//! Atward implements TVL's redirection service, living at //! atward.tvl.fyi //! //! This service is designed to be added as a search engine to web //! browsers and attempts to send users to useful locations based on //! their search query (falling back to another search engine). use regex::Regex; use rouille::Response; /// A query type supported by atward. It consists of a pattern on /// which to match and trigger the query, and a function to execute /// that returns the target URL. struct Query { /// Regular expression on which to match the query string. pattern: Regex, /// Function to construct the target URL. If the pattern matches, /// this is invoked with the captured matches and the entire URI. /// /// Returning `None` causes atward to fall through to the next /// query (and eventually to the default search engine). target: for<'s> fn(&'s str, regex::Captures<'s>) -> Option, } /// Definition of all supported queries in atward. fn queries() -> Vec { vec![ // Bug IDs (e.g. b/123) Query { pattern: Regex::new("^b/(?P\\d+)$").unwrap(), target: |_, captures| Some(format!("https://b.tvl.fyi/{}", &captures["bug"])), }, ] } /// Attempt to match against all known query types, and return the /// destination URL if one is found. fn dispatch(queries: &[Query], uri: &str) -> Option { for query in queries { if let Some(captures) = query.pattern.captures(uri) { if let Some(destination) = (query.target)(uri, captures) { return Some(destination); } } } None } fn fallback() -> Response { Response::text("no match for atward whimchst query").with_status_code(404) } fn main() { let queries = queries(); let port = std::env::var("ATWARD_PORT").unwrap_or("28973".to_string()); let address = format!("0.0.0.0:{}", port); rouille::start_server(&address, move |request| { rouille::log(&request, std::io::stderr(), || { match dispatch(&queries, &request.url()) { None => fallback(), Some(destination) => Response::redirect_303(destination), } }) }); } #[cfg(test)] mod tests { use super::*; #[test] fn bug_query() { assert_eq!( dispatch(&queries(), "b/42"), Some("https://b.tvl.fyi/42".to_string()) ); assert_eq!(dispatch(&queries(), "something only mentioning b/42"), None,); assert_eq!(dispatch(&queries(), "b/invalid"), None,); } }