retch-sysinfo 0.1.41

// SPDX-FileCopyrightText: 2026 Ken Tobias
// SPDX-License-Identifier: GPL-3.0-or-later

//! Installed package count detection.
//!
//! Supports Pacman (Arch), Dpkg (Debian), XBPS (Void), RPM (Fedora/RHEL) on Linux,
//! Homebrew (Formulae and Casks) and MacPorts on macOS, and Scoop/Chocolatey on Windows.

pub(crate) fn detect_packages() -> Option<usize> {
    #[cfg(target_os = "macos")]
    {
        let mut count = 0;

        for cellar_path in &["/opt/homebrew/Cellar", "/usr/local/Cellar"] {
            if let Ok(entries) = std::fs::read_dir(cellar_path) {
                count += entries.filter_map(|e| e.ok()).count();
            }
        }

        for cask_path in &["/opt/homebrew/Caskroom", "/usr/local/Caskroom"] {
            if let Ok(entries) = std::fs::read_dir(cask_path) {
                count += entries.filter_map(|e| e.ok()).count();
            }
        }

        if let Ok(entries) = std::fs::read_dir("/opt/local/var/macports/software") {
            count += entries.filter_map(|e| e.ok()).count();
        }

        if count > 0 {
            Some(count)
        } else {
            None
        }
    }

    #[cfg(target_os = "windows")]
    {
        let mut count = 0;

        if let Some(home) = dirs::home_dir() {
            let scoop_dir = std::env::var("SCOOP")
                .map(std::path::PathBuf::from)
                .unwrap_or_else(|_| home.join("scoop"));
            if let Ok(entries) = std::fs::read_dir(scoop_dir.join("apps")) {
                count += entries.filter_map(|e| e.ok()).count();
            }
        }

        let choco_install = std::env::var("ChocolateyInstall")
            .unwrap_or_else(|_| "C:\\ProgramData\\chocolatey".to_string());
        if let Ok(entries) = std::fs::read_dir(std::path::Path::new(&choco_install).join("lib")) {
            count += entries.filter_map(|e| e.ok()).count();
        }

        if count > 0 {
            Some(count)
        } else {
            None
        }
    }

    #[cfg(not(any(target_os = "macos", target_os = "windows")))]
    {
        if let Ok(entries) = std::fs::read_dir("/var/lib/pacman/local") {
            let count = entries.filter_map(|e| e.ok()).count();
            if count > 0 {
                return Some(count);
            }
        }

        if let Ok(entries) = std::fs::read_dir("/var/lib/dpkg/info") {
            let count = entries
                .filter_map(|e| e.ok())
                .filter(|e| e.path().extension().is_some_and(|ext| ext == "list"))
                .count();
            if count > 0 {
                return Some(count);
            }
        }

        if let Ok(entries) = std::fs::read_dir("/var/db/pkg") {
            let count: usize = entries
                .filter_map(|e| e.ok())
                .map(|e| {
                    std::fs::read_dir(e.path())
                        .map(|d| d.filter(|_| true).count())
                        .unwrap_or(0)
                })
                .sum();
            if count > 0 {
                return Some(count);
            }
        }

        if let Ok(entries) = std::fs::read_dir("/var/db/xbps") {
            let count = entries
                .filter_map(|e| e.ok())
                .filter(|e| e.path().extension().is_some_and(|ext| ext == "plist"))
                .count();
            if count > 0 {
                return Some(count);
            }
        }

        let rpm_db = "/var/lib/rpm/rpmdb.sqlite";
        if std::path::Path::new(rpm_db).exists() {
            match rusqlite::Connection::open(rpm_db) {
                Ok(conn) => {
                    if let Ok(count) = conn.query_row("SELECT COUNT(*) FROM Packages", [], |row| {
                        row.get::<_, i64>(0)
                    }) {
                        if count > 0 {
                            return Some(count as usize);
                        }
                    }
                }
                Err(e) => {
                    eprintln!("warning: failed to open RPM database at {}: {}", rpm_db, e);
                }
            }
        }

        None
    }
}