1 files changed, 175 insertions, 0 deletions
diff --git a/src/hooks/sed.rs b/src/hooks/sed.rs
new file mode 100644
index 0000000..095eb14
--- /dev/null
+++ b/src/hooks/sed.rs
@@ -0,0 +1,175 @@
+use anyhow::{anyhow, Result};
+use irc::client::prelude::*;
+
+use sedregex::ReplaceCommand;
+
+use std::cell::RefCell;
+
+static LOG_MAX_SIZE: usize = 10000;
+
+thread_local!(static LOG: RefCell<Vec::<(String, String)>> = RefCell::new(Vec::with_capacity(LOG_MAX_SIZE)));
+thread_local!(static RE: regex::Regex = regex::Regex::new(r"^s/").unwrap());
+
+pub fn log(_bot: &crate::Bot, msg: Message) -> Result<()> {
+    log_msg(msg)
+}
+
+fn log_msg(msg: Message) -> Result<()> {
+    if let Command::PRIVMSG(_, text) = msg.command.clone() {
+        LOG.with(|log_cell| {
+            let mut log = log_cell.borrow_mut();
+            if log.len() >= LOG_MAX_SIZE {
+                let _ = log.pop();
+            }
+            log.push((msg.source_nickname().unwrap().to_string(), text))
+        });
+    }
+    Ok(())
+}
+
+pub fn replace(bot: &crate::Bot, msg: Message) -> Result<()> {
+    match find_and_replace(&msg) {
+        Ok(res) => {
+            bot.send_privmsg(msg.response_target().unwrap(), res.as_str())
+                .unwrap();
+            Ok(())
+        }
+        Err(_) => Ok(()),
+    }
+}
+
+fn find_and_replace(msg: &Message) -> Result<String> {
+    if let Command::PRIVMSG(_, text) = msg.command.clone() {
+        let cmd = match ReplaceCommand::new(text.as_str()) {
+            Ok(cmd) => cmd,
+            Err(_) => return Err(anyhow!("building replace command failed")),
+        };
+
+        return LOG.with(|log_cell| {
+            log_cell
+                .borrow()
+                .iter()
+                .rev()
+                .find(|(_, text)| cmd.expr.is_match(text) && !RE.with(|re| re.is_match(text)))
+                .and_then(|(nick, text)| Some(format!("<{}> {}", nick, cmd.execute(text))))
+                .map_or(Err(anyhow!("replace failed")), |v| Ok(v))
+        });
+    }
+
+    Err(anyhow!("not a privmsg"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test::Bencher;
+
+    fn populate_log() {
+        LOG.with(|log_cell| {
+            let mut log = log_cell.borrow_mut();
+            log.push((
+                "user".to_string(),
+                "this is a long message which will be replaced".to_string(),
+            ));
+            for _ in 0..LOG_MAX_SIZE-1 {
+                log.push((
+                    "user".to_string(),
+                    "this is a long message which doesn't matter".to_string(),
+                ))
+            }
+        });
+    }
+
+    #[test]
+    fn test_log_limit() {
+        populate_log();
+
+        LOG.with(|log_cell| {
+            let log = log_cell.borrow();
+            assert_eq!(log.len(), LOG_MAX_SIZE)
+        });
+
+        log_msg(Message {
+            tags: None,
+            prefix: Some(Prefix::Nickname(
+                "user".to_string(),
+                "username".to_string(),
+                "userhost".to_string(),
+            )),
+            command: Command::PRIVMSG(
+                "#channel".to_string(),
+                "this is the 10001th message".to_string(),
+            ),
+        })
+        .unwrap();
+
+        LOG.with(|log_cell| {
+            let log = log_cell.borrow();
+            assert_eq!(log.len(), LOG_MAX_SIZE)
+        });
+    }
+
+    #[test]
+    fn test_replace() {
+        populate_log();
+        assert_eq!(
+            find_and_replace(&Message {
+                tags: None,
+                prefix: None,
+                command: Command::PRIVMSG(
+                    "#channel".to_string(),
+                    "s/will be/has been/".to_string(),
+                ),
+            })
+            .unwrap(),
+            "<user> this is a long message which has been replaced"
+        )
+    }
+
+    #[test]
+    fn test_replace_complex() {
+        populate_log();
+        assert_eq!(
+            find_and_replace(&Message {
+                tags: None,
+                prefix: None,
+                command: Command::PRIVMSG(
+                    "#channel".to_string(),
+                    "s/(will).*(be)/$2 $1/".to_string(),
+                ),
+            })
+            .unwrap(),
+            "<user> this is a long message which be will replaced"
+        )
+    }
+
+    #[bench]
+    fn bench_replace(b: &mut Bencher) {
+        populate_log();
+        b.iter(|| {
+            find_and_replace(&Message {
+                tags: None,
+                prefix: None,
+                command: Command::PRIVMSG(
+                    "#channel".to_string(),
+                    "s/will be/has been/".to_string(),
+                ),
+            })
+        });
+    }
+
+    #[bench]
+    fn bench_replace_complex(b: &mut Bencher) {
+        populate_log();
+        b.iter(|| {
+            find_and_replace(&Message {
+                tags: None,
+                prefix: None,
+                command: Command::PRIVMSG(
+                    "#channel".to_string(),
+                    "s/will be/has been/".to_string(),
+                ),
+            })
+        });
+    }
+}