use crate::args;
use std::path::{Path, PathBuf};

pub fn validate_and_prepare_dir_output(cfg: &args::Config) -> Result<PathBuf, String> {
    if !cfg.output_provided { return Err("when input is a directory, -o/--output must be provided".into()); }

    let out_root = PathBuf::from(&cfg.output);
    if out_root.exists() && !out_root.is_dir() { return Err(format!("output must be a directory, got file: {}", out_root.display())); }
    std::fs::create_dir_all(&out_root).map_err(|e| format!("failed to create output dir {}: {e}", out_root.display()))?;
    Ok(out_root) }

pub fn walk_files_recursive(root: &Path) -> Result<Vec<PathBuf>, String> {
    let mut out = Vec::new();
    let mut stack = vec![root.to_path_buf()];

    while let Some(dir) = stack.pop() {
          let rd = std::fs::read_dir(&dir).map_err(|e| format!("failed to read dir {}: {e}", dir.display()))?;

          for entry in rd {
              let entry = entry.map_err(|e| format!("failed to read dir entry: {e}"))?;
              let ty = entry.file_type().map_err(|e| format!("failed to stat {}: {e}", entry.path().display()))?;
              if ty.is_dir() { stack.push(entry.path()); } else if ty.is_file() { out.push(entry.path()); } } }

    Ok(out) }