use std::path::PathBuf;

/// Minimal task runner: read nyash.toml [env] and [tasks], run the named task via shell
pub(super) fn run_named_task(name: &str) -> Result<(), String> {
    let cfg_path = "nyash.toml";
    let text = std::fs::read_to_string(cfg_path).map_err(|e| format!("read {}: {}", cfg_path, e))?;
    let doc = toml::from_str::<toml::Value>(&text).map_err(|e| format!("parse {}: {}", cfg_path, e))?;
    // Apply [env]
    if let Some(env_tbl) = doc.get("env").and_then(|v| v.as_table()) {
        for (k, v) in env_tbl.iter() {
            if let Some(s) = v.as_str() { std::env::set_var(k, s); }
        }
    }
    // Lookup [tasks]
    let tasks = doc.get("tasks").and_then(|v| v.as_table()).ok_or("[tasks] not found in nyash.toml")?;
    let cmd = tasks.get(name).and_then(|v| v.as_str()).ok_or_else(|| format!("task '{}' not found", name))?;
    // Basic variable substitution
    let root = std::env::current_dir().unwrap_or(PathBuf::from(".")).display().to_string();
    let cmd = cmd.replace("{root}", &root);
    // Run via shell
    #[cfg(windows)]
    let status = std::process::Command::new("cmd").args(["/C", &cmd]).status().map_err(|e| e.to_string())?;
    #[cfg(not(windows))]
    let status = std::process::Command::new("sh").arg("-lc").arg(&cmd).status().map_err(|e| e.to_string())?;
    if !status.success() { return Err(format!("task '{}' failed with status {:?}", name, status.code())); }
    Ok(())
}