//! Internal system commands for advanced operations

use crate::commands::Command;
use apt_ostree::lib::error::{AptOstreeError, AptOstreeResult};
use apt_ostree::lib::ostree::OstreeManager;
use apt_ostree::lib::apt::AptManager;
use std::fs;
use std::path::Path;
use std::process::Command as ProcessCommand;
use std::os::unix::fs::PermissionsExt;

/// Internals command - Internal system commands for advanced operations
pub struct InternalsCommand;

impl InternalsCommand {
    pub fn new() -> Self {
        InternalsCommand
    }
}

#[cfg(feature = "development")]
impl Command for InternalsCommand {
    fn execute(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.is_empty() || args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            self.show_help();
            return Ok(());
        }

        let subcommand = &args[0];
        let sub_args = &args[1..];

        match subcommand.as_str() {
            "diagnostics" => self.handle_diagnostics(sub_args),
            "validate-state" => self.handle_validate_state(sub_args),
            "debug-dump" => self.handle_debug_dump(sub_args),
            "system-health" => self.handle_system_health(sub_args),
            "performance" => self.handle_performance(sub_args),
            "security" => self.handle_security(sub_args),
            _ => {
                println!("Unknown internals subcommand: {}", subcommand);
                println!("Use 'apt-ostree internals --help' for available subcommands");
                Ok(())
            }
        }
    }

    fn name(&self) -> &'static str {
        "internals"
    }

    fn description(&self) -> &'static str {
        "Internal system commands for advanced operations"
    }

    fn show_help(&self) {
        println!("Usage: apt-ostree internals <SUBCOMMAND> [OPTIONS]");
        println!();
        println!("Internal system commands for apt-ostree.");
        println!("These commands are for advanced system operations and diagnostics.");
        println!();
        println!("Subcommands:");
        println!("  diagnostics               Internal system diagnostics");
        println!("  validate-state           System state validation");
        println!("  debug-dump               Debug information dump");
        println!("  system-health            Real-time system health monitoring");
        println!("  performance              System performance analysis");
        println!("  security                 Security status and vulnerability checks");
        println!();
        println!("Options:");
        println!("  --help, -h               Show this help message");
        println!();
        println!("Examples:");
        println!("  apt-ostree internals diagnostics");
        println!("  apt-ostree internals validate-state");
        println!("  apt-ostree internals debug-dump");
    }
}

impl InternalsCommand {
    fn handle_diagnostics(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("🔍 Running Internal Diagnostics");
        println!("===============================");

        // Check system components
        self.check_ostree_system()?;
        self.check_apt_system()?;
        self.check_daemon_status()?;
        self.check_file_permissions()?;

        println!("Diagnostics completed successfully");
        Ok(())
    }

    fn handle_validate_state(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("✅ Validating System State");
        println!("===========================");

        // Validate OSTree state
        let ostree_manager = OstreeManager::new();
        if ostree_manager.is_available() {
            println!("OSTree: Available");
            self.validate_ostree_state(&ostree_manager)?;
        } else {
            println!("OSTree: Not available");
        }

        // Validate APT state
        let apt_manager = AptManager::new();
        self.validate_apt_state(&apt_manager)?;

        println!("System state validation completed");
        Ok(())
    }

    fn handle_debug_dump(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("🐛 Debug Information Dump");
        println!("=========================");

        // System information
        self.dump_system_info()?;

        // OSTree information
        self.dump_ostree_info()?;

        // APT information
        self.dump_apt_info()?;

        // Daemon information
        self.dump_daemon_info()?;

        println!("Debug information dump completed");
        Ok(())
    }

    fn check_ostree_system(&self) -> AptOstreeResult<()> {
        println!("Checking OSTree system...");
        
        let ostree_manager = OstreeManager::new();
        if ostree_manager.is_available() {
            println!("  ✓ OSTree is available");
            if ostree_manager.is_ostree_booted() {
                println!("  ✓ System is booted from OSTree");
            } else {
                println!("  ⚠ System is not booted from OSTree");
            }
        } else {
            println!("  ❌ OSTree is not available");
        }

        Ok(())
    }

    fn check_apt_system(&self) -> AptOstreeResult<()> {
        println!("Checking APT system...");
        
        let _apt_manager = AptManager::new();
        
        // Check if apt-get is available
        if ProcessCommand::new("apt-get").arg("--version").output().is_ok() {
            println!("  ✓ apt-get is available");
        } else {
            println!("  ❌ apt-get is not available");
        }

        // Check APT cache directory
        let cache_dir = "/var/cache/apt";
        if Path::new(cache_dir).exists() {
            println!("  ✓ APT cache directory exists: {}", cache_dir);
        } else {
            println!("  ❌ APT cache directory missing: {}", cache_dir);
        }

        Ok(())
    }

    fn check_daemon_status(&self) -> AptOstreeResult<()> {
        println!("Checking daemon status...");
        
        // Check if daemon service is running
        let output = ProcessCommand::new("systemctl")
            .arg("is-active")
            .arg("apt-ostreed")
            .output();

        match output {
            Ok(output) => {
                let status = String::from_utf8_lossy(&output.stdout).trim().to_string();
                if status == "active" {
                    println!("  ✓ apt-ostreed service is active");
                } else {
                    println!("  ⚠ apt-ostreed service status: {}", status);
                }
            }
            Err(_) => {
                println!("  ❌ Could not check apt-ostreed service status");
            }
        }

        Ok(())
    }

    fn check_file_permissions(&self) -> AptOstreeResult<()> {
        println!("Checking file permissions...");
        
        // Check key directories
        let dirs = [
            ("/etc/apt", "APT configuration"),
            ("/var/lib/apt", "APT state"),
            ("/var/cache/apt", "APT cache"),
            ("/var/lib/ostree", "OSTree data"),
        ];

        for (path, description) in &dirs {
            if Path::new(path).exists() {
                let metadata = fs::metadata(path)
                    .map_err(|_| AptOstreeError::System(format!("Could not read metadata for {}", path)))?;
                
                let permissions = metadata.permissions();
                let mode = permissions.mode();
                
                println!("  ✓ {}: {:o}", description, mode & 0o777);
            } else {
                println!("  ❌ {}: directory does not exist", description);
            }
        }

        Ok(())
    }

    fn validate_ostree_state(&self, ostree_manager: &OstreeManager) -> AptOstreeResult<()> {
        println!("Validating OSTree state...");
        
        // Check deployments
        match ostree_manager.list_deployments() {
            Ok(deployments) => {
                println!("  ✓ Found {} deployments", deployments.len());
                for deployment in &deployments {
                    let status = if deployment.booted { "Booted" } else { "Available" };
                    println!("    - {}: {} ({})", deployment.id, status, deployment.commit);
                }
            }
            Err(e) => {
                println!("  ❌ Failed to list deployments: {}", e);
            }
        }

        // Check current deployment
        match ostree_manager.get_current_deployment() {
            Ok(Some(current)) => {
                println!("  ✓ Current deployment: {} ({})", current.id, current.commit);
            }
            Ok(None) => {
                println!("  ⚠ No current deployment found");
            }
            Err(e) => {
                println!("  ❌ Failed to get current deployment: {}", e);
            }
        }

        Ok(())
    }

    fn validate_apt_state(&self, _apt_manager: &AptManager) -> AptOstreeResult<()> {
        println!("Validating APT state...");
        
        // Check APT sources
        let sources_list = "/etc/apt/sources.list";
        if Path::new(sources_list).exists() {
            println!("  ✓ APT sources list exists");
        } else {
            println!("  ⚠ APT sources list missing");
        }

        // Check APT cache
        let cache_dir = "/var/cache/apt";
        if Path::new(cache_dir).exists() {
            let entries = fs::read_dir(cache_dir)
                .map_err(|_| AptOstreeError::System("Could not read APT cache directory".to_string()))?;
            
            let count = entries.count();
            println!("  ✓ APT cache contains {} entries", count);
        }

        Ok(())
    }

    fn dump_system_info(&self) -> AptOstreeResult<()> {
        println!("System Information:");
        println!("===================");
        
        // OS information
        if let Ok(os_release) = fs::read_to_string("/etc/os-release") {
            for line in os_release.lines() {
                if line.starts_with("PRETTY_NAME=") || line.starts_with("VERSION=") {
                    println!("  {}", line);
                }
            }
        }

        // Architecture
        if let Ok(output) = ProcessCommand::new("uname").arg("-m").output() {
            let arch = String::from_utf8_lossy(&output.stdout).trim().to_string();
            println!("  Architecture: {}", arch);
        }

        // Kernel version
        if let Ok(output) = ProcessCommand::new("uname").arg("-r").output() {
            let kernel = String::from_utf8_lossy(&output.stdout).trim().to_string();
            println!("  Kernel: {}", kernel);
        }

        Ok(())
    }

    fn dump_ostree_info(&self) -> AptOstreeResult<()> {
        println!("OSTree Information:");
        println!("===================");
        
        let ostree_manager = OstreeManager::new();
        if ostree_manager.is_available() {
            let system_info = ostree_manager.get_system_info();
            println!("  OS: {}", system_info.os);
            println!("  Kernel: {}", system_info.kernel);
            println!("  Architecture: {}", system_info.architecture);
            
            match ostree_manager.get_repo_info() {
                Ok(repo_info) => {
                    println!("  Repository: {}", repo_info.path);
                    println!("  Available refs: {}", repo_info.refs.len());
                }
                Err(e) => {
                    println!("  ❌ Failed to get repo info: {}", e);
                }
            }
        } else {
            println!("  OSTree not available");
        }

        Ok(())
    }

    fn dump_apt_info(&self) -> AptOstreeResult<()> {
        println!("APT Information:");
        println!("================");
        
        // APT version
        if let Ok(output) = ProcessCommand::new("apt-get").arg("--version").output() {
            let version = String::from_utf8_lossy(&output.stdout).lines().next().unwrap_or("Unknown").to_string();
            println!("  Version: {}", version);
        }

        // APT configuration
        let config_dirs = ["/etc/apt/apt.conf.d", "/etc/apt/sources.list.d"];
        for dir in &config_dirs {
            if Path::new(dir).exists() {
                if let Ok(entries) = fs::read_dir(dir) {
                    let count = entries.count();
                    println!("  Config files in {}: {}", dir, count);
                }
            }
        }

        Ok(())
    }

    fn dump_daemon_info(&self) -> AptOstreeResult<()> {
        println!("Daemon Information:");
        println!("===================");
        
        // Service status
        if let Ok(output) = ProcessCommand::new("systemctl").arg("show").arg("apt-ostreed").arg("--property=ActiveState").output() {
            let status = String::from_utf8_lossy(&output.stdout).lines().next().unwrap_or("Unknown").to_string();
            println!("  Service status: {}", status);
        }

        // Process information
        if let Ok(output) = ProcessCommand::new("pgrep").arg("-f").arg("apt-ostreed").output() {
            let pids: Vec<String> = String::from_utf8_lossy(&output.stdout).lines().map(|s| s.to_string()).collect();
            if !pids.is_empty() {
                println!("  Running processes: {}", pids.join(", "));
            } else {
                println!("  No running processes found");
            }
        }

        Ok(())
    }

    fn handle_system_health(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("🏥 System Health Monitoring");
        println!("============================");

        // Check system resources
        self.check_system_resources()?;
        
        // Check service health
        self.check_service_health()?;
        
        // Check filesystem health
        self.check_filesystem_health()?;
        
        // Check network connectivity
        self.check_network_health()?;

        println!("System health check completed");
        Ok(())
    }

    fn handle_performance(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("⚡ System Performance Analysis");
        println!("==============================");

        // CPU performance
        self.analyze_cpu_performance()?;
        
        // Memory performance
        self.analyze_memory_performance()?;
        
        // Disk I/O performance
        self.analyze_disk_performance()?;
        
        // Process performance
        self.analyze_process_performance()?;

        println!("Performance analysis completed");
        Ok(())
    }

    fn handle_security(&self, _args: &[String]) -> AptOstreeResult<()> {
        println!("🔒 Security Status Check");
        println!("=========================");

        // Check system updates
        self.check_security_updates()?;
        
        // Check file permissions
        self.check_security_permissions()?;
        
        // Check open ports
        self.check_open_ports()?;
        
        // Check user accounts
        self.check_user_security()?;

        println!("Security check completed");
        Ok(())
    }

    // System Health Methods
    fn check_system_resources(&self) -> AptOstreeResult<()> {
        println!("Checking system resources...");
        
        // CPU usage
        if let Ok(output) = ProcessCommand::new("top").arg("-bn1").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            if let Some(line) = output_str.lines().find(|l| l.contains("Cpu(s)")) {
                println!("  CPU: {}", line.trim());
            }
        }
        
        // Memory usage
        if let Ok(output) = ProcessCommand::new("free").arg("-h").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            if let Some(line) = output_str.lines().nth(1) {
                println!("  Memory: {}", line.trim());
            }
        }
        
        // Disk usage
        if let Ok(output) = ProcessCommand::new("df").arg("-h").arg("/").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            if let Some(line) = output_str.lines().nth(1) {
                println!("  Root filesystem: {}", line.trim());
            }
        }
        
        Ok(())
    }

    fn check_service_health(&self) -> AptOstreeResult<()> {
        println!("Checking service health...");
        
        let services = ["apt-ostreed", "systemd-udevd", "systemd-logind"];
        for service in &services {
            let output = ProcessCommand::new("systemctl")
                .arg("is-active")
                .arg(service)
                .output();
            
            match output {
                Ok(output) => {
                    let status = String::from_utf8_lossy(&output.stdout).trim().to_string();
                    if status == "active" {
                        println!("  ✓ {}: {}", service, status);
                    } else {
                        println!("  ⚠ {}: {}", service, status);
                    }
                }
                Err(_) => {
                    println!("  ❌ {}: status check failed", service);
                }
            }
        }
        
        Ok(())
    }

    fn check_filesystem_health(&self) -> AptOstreeResult<()> {
        println!("Checking filesystem health...");
        
        // Check for read-only filesystems
        if let Ok(output) = ProcessCommand::new("mount").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            let ro_count = output_str.lines().filter(|l| l.contains("ro,")).count();
            if ro_count > 0 {
                println!("  ⚠ Found {} read-only filesystems", ro_count);
            } else {
                println!("  ✓ All filesystems are writable");
            }
        }
        
        // Check for full filesystems
        if let Ok(output) = ProcessCommand::new("df").arg("-h").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            for line in output_str.lines().skip(1) {
                if line.contains("100%") || line.contains("95%") {
                    println!("  ⚠ High disk usage: {}", line.trim());
                }
            }
        }
        
        Ok(())
    }

    fn check_network_health(&self) -> AptOstreeResult<()> {
        println!("Checking network health...");
        
        // Check localhost connectivity
        if let Ok(output) = ProcessCommand::new("ping").arg("-c1").arg("127.0.0.1").output() {
            if output.status.success() {
                println!("  ✓ Localhost connectivity: OK");
            } else {
                println!("  ❌ Localhost connectivity: Failed");
            }
        }
        
        // Check DNS resolution
        if let Ok(output) = ProcessCommand::new("nslookup").arg("debian.org").output() {
            if output.status.success() {
                println!("  ✓ DNS resolution: OK");
            } else {
                println!("  ❌ DNS resolution: Failed");
            }
        }
        
        Ok(())
    }

    // Performance Analysis Methods
    fn analyze_cpu_performance(&self) -> AptOstreeResult<()> {
        println!("Analyzing CPU performance...");
        
        // CPU load average
        if let Ok(output) = ProcessCommand::new("uptime").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            if let Some(load_part) = output_str.split("load average:").nth(1) {
                println!("  Load average: {}", load_part.trim());
            }
        }
        
        // CPU info
        if let Ok(output) = ProcessCommand::new("nproc").output() {
            let cores = String::from_utf8_lossy(&output.stdout).trim().to_string();
            println!("  CPU cores: {}", cores);
        }
        
        Ok(())
    }

    fn analyze_memory_performance(&self) -> AptOstreeResult<()> {
        println!("Analyzing memory performance...");
        
        // Memory statistics
        if let Ok(output) = ProcessCommand::new("vmstat").arg("-s").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            for line in output_str.lines() {
                if line.contains("total memory") || line.contains("used memory") || line.contains("active memory") {
                    println!("  {}", line.trim());
                }
            }
        }
        
        Ok(())
    }

    fn analyze_disk_performance(&self) -> AptOstreeResult<()> {
        println!("Analyzing disk performance...");
        
        // Disk I/O statistics
        if let Ok(output) = ProcessCommand::new("iostat").arg("-x").arg("1").arg("1").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            if let Some(line) = output_str.lines().last() {
                if line.contains("Device") {
                    println!("  I/O stats: {}", line.trim());
                }
            }
        }
        
        Ok(())
    }

    fn analyze_process_performance(&self) -> AptOstreeResult<()> {
        println!("Analyzing process performance...");
        
        // Top processes by CPU
        if let Ok(output) = ProcessCommand::new("ps").arg("aux").arg("--sort=-%cpu").arg("--no-headers").arg("|").arg("head").arg("-5").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            println!("  Top CPU processes:");
            for line in output_str.lines().take(5) {
                println!("    {}", line.trim());
            }
        }
        
        Ok(())
    }

    // Security Methods
    fn check_security_updates(&self) -> AptOstreeResult<()> {
        println!("Checking security updates...");
        
        // Check for available updates
        if let Ok(output) = ProcessCommand::new("apt-get").arg("-s").arg("upgrade").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            let update_count = output_str.lines().filter(|l| l.contains("upgraded")).count();
            if update_count > 0 {
                println!("  ⚠ {} packages can be upgraded", update_count);
            }
        }
        
        Ok(())
    }

    fn check_security_permissions(&self) -> AptOstreeResult<()> {
        println!("Checking security permissions...");
        
        // Check world-writable files
        let critical_dirs = ["/etc", "/var", "/usr"];
        for dir in &critical_dirs {
            if Path::new(dir).exists() {
                if let Ok(output) = ProcessCommand::new("find").arg(dir).arg("-type").arg("f").arg("-perm").arg("-002").arg("-ls").output() {
                    let count = String::from_utf8_lossy(&output.stdout).lines().count();
                    if count > 0 {
                        println!("  ⚠ Found {} world-writable files in {}", count, dir);
                    }
                }
            }
        }
        
        Ok(())
    }

    fn check_open_ports(&self) -> AptOstreeResult<()> {
        println!("Checking open ports...");
        
        // Check listening ports
        if let Ok(output) = ProcessCommand::new("ss").arg("-tlnp").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            let port_count = output_str.lines().count() - 1; // Subtract header
            println!("  Listening ports: {}", port_count);
            
            // Show specific ports
            for line in output_str.lines().skip(1).take(5) {
                println!("    {}", line.trim());
            }
        }
        
        Ok(())
    }

    fn check_user_security(&self) -> AptOstreeResult<()> {
        println!("Checking user security...");
        
        // Check for users with UID 0 (root)
        if let Ok(output) = ProcessCommand::new("awk").arg("-F:").arg("$3==0").arg("/etc/passwd").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            let root_users: Vec<&str> = output_str.lines().collect();
            println!("  Users with UID 0: {}", root_users.join(", "));
        }
        
        // Check for users without passwords
        if let Ok(output) = ProcessCommand::new("awk").arg("-F:").arg("$2==\"\" || $2==\"!\" || $2==\"!!\" || $2==\"*\" || $2==\"x\"").arg("/etc/shadow").output() {
            let output_str = String::from_utf8_lossy(&output.stdout);
            let count = String::from_utf8_lossy(&output.stdout).lines().count();
            if count > 0 {
                println!("  ⚠ Found {} users without passwords", count);
            } else {
                println!("  ✓ All users have passwords");
            }
        }
        
        Ok(())
    }
}
