armybox 0.3.0

//! truncate - shrink or extend the size of a file
//!
//! GNU coreutils compatible implementation.

use crate::sys;
use crate::applets::{get_arg, has_opt};

/// truncate - shrink or extend the size of a file
///
/// # Synopsis
/// ```text
/// truncate -s SIZE file...
/// ```
///
/// # Description
/// Shrink or extend the size of each FILE to the specified size.
///
/// # Options
/// - `-s SIZE`: Set or adjust the file size
///
/// # Exit Status
/// - 0: Success
/// - >0: An error occurred
pub fn truncate(argc: i32, argv: *const *const u8) -> i32 {
    let mut size: i64 = 0;
    let mut size_set = false;
    let mut exit_code = 0;

    // First pass: find size option
    let mut i = 1;
    while i < argc {
        if let Some(arg) = unsafe { get_arg(argv, i) } {
            if arg.len() > 0 && arg[0] == b'-' {
                if has_opt(arg, b's') && i + 1 < argc {
                    if let Some(s) = unsafe { get_arg(argv, i + 1) } {
                        size = sys::parse_u64(s).unwrap_or(0) as i64;
                        size_set = true;
                        i += 1;
                    }
                }
            }
        }
        i += 1;
    }

    // Second pass: process files
    for j in 1..argc {
        if let Some(arg) = unsafe { get_arg(argv, j) } {
            if arg.len() > 0 && arg[0] == b'-' {
                if has_opt(arg, b's') {
                    continue; // Skip the -s and its argument
                }
                continue;
            }

            // Check if this is the size argument
            if j > 1 {
                if let Some(prev) = unsafe { get_arg(argv, j - 1) } {
                    if prev.len() >= 2 && prev[0] == b'-' && has_opt(prev, b's') {
                        continue; // This is the size argument, skip it
                    }
                }
            }

            if unsafe { libc::truncate(arg.as_ptr() as *const i8, size) } < 0 {
                sys::perror(arg);
                exit_code = 1;
            }
        }
    }

    if !size_set {
        // No files processed without -s
    }

    exit_code
}

#[cfg(test)]
mod tests {
    extern crate std;
    use std::sync::atomic::{AtomicUsize, Ordering};

    static TEST_COUNTER: AtomicUsize = AtomicUsize::new(0);
    use std::process::Command;
    use std::fs;
    use std::path::PathBuf;

    fn get_armybox_path() -> PathBuf {
        if let Ok(path) = std::env::var("ARMYBOX_PATH") {
            return PathBuf::from(path);
        }
        let manifest_dir = std::env::var("CARGO_MANIFEST_DIR")
            .map(PathBuf::from)
            .unwrap_or_else(|_| std::env::current_dir().unwrap());
        let release = manifest_dir.join("target/release/armybox");
        if release.exists() { return release; }
        manifest_dir.join("target/debug/armybox")
    }

    fn setup() -> PathBuf {
        let counter = TEST_COUNTER.fetch_add(1, Ordering::SeqCst);
        let dir = std::env::temp_dir().join(format!("armybox_truncate_test_{}_{}",  std::process::id(), counter));
        let _ = fs::remove_dir_all(&dir);
        fs::create_dir_all(&dir).unwrap();
        dir
    }

    fn cleanup(dir: &std::path::Path) {
        let _ = fs::remove_dir_all(dir);
    }

    #[test]
    fn test_truncate_shrink() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let dir = setup();
        let file = dir.join("file.txt");
        fs::write(&file, "hello world!").unwrap();
        assert_eq!(fs::metadata(&file).unwrap().len(), 12);

        let output = Command::new(&armybox)
            .args(["truncate", "-s", "5", file.to_str().unwrap()])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(0));
        assert_eq!(fs::metadata(&file).unwrap().len(), 5);
        assert_eq!(fs::read_to_string(&file).unwrap(), "hello");
        cleanup(&dir);
    }

    #[test]
    fn test_truncate_extend() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let dir = setup();
        let file = dir.join("file.txt");
        fs::write(&file, "hi").unwrap();
        assert_eq!(fs::metadata(&file).unwrap().len(), 2);

        let output = Command::new(&armybox)
            .args(["truncate", "-s", "10", file.to_str().unwrap()])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(0));
        assert_eq!(fs::metadata(&file).unwrap().len(), 10);
        cleanup(&dir);
    }

    #[test]
    fn test_truncate_to_zero() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let dir = setup();
        let file = dir.join("file.txt");
        fs::write(&file, "content").unwrap();

        let output = Command::new(&armybox)
            .args(["truncate", "-s", "0", file.to_str().unwrap()])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(0));
        assert_eq!(fs::metadata(&file).unwrap().len(), 0);
        cleanup(&dir);
    }

    #[test]
    fn test_truncate_nonexistent() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let output = Command::new(&armybox)
            .args(["truncate", "-s", "10", "/nonexistent/file"])
            .output()
            .unwrap();

        assert_ne!(output.status.code(), Some(0));
    }
}