use anyhow::Result;
use async_trait::async_trait;
use cm_dashboard_shared::{AgentData, ServiceData, SubServiceData, SubServiceMetric, Status};
use std::process::Command;
use std::sync::RwLock;
use std::time::Instant;
use tracing::debug;

use super::{Collector, CollectorError};
use crate::config::SystemdConfig;

/// Systemd collector for monitoring systemd services with structured data output
pub struct SystemdCollector {
    /// Cached state with thread-safe interior mutability
    state: RwLock<ServiceCacheState>,
    /// Configuration for service monitoring
    config: SystemdConfig,
}

/// Internal state for service caching
#[derive(Debug, Clone)]
struct ServiceCacheState {
    /// Last collection time for performance tracking
    last_collection: Option<Instant>,
    /// Cached complete service data with sub-services
    cached_service_data: Vec<ServiceData>,
    /// Interesting services to monitor (cached after discovery)
    monitored_services: Vec<String>,
    /// Cached service status information from discovery
    service_status_cache: std::collections::HashMap<String, ServiceStatusInfo>,
    /// Last time services were discovered
    last_discovery_time: Option<Instant>,
    /// How often to rediscover services (from config)
    discovery_interval_seconds: u64,
    /// Cached nginx site latency metrics
    nginx_site_metrics: Vec<(String, f32)>,
    /// Last time nginx sites were checked
    last_nginx_check_time: Option<Instant>,
    /// How often to check nginx site latency (configurable)
    nginx_check_interval_seconds: u64,
}

/// Cached service status information from systemctl list-units
#[derive(Debug, Clone)]
struct ServiceStatusInfo {
    load_state: String,
    active_state: String,
    sub_state: String,
}

impl SystemdCollector {
    pub fn new(config: SystemdConfig) -> Self {
        let state = ServiceCacheState {
            last_collection: None,
            cached_service_data: Vec::new(),
            monitored_services: Vec::new(),
            service_status_cache: std::collections::HashMap::new(),
            last_discovery_time: None,
            discovery_interval_seconds: config.interval_seconds,
            nginx_site_metrics: Vec::new(),
            last_nginx_check_time: None,
            nginx_check_interval_seconds: config.nginx_check_interval_seconds,
        };

        Self {
            state: RwLock::new(state),
            config,
        }
    }

    /// Collect service data and populate AgentData
    async fn collect_service_data(&self, agent_data: &mut AgentData) -> Result<(), CollectorError> {
        let start_time = Instant::now();
        debug!("Collecting systemd services metrics");

        // Get cached services (discovery only happens when needed)
        let monitored_services = match self.get_monitored_services() {
            Ok(services) => services,
            Err(e) => {
                debug!("Failed to get monitored services: {}", e);
                return Ok(());
            }
        };

        // Collect service data for each monitored service
        let mut complete_service_data = Vec::new();
        for service_name in &monitored_services {
            match self.get_service_status(service_name) {
                Ok((active_status, _detailed_info)) => {
                    let memory_mb = self.get_service_memory_usage(service_name).await.unwrap_or(0.0);
                    let disk_gb = self.get_service_disk_usage(service_name).await.unwrap_or(0.0);
                    
                    let mut sub_services = Vec::new();

                    // Sub-service metrics for specific services (always include cached results)
                    if service_name.contains("nginx") && active_status == "active" {
                        let nginx_sites = self.get_nginx_site_metrics();
                        for (site_name, latency_ms) in nginx_sites {
                            let site_status = if latency_ms >= 0.0 && latency_ms < self.config.nginx_latency_critical_ms {
                                "active"
                            } else {
                                "failed"
                            };
                            
                            let mut metrics = Vec::new();
                            metrics.push(SubServiceMetric {
                                label: "latency_ms".to_string(),
                                value: latency_ms,
                                unit: Some("ms".to_string()),
                            });
                            
                            sub_services.push(SubServiceData {
                                name: site_name.clone(),
                                service_status: self.calculate_service_status(&site_name, &site_status),
                                metrics,
                            });
                        }
                    }

                    if service_name.contains("docker") && active_status == "active" {
                        debug!("Collecting Docker sub-services for service: {}", service_name);

                        let docker_containers = self.get_docker_containers();
                        debug!("Found {} Docker containers", docker_containers.len());
                        for (container_name, container_status) in docker_containers {
                            // For now, docker containers have no additional metrics
                            // Future: could add memory_mb, cpu_percent, restart_count, etc.
                            let metrics = Vec::new();

                            sub_services.push(SubServiceData {
                                name: container_name.clone(),
                                service_status: self.calculate_service_status(&container_name, &container_status),
                                metrics,
                            });
                        }

                        // Add Docker images
                        let docker_images = self.get_docker_images();
                        debug!("Found {} Docker images", docker_images.len());
                        for (image_name, image_status, image_size) in docker_images {
                            let mut metrics = Vec::new();
                            metrics.push(SubServiceMetric {
                                label: "size".to_string(),
                                value: 0.0, // Size as string in name instead
                                unit: None,
                            });

                            sub_services.push(SubServiceData {
                                name: format!("{} ({})", image_name, image_size),
                                service_status: self.calculate_service_status(&image_name, &image_status),
                                metrics,
                            });
                        }

                        debug!("Total Docker sub-services added: {}", sub_services.len());
                    }

                    // Create complete service data
                    let service_data = ServiceData {
                        name: service_name.clone(),
                        memory_mb,
                        disk_gb,
                        user_stopped: false, // TODO: Integrate with service tracker
                        service_status: self.calculate_service_status(service_name, &active_status),
                        sub_services,
                    };

                    // Add to AgentData and cache
                    agent_data.services.push(service_data.clone());
                    complete_service_data.push(service_data);
                }
                Err(e) => {
                    debug!("Failed to get status for service {}: {}", service_name, e);
                }
            }
        }

        // Update cached state
        {
            let mut state = self.state.write().unwrap();
            state.last_collection = Some(start_time);
            state.cached_service_data = complete_service_data;
        }

        let elapsed = start_time.elapsed();
        debug!("Systemd collection completed in {:?} with {} services", elapsed, agent_data.services.len());

        Ok(())
    }

    /// Get monitored services, discovering them if needed or cache is expired
    fn get_monitored_services(&self) -> Result<Vec<String>> {
        // Check if we need discovery without holding the lock
        let needs_discovery = {
            let state = self.state.read().unwrap();
            match state.last_discovery_time {
                None => true, // First time
                Some(last_time) => {
                    let elapsed = last_time.elapsed().as_secs();
                    elapsed >= state.discovery_interval_seconds
                }
            }
        };

        if needs_discovery {
            debug!("Discovering systemd services (cache expired or first run)");
            match self.discover_services_internal() {
                Ok((services, status_cache)) => {
                    if let Ok(mut state) = self.state.write() {
                        state.monitored_services = services.clone();
                        state.service_status_cache = status_cache;
                        state.last_discovery_time = Some(Instant::now());
                        debug!("Auto-discovered {} services to monitor: {:?}", 
                            state.monitored_services.len(), state.monitored_services);
                        return Ok(services);
                    }
                }
                Err(e) => {
                    debug!("Failed to discover services, using cached list: {}", e);
                }
            }
        }

        // Return cached services
        let state = self.state.read().unwrap();
        Ok(state.monitored_services.clone())
    }

    /// Get nginx site metrics, checking them if cache is expired (like old working version)
    fn get_nginx_site_metrics(&self) -> Vec<(String, f32)> {
        let mut state = self.state.write().unwrap();

        // Check if we need to refresh nginx site metrics
        let needs_refresh = match state.last_nginx_check_time {
            None => true, // First time
            Some(last_time) => {
                let elapsed = last_time.elapsed().as_secs();
                elapsed >= state.nginx_check_interval_seconds
            }
        };

        if needs_refresh {
            // Only check nginx sites if nginx service is active
            if state.monitored_services.iter().any(|s| s.contains("nginx")) {
                let fresh_metrics = self.get_nginx_sites_internal();
                state.nginx_site_metrics = fresh_metrics;
                state.last_nginx_check_time = Some(Instant::now());
            }
        }

        state.nginx_site_metrics.clone()
    }

    /// Auto-discover interesting services to monitor
    fn discover_services_internal(&self) -> Result<(Vec<String>, std::collections::HashMap<String, ServiceStatusInfo>)> {
        // First: Get all service unit files
        let unit_files_output = Command::new("systemctl")
            .args(&["list-unit-files", "--type=service", "--no-pager", "--plain"])
            .output()?;

        if !unit_files_output.status.success() {
            return Err(anyhow::anyhow!("systemctl list-unit-files command failed"));
        }

        // Second: Get runtime status of all units
        let units_status_output = Command::new("systemctl")
            .args(&["list-units", "--type=service", "--all", "--no-pager", "--plain"])
            .output()?;

        if !units_status_output.status.success() {
            return Err(anyhow::anyhow!("systemctl list-units command failed"));
        }

        let unit_files_str = String::from_utf8(unit_files_output.stdout)?;
        let units_status_str = String::from_utf8(units_status_output.stdout)?;
        let mut services = Vec::new();

        let excluded_services = &self.config.excluded_services;
        let service_name_filters = &self.config.service_name_filters;

        // Parse all service unit files
        let mut all_service_names = std::collections::HashSet::new();
        for line in unit_files_str.lines() {
            let fields: Vec<&str> = line.split_whitespace().collect();
            if fields.len() >= 2 && fields[0].ends_with(".service") {
                let service_name = fields[0].trim_end_matches(".service");
                all_service_names.insert(service_name.to_string());
            }
        }

        // Parse runtime status for all units
        let mut status_cache = std::collections::HashMap::new();
        for line in units_status_str.lines() {
            let fields: Vec<&str> = line.split_whitespace().collect();
            if fields.len() >= 4 && fields[0].ends_with(".service") {
                let service_name = fields[0].trim_end_matches(".service");
                let load_state = fields.get(1).unwrap_or(&"unknown").to_string();
                let active_state = fields.get(2).unwrap_or(&"unknown").to_string();
                let sub_state = fields.get(3).unwrap_or(&"unknown").to_string();

                status_cache.insert(service_name.to_string(), ServiceStatusInfo {
                    load_state,
                    active_state,
                    sub_state,
                });
            }
        }

        // For services found in unit files but not in runtime status, set default inactive status
        for service_name in &all_service_names {
            if !status_cache.contains_key(service_name) {
                status_cache.insert(service_name.to_string(), ServiceStatusInfo {
                    load_state: "not-loaded".to_string(),
                    active_state: "inactive".to_string(),
                    sub_state: "dead".to_string(),
                });
            }
        }

        // Process all discovered services and apply filters
        for service_name in &all_service_names {
            // Skip excluded services first
            let mut is_excluded = false;
            for excluded in excluded_services {
                if service_name.contains(excluded) {
                    is_excluded = true;
                    break;
                }
            }

            if is_excluded {
                continue;
            }

            // Check if this service matches our filter patterns (supports wildcards)
            for pattern in service_name_filters {
                if self.matches_pattern(service_name, pattern) {
                    services.push(service_name.to_string());
                    break;
                }
            }
        }

        Ok((services, status_cache))
    }

    /// Get service status from cache (if available) or fallback to systemctl
    fn get_service_status(&self, service: &str) -> Result<(String, String)> {
        // Try to get status from cache first
        if let Ok(state) = self.state.read() {
            if let Some(cached_info) = state.service_status_cache.get(service) {
                let active_status = cached_info.active_state.clone();
                let detailed_info = format!(
                    "LoadState={}\nActiveState={}\nSubState={}",
                    cached_info.load_state,
                    cached_info.active_state,
                    cached_info.sub_state
                );
                return Ok((active_status, detailed_info));
            }
        }

        // Fallback to systemctl if not in cache
        let output = Command::new("systemctl")
            .args(&["is-active", &format!("{}.service", service)])
            .output()?;

        let active_status = String::from_utf8(output.stdout)?.trim().to_string();

        // Get more detailed info
        let output = Command::new("systemctl")
            .args(&["show", &format!("{}.service", service), "--property=LoadState,ActiveState,SubState"])
            .output()?;

        let detailed_info = String::from_utf8(output.stdout)?;
        Ok((active_status, detailed_info))
    }

    /// Check if service name matches pattern (supports wildcards like nginx*)
    fn matches_pattern(&self, service_name: &str, pattern: &str) -> bool {
        if pattern.contains('*') {
            if pattern.ends_with('*') {
                // Pattern like "nginx*" - match if service starts with "nginx"
                let prefix = &pattern[..pattern.len() - 1];
                service_name.starts_with(prefix)
            } else if pattern.starts_with('*') {
                // Pattern like "*backup" - match if service ends with "backup"
                let suffix = &pattern[1..];
                service_name.ends_with(suffix)
            } else {
                // Pattern like "nginx*backup" - simple glob matching
                self.simple_glob_match(service_name, pattern)
            }
        } else {
            // Exact match
            service_name == pattern
        }
    }

    /// Simple glob matching for patterns with * in the middle
    fn simple_glob_match(&self, text: &str, pattern: &str) -> bool {
        let parts: Vec<&str> = pattern.split('*').collect();
        let mut pos = 0;
        
        for part in parts {
            if part.is_empty() {
                continue;
            }
            if let Some(found_pos) = text[pos..].find(part) {
                pos += found_pos + part.len();
            } else {
                return false;
            }
        }
        true
    }

    /// Get disk usage for a specific service
    async fn get_service_disk_usage(&self, service_name: &str) -> Result<f32, CollectorError> {
        // Check if this service has configured directory paths
        if let Some(dirs) = self.config.service_directories.get(service_name) {
            // Service has configured paths - use the first accessible one
            for dir in dirs {
                if let Some(size) = self.get_directory_size(dir) {
                    return Ok(size);
                }
            }
            // If configured paths failed, return 0
            return Ok(0.0);
        }

        // No configured path - try to get WorkingDirectory from systemctl
        let output = Command::new("systemctl")
            .args(&["show", &format!("{}.service", service_name), "--property=WorkingDirectory"])
            .output()
            .map_err(|e| CollectorError::SystemRead {
                path: format!("WorkingDirectory for {}", service_name),
                error: e.to_string(),
            })?;

        let output_str = String::from_utf8_lossy(&output.stdout);
        for line in output_str.lines() {
            if line.starts_with("WorkingDirectory=") && !line.contains("[not set]") {
                let dir = line.strip_prefix("WorkingDirectory=").unwrap_or("");
                if !dir.is_empty() && dir != "/" {
                    return Ok(self.get_directory_size(dir).unwrap_or(0.0));
                }
            }
        }

        Ok(0.0)
    }
    
    /// Get size of a directory in GB
    fn get_directory_size(&self, path: &str) -> Option<f32> {
        let output = Command::new("sudo")
            .args(&["du", "-sb", path])
            .output()
            .ok()?;

        if !output.status.success() {
            // Log permission errors for debugging but don't spam logs
            let stderr = String::from_utf8_lossy(&output.stderr);
            if stderr.contains("Permission denied") {
                debug!("Permission denied accessing directory: {}", path);
            } else {
                debug!("Failed to get size for directory {}: {}", path, stderr);
            }
            return None;
        }

        let output_str = String::from_utf8(output.stdout).ok()?;
        let size_str = output_str.split_whitespace().next()?;
        if let Ok(size_bytes) = size_str.parse::<u64>() {
            let size_gb = size_bytes as f32 / (1024.0 * 1024.0 * 1024.0);
            // Return size even if very small (minimum 0.001 GB = 1MB for visibility)
            if size_gb > 0.0 {
                Some(size_gb.max(0.001))
            } else {
                None
            }
        } else {
            None
        }
    }

    /// Calculate service status, taking user-stopped services into account
    fn calculate_service_status(&self, service_name: &str, active_status: &str) -> Status {
        match active_status.to_lowercase().as_str() {
            "active" => Status::Ok,
            "inactive" | "dead" => {
                debug!("Service '{}' is inactive - treating as Inactive status", service_name);
                Status::Inactive
            },
            "failed" | "error" => Status::Critical,
            "activating" | "deactivating" | "reloading" | "starting" | "stopping" => {
                debug!("Service '{}' is transitioning - treating as Pending", service_name);
                Status::Pending
            },
            _ => Status::Unknown,
        }
    }

    /// Get memory usage for a specific service
    async fn get_service_memory_usage(&self, service_name: &str) -> Result<f32, CollectorError> {
        let output = Command::new("systemctl")
            .args(&["show", &format!("{}.service", service_name), "--property=MemoryCurrent"])
            .output()
            .map_err(|e| CollectorError::SystemRead {
                path: format!("memory usage for {}", service_name),
                error: e.to_string(),
            })?;

        let output_str = String::from_utf8_lossy(&output.stdout);
        
        for line in output_str.lines() {
            if line.starts_with("MemoryCurrent=") {
                if let Some(mem_str) = line.strip_prefix("MemoryCurrent=") {
                    if mem_str != "[not set]" {
                        if let Ok(memory_bytes) = mem_str.parse::<u64>() {
                            return Ok(memory_bytes as f32 / (1024.0 * 1024.0)); // Convert to MB
                        }
                    }
                }
            }
        }

        Ok(0.0)
    }

    /// Check if service collection cache should be updated
    fn should_update_cache(&self) -> bool {
        let state = self.state.read().unwrap();

        match state.last_collection {
            None => true,
            Some(last) => {
                let cache_duration = std::time::Duration::from_secs(30);
                last.elapsed() > cache_duration
            }
        }
    }

    /// Get cached complete service data with sub-services if available and fresh
    fn get_cached_complete_services(&self) -> Option<Vec<ServiceData>> {
        if !self.should_update_cache() {
            let state = self.state.read().unwrap();
            Some(state.cached_service_data.clone())
        } else {
            None
        }
    }

    /// Get nginx sites with latency checks (internal - no caching)
    fn get_nginx_sites_internal(&self) -> Vec<(String, f32)> {
        let mut sites = Vec::new();

        // Discover nginx sites from configuration
        let discovered_sites = self.discover_nginx_sites();

        // Always add all discovered sites, even if checks fail (like old version)
        for (site_name, url) in &discovered_sites {
            match self.check_site_latency(url) {
                Ok(latency_ms) => {
                    sites.push((site_name.clone(), latency_ms));
                }
                Err(_) => {
                    // Site is unreachable - use -1.0 to indicate error (like old version)
                    sites.push((site_name.clone(), -1.0));
                }
            }
        }

        sites
    }

    /// Discover nginx sites from configuration
    fn discover_nginx_sites(&self) -> Vec<(String, String)> {
        // Use the same approach as the old working agent: get nginx config from systemd
        let config_content = match self.get_nginx_config_from_systemd() {
            Some(content) => content,
            None => {
                debug!("Could not get nginx config from systemd, trying nginx -T fallback");
                match self.get_nginx_config_via_command() {
                    Some(content) => content,
                    None => {
                        debug!("Could not get nginx config via any method");
                        return Vec::new();
                    }
                }
            }
        };

        // Parse the config content to extract sites
        self.parse_nginx_config_for_sites(&config_content)
    }

    /// Fallback: get nginx config via nginx -T command
    fn get_nginx_config_via_command(&self) -> Option<String> {
        let output = Command::new("nginx")
            .args(&["-T"])
            .output()
            .ok()?;

        if !output.status.success() {
            debug!("nginx -T failed");
            return None;
        }

        Some(String::from_utf8_lossy(&output.stdout).to_string())
    }

    /// Get nginx config from systemd service definition (NixOS compatible)
    fn get_nginx_config_from_systemd(&self) -> Option<String> {
        let output = Command::new("systemctl")
            .args(&["show", "nginx", "--property=ExecStart", "--no-pager"])
            .output()
            .ok()?;

        if !output.status.success() {
            debug!("Failed to get nginx ExecStart from systemd");
            return None;
        }

        let stdout = String::from_utf8_lossy(&output.stdout);
        debug!("systemctl show nginx output: {}", stdout);

        // Parse ExecStart to extract -c config path
        for line in stdout.lines() {
            if line.starts_with("ExecStart=") {
                debug!("Found ExecStart line: {}", line);
                if let Some(config_path) = self.extract_config_path_from_exec_start(line) {
                    debug!("Extracted config path: {}", config_path);
                    return std::fs::read_to_string(&config_path).ok();
                }
            }
        }

        None
    }

    /// Extract config path from ExecStart line
    fn extract_config_path_from_exec_start(&self, exec_start: &str) -> Option<String> {
        // Remove ExecStart= prefix
        let exec_part = exec_start.strip_prefix("ExecStart=")?;
        debug!("Parsing exec part: {}", exec_part);

        // Handle NixOS format: ExecStart={ path=...; argv[]=...nginx -c /config; ... }
        if exec_part.contains("argv[]=") {
            // Extract the part after argv[]=
            let argv_start = exec_part.find("argv[]=")?;
            let argv_part = &exec_part[argv_start + 7..]; // Skip "argv[]="
            debug!("Found NixOS argv part: {}", argv_part);

            // Look for -c flag followed by config path
            if let Some(c_pos) = argv_part.find(" -c ") {
                let after_c = &argv_part[c_pos + 4..];
                // Find the config path (until next space or semicolon)
                let config_path = after_c.split([' ', ';']).next()?;
                return Some(config_path.to_string());
            }
        } else {
            // Handle traditional format: ExecStart=/path/nginx -c /config
            debug!("Parsing traditional format");
            if let Some(c_pos) = exec_part.find(" -c ") {
                let after_c = &exec_part[c_pos + 4..];
                let config_path = after_c.split_whitespace().next()?;
                return Some(config_path.to_string());
            }
        }

        None
    }

    /// Parse nginx config content to extract server names and build site list
    fn parse_nginx_config_for_sites(&self, config_content: &str) -> Vec<(String, String)> {
        let mut sites = Vec::new();
        let lines: Vec<&str> = config_content.lines().collect();
        let mut i = 0;

        debug!("Parsing nginx config with {} lines", lines.len());

        while i < lines.len() {
            let line = lines[i].trim();
            if line.starts_with("server") && line.contains("{") {
                if let Some(server_name) = self.parse_server_block(&lines, &mut i) {
                    let url = format!("https://{}", server_name);
                    sites.push((server_name.clone(), url));
                }
            }
            i += 1;
        }

        debug!("Discovered {} nginx sites total", sites.len());
        sites
    }

    /// Parse a server block to extract the primary server_name
    fn parse_server_block(&self, lines: &[&str], start_index: &mut usize) -> Option<String> {
        let mut server_names = Vec::new();
        let mut has_redirect = false;
        let mut i = *start_index + 1;
        let mut brace_count = 1;

        // Parse until we close the server block
        while i < lines.len() && brace_count > 0 {
            let trimmed = lines[i].trim();

            // Track braces
            brace_count += trimmed.matches('{').count();
            brace_count -= trimmed.matches('}').count();

            // Extract server_name
            if trimmed.starts_with("server_name") {
                if let Some(names_part) = trimmed.strip_prefix("server_name") {
                    let names_clean = names_part.trim().trim_end_matches(';');
                    for name in names_clean.split_whitespace() {
                        if name != "_"
                            && !name.is_empty()
                            && name.contains('.')
                            && !name.starts_with('$')
                        {
                            server_names.push(name.to_string());
                            debug!("Found server_name in block: {}", name);
                        }
                    }
                }
            }

            // Check for redirects (skip redirect-only servers)
            if trimmed.contains("return") && (trimmed.contains("301") || trimmed.contains("302")) {
                has_redirect = true;
            }

            i += 1;
        }

        *start_index = i - 1;

        if !server_names.is_empty() && !has_redirect {
            return Some(server_names[0].clone());
        }

        None
    }

    /// Check site latency using HTTP GET requests
    fn check_site_latency(&self, url: &str) -> Result<f32, Box<dyn std::error::Error>> {
        use std::time::Duration;
        use std::time::Instant;

        let start = Instant::now();

        // Create HTTP client with timeouts from configuration
        let client = reqwest::blocking::Client::builder()
            .timeout(Duration::from_secs(self.config.http_timeout_seconds))
            .connect_timeout(Duration::from_secs(self.config.http_connect_timeout_seconds))
            .redirect(reqwest::redirect::Policy::limited(10))
            .build()?;

        // Make GET request and measure latency
        let response = client.get(url).send()?;
        let latency = start.elapsed().as_millis() as f32;

        // Check if response is successful (2xx or 3xx status codes)
        if response.status().is_success() || response.status().is_redirection() {
            Ok(latency)
        } else {
            Err(format!(
                "HTTP request failed for {} with status: {}",
                url,
                response.status()
            )
            .into())
        }
    }

    /// Get docker containers as sub-services
    fn get_docker_containers(&self) -> Vec<(String, String)> {
        let mut containers = Vec::new();

        // Check if docker is available (use sudo for permissions)
        // Use -a to show ALL containers (running and stopped)
        let output = Command::new("sudo")
            .args(&["docker", "ps", "-a", "--format", "{{.Names}},{{.Status}}"])
            .output();

        let output = match output {
            Ok(out) if out.status.success() => out,
            _ => return containers, // Docker not available or failed
        };

        let output_str = match String::from_utf8(output.stdout) {
            Ok(s) => s,
            Err(_) => return containers,
        };

        for line in output_str.lines() {
            if line.trim().is_empty() {
                continue;
            }

            let parts: Vec<&str> = line.split(',').collect();
            if parts.len() >= 2 {
                let container_name = parts[0].trim();
                let status_str = parts[1].trim();

                let container_status = if status_str.contains("Up") {
                    "active"
                } else if status_str.contains("Exited") || status_str.contains("Created") {
                    "inactive" // Stopped/created containers are inactive
                } else {
                    "failed" // Other states (restarting, paused, dead) → failed
                };
                
                containers.push((format!("docker_{}", container_name), container_status.to_string()));
            }
        }

        containers
    }

    /// Get docker images as sub-services
    fn get_docker_images(&self) -> Vec<(String, String, String)> {
        let mut images = Vec::new();

        debug!("Collecting Docker images");

        // Check if docker is available (use sudo for permissions)
        let output = Command::new("sudo")
            .args(&["docker", "images", "--format", "{{.Repository}}:{{.Tag}},{{.Size}}"])
            .output();

        let output = match output {
            Ok(out) if out.status.success() => out,
            Ok(out) => {
                debug!("Docker images command failed with status: {}", out.status);
                return images;
            }
            Err(e) => {
                debug!("Docker images command error: {}", e);
                return images;
            }
        };

        let output_str = match String::from_utf8(output.stdout) {
            Ok(s) => s,
            Err(_) => return images,
        };

        for line in output_str.lines() {
            if line.trim().is_empty() {
                continue;
            }

            let parts: Vec<&str> = line.split(',').collect();
            if parts.len() >= 2 {
                let image_name = parts[0].trim();
                let size = parts[1].trim();

                // Skip <none>:<none> images (dangling images)
                if image_name.contains("<none>") {
                    continue;
                }

                images.push((
                    format!("image_{}", image_name),
                    "active".to_string(), // Images are always "active" (present)
                    size.to_string()
                ));
            }
        }

        images
    }
}

#[async_trait]
impl Collector for SystemdCollector {
    async fn collect_structured(&self, agent_data: &mut AgentData) -> Result<(), CollectorError> {
        // Use cached complete data if available and fresh
        if let Some(cached_complete_services) = self.get_cached_complete_services() {
            for service_data in cached_complete_services {
                agent_data.services.push(service_data);
            }
            Ok(())
        } else {
            // Collect fresh data
            self.collect_service_data(agent_data).await
        }
    }
}