package git

import (
	"io"
	"regexp"

	"github.com/xor-gate/sshfp"
	"gopkg.in/src-d/go-git.v4/plumbing/transport"
	gitssh "gopkg.in/src-d/go-git.v4/plumbing/transport/ssh"
)

// repositoryDirName is the folder name where the repository is cloned
const repositoryDirName = "repository"

// Authorization returns a transport.AuthMethod that can be used to create a repository bucket. This AuthMetod uses
// SSH using a private key file.
func Authorization(username string, privateKeyFile string, sshfpEntries ...io.Reader) (transport.AuthMethod, error) {
	pk, err := gitssh.NewPublicKeysFromFile(username, privateKeyFile, "")
	if err != nil {
		return nil, err
	}

	mc, err := sshfp.NewMemoryCache()
	if err != nil {
		return nil, err
	}

	if len(sshfpEntries) == 1 && sshfpEntries[0] != nil {
		var entries []*sshfp.Entry
		entries, err = sshfp.ParseZone(sshfpEntries[0])
		if err != nil {
			return nil, err
		}

		err = mc.Add(entries...)
		if err != nil {
			return nil, err
		}
	}

	hkcb, err := sshfp.NewResolver(sshfp.WithCache(mc), sshfp.WithDNSClientConfigFromFile("/etc/resolv.conf"))
	if err != nil {
		return nil, err
	}

	pk.HostKeyCallbackHelper.HostKeyCallback = hkcb.HostKeyCallback
	return pk, nil
}

// sanitizePathString converts any repository uri to a valid directory uri
func sanitizePathString(in string) string {
	// TODO this is kind of a hack. Need same method as golang dep (cache).
	reg, err := regexp.Compile(`[/@\\?%\*:|"<>\. ]+`)
	if err != nil {
		return in
	}
	return reg.ReplaceAllString(in, "")
}