Harden bot: line cap, send throttle, panic isolation, verbose flag, weather cache, tests

src/bot/modules/weather.rs

@@ -1,16 +1,18 @@
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashMap};
 use std::fs;
 use std::io::{self, Read, Write};
 use std::iter::Peekable;
 use std::net::{TcpStream, ToSocketAddrs};
 use std::path::{Path, PathBuf};
 use std::str::Chars;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 use native_tls::TlsConnector;
 
 use crate::bot::module::{Action, Command, CommandSpec, Module};
 
+const CACHE_TTL: Duration = Duration::from_secs(600);
+
 const COMMANDS: &[CommandSpec] = &[
     CommandSpec { name: "add", usage: "add <location>", about: "save your weather location" },
     CommandSpec { name: "w", usage: "w [location]", about: "weather for your saved location" },
@@ -19,6 +21,7 @@ const COMMANDS: &[CommandSpec] = &[
 pub struct Weather {
     store: Store,
     path: PathBuf,
+    cache: HashMap<String, (Instant, String)>,
 }
 
 impl Weather {
@@ -32,7 +35,7 @@ impl Weather {
     }
 
     pub fn with_path(path: PathBuf) -> Weather {
-        Weather { store: Store::load(&path), path }
+        Weather { store: Store::load(&path), path, cache: HashMap::new() }
     }
 
     pub fn location_of(&self, nick: &str) -> Option<&str> {
@@ -74,8 +77,17 @@ impl Module for Weather {
                         cmd.sender, cmd.prefix
                     ))];
                 };
+                let key = loc.to_lowercase();
+                if let Some((at, text)) = self.cache.get(&key) {
+                    if at.elapsed() < CACHE_TTL {
+                        return vec![Action::reply(text.clone())];
+                    }
+                }
                 match fetch_weather(&loc) {
-                    Ok(text) => vec![Action::reply(text)],
+                    Ok(text) => {
+                        self.cache.insert(key, (Instant::now(), text.clone()));
+                        vec![Action::reply(text)]
+                    }
                     Err(e) => vec![Action::reply(format!("weather unavailable: {e}"))],
                 }
             }