModelList from './core/ModelList'
import setupTreeModel from './TreeModel'

import { BEHAVIOR_TYPE } from './const'

const TreeList = compose(
    Store, BehaviorList, {
        init: initializeTreeList,
        methods: {
            createTree,
            addTree,
            hasTree,
            getTree,
            destroyTree,
            listTrees,
        },
    },
)

const bList = Symbol('list of trees')

function initializeTreeList() {
    const getBehaviorMaxChildren = (behaviorId) => {
        const behavior = this.getBehavior(behaviorId)
        if (behavior === null) {
            return 0
        }
        switch (behavior.getType()) {
        case BEHAVIOR_TYPE.LEAF: return 0
        case BEHAVIOR_TYPE.SUBTREE: return 0
        case BEHAVIOR_TYPE.DECORATOR: return 1
        default: return behavior.getMaxChildren() || Infinity
        }
    }

    const TreeModel = setupTreeModel(this.store).methods({ getBehaviorMaxChildren })

    this[bList] = setupModelList(
        TreeModel,
        this.store.select(this.store.selectors.trees),
    )
    this[bList].attachCountProperty(this, 'treeCount')
}

/**
 * Create a new tree based on passed option.
 * Useful to override when tree model needs to be extended.
 * @param {Tree} tree
 * @return {TreeModel}
 */
function addTree(tree) {
    return this[bList].create(tree)
}

/**
 * Creates new tree and adds it to the list.
 * @param {String} treeName
 * @param {String=} treeDescription
 * @return {TreeModel} created tree
 */
function createTree(treeName, treeDescription = '') {
    invariant(treeName && treeName.length, oneLine`
        Method createTree is expecting name of tree being added.
    `)

    return this.addTree({
        name: treeName,
        description: treeDescription,
    })
}

/**
 * Checks if tree by specified ID exists in the list.
 * @param {Identity} treeId
 * @return {Boolean}
 */
function hasTree(treeId) {
    return this[bList].has(treeId)
}

/**
 * Returns tree model by specified ID
 * @param  {Identity} treeId
 * @return {TreeModel} Returns NULL if tree not found
 */
function getTree(treeId) {
    return this[bList].get(treeId)
}

/**
 * Removes tree by specified ID from the list.
 * @param  {string} treeId
 */
function destroyTree(treeId) {
    const treeModel = this.getTree(treeId)

    if (treeModel === null) {
        warning(false, oneLine`
            Trying to remove tree with id %s that is not on the list.
        `, treeId)
    } else {
        treeModel.destroy()
    }
}

/**
 * Returns list of existing trees.
 * @return {TreeModel[]}
 */
function listTrees() {
    return this[bList].getAll()
}

export default TreeList