feat: add file logging via LOG_FILE environment variable

src/main.rs

@@ -6,13 +6,27 @@ mod events;
 mod http;
 mod lua;
 
-use azalea::{brigadier::prelude::CommandDispatcher, prelude::*};
+use azalea::{
+    DefaultBotPlugins, DefaultPlugins, brigadier::prelude::CommandDispatcher, prelude::*,
+};
+use bevy_app::PluginGroup;
+use bevy_log::{
+    LogPlugin,
+    tracing_subscriber::{Layer, fmt::layer},
+};
 use clap::Parser;
 use commands::{CommandSource, register};
 use events::handle_event;
 use futures::lock::Mutex;
 use mlua::{Function, Lua};
-use std::{collections::HashMap, net::SocketAddr, path::PathBuf, sync::Arc};
+use std::{
+    collections::HashMap,
+    env,
+    fs::{OpenOptions, read_to_string},
+    net::SocketAddr,
+    path::PathBuf,
+    sync::Arc,
+};
 
 const DEFAULT_SCRIPT_PATH: &str = "errornowatcher.lua";
 
@@ -32,13 +46,15 @@ async fn main() -> anyhow::Result<()> {
     let script_path = args.script.unwrap_or(PathBuf::from(DEFAULT_SCRIPT_PATH));
 
     let lua = Lua::new();
+    let globals = lua.globals();
+    globals.set("script_path", &*script_path)?;
+    lua::register_functions(&lua, &globals)?;
+
     lua.load(
-        std::fs::read_to_string(&script_path)
+        read_to_string(script_path)
             .expect(&(DEFAULT_SCRIPT_PATH.to_owned() + " should be in current directory")),
     )
     .exec()?;
-
-    let globals = lua.globals();
     let server = globals
         .get::<String>("Server")
         .expect("Server should be in lua globals");
@@ -46,13 +62,27 @@ async fn main() -> anyhow::Result<()> {
         .get::<String>("Username")
         .expect("Username should be in lua globals");
 
-    globals.set("script_path", script_path)?;
-    lua::register_functions(&lua, &globals)?;
-
     let mut commands = CommandDispatcher::new();
     register(&mut commands);
 
-    let Err(error) = ClientBuilder::new()
+    let Err(error) = ClientBuilder::new_without_plugins()
+        .add_plugins(DefaultPlugins.set(LogPlugin {
+            custom_layer: |_| {
+                env::var("LOG_FILE").ok().map(|log_file| {
+                    layer()
+                        .with_writer(
+                            OpenOptions::new()
+                                .append(true)
+                                .create(true)
+                                .open(log_file)
+                                .expect("should have been able to open log file"),
+                        )
+                        .boxed()
+                })
+            },
+            ..Default::default()
+        }))
+        .add_plugins(DefaultBotPlugins)
         .set_handler(handle_event)
         .set_state(State {
             lua,