package stdos

import (
	"net/http"
	"os"
	"path"

	"github.com/markbates/pkger/here"
	"github.com/markbates/pkger/pkging"
)

var _ pkging.File = &File{}

type File struct {
	*os.File
	info   *pkging.FileInfo
	her    here.Info
	path   here.Path
	pkging pkging.Pkger
}

// Close closes the File, rendering it unusable for I/O.
func (f *File) Close() error {
	return f.File.Close()
}

// Abs returns an absolute representation of the file. If the path is not absolute it will be joined with the current working directory to turn it into an absolute path. The absolute path name for a given file is not guaranteed to be unique. Abs calls Clean on the result.
func (f *File) Abs() (string, error) {
	return f.pkging.AbsPath(f.path)
}

// Info returns the here.Info of the file
func (f *File) Info() here.Info {
	return f.her
}

// Name retuns the name of the file in pkger format
func (f File) Name() string {
	return f.path.String()
}

// Readdir reads the contents of the directory associated with file and returns a slice of up to n FileInfo values, as would be returned by Lstat, in directory order. Subsequent calls on the same file will yield further FileInfos.
//
// If n > 0, Readdir returns at most n FileInfo structures. In this case, if Readdir returns an empty slice, it will return a non-nil error explaining why. At the end of a directory, the error is io.EOF.
//
// If n <= 0, Readdir returns all the FileInfo from the directory in a single slice. In this case, if Readdir succeeds (reads all the way to the end of the directory), it returns the slice and a nil error. If it encounters an error before the end of the directory, Readdir returns the FileInfo read until that point and a non-nil error.
func (f *File) Readdir(count int) ([]os.FileInfo, error) {
	return f.File.Readdir(count)
}

// Open implements the http.FileSystem interface. A FileSystem implements access to a collection of named files. The elements in a file path are separated by slash ('/', U+002F) characters, regardless of host operating system convention.
func (f *File) Open(name string) (http.File, error) {
	fp := path.Join(f.Path().Name, name)
	f2, err := f.pkging.Open(fp)
	if err != nil {
		return nil, err
	}
	return f2, nil
}

// Path returns the here.Path of the file
func (f *File) Path() here.Path {
	return f.path
}

// Stat returns the FileInfo structure describing file. If there is an error, it will be of type *PathError.
func (f *File) Stat() (os.FileInfo, error) {
	if f.info != nil {
		return f.info, nil
	}

	info, err := f.File.Stat()
	if err != nil {
		return nil, err
	}
	f.info = pkging.NewFileInfo(info)
	return f.info, nil
}