use apt_ostree::lib::error::{AptOstreeError, AptOstreeResult};
use apt_ostree::lib::ostree::OstreeManager;
use crate::commands::Command;

/// Experimental command - Provides experimental/advanced features
pub struct ExCommand;

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

impl Command for ExCommand {
    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() {
            "unpack" => self.handle_unpack(sub_args),
            "history" => self.handle_history(sub_args),
            "initramfs-etc" => self.handle_initramfs_etc(sub_args),
            "module" => self.handle_module(sub_args),
            "rebuild" => self.handle_rebuild(sub_args),
            "deploy-from-self" => self.handle_deploy_from_self(sub_args),
            _ => {
                println!("Unknown experimental subcommand: {}", subcommand);
                println!("Use 'apt-ostree ex --help' for available subcommands");
                Ok(())
            }
        }
    }

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

    fn description(&self) -> &'static str {
        "Experimental commands and advanced features"
    }

    fn show_help(&self) {
        println!("Usage: apt-ostree ex <SUBCOMMAND> [OPTIONS]");
        println!();
        println!("Experimental commands and advanced features for apt-ostree.");
        println!("These commands are experimental and may change or be removed.");
        println!();
        println!("Subcommands:");
        println!("  unpack              Unpack OSTree commit to filesystem");
        println!("  history             Show commit history");
        println!("  initramfs-etc       Manage initramfs /etc files");
        println!("  module              Manage kernel modules");
        println!("  rebuild             Rebuild OSTree tree");
        println!("  deploy-from-self    Deploy from current system");
        println!();
        println!("Options:");
        println!("  --help, -h          Show this help message");
        println!();
        println!("Examples:");
        println!("  apt-ostree ex unpack /path/to/commit /path/to/dest");
        println!("  apt-ostree ex history --limit 10");
        println!("  apt-ostree ex initramfs-etc --add /etc/fstab");
    }
}

impl ExCommand {
    fn handle_unpack(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex unpack <COMMIT> <DESTINATION>");
            println!();
            println!("Unpack an OSTree commit to a filesystem location.");
            println!();
            println!("Arguments:");
            println!("  COMMIT              OSTree commit hash or ref");
            println!("  DESTINATION         Destination directory path");
            println!();
            println!("Options:");
            println!("  --help, -h          Show this help message");
            return Ok(());
        }

        if args.len() < 2 {
            return Err(AptOstreeError::InvalidArgument("unpack requires commit and destination arguments".to_string()));
        }

        let commit = &args[0];
        let destination = &args[1];

        println!("🔓 Unpacking OSTree Commit");
        println!("==========================");
        println!("Commit: {}", commit);
        println!("Destination: {}", destination);
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }
        
        if !ostree_manager.is_ostree_booted() {
            return Err(AptOstreeError::System("System is not booted from OSTree".to_string()));
        }
        
        // Validate destination path
        let dest_path = std::path::Path::new(destination);
        if dest_path.exists() {
            if !dest_path.is_dir() {
                return Err(AptOstreeError::System("Destination must be a directory".to_string()));
            }
            
            // Check if directory is empty
            if let Ok(entries) = std::fs::read_dir(dest_path) {
                if entries.count() > 0 {
                    println!("⚠️  Warning: Destination directory is not empty");
                    println!("  This may cause conflicts during unpacking");
                }
            }
        } else {
            // Create destination directory
            println!("Creating destination directory: {}", destination);
            if let Err(e) = std::fs::create_dir_all(dest_path) {
                return Err(AptOstreeError::System(format!("Failed to create destination directory: {}", e)));
            }
        }
        
        // Check if commit exists
        println!("Validating commit: {}", commit);
        
        let commit_check = std::process::Command::new("ostree")
            .arg("log")
            .arg(commit)
            .output();
            
        match commit_check {
            Ok(output) if output.status.success() => {
                let log_output = String::from_utf8_lossy(&output.stdout);
                if let Some(first_line) = log_output.lines().next() {
                    println!("✅ Commit found: {}", first_line.trim());
                }
            }
            Ok(_) => {
                println!("⚠️  Commit validation completed with warnings");
            }
            Err(_) => {
                return Err(AptOstreeError::System(format!("Commit {} not found or invalid", commit)));
            }
        }
        
        // Simulate unpacking process
        println!("\nStarting unpack process...");
        println!("  Source: {}", commit);
        println!("  Destination: {}", destination);
        println!("  Mode: read-only extraction");
        
        // Check available disk space
        let disk_space = std::process::Command::new("df")
            .arg("-h")
            .arg(destination)
            .output();
            
        if let Ok(output) = disk_space {
            if output.status.success() {
                let space_output = String::from_utf8_lossy(&output.stdout);
                if let Some(space_line) = space_output.lines().nth(1) {
                    let parts: Vec<&str> = space_line.split_whitespace().collect();
                    if parts.len() >= 4 {
                        let available = parts[3];
                        println!("  Available space: {}", available);
                    }
                }
            }
        }
        
        // Simulate progress
        println!("  Progress: 0% - Initializing...");
        std::thread::sleep(std::time::Duration::from_millis(500));
        
        println!("  Progress: 25% - Reading commit metadata...");
        std::thread::sleep(std::time::Duration::from_millis(500));
        
        println!("  Progress: 50% - Extracting files...");
        std::thread::sleep(std::time::Duration::from_millis(500));
        
        println!("  Progress: 75% - Verifying integrity...");
        std::thread::sleep(std::time::Duration::from_millis(500));
        
        println!("  Progress: 100% - Unpacking completed");
        
        // Show summary
        println!("\nUnpacking Summary:");
        println!("  ✅ Commit: {} successfully unpacked", commit);
        println!("  📁 Destination: {}", destination);
        println!("  📊 Files extracted: ~15,000 (simulated)");
        println!("  💾 Size: ~2.5 GB (simulated)");
        println!("  ⏱️  Duration: ~2 seconds (simulated)");
        
        println!("\nNote: This is a simulation. In a real implementation, this would:");
        println!("  - Extract the actual OSTree commit to the destination");
        println!("  - Preserve file permissions and metadata");
        println!("  - Handle hard links and symbolic links");
        println!("  - Verify file integrity");
        
        Ok(())
    }

    fn handle_history(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex history [OPTIONS]");
            println!();
            println!("Show OSTree commit history.");
            println!();
            println!("Options:");
            println!("  --limit <N>         Limit number of commits shown");
            println!("  --since <DATE>      Show commits since date");
            println!("  --until <DATE>      Show commits until date");
            println!("  --help, -h          Show this help message");
            return Ok(());
        }

        println!("📜 OSTree Commit History");
        println!("========================");

        // Parse options
        let mut limit = 50;
        let mut since = None;
        let mut until = None;

        let mut i = 0;
        while i < args.len() {
            match args[i].as_str() {
                "--limit" => {
                    if i + 1 < args.len() {
                        limit = args[i + 1].parse().unwrap_or(50);
                        i += 1;
                    }
                }
                "--since" => {
                    if i + 1 < args.len() {
                        since = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                "--until" => {
                    if i + 1 < args.len() {
                        until = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                _ => {}
            }
            i += 1;
        }

        println!("Limit: {}", limit);
        if let Some(ref s) = since {
            println!("Since: {}", s);
        }
        if let Some(ref u) = until {
            println!("Until: {}", u);
        }
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }

        println!("Status: History retrieval initiated");
        println!("Next: Implement real history logic when daemon is ready");
        println!();
        println!("Note: This is an experimental feature");

        Ok(())
    }

    fn handle_initramfs_etc(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex initramfs-etc [OPTIONS]");
            println!();
            println!("Manage initramfs /etc files.");
            println!();
            println!("Options:");
            println!("  --add <FILE>         Add file to initramfs /etc");
            println!("  --remove <FILE>      Remove file from initramfs /etc");
            println!("  --list               List current initramfs /etc files");
            println!("  --help, -h           Show this help message");
            return Ok(());
        }

        println!("📁 Initramfs /etc Management");
        println!("=============================");

        // Parse options
        let mut add_file = None;
        let mut remove_file = None;
        let mut list_files = false;

        let mut i = 0;
        while i < args.len() {
            match args[i].as_str() {
                "--add" => {
                    if i + 1 < args.len() {
                        add_file = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                "--remove" => {
                    if i + 1 < args.len() {
                        remove_file = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                "--list" => list_files = true,
                _ => {}
            }
            i += 1;
        }

        if let Some(ref file) = add_file {
            println!("Add file: {}", file);
        }
        if let Some(ref file) = remove_file {
            println!("Remove file: {}", file);
        }
        if list_files {
            println!("List files: enabled");
        }
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }

        println!("Status: Initramfs /etc operation initiated");
        println!("Next: Implement real initramfs /etc logic when daemon is ready");
        println!();
        println!("Note: This is an experimental feature");

        Ok(())
    }

    fn handle_module(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex module [OPTIONS]");
            println!();
            println!("Manage kernel modules in OSTree deployments.");
            println!();
            println!("Options:");
            println!("  --install <MODULE>   Install kernel module");
            println!("  --remove <MODULE>    Remove kernel module");
            println!("  --list               List installed modules");
            println!("  --help, -h           Show this help message");
            return Ok(());
        }

        println!("🔧 Kernel Module Management");
        println!("============================");

        // Parse options
        let mut install_module = None;
        let mut remove_module = None;
        let mut list_modules = false;

        let mut i = 0;
        while i < args.len() {
            match args[i].as_str() {
                "--install" => {
                    if i + 1 < args.len() {
                        install_module = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                "--remove" => {
                    if i + 1 < args.len() {
                        remove_module = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                "--list" => list_modules = true,
                _ => {}
            }
            i += 1;
        }

        if let Some(ref module) = install_module {
            println!("Install module: {}", module);
        }
        if let Some(ref module) = remove_module {
            println!("Remove module: {}", module);
        }
        if list_modules {
            println!("List modules: enabled");
        }
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }

        println!("Status: Module operation initiated");
        println!("Next: Implement real module logic when daemon is ready");
        println!();
        println!("Note: This is an experimental feature");

        Ok(())
    }

    fn handle_rebuild(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex rebuild [OPTIONS]");
            println!();
            println!("Rebuild OSTree tree from current state.");
            println!();
            println!("Options:");
            println!("  --force              Force rebuild even if no changes");
            println!("  --output <PATH>      Output path for rebuilt tree");
            println!("  --help, -h           Show this help message");
            return Ok(());
        }

        println!("🔨 OSTree Tree Rebuild");
        println!("======================");

        // Parse options
        let mut force = false;
        let mut output_path = None;

        let mut i = 0;
        while i < args.len() {
            match args[i].as_str() {
                "--force" => force = true,
                "--output" => {
                    if i + 1 < args.len() {
                        output_path = Some(args[i + 1].clone());
                        i += 1;
                    }
                }
                _ => {}
            }
            i += 1;
        }

        if force {
            println!("Force rebuild: enabled");
        }
        if let Some(ref path) = output_path {
            println!("Output path: {}", path);
        }
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }

        println!("Status: Rebuild operation initiated");
        println!("Next: Implement real rebuild logic when daemon is ready");
        println!();
        println!("Note: This is an experimental feature");

        Ok(())
    }

    fn handle_deploy_from_self(&self, args: &[String]) -> AptOstreeResult<()> {
        if args.contains(&"--help".to_string()) || args.contains(&"-h".to_string()) {
            println!("Usage: apt-ostree ex deploy-from-self [OPTIONS]");
            println!();
            println!("Deploy OSTree tree from current system state.");
            println!();
            println!("Options:");
            println!("  --ref <REF>          OSTree reference name");
            println!("  --help, -h           Show this help message");
            return Ok(());
        }

        println!("🚀 Deploy from Current System");
        println!("=============================");

        // Parse options
        let mut ref_name = "debian/13/x86_64".to_string();

        let mut i = 0;
        while i < args.len() {
            if args[i] == "--ref" && i + 1 < args.len() {
                ref_name = args[i + 1].clone();
                i += 1;
            }
            i += 1;
        }

        println!("Reference: {}", ref_name);
        println!();

        // Check if we're on an OSTree system
        let ostree_manager = OstreeManager::new();
        if !ostree_manager.is_available() {
            return Err(AptOstreeError::System("OSTree not available on this system".to_string()));
        }

        println!("Status: Deploy from self operation initiated");
        println!("Next: Implement real deploy from self logic when daemon is ready");
        println!();
        println!("Note: This is an experimental feature");

        Ok(())
    }
}
