Add logging

1 files changed, 54 insertions, 0 deletions

diff --git a/src/logging.rs b/src/logging.rs
new file mode 100644
index 0000000..fd81dba
--- /dev/null
+++ b/src/logging.rs
@@ -0,0 +1,54 @@
+use std::{io::Error, path::PathBuf, str::FromStr};
+
+use tracing_error::ErrorLayer;
+use tracing_subscriber::{self, Layer, layer::SubscriberExt, util::SubscriberInitExt};
+
+const LOG_FILE: &'static str = "equity-tracker.log";
+
+const LOG_LEVEL: &'static str = "LOG_LEVEL";
+const DEFAULT_LOG_LEVEL: &'static str = "DEBUG";
+
+const LOG_DIRECTORY: &'static str = "LOG_DIRECTORY";
+const DEFAULT_LOG_DIRECTORY: &'static str = "./target";
+
+/// Either retrieves the environment variable or uses a default value
+fn get_env_var(var_name: &'static str, default: &'static str) -> String {
+    if let Ok(env_var) = std::env::var(var_name) {
+        env_var
+    } else {
+        default.into()
+    }
+}
+
+/// Provides a PathBuf of the configured log directory, or the target directory
+fn get_log_directory() -> std::io::Result<PathBuf> {
+    let env_dir = get_env_var(LOG_DIRECTORY, DEFAULT_LOG_DIRECTORY);
+    let path = PathBuf::from_str(&env_dir).map_err(|e| Error::other(e))?;
+
+    Ok(path)
+}
+
+/// Configure the logging through tracing
+pub fn initialize_logging() -> std::io::Result<()> {
+    let directory = get_log_directory()?;
+    std::fs::create_dir_all(directory.clone())?;
+
+    let log_path = directory.join(LOG_FILE);
+    let log_file = std::fs::File::create(log_path)?;
+
+    let log_filter = get_env_var(LOG_LEVEL, DEFAULT_LOG_LEVEL);
+    let file_subscriber = tracing_subscriber::fmt::layer()
+        .with_file(true)
+        .with_line_number(true)
+        .with_target(false)
+        .with_ansi(false)
+        .with_writer(log_file)
+        .with_filter(tracing_subscriber::filter::EnvFilter::builder().parse_lossy(log_filter));
+
+    tracing_subscriber::registry()
+        .with(file_subscriber)
+        .with(ErrorLayer::default())
+        .init();
+
+    Ok(())
+}