Add logging infrastructure (#302)

* Add logging dependencies

* Initialise logging

2 files changed, 26 insertions, 3 deletions

diff --git a/src/cli.rs b/src/cli.rs
index e466af9..5e1a0e2 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,8 +1,11 @@
-use std::net::Ipv4Addr;
+use std::{net::Ipv4Addr, path::PathBuf};
 
 use clap::{Args, Parser};
+use clap_verbosity_flag::{InfoLevel, Verbosity};
+use derivative::Derivative;
 
-#[derive(Clone, Debug, Default, Parser)]
+#[derive(Clone, Debug, Derivative, Parser)]
+#[derivative(Default)]
 #[command(name = "bandwhich", version)]
 pub struct Opt {
     #[arg(short, long)]
@@ -25,6 +28,14 @@ pub struct Opt {
     /// A dns server ip to use instead of the system default
     pub dns_server: Option<Ipv4Addr>,
 
+    #[arg(long)]
+    /// Enable logging to a file
+    pub log_to: Option<PathBuf>,
+
+    #[command(flatten)]
+    #[derivative(Default(value = "Verbosity::new(0, 0)"))]
+    pub verbosity: Verbosity<InfoLevel>,
+
     #[command(flatten)]
     pub render_opts: RenderOpts,
 }
diff --git a/src/main.rs b/src/main.rs
index 2ba7f97..f55a116 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,6 +9,7 @@ mod tests;
 
 use std::{
     collections::HashMap,
+    fs::File,
     sync::{
         atomic::{AtomicBool, AtomicUsize, Ordering},
         Arc, Mutex, RwLock,
@@ -29,6 +30,7 @@ use network::{
 };
 use pnet::datalink::{DataLinkReceiver, NetworkInterface};
 use ratatui::backend::{Backend, CrosstermBackend};
+use simplelog::WriteLogger;
 
 use crate::cli::Opt;
 
@@ -36,8 +38,18 @@ const DISPLAY_DELTA: Duration = Duration::from_millis(1000);
 
 fn main() -> anyhow::Result<()> {
     let opts = Opt::parse();
-    let os_input = os::get_input(opts.interface.as_deref(), !opts.no_resolve, opts.dns_server)?;
 
+    // init logging
+    if let Some(ref log_path) = opts.log_to {
+        let log_file = File::options().create_new(true).open(log_path)?;
+        WriteLogger::init(
+            opts.verbosity.log_level_filter(),
+            Default::default(),
+            log_file,
+        )?;
+    }
+
+    let os_input = os::get_input(opts.interface.as_deref(), !opts.no_resolve, opts.dns_server)?;
     if opts.raw {
         let terminal_backend = RawTerminalBackend {};
         start(terminal_backend, os_input, opts);