Create euphoxide-bot crate

euphoxide-bot/src/command/bang.rs

@@ -0,0 +1,232 @@
+//! Euphoria-style `!foo` and `!foo @bar` command wrappers.
+
+use async_trait::async_trait;
+use euphoxide::{api::Message, nick};
+
+use crate::bot::Bot;
+
+use super::{Command, Context, Info, Propagate};
+
+// TODO Don't ignore leading whitespace?
+// I'm not entirely happy with how commands handle whitespace, and on euphoria,
+// prefixing commands with whitespace is traditionally used to not trigger them.
+
+/// Parse leading whitespace followed by an prefix-initiated command.
+///
+/// Returns the command name and the remaining text with one leading whitespace
+/// removed. The remaining text may be the empty string.
+pub fn parse_prefix_initiated<'a>(text: &'a str, prefix: &str) -> Option<(&'a str, &'a str)> {
+    let text = text.trim_start();
+    let text = text.strip_prefix(prefix)?;
+    let (name, rest) = text.split_once(char::is_whitespace).unwrap_or((text, ""));
+    if name.is_empty() {
+        return None;
+    }
+    Some((name, rest))
+}
+
+pub struct Global<C> {
+    prefix: String,
+    name: String,
+    inner: C,
+}
+
+impl<C> Global<C> {
+    pub fn new<S: ToString>(name: S, inner: C) -> Self {
+        Self {
+            prefix: "!".to_string(),
+            name: name.to_string(),
+            inner,
+        }
+    }
+
+    pub fn with_prefix<S: ToString>(mut self, prefix: S) -> Self {
+        self.prefix = prefix.to_string();
+        self
+    }
+}
+
+#[async_trait]
+impl<S, E, C> Command<S, E> for Global<C>
+where
+    S: Send + Sync,
+    C: Command<S, E> + Sync,
+{
+    fn info(&self, ctx: &Context) -> Info {
+        self.inner
+            .info(ctx)
+            .with_prepended_trigger(format!("{}{}", self.prefix, self.name))
+    }
+
+    async fn execute(
+        &self,
+        arg: &str,
+        msg: &Message,
+        ctx: &Context,
+        bot: &Bot<S, E>,
+    ) -> Result<Propagate, E> {
+        let Some((name, rest)) = parse_prefix_initiated(arg, &self.prefix) else {
+            return Ok(Propagate::Yes);
+        };
+
+        if name != self.name {
+            return Ok(Propagate::Yes);
+        }
+
+        self.inner.execute(rest, msg, ctx, bot).await
+    }
+}
+
+pub struct General<C> {
+    prefix: String,
+    name: String,
+    inner: C,
+}
+
+impl<C> General<C> {
+    pub fn new<S: ToString>(name: S, inner: C) -> Self {
+        Self {
+            prefix: "!".to_string(),
+            name: name.to_string(),
+            inner,
+        }
+    }
+
+    pub fn with_prefix<S: ToString>(mut self, prefix: S) -> Self {
+        self.prefix = prefix.to_string();
+        self
+    }
+}
+
+#[async_trait]
+impl<S, E, C> Command<S, E> for General<C>
+where
+    S: Send + Sync,
+    C: Command<S, E> + Sync,
+{
+    fn info(&self, ctx: &Context) -> Info {
+        self.inner
+            .info(ctx)
+            .with_prepended_trigger(format!("{}{}", self.prefix, self.name))
+    }
+
+    async fn execute(
+        &self,
+        arg: &str,
+        msg: &Message,
+        ctx: &Context,
+        bot: &Bot<S, E>,
+    ) -> Result<Propagate, E> {
+        let Some((name, rest)) = parse_prefix_initiated(arg, &self.prefix) else {
+            return Ok(Propagate::Yes);
+        };
+
+        if name != self.name {
+            return Ok(Propagate::Yes);
+        }
+
+        if parse_prefix_initiated(rest, "@").is_some() {
+            // The command looks like a specific command. If we treated it like
+            // a general command match, we would interpret other bots' specific
+            // commands as general commands.
+            return Ok(Propagate::Yes);
+        }
+
+        self.inner.execute(rest, msg, ctx, bot).await
+    }
+}
+
+pub struct Specific<C> {
+    prefix: String,
+    name: String,
+    inner: C,
+}
+
+impl<C> Specific<C> {
+    pub fn new<S: ToString>(name: S, inner: C) -> Self {
+        Self {
+            prefix: "!".to_string(),
+            name: name.to_string(),
+            inner,
+        }
+    }
+
+    pub fn with_prefix<S: ToString>(mut self, prefix: S) -> Self {
+        self.prefix = prefix.to_string();
+        self
+    }
+}
+
+#[async_trait]
+impl<S, E, C> Command<S, E> for Specific<C>
+where
+    S: Send + Sync,
+    C: Command<S, E> + Sync,
+{
+    fn info(&self, ctx: &Context) -> Info {
+        let nick = nick::mention(&ctx.joined.session.name);
+        self.inner
+            .info(ctx)
+            .with_prepended_trigger(format!("{}{} @{nick}", self.prefix, self.name))
+    }
+
+    async fn execute(
+        &self,
+        arg: &str,
+        msg: &Message,
+        ctx: &Context,
+        bot: &Bot<S, E>,
+    ) -> Result<Propagate, E> {
+        let Some((name, rest)) = parse_prefix_initiated(arg, &self.prefix) else {
+            return Ok(Propagate::Yes);
+        };
+
+        if name != self.name {
+            return Ok(Propagate::Yes);
+        }
+
+        let Some((nick, rest)) = parse_prefix_initiated(rest, "@") else {
+            return Ok(Propagate::Yes);
+        };
+
+        if nick::normalize(nick) != nick::normalize(&ctx.joined.session.name) {
+            return Ok(Propagate::Yes);
+        }
+
+        self.inner.execute(rest, msg, ctx, bot).await
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::parse_prefix_initiated;
+
+    #[test]
+    fn test_parse_prefixed() {
+        assert_eq!(parse_prefix_initiated("!foo", "!"), Some(("foo", "")));
+        assert_eq!(parse_prefix_initiated("    !foo", "!"), Some(("foo", "")));
+        assert_eq!(
+            parse_prefix_initiated("!foo    ", "!"),
+            Some(("foo", "   "))
+        );
+        assert_eq!(
+            parse_prefix_initiated("    !foo    ", "!"),
+            Some(("foo", "   "))
+        );
+        assert_eq!(
+            parse_prefix_initiated("!foo @bar", "!"),
+            Some(("foo", "@bar"))
+        );
+        assert_eq!(
+            parse_prefix_initiated("!foo    @bar", "!"),
+            Some(("foo", "   @bar"))
+        );
+        assert_eq!(
+            parse_prefix_initiated("!foo @bar   ", "!"),
+            Some(("foo", "@bar   "))
+        );
+        assert_eq!(parse_prefix_initiated("! foo @bar", "!"), None);
+        assert_eq!(parse_prefix_initiated("!", "!"), None);
+        assert_eq!(parse_prefix_initiated("?foo", "!"), None);
+    }
+}