//! System Logger Implementation
//!
//! This module implements the system-wide logging functionality that captures
//! all non-job-specific logs from every component with target-based filtering.

use crate::{LoggerError, Result, custom_formatter::HeroFormatter};
use std::path::{Path, PathBuf};
use tracing_subscriber::{
    filter::{EnvFilter, LevelFilter},
    fmt,
    layer::SubscriberExt,
    util::SubscriberInitExt,
    Layer,
};
use tracing_appender::{non_blocking::WorkerGuard, rolling};

/// Initialize the system logger with component-based filtering
///
/// This creates multiple file appenders, each filtered by a specific tracing target:
/// - `tracing::info!(target: "supervisor", ...)` -> `logs/supervisor/`
/// - `tracing::info!(target: "osis_actor", ...)` -> `logs/actor/osis/`
/// - etc.
pub fn init_system_logger<P: AsRef<Path>>(
    logs_root: P,
    components: &[String],
) -> Result<Vec<WorkerGuard>> {
    let logs_root = logs_root.as_ref();
    
    // Ensure log directories exist
    crate::utils::ensure_log_directories(logs_root, components)?;
    
    let mut guards = Vec::new();
    let mut layers = Vec::new();
    
    // Create a layer for each component
    for component in components {
        let (layer, guard) = create_component_layer(logs_root, component)?;
        layers.push(layer);
        guards.push(guard);
    }
    
    // Create the registry with all layers
    let registry = tracing_subscriber::registry();
    
    // Add all component layers to the registry
    let collected_layers = layers.into_iter().collect::<Vec<_>>();
    let registry = registry.with(collected_layers);
    
    // Add console output for development
    let console_layer = fmt::layer()
        .with_target(true)
        .with_thread_ids(true)
        .with_file(true)
        .with_line_number(true)
        .with_filter(EnvFilter::from_default_env().add_directive(LevelFilter::INFO.into()));
    
    // Set as global default
    registry.with(console_layer).init();
    
    tracing::info!(target: "hero_logger", "System logger initialized with {} components", components.len());
    
    Ok(guards)
}

/// Create a filtered layer for a specific component
fn create_component_layer<P: AsRef<Path>>(
    logs_root: P,
    component: &str,
) -> Result<(Box<dyn Layer<tracing_subscriber::Registry> + Send + Sync>, WorkerGuard)> {
    let logs_root = logs_root.as_ref();
    
    // Determine the log directory based on component type
    let log_dir = if component == "supervisor" {
        logs_root.join("supervisor")
    } else {
        // Extract actor type from component name (e.g., "osis_actor" -> "osis")
        let actor_type = component.strip_suffix("_actor").unwrap_or(component);
        logs_root.join("actor").join(actor_type)
    };
    
    // Create hourly rolling file appender
    let file_appender = rolling::hourly(&log_dir, "log");
    let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);
    
    // Create a formatted layer with custom Hero formatter and target filtering
    let layer = fmt::layer()
        .with_writer(non_blocking)
        .event_format(HeroFormatter::new())
        .with_ansi(false) // No ANSI colors in log files
        .with_filter(
            EnvFilter::new(format!("{}=trace", component))
                .add_directive(LevelFilter::INFO.into())
        );
    
    Ok((layer.boxed(), guard))
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::TempDir;
    use tracing::{info, warn};
    use std::time::Duration;
    use tokio::time::sleep;

    #[tokio::test]
    async fn test_system_logger_initialization() {
        let temp_dir = TempDir::new().unwrap();
        let logs_root = temp_dir.path();
        
        let components = vec![
            "supervisor".to_string(),
            "osis_actor".to_string(),
            "sal_actor".to_string(),
        ];
        
        let _guards = init_system_logger(logs_root, &components).unwrap();
        
        // Test logging to different targets
        info!(target: "supervisor", "Supervisor started");
        info!(target: "osis_actor", "OSIS actor ready");
        info!(target: "sal_actor", "SAL actor ready");
        
        // Give some time for async writing
        sleep(Duration::from_millis(100)).await;
        
        // Verify directories were created
        assert!(logs_root.join("supervisor").exists());
        assert!(logs_root.join("actor/osis").exists());
        assert!(logs_root.join("actor/sal").exists());
    }

    #[tokio::test]
    async fn test_component_layer_creation() {
        let temp_dir = TempDir::new().unwrap();
        let logs_root = temp_dir.path();
        
        // Create supervisor layer
        let (supervisor_layer, _guard1) = create_component_layer(logs_root, "supervisor").unwrap();
        assert!(logs_root.join("supervisor").exists());
        
        // Create actor layer
        let (actor_layer, _guard2) = create_component_layer(logs_root, "osis_actor").unwrap();
        assert!(logs_root.join("actor/osis").exists());
    }

    #[tokio::test]
    async fn test_multiple_components() {
        let temp_dir = TempDir::new().unwrap();
        let logs_root = temp_dir.path();
        
        let components = vec![
            "supervisor".to_string(),
            "osis_actor".to_string(),
            "sal_actor".to_string(),
            "v_actor".to_string(),
            "python_actor".to_string(),
        ];
        
        let guards = init_system_logger(logs_root, &components).unwrap();
        assert_eq!(guards.len(), components.len());
        
        // Test that all directories were created
        assert!(logs_root.join("supervisor").exists());
        assert!(logs_root.join("actor/osis").exists());
        assert!(logs_root.join("actor/sal").exists());
        assert!(logs_root.join("actor/v").exists());
        assert!(logs_root.join("actor/python").exists());
    }
}