// file_util.go
package utils

import (
	"errors"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

func FileSize(filePath string) (size int64) {
	info, err := os.Stat(filePath)
	if err == nil {
		size = info.Size()
	} else {
		size = -1
	}
	return
}

func IsRegularFile(filePath string) bool {
	if filePath != "" {
		info, err := os.Stat(filePath)
		// return (err == nil || os.IsExist(err)) && info.Mode().IsRegular()
		return (err == nil || errors.Is(err, os.ErrExist)) && info.Mode().IsRegular()
	}
	return false
}

func IsDirectory(filePath string) bool {
	if filePath != "" {
		info, err := os.Stat(filePath)
		return (err == nil || errors.Is(err, os.ErrExist)) && info.Mode().IsDir()
	}
	return false
}

func IsSymLink(filePath string) bool {
	if filePath != "" {
		info, err := os.Stat(filePath)
		return (err == nil || errors.Is(err, os.ErrExist)) && (info.Mode()&os.ModeSymlink != 0)
	}
	return false
}

func IsSymLinkByDirEntry(e os.DirEntry) bool {
	info, _ := e.Info()
	return info.Mode()&os.ModeSymlink != 0
}

func StreamIsTerminal(fh *os.File) bool {
	var isTerminal bool = false
	if fh != nil {
		fi, _ := fh.Stat()
		isTerminal = (fi.Mode() & os.ModeCharDevice) != 0
	}
	return isTerminal
}

/*
 * Ispirata a https://stackoverflow.com/a/50741908
 */
func MoveFile(sourcePath, destPath string) (int64, error) {
	var size int64 = 0

	err := os.Rename(sourcePath, destPath)
	if err != nil {
		inputFile, err := os.Open(sourcePath)
		if err != nil {
			return 0, fmt.Errorf("Couldn't open source file: %s", err)
		}
		outputFile, err := os.Create(destPath)
		if err != nil {
			inputFile.Close()
			return 0, fmt.Errorf("Couldn't open dest file: %s", err)
		}
		defer outputFile.Close()
		size, err = io.Copy(outputFile, inputFile)
		inputFile.Close()
		if err != nil {
			return 0, fmt.Errorf("Writing to output file failed: %s", err)
		}
		// The copy was successful, so now delete the original file
		err = os.Remove(sourcePath)
		if err != nil {
			return 0, fmt.Errorf("Failed removing original file: %s", err)
		}
	}
	return size, nil
}

func ParseMemSize(s string) (size int64, err error) {
	const MULTIPLES = "BKMGTP"
	// s = strings.TrimSpace(s)
	if len(s) != 0 {
		s = strings.ToUpper(s)
		s = strings.ReplaceAll(s, ".", "")
		s = strings.ReplaceAll(s, ",", "")
		s = strings.ReplaceAll(s, " ", "")
		pos := strings.IndexAny(s, MULTIPLES)
		if pos >= 0 {
			size, err = strconv.ParseInt(s[0:pos], 10, 64)
			mul := strings.IndexByte(MULTIPLES, s[pos])
			for ; mul > 0; mul-- {
				size = size * 1_000
			}
		} else {
			size, err = strconv.ParseInt(s, 10, 64)
		}
	} else {
		err = errors.New("Empty string")
	}
	return
}