use crate::cfg::config::Config;
use std::{
    fs::{self, File, create_dir_all},
    io,
    os::unix::fs::PermissionsExt,
    path::Path,
};

use flate2::read::GzDecoder;
use tar::Archive;
use toml;

use super::types::{Build, Install, Package, Setts};

pub trait ArchiveOperations {
    fn extract_archive(path_to_archive: &str) -> Result<(), std::io::Error>;
    fn check(path_to_archive: String) -> Result<bool, std::io::Error>;
    fn loadmeta(
        minimal_package_meta: &mut Package,
    ) -> Result<(Install, Option<Setts>, Option<Build>), std::io::Error>;
    fn validate_custom_script(script: &str) -> Result<(), std::io::Error>;
    fn validate_path(path: &str, base_dir: &Path) -> Result<std::path::PathBuf, std::io::Error>;
}

impl ArchiveOperations for Package {
    /// Extracts a .tar.gz archive to the cache directory specified in Config.
    ///
    /// This function handles opening the archive file, decompressing it with GzDecoder,
    /// and unpacking the contents into the configured cache directory.
    ///
    /// # Arguments
    /// * `path_to_archive` - A string representing the path to the .tar.gz file.
    ///
    /// # Returns
    /// * `Ok(())` if the archive is successfully unpacked.
    /// * `Err(std::io::Error)` if there's an issue opening, reading, or unpacking the archive.
    fn extract_archive(path_to_archive: &str) -> Result<(), std::io::Error> {
        let config = Config::parse().map_err(|e| std::io::Error::other(e.to_string()))?;
        let cache_dir = &config.paths.cache_dir;
        create_dir_all(cache_dir)?;

        for meta_name in ["INSTALL", "SETTS", "BUILD"] {
            let meta_path = Path::new(cache_dir).join(meta_name);
            if meta_path.exists() {
                fs::remove_file(&meta_path)?;
            }
        }
        let file = File::open(path_to_archive)?;
        let gz = GzDecoder::new(file);
        let mut archive = Archive::new(gz);
        // Unpack directly into the cache directory. Игнорируем AlreadyExists, чтобы не мешать валидации.
        match archive.unpack(cache_dir) {
            Ok(()) => Ok(()),
            Err(e) if e.kind() == io::ErrorKind::AlreadyExists => Ok(()),
            Err(e) => Err(e),
        }
    }

    /// Load meta information from the .mesk archive.
    ///
    /// This function parses the meta information from the .mesk archive,
    /// which includes the package name, version, architecture, description,
    /// installation path, user, group, mode, and custom installation script
    /// and deserializing this information. Returns (Install, Option<Setts>, Option<Build>)
    ///
    /// The function expects the 'INSTALL', 'SETTS', and 'BUILD' files to be present
    /// in the `config.paths.cache_dir`. It specifically requires the 'INSTALL' file.
    ///
    /// # Errors
    ///
    /// Returns an error if the `cache_dir` cannot be created, if the required 'INSTALL' file
    /// is not found, or if the 'INSTALL' file is empty.
    #[allow(clippy::type_complexity)]
    fn loadmeta(
        minimal_package_meta: &mut Self,
    ) -> Result<(Install, Option<Setts>, Option<Build>), std::io::Error> {
        // Changed return type for more flexibility
        /*
                Example INSTALL format:
                [package]
                name = "my-package"
                version = "1.0.0"
                arch = "X86_64"
                descr = "Just example INSTALL script"

                [install]
                path = "/usr/bin/my-package"
                user = "root"
                group = "root"
                mode = "755"

                # Also [install] can be
                # path = "/usr/bin/my-package"
                # user = "root"
                # group = "root"
                # mode = "755"
                # custom_script = "./install.sh" OR
                # custom_script = """
                #     echo "Installing my-package"
                #     sudo apt-get install my-package
                # """
        */

        let config = Config::parse().map_err(|e| std::io::Error::other(e.to_string()))?;

        fs::create_dir_all(&config.paths.cache_dir)?;

        let cache_dir = &config.paths.cache_dir;
        let install_path =
            Path::new(cache_dir).join(format!("{}/INSTALL", minimal_package_meta.name));
        let setts_path = Path::new(cache_dir).join(format!("{}/SETTS", minimal_package_meta.name));
        let build_path = Path::new(cache_dir).join(format!("{}/BUILD", minimal_package_meta.name));

        if !install_path.exists() {
            return Err(io::Error::new(
                io::ErrorKind::NotFound,
                "File INSTALL not found in cache directory",
            ));
        }

        let install_content = fs::read_to_string(&install_path)?;
        let install_meta: Install = toml::from_str(&install_content)
            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;

        let mut setts_meta: Option<Setts> = None;
        let mut build_meta: Option<Build> = None;

        if setts_path.exists() {
            let setts_content = fs::read_to_string(&setts_path)?;
            setts_meta = Some(
                toml::from_str(&setts_content)
                    .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?,
            );
        }

        if build_path.exists() {
            let build_content = fs::read_to_string(&build_path)?;
            build_meta = Some(
                toml::from_str(&build_content)
                    .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?,
            );
        }

        if let Some(ref _script) = install_meta.install.custom_script {
            log::warn!(
                "Custom script found for package: {}",
                install_meta.package.name
            );
        } else {
            log::info!(
                "No custom script for package: {}",
                install_meta.package.name
            );
        }

        Ok((install_meta, setts_meta, build_meta))
    }

    /// Checks if the archive contains INSTALL, SETTS and BUILD files.
    ///
    /// Checks if INSTALL file exists and is not empty. If it does not exist or is empty, returns an error.
    /// Checks SETTS and BUILD (if present) and logs предупреждения, если они пустые или отсутствуют.
    /// Ожидаем структуру: <cachedir>/<packagename>/{INSTALL, SETTS, BUILD, ...}.
    ///
    /// # Errors
    /// * Returns an error if INSTALL file does not exist or is empty.
    /// * Returns an error if INSTALL file is empty.
    fn check(path_to_archive: String) -> Result<bool, std::io::Error> {
        Self::extract_archive(&path_to_archive)?;

        let config = Config::parse().map_err(|e| std::io::Error::other(e.to_string()))?;
        let cache_root = Path::new(&config.paths.cache_dir);

        // Рекурсивно находим все файлы INSTALL под cache_root
        fn find_install(root: &Path) -> Result<Vec<std::path::PathBuf>, std::io::Error> {
            let mut installs = Vec::new();
            for entry in fs::read_dir(root)? {
                let entry = entry?;
                let path = entry.path();
                if path.is_dir() {
                    installs.extend(find_install(&path)?);
                } else if path.file_name().and_then(|n| n.to_str()) == Some("INSTALL") {
                    installs.push(path);
                }
            }
            Ok(installs)
        }

        let installs = find_install(cache_root)?;
        if installs.is_empty() {
            return Err(std::io::Error::new(
                std::io::ErrorKind::NotFound,
                "INSTALL file not found in archive",
            ));
        }
        if installs.len() > 1 {
            return Err(std::io::Error::new(
                std::io::ErrorKind::InvalidData,
                "Multiple INSTALL files found in archive; expected exactly one",
            ));
        }

        let install_path = &installs[0];
        let pkg_dir = install_path.parent().ok_or_else(|| {
            std::io::Error::new(
                std::io::ErrorKind::InvalidData,
                "INSTALL has no parent directory",
            )
        })?;

        // Проверим, что структура именно <cachedir>/<packagename>/INSTALL
        if pkg_dir.parent() != Some(cache_root) {
            return Err(std::io::Error::new(
                std::io::ErrorKind::InvalidData,
                "Invalid meta-files layout: expected <cachedir>/<packagename>/INSTALL",
            ));
        }

        let setts_path = pkg_dir.join("SETTS");
        let build_path = pkg_dir.join("BUILD");

        let install_content = std::fs::read_to_string(install_path)?;
        if install_content.trim().is_empty() {
            return Err(std::io::Error::new(
                std::io::ErrorKind::InvalidData,
                "INSTALL file is empty",
            ));
        }

        if !setts_path.exists() {
            log::warn!("SETTS file not found in archive. Make sure you dont need this.");
        } else {
            let setts_content = std::fs::read_to_string(&setts_path)?;
            if setts_content.trim().is_empty() {
                log::warn!("SETTS file is empty. Make sure you dont need this.");
            }
        }

        if !build_path.exists() {
            log::warn!("BUILD file not found in archive. Make sure you dont need this.");
        } else {
            let build_content = std::fs::read_to_string(&build_path)?;
            if build_content.trim().is_empty() {
                log::warn!("BUILD file is empty. Make sure you dont need this.");
            }
        }

        let content = std::fs::read_to_string(install_path).map_err(|e| {
            log::warn!("Failed to read file: {}", e);
            e
        })?;
        let install_content: Result<Install, toml::de::Error> = toml::from_str(&content);

        log::info!("Validating arch...");
        let install_parsed = match install_content {
            Ok(v) => v,
            Err(e) => {
                log::error!("Arch mismatch while parsing INSTALL: {}", e);
                return Err(std::io::Error::new(
                    std::io::ErrorKind::InvalidData,
                    format!("Arch mismatch: {}", e),
                ));
            }
        };
        if std::env::consts::ARCH != install_parsed.package.arch.as_str() {
            let pkg_arch = &install_parsed.package.arch;
            log::error!(
                "Arch mismatch. Package arch: {:?}, Host arch: {}",
                pkg_arch,
                std::env::consts::ARCH
            );
            return Err(std::io::Error::new(
                std::io::ErrorKind::InvalidData,
                "Arch mismatch",
            ));
        }

        Ok(true)
    }

    /// Validates a custom script for security and basic syntax
    /// Now only minimal validation is performed
    fn validate_custom_script(script: &str) -> Result<(), std::io::Error> {
        // Check for dangerous commands
        let dangerous_patterns = [
            "rm -rf /",
            "sudo rm",
            "chmod 777",
            "chown root",
            "dd if=",
            "mkfs",
            "fdisk",
            "format",
            ":(){ :|:& };:",
        ];

        for pattern in &dangerous_patterns {
            if script.contains(pattern) {
                return Err(std::io::Error::other(format!(
                    "Dangerous command detected in script: {}",
                    pattern
                )));
            }
        }

        // Check for script path existence if it's a file path
        if script.starts_with("./") {
            let script_path = Path::new(script);
            if !script_path.exists() {
                return Err(std::io::Error::other(format!(
                    "Script file not found: {}",
                    script
                )));
            }

            // Check if it's executable
            let metadata = fs::metadata(script_path)?;
            if !metadata.permissions().mode() & 0o111 != 0 {
                log::warn!("Script {} is not executable", script);
            }
        }

        Ok(())
    }

    /// Validates and sanitizes a file path for security
    fn validate_path(path: &str, base_dir: &Path) -> Result<std::path::PathBuf, std::io::Error> {
        let path = Path::new(path);

        // Convert to absolute path
        let absolute_path = if path.is_absolute() {
            path.to_path_buf()
        } else {
            base_dir.join(path)
        };

        // Normalize the path
        let normalized = match absolute_path.canonicalize() {
            Ok(p) => p,
            Err(_) => {
                // If canonicalization fails, at least clean up the path
                let mut cleaned = std::path::PathBuf::new();
                for component in absolute_path.components() {
                    match component {
                        std::path::Component::ParentDir => {
                            // Don't go above base directory
                            if cleaned.pop() {
                                // Successfully removed parent
                            } else {
                                return Err(std::io::Error::other(
                                    "Path traversal attempt detected",
                                ));
                            }
                        }
                        std::path::Component::CurDir => {
                            // Skip current directory
                        }
                        _ => cleaned.push(component),
                    }
                }
                cleaned
            }
        };

        // Ensure the path is within the base directory (for relative paths)
        if !path.is_absolute()
            && let Ok(base_absolute) = base_dir.canonicalize()
            && !normalized.starts_with(&base_absolute)
        {
            return Err(std::io::Error::other(
                "Path is outside of allowed directory",
            ));
        }

        Ok(normalized)
    }
}