package service
import (
"fmt"
"os"
"path"
"path/filepath"
"strings"
"github.com/pkg/errors"
)
const filePerms = 0600
func pathExists(path string) (bool, error) {
if _, err := os.Stat(path); err == nil {
return true, nil
} else if os.IsNotExist(err) {
return false, nil
} else {
return false, err
}
}
func nextPathIfExists(p string) (string, error) {
for i := 0; i < 1000; i++ {
out := incPath(p, i)
exists, err := pathExists(out)
if err != nil {
return "", err
}
if !exists {
return out, nil
}
}
return "", errors.Errorf("file exists %s", p)
}
func incPath(p string, n int) string {
if n == 0 {
return p
}
ext := path.Ext(p)
base := strings.TrimSuffix(p, ext)
return fmt.Sprintf("%s-%d%s", base, n+1, ext)
}
func isDir(path string) (bool, error) {
if path == "" {
return false, nil
}
exists, err := pathExists(path)
if err != nil {
return false, err
}
if !exists {
return false, err
}
fi, err := os.Stat(path)
if err != nil {
return false, err
}
switch mode := fi.Mode(); {
case mode.IsDir():
return true, nil
case mode.IsRegular():
return false, nil
default:
return false, nil
}
}
func resolveOutPath(out string, in string, inSuffix string) (string, error) {
dir, err := isDir(out)
if err != nil {
return "", err
}
if dir {
_, inFile := filepath.Split(in)
out = filepath.Join(out, inFile)
}
if out == "" {
out = in
}
out = strings.TrimSuffix(out, inSuffix)
if !filepath.IsAbs(out) {
inDir, _ := filepath.Split(in)
out = filepath.Join(inDir, out)
}
exists, err := pathExists(out)
if err != nil {
return "", err
}
if exists {
next, err := nextPathIfExists(out)
if err != nil {
return "", err
}
out = next
}
return out, nil
}