feat(logs): log to stderr and a file

Signed-off-by: Awiteb <a@4rs.nl>

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - New command `repo state` - by Awiteb
 - Support pull requests - by Awiteb
 - Add `--personal-fork` flag to `repo announce` command - by Awiteb
+- Log to stderr and a file - by Awiteb
 
 ### Breaking Change
 

src/cli/utils.rs

@@ -14,7 +14,12 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://gnu.org/licenses/gpl-3.0.html>.
 
-use std::io::{self, Write};
+use std::{
+    fs,
+    io::{self, Write},
+};
+
+use crate::error::{N34Error, N34Result};
 
 /// Displays the given prompt and reads a line of input from the user.
 pub fn read_line(prompt: &str) -> io::Result<String> {
@@ -43,3 +48,39 @@ pub fn prompt_bool(prompt: &str) -> io::Result<bool> {
         }
     }
 }
+
+/// Opens the logs file for writing. If the file size exceeds 5MB, it is opened
+/// in write mode, otherwise in append mode.
+pub fn logs_file() -> N34Result<fs::File> {
+    const FIVE_MB: u64 = 1024 * 1024 * 5;
+
+    let logs_path = dirs::data_local_dir()
+        .ok_or(N34Error::CanNotFindDataPath)?
+        .join("n34")
+        .join("logs.log");
+
+    tracing::info!(path = %logs_path.display(), "Logs file");
+
+    if let Some(parent) = logs_path.parent()
+        && !parent.exists()
+    {
+        fs::create_dir_all(parent)?;
+    }
+
+    _ = fs::File::create_new(&logs_path);
+
+    let is_large = if let Ok(file) = fs::File::open(&logs_path)
+        && let Ok(metadata) = file.metadata()
+    {
+        metadata.len() >= FIVE_MB
+    } else {
+        false
+    };
+
+    fs::OpenOptions::new()
+        .write(true)
+        .append(!is_large)
+        .truncate(is_large)
+        .open(&logs_path)
+        .map_err(N34Error::from)
+}

src/error.rs

@@ -55,6 +55,11 @@ pub enum N34Error {
     Keyring(#[from] nostr_keyring::Error),
     #[error("{0}")]
     Config(#[from] ConfigError),
+    #[error(
+        "Could not determine the default data path: both `$XDG_CONFIG_HOME` and `$HOME` \
+         environment variables are missing or unset."
+    )]
+    CanNotFindDataPath,
     #[error("No editor specified in the `EDITOR` environment variable")]
     EditorNotFound,
     #[error("The file you edited is empty. Please save your changes before exiting the editor.")]

src/main.rs

@@ -22,13 +22,14 @@ pub mod error;
 pub mod nostr_utils;
 
 use std::{
+    fs::File,
     process::ExitCode,
     sync::atomic::{AtomicBool, Ordering},
 };
 
 use clap::Parser;
 use clap_verbosity_flag::Verbosity;
-use tracing::Level;
+use tracing::{Level, level_filters::LevelFilter};
 use tracing_subscriber::{Layer, filter, layer::SubscriberExt};
 
 use self::cli::Cli;
@@ -37,42 +38,64 @@ use self::cli::Cli;
 /// open.
 static EDITOR_OPEN: AtomicBool = AtomicBool::new(false);
 
+/// Returns the stderr log layer
+fn stderr_log_layer<S>() -> impl Layer<S>
+where
+    S: tracing::Subscriber + for<'a> tracing_subscriber::registry::LookupSpan<'a>,
+{
+    tracing_subscriber::fmt::layer()
+        .with_ansi(true)
+        .with_writer(std::io::stderr)
+        .without_time()
+}
+
 /// Configures the logging level based on the provided verbosity.
 ///
 /// When verbosity is set to TRACE, includes file and line numbers in logs.
-fn set_log_level(verbosity: Verbosity) {
+fn set_log_level(verbosity: Verbosity, logs_file: File) {
-    let is_trace = verbosity
+    let editor_filter = filter::dynamic_filter_fn(move |m, _| {
-        .tracing_level()
-        .is_some_and(|l| l == tracing::Level::TRACE);
-
-    let logs_filter = filter::dynamic_filter_fn(move |m, _| {
         // Disable all logs while editor is open
         verbosity.tracing_level().unwrap_or(Level::ERROR) >= *m.level()
+            && (m.name().starts_with("event src") || m.name().contains("nostr"))
             && !EDITOR_OPEN.load(Ordering::Relaxed)
     });
 
-    let logs_layer = tracing_subscriber::fmt::layer()
+    let file_layer = tracing_subscriber::fmt::layer()
-        .with_file(is_trace)
+        .with_ansi(false)
-        .with_line_number(is_trace)
+        .with_writer(logs_file)
-        .without_time();
+        .with_file(true)
-    let subscriber = tracing_subscriber::registry().with(logs_layer.with_filter(logs_filter));
+        .with_line_number(true)
+        .with_filter(LevelFilter::TRACE);
+
+    let subscriber = tracing_subscriber::registry()
+        .with(stderr_log_layer().with_filter(editor_filter))
+        .with(file_layer);
     tracing::subscriber::set_global_default(subscriber).ok();
 }
 
+async fn try_main() -> error::N34Result<()> {
+    // Initialize a thread-local subscriber for logging during CLI parsing and
+    // post-processing.
+    let guard =
+        tracing::subscriber::set_default(tracing_subscriber::registry().with(stderr_log_layer()));
+
+    let cli = cli::post_cli(Cli::parse())?;
+    let logs_file = cli::utils::logs_file()?;
+
+    // Replace the thread-local subscriber with a global default subscriber based on
+    // the CLI verbosity level.
+    drop(guard);
+    set_log_level(cli.verbosity, logs_file);
+
+    cli.run().await?;
+
+    Ok(())
+}
+
 #[tokio::main]
 async fn main() -> ExitCode {
-    let cli = match cli::post_cli(Cli::parse()) {
+    if let Err(err) = try_main().await {
-        Ok(cli) => cli,
-        Err(err) => {
         eprintln!("{err}");
-            return ExitCode::FAILURE;
-        }
-    };
-
-    set_log_level(cli.verbosity);
-
-    if let Err(err) = cli.run().await {
-        tracing::error!("{err}");
         return err.exit_code();
     }