update.go

package main

import (
	"archive/zip"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/dustin/go-humanize"
)

// WriteCounter -  Can be used to count the number of bytes which is written
type WriteCounter struct {
	Total uint64
}

func (wc *WriteCounter) Write(p []byte) (int, error) {
	n := len(p)
	wc.Total += uint64(n)
	wc.PrintProgress()
	return n, nil
}

// PrintProgress prints the progress of a file write
func (wc WriteCounter) PrintProgress() {
	// Clear the line by using a character return to go back to the start and remove
	// the remaining characters by filling it with spaces
	fmt.Printf("\r%s", strings.Repeat(" ", 50))

	// Return again and print current status of download
	// We use the humanize package to print the bytes in a meaningful way (e.g. 10 MB)
	fmt.Printf("\rDownloading... %s complete", humanize.Bytes(wc.Total))
}

// DownloadDatabase - Download the lastest version of IP2Location
func DownloadDatabase(dbFileName string, path string, tmpPath string) {
	fmt.Println("Download Started")

	fileURL := "https://github.com/javadmohebbi/IP2Location/raw/master/dist/IP2LOCATION-LITE-DB11.IPV6.BIN.ZIP"
	err := DownloadFile(fileURL, tmpPath, path)
	if err != nil {
		panic(err)
	}

	fmt.Println("Download Finished")
}

// DownloadFile - Download File and rename it to the one that we want
func DownloadFile(url string, tmpPath string, filepath string) error {

	// Create the file with .tmp extension, so that we won't overwrite a
	// file until it's downloaded fully
	out, err := os.Create(tmpPath + dbFileName + ".tmp")
	if err != nil {
		return err
	}
	defer out.Close()

	// Get the data
	resp, err := http.Get(url)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	// Create our bytes counter and pass it to be used alongside our writer
	counter := &WriteCounter{}
	_, err = io.Copy(out, io.TeeReader(resp.Body, counter))
	if err != nil {
		return err
	}

	// The progress use the same line so print a new line once it's finished downloading
	fmt.Println()

	// Rename the tmp file back to the original file
	// err = os.Rename(filepath+".tmp", filepath+".ZIP")
	// if err != nil {
	// 	return err
	// }
	// fmt.Println(filepath)
	files, err := Unzip(tmpPath+dbFileName+".tmp", filepath+"/db")
	if err != nil {
		log.Fatal(err)
	}
	err = os.Remove(tmpPath + dbFileName + ".tmp")

	fmt.Println("Unzipped:\n" + strings.Join(files, "\n"))

	return nil
}

// Unzip will decompress a zip archive, moving all files and folders
// within the zip file (parameter 1) to an output directory (parameter 2).
func Unzip(src string, dest string) ([]string, error) {

	var filenames []string

	r, err := zip.OpenReader(src)
	if err != nil {
		return filenames, err
	}
	defer r.Close()

	for _, f := range r.File {

		// Store filename/path for returning and using later on
		fpath := filepath.Join(dest, f.Name)

		// Check for ZipSlip. More Info: http://bit.ly/2MsjAWE
		if !strings.HasPrefix(fpath, filepath.Clean(dest)+string(os.PathSeparator)) {
			return filenames, fmt.Errorf("%s: illegal file path", fpath)
		}

		filenames = append(filenames, fpath)

		if f.FileInfo().IsDir() {
			// Make Folder
			os.MkdirAll(fpath, os.ModePerm)
			continue
		}

		// Make File
		if err = os.MkdirAll(filepath.Dir(fpath), os.ModePerm); err != nil {
			return filenames, err
		}

		outFile, err := os.OpenFile(fpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
		if err != nil {
			return filenames, err
		}

		rc, err := f.Open()
		if err != nil {
			return filenames, err
		}

		_, err = io.Copy(outFile, rc)

		// Close the file without defer to close before next iteration of loop
		outFile.Close()
		rc.Close()

		if err != nil {
			return filenames, err
		}
	}
	return filenames, nil
}