//! Global unlost logging with daily rotation.

//!

//! Logs are stored in the unlost data directory (`~/.unlost/logs/`) as daily rotating files.

//! All unlost instances share the same log files, making debugging easier.

use tracing_appender::rolling::{RollingFileAppender, Rotation};

/// A guard that must be kept alive for the duration of the program to ensure

/// logs are flushed. When dropped, the non-blocking writer will flush remaining logs.

pub struct LogGuard {

_guard: tracing_appender::non_blocking::WorkerGuard,

}

/// Initialize logging to both stderr and a file in the unlost data directory.

/// Returns a guard that must be kept alive for the duration of logging.

///

/// Log files are created at `~/.unlost/logs/unlost.YYYY-MM-DD.log`.

pub fn init_logging(filter: tracing_subscriber::EnvFilter) -> LogGuard {

use tracing_subscriber::layer::SubscriberExt;

use tracing_subscriber::util::SubscriberInitExt;

let log_dir = crate::unlost_data_root().join("logs");

std::fs::create_dir_all(&log_dir).ok();

let file_appender = RollingFileAppender::new(Rotation::DAILY, &log_dir, "unlost.log");

let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);

tracing_subscriber::registry()

.with(filter)

.with(

tracing_subscriber::fmt::layer()

.with_writer(std::io::stderr)

.with_ansi(true),

)

.with(

tracing_subscriber::fmt::layer()

.with_writer(non_blocking)

.with_ansi(false),

)

.init();

LogGuard { _guard: guard }

}

/// Initialize logging to file only (no stderr).

/// Useful for shims/companions where stdout/stderr are used for protocol communication.

pub fn init_logging_file_only(filter: tracing_subscriber::EnvFilter) -> LogGuard {

use tracing_subscriber::layer::SubscriberExt;

use tracing_subscriber::util::SubscriberInitExt;

let log_dir = crate::unlost_data_root().join("logs");

std::fs::create_dir_all(&log_dir).ok();

let file_appender = RollingFileAppender::new(Rotation::DAILY, &log_dir, "unlost.log");

let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);

tracing_subscriber::registry()

.with(filter)

.with(

tracing_subscriber::fmt::layer()

.with_writer(non_blocking)

.with_ansi(false),

)

.init();

LogGuard { _guard: guard }

}

/// Create a filter for unlost logs at the given level, keeping dependencies quiet.

pub fn create_filter(level: &str) -> tracing_subscriber::EnvFilter {

tracing_subscriber::EnvFilter::try_from_default_env().unwrap_or_else(|_| {

tracing_subscriber::EnvFilter::new(format!("unlost={},lance=warn,lancedb=warn", level))

})

}