Files
homarr/packages/api/src/services/duckduckgo-bangs.ts
T

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TypeScript

import { duckDuckGoBangsRequestHandler } from "@homarr/request-handler/duckduckgo-bangs";
import type { DuckDuckGoBang } from "@homarr/request-handler/duckduckgo-bangs";
// DuckDuckGo bang keys are intentionally short:
// - `t`: token (e.g. "yt"), `s`: display name, `u`: URL template (contains `{{{s}}}`)
// - `d`: domain, `c`: category, `sc`: subcategory, `r`: rank (optional)
const normalizeBangToken = (token: string) => token.toLowerCase().trim();
/**
* Binary search to find the first index where bang.t >= tokenPrefix.
* This is O(log n) vs O(n) for findIndex, which matters because DuckDuckGo
* has ~13,000+ bangs. Combined with the pre-sorted data, this allows
* efficient prefix matching by finding the start position and iterating
* only through consecutive matches.
*/
const lowerBound = (arr: DuckDuckGoBang[], tokenPrefix: string) => {
let low = 0;
let high = arr.length;
while (low < high) {
const mid = (low + high) >> 1;
const midBang = arr[mid];
// Must use the same ordering as the source list sort (localeCompare),
// otherwise binary search can miss tokens with symbols like "&" or "_".
if (!midBang || midBang.t.localeCompare(tokenPrefix) >= 0) {
high = mid;
continue;
}
low = mid + 1;
}
return low;
};
export const searchDuckDuckGoBangsAsync = async (input: {
query: string;
limit: number;
}): Promise<DuckDuckGoBang[]> => {
const queryTokenPrefix = normalizeBangToken(input.query);
if (!queryTokenPrefix) return [];
const { data: allBangs } = await duckDuckGoBangsRequestHandler.handler({}).getDataAsync();
const startIndex = lowerBound(allBangs, queryTokenPrefix);
const matches: DuckDuckGoBang[] = [];
for (let index = startIndex; index < allBangs.length; index++) {
const bang = allBangs[index];
if (!bang) break;
if (!bang.t.startsWith(queryTokenPrefix)) break;
matches.push(bang);
if (matches.length >= input.limit) break;
}
return matches;
};