package dir

import (
	"fmt"
	"io/fs"
	"os"
	"path/filepath"
)

func check(err error) {
	if err != nil {
		panic(err)
	}
}

func createEmptyFile(p string) {
	check(os.WriteFile(p, []byte(""), 0700))
}

func Dir() {
	dirPath := "/tmp/gobyex-tempdir"
	err := os.Mkdir(dirPath, 0700)
	check(err)
	defer os.RemoveAll(dirPath)

	createEmptyFile(filepath.Join(dirPath, "file1"))

	check(os.MkdirAll(filepath.Join(dirPath, "child", "grandchild"), 0700))

	createEmptyFile(filepath.Join(dirPath, "child", "grandchild", "file1"))
	createEmptyFile(filepath.Join(dirPath, "child", "grandchild", "file2"))
	createEmptyFile(filepath.Join(dirPath, "child", "grandchild", "file3"))

	check(os.Mkdir(filepath.Join(dirPath, "child", "grandchild", "dir1"), 0700))

	entries, err := os.ReadDir(filepath.Join(dirPath, "child", "grandchild"))
	check(err)

	fmt.Println("Lisitng", filepath.Join(dirPath, "child", "grandchild"))
	for _, entry := range entries {
		fmt.Printf("%s, is dir? %t\n", entry.Name(), entry.IsDir())
	}

	check(os.Chdir(dirPath))

	entries, err = os.ReadDir(".")
	check(err)

	fmt.Println("Listing", dirPath)
	for _, entry := range entries {
		fmt.Printf("%s, is dir? %t\n", entry.Name(), entry.IsDir())
	}

	fmt.Println("Walking the file tree at", dirPath)
	// WalkDir is more efficient than Walk
	check(filepath.WalkDir(".", walk))
}

func walk(p string, d fs.DirEntry, err error) error {
	if err != nil {
		return err
	}

	fmt.Println("  ", p, "is dir?", d.IsDir())
	return nil
}