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//! Unix socket protocol for daemon ↔ CLI.
//!
//! Simple line-oriented text protocol:
//! SHORTEN <ttl_secs> <slug|auto> <url>\n
//! RESOLVE <slug>\n
//! DEL <slug>\n
//! LIST\n
//! STATUS\n
//! SHUTDOWN\n
//!
//! Responses:
//! OK <data>\n
//! ERR <message>\n
/// A parsed request received from the CLI over the Unix socket.
pub enum Request {
Shorten {
ttl_secs: u64,
slug: String,
target_url: String,
},
Resolve {
slug: String,
},
Del {
slug: String,
},
List,
Status,
Shutdown,
}
/// A response sent back to the CLI over the Unix socket.
pub enum Response {
Ok(String),
Err(String),
}
/// Parse a single protocol line into a [`Request`].
pub fn parse_request(line: &str) -> Result<Request, String> {
let line = line.trim();
if line.is_empty() {
return Err("empty request".into());
}
let mut parts = line.splitn(4, ' ');
let cmd = parts.next().unwrap();
match cmd {
"SHORTEN" => {
let ttl_str = parts
.next()
.ok_or("SHORTEN requires: SHORTEN <ttl> <slug> <url>")?;
let slug = parts
.next()
.ok_or("SHORTEN requires: SHORTEN <ttl> <slug> <url>")?;
let target_url = parts
.next()
.ok_or("SHORTEN requires: SHORTEN <ttl> <slug> <url>")?;
let ttl_secs: u64 =
ttl_str.parse().map_err(|_| "invalid TTL number")?;
Ok(Request::Shorten {
ttl_secs,
slug: slug.to_string(),
target_url: target_url.to_string(),
})
}
"RESOLVE" => {
let slug = parts.next().ok_or("RESOLVE requires: RESOLVE <slug>")?;
Ok(Request::Resolve {
slug: slug.to_string(),
})
}
"DEL" => {
let slug = parts.next().ok_or("DEL requires: DEL <slug>")?;
Ok(Request::Del {
slug: slug.to_string(),
})
}
"LIST" => Ok(Request::List),
"STATUS" => Ok(Request::Status),
"SHUTDOWN" => Ok(Request::Shutdown),
_ => Err(format!("unknown command: {cmd}")),
}
}
/// Serialize a [`Response`] into a protocol line.
pub fn format_response(r: &Response) -> String {
match r {
Response::Ok(data) => format!("OK {data}\n"),
Response::Err(msg) => format!("ERR {msg}\n"),
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_shorten() {
let r =
parse_request("SHORTEN 0 auto https://example.com").unwrap();
match r {
Request::Shorten {
ttl_secs,
slug,
target_url,
} => {
assert_eq!(ttl_secs, 0);
assert_eq!(slug, "auto");
assert_eq!(target_url, "https://example.com");
}
_ => panic!("expected Shorten"),
}
}
#[test]
fn parse_shorten_custom_slug() {
let r =
parse_request("SHORTEN 3600 myslug https://example.com").unwrap();
match r {
Request::Shorten { slug, .. } => assert_eq!(slug, "myslug"),
_ => panic!("expected Shorten"),
}
}
#[test]
fn parse_resolve() {
let r = parse_request("RESOLVE abc123").unwrap();
match r {
Request::Resolve { slug } => assert_eq!(slug, "abc123"),
_ => panic!("expected Resolve"),
}
}
#[test]
fn parse_status() {
assert!(matches!(
parse_request("STATUS").unwrap(),
Request::Status
));
}
#[test]
fn parse_list() {
assert!(matches!(parse_request("LIST").unwrap(), Request::List));
}
#[test]
fn parse_empty_fails() {
assert!(parse_request("").is_err());
}
#[test]
fn parse_unknown_fails() {
assert!(parse_request("FOOBAR").is_err());
}
}
|