// ref : https://medium.com/weekly-webtips/js-implementing-auto-complete-f4c5a5d5c009 interface Node { value: [] isLeaf: boolean children: Record<string, Node> } export class NcAutocompleteTree { trie: Record<string, any> suggestions: Record<string, any>[] constructor() { this.trie = {} this.suggestions = [] } newNode(): Node { return { value: [], isLeaf: false, children: {}, } } add(word: Record<string, any>) { if (Object.keys(this.trie).length === 0) { this.trie = this.newNode() } let root = this.trie for (const letter of word.text.toLowerCase()) { if (!(letter in root.children)) { root.children[letter] = this.newNode() } root = root.children[letter] } root.value = root.value || [] root.value.push(word) root.isLeaf = true } find(word: string) { let root = this.trie for (const letter of word) { if (letter in root.children) { root = root.children[letter] } else { return null // if not found return null } } return root // return the root where it ends search } traverse(root: Node) { if (root.isLeaf) { this.suggestions.push(...root.value) } for (const letter in root.children) { this.traverse(root.children[letter]) } } complete(word: string, CHILDREN = null) { this.suggestions = [] const root = this.find(word.toLowerCase()) if (!root) { return this.suggestions } // cannot suggest anything this.suggestions.push(...root.value) const children = root.children let spread = 0 for (const letter in children) { this.traverse(children[letter]) spread++ if (CHILDREN && spread === CHILDREN) { break } } return this.suggestions } }