package util

import (
	"io/fs"
	"os"

	"codeberg.org/gruf/go-fastpath"
)

// WalkDir traverses the dir tree of the supplied path, performing the supplied walkFn on each entry
func WalkDir(pb *fastpath.Builder, path string, walkFn func(string, fs.DirEntry)) error {
	// Read supplied dir path
	dirEntries, err := os.ReadDir(path)
	if err != nil {
		return err
	}

	// Iter entries
	for _, entry := range dirEntries {
		// Pass to walk fn
		walkFn(path, entry)

		// Recurse dir entries
		if entry.IsDir() {
			err = WalkDir(pb, pb.Join(path, entry.Name()), walkFn)
			if err != nil {
				return err
			}
		}
	}

	return nil
}

// CleanDirs traverses the dir tree of the supplied path, removing any folders with zero children
func CleanDirs(path string) error {
	// Acquire builder
	pb := GetPathBuilder()
	defer PutPathBuilder(pb)

	// Get dir entries
	entries, err := os.ReadDir(path)
	if err != nil {
		return err
	}

	// Recurse dirs
	for _, entry := range entries {
		if entry.IsDir() {
			err := cleanDirs(pb, pb.Join(path, entry.Name()))
			if err != nil {
				return err
			}
		}
	}
	return nil
}

// cleanDirs performs the actual dir cleaning logic for the exported version
func cleanDirs(pb *fastpath.Builder, path string) error {
	// Get dir entries
	entries, err := os.ReadDir(path)
	if err != nil {
		return err
	}

	// If no entries, delete
	if len(entries) < 1 {
		return os.Remove(path)
	}

	// Recurse dirs
	for _, entry := range entries {
		if entry.IsDir() {
			err := cleanDirs(pb, pb.Join(path, entry.Name()))
			if err != nil {
				return err
			}
		}
	}
	return nil
}