//go:build ignore

package main

import (
	"archive/tar"
	"compress/gzip"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path"
	"path/filepath"
	"strings"

	"code.gitea.io/gitea/modules/util"
)

func main() {
	var (
		prefix         = "gitea-licenses"
		url            = "https://api.github.com/repos/spdx/license-list-data/tarball"
		githubApiToken = ""
		githubUsername = ""
		destination    = ""
	)

	flag.StringVar(&destination, "dest", "options/license/", "destination for the licenses")
	flag.StringVar(&githubUsername, "username", "", "github username")
	flag.StringVar(&githubApiToken, "token", "", "github api token")
	flag.Parse()

	file, err := os.CreateTemp(os.TempDir(), prefix)
	if err != nil {
		log.Fatalf("Failed to create temp file. %s", err)
	}

	defer util.Remove(file.Name())

	if err := os.RemoveAll(destination); err != nil {
		log.Fatalf("Cannot clean destination folder: %v", err)
	}

	if err := os.MkdirAll(destination, 0o755); err != nil {
		log.Fatalf("Cannot create destination: %v", err)
	}

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		log.Fatalf("Failed to download archive. %s", err)
	}

	if len(githubApiToken) > 0 && len(githubUsername) > 0 {
		req.SetBasicAuth(githubUsername, githubApiToken)
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Fatalf("Failed to download archive. %s", err)
	}

	defer resp.Body.Close()

	if _, err := io.Copy(file, resp.Body); err != nil {
		log.Fatalf("Failed to copy archive to file. %s", err)
	}

	if _, err := file.Seek(0, 0); err != nil {
		log.Fatalf("Failed to reset seek on archive. %s", err)
	}

	gz, err := gzip.NewReader(file)
	if err != nil {
		log.Fatalf("Failed to gunzip the archive. %s", err)
	}

	tr := tar.NewReader(gz)

	for {
		hdr, err := tr.Next()

		if err == io.EOF {
			break
		}

		if err != nil {
			log.Fatalf("Failed to iterate archive. %s", err)
		}

		if !strings.Contains(hdr.Name, "/text/") {
			continue
		}

		if filepath.Ext(hdr.Name) != ".txt" {
			continue
		}

		if strings.HasPrefix(filepath.Base(hdr.Name), "README") {
			continue
		}

		if strings.HasPrefix(filepath.Base(hdr.Name), "deprecated_") {
			continue
		}
		out, err := os.Create(path.Join(destination, strings.TrimSuffix(filepath.Base(hdr.Name), ".txt")))
		if err != nil {
			log.Fatalf("Failed to create new file. %s", err)
		}

		defer out.Close()

		if _, err := io.Copy(out, tr); err != nil {
			log.Fatalf("Failed to write new file. %s", err)
		} else {
			fmt.Printf("Written %s\n", out.Name())
		}
	}

	fmt.Println("Done")
}
