Add bot::command and bot::commands

src/bot/command.rs

@@ -0,0 +1,76 @@
+use async_trait::async_trait;
+
+use crate::api::{self, Message, MessageId};
+use crate::conn::{self, ConnTx, Joined};
+
+use super::instance::InstanceConfig;
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub enum Kind {
+    /// Global commands always respond. They override any specific or general
+    /// commands of the same name.
+    Global,
+    /// General commands only respond if no nick is specified.
+    General,
+    /// Specific commands only respond if the bot's current nick is specified.
+    Specific,
+}
+
+impl Kind {
+    pub fn global_and_general_usage(cmd_name: &str) -> String {
+        format!("!{cmd_name}")
+    }
+
+    pub fn specific_nick(nick: &str) -> String {
+        nick.replace(char::is_whitespace, "")
+    }
+
+    pub fn specific_usage(cmd_name: &str, nick: &str) -> String {
+        format!("!{cmd_name} @{}", Self::specific_nick(nick))
+    }
+
+    pub fn usage(self, cmd_name: &str, nick: &str) -> String {
+        match self {
+            Self::Global | Self::General => Self::global_and_general_usage(cmd_name),
+            Self::Specific => Self::specific_usage(cmd_name, nick),
+        }
+    }
+}
+
+pub struct Context {
+    pub kind: Kind,
+    pub config: InstanceConfig,
+    pub conn_tx: ConnTx,
+    pub joined: Joined,
+}
+
+impl Context {
+    pub async fn send<S: ToString>(&self, content: S) -> Result<Message, conn::Error> {
+        let cmd = api::Send {
+            content: content.to_string(),
+            parent: None,
+        };
+        Ok(self.conn_tx.send(cmd).await?.0)
+    }
+
+    pub async fn reply<S: ToString>(
+        &self,
+        parent: MessageId,
+        content: S,
+    ) -> Result<Message, conn::Error> {
+        let cmd = api::Send {
+            content: content.to_string(),
+            parent: Some(parent),
+        };
+        Ok(self.conn_tx.send(cmd).await?.0)
+    }
+}
+
+#[async_trait]
+pub trait Command<B> {
+    fn description(&self) -> Option<String> {
+        None
+    }
+
+    async fn execute(&self, arg: &str, msg: &Message, ctx: &Context, bot: &mut B);
+}