// ABOUTME: Power actions — reboot and shutdown via systemctl.
// ABOUTME: Wrappers around system commands for the lockscreen UI.

use std::fmt;
use std::process::Command;

#[derive(Debug)]
pub enum PowerError {
    CommandFailed { action: &'static str, message: String },
    Timeout { action: &'static str },
}

impl fmt::Display for PowerError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            PowerError::CommandFailed { action, message } => write!(f, "{action} failed: {message}"),
            PowerError::Timeout { action } => write!(f, "{action} timed out"),
        }
    }
}

impl std::error::Error for PowerError {}

fn run_command(action: &'static str, program: &str, args: &[&str]) -> Result<(), PowerError> {
    let output = Command::new(program)
        .args(args)
        .stderr(std::process::Stdio::piped())
        .output()
        .map_err(|e| PowerError::CommandFailed { action, message: e.to_string() })?;
    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        return Err(PowerError::CommandFailed {
            action, message: format!("exit code {}: {}", output.status, stderr.trim()),
        });
    }
    Ok(())
}

pub fn reboot() -> Result<(), PowerError> { run_command("reboot", "/usr/bin/systemctl", &["--no-ask-password", "reboot"]) }
pub fn shutdown() -> Result<(), PowerError> { run_command("shutdown", "/usr/bin/systemctl", &["--no-ask-password", "poweroff"]) }

#[cfg(test)]
mod tests {
    use super::*;

    #[test] fn power_error_display() { assert_eq!(PowerError::CommandFailed { action: "reboot", message: "fail".into() }.to_string(), "reboot failed: fail"); }
    #[test] fn timeout_display() { assert_eq!(PowerError::Timeout { action: "shutdown" }.to_string(), "shutdown timed out"); }
    #[test] fn missing_binary() { assert!(run_command("test", "nonexistent-xyz", &[]).is_err()); }
    #[test] fn nonzero_exit() { assert!(run_command("test", "false", &[]).is_err()); }
    #[test] fn success() { assert!(run_command("test", "true", &[]).is_ok()); }
}