package cmd

import (
	"encoding/base64"
	"fmt"
	"io/ioutil"
	"os"
	"path"
	"path/filepath"
	"strings"

	"github.com/drakkan/sftpgo/dataprovider"
	"github.com/drakkan/sftpgo/service"
	"github.com/drakkan/sftpgo/sftpd"
	"github.com/drakkan/sftpgo/vfs"
	"github.com/spf13/cobra"
)

var (
	directoryToServe             string
	portableSFTPDPort            int
	portableAdvertiseService     bool
	portableAdvertiseCredentials bool
	portableUsername             string
	portablePassword             string
	portableLogFile              string
	portablePublicKeys           []string
	portablePermissions          []string
	portableSSHCommands          []string
	portableAllowedExtensions    []string
	portableDeniedExtensions     []string
	portableFsProvider           int
	portableS3Bucket             string
	portableS3Region             string
	portableS3AccessKey          string
	portableS3AccessSecret       string
	portableS3Endpoint           string
	portableS3StorageClass       string
	portableS3KeyPrefix          string
	portableGCSBucket            string
	portableGCSCredentialsFile   string
	portableGCSAutoCredentials   int
	portableGCSStorageClass      string
	portableGCSKeyPrefix         string
	portableCmd                  = &cobra.Command{
		Use:   "portable",
		Short: "Serve a single directory",
		Long: `To serve the current working directory with auto generated credentials simply use:

sftpgo portable

Please take a look at the usage below to customize the serving parameters`,
		Run: func(cmd *cobra.Command, args []string) {
			portableDir := directoryToServe
			if !filepath.IsAbs(portableDir) {
				if portableFsProvider == 0 {
					portableDir, _ = filepath.Abs(portableDir)
				} else {
					portableDir = os.TempDir()
				}
			}
			permissions := make(map[string][]string)
			permissions["/"] = portablePermissions
			portableGCSCredentials := ""
			if portableFsProvider == 2 && len(portableGCSCredentialsFile) > 0 {
				fi, err := os.Stat(portableGCSCredentialsFile)
				if err != nil {
					fmt.Printf("Invalid GCS credentials file: %v\n", err)
					return
				}
				if fi.Size() > 1048576 {
					fmt.Printf("Invalid GCS credentials file: %#v is too big %v/1048576 bytes\n", portableGCSCredentialsFile,
						fi.Size())
					return
				}
				creds, err := ioutil.ReadFile(portableGCSCredentialsFile)
				if err != nil {
					fmt.Printf("Unable to read credentials file: %v\n", err)
				}
				portableGCSCredentials = base64.StdEncoding.EncodeToString(creds)
				portableGCSAutoCredentials = 0
			}
			service := service.Service{
				ConfigDir:     filepath.Clean(defaultConfigDir),
				ConfigFile:    defaultConfigName,
				LogFilePath:   portableLogFile,
				LogMaxSize:    defaultLogMaxSize,
				LogMaxBackups: defaultLogMaxBackup,
				LogMaxAge:     defaultLogMaxAge,
				LogCompress:   defaultLogCompress,
				LogVerbose:    defaultLogVerbose,
				Shutdown:      make(chan bool),
				PortableMode:  1,
				PortableUser: dataprovider.User{
					Username:    portableUsername,
					Password:    portablePassword,
					PublicKeys:  portablePublicKeys,
					Permissions: permissions,
					HomeDir:     portableDir,
					Status:      1,
					FsConfig: dataprovider.Filesystem{
						Provider: portableFsProvider,
						S3Config: vfs.S3FsConfig{
							Bucket:       portableS3Bucket,
							Region:       portableS3Region,
							AccessKey:    portableS3AccessKey,
							AccessSecret: portableS3AccessSecret,
							Endpoint:     portableS3Endpoint,
							StorageClass: portableS3StorageClass,
							KeyPrefix:    portableS3KeyPrefix,
						},
						GCSConfig: vfs.GCSFsConfig{
							Bucket:               portableGCSBucket,
							Credentials:          portableGCSCredentials,
							AutomaticCredentials: portableGCSAutoCredentials,
							StorageClass:         portableGCSStorageClass,
							KeyPrefix:            portableGCSKeyPrefix,
						},
					},
					Filters: dataprovider.UserFilters{
						FileExtensions: parseFileExtensionsFilters(),
					},
				},
			}
			if err := service.StartPortableMode(portableSFTPDPort, portableSSHCommands, portableAdvertiseService,
				portableAdvertiseCredentials); err == nil {
				service.Wait()
			}
		},
	}
)

func init() {
	portableCmd.Flags().StringVarP(&directoryToServe, "directory", "d", ".",
		"Path to the directory to serve. This can be an absolute path or a path relative to the current directory")
	portableCmd.Flags().IntVarP(&portableSFTPDPort, "sftpd-port", "s", 0, "0 means a random non privileged port")
	portableCmd.Flags().StringSliceVarP(&portableSSHCommands, "ssh-commands", "c", sftpd.GetDefaultSSHCommands(),
		"SSH commands to enable. \"*\" means any supported SSH command including scp")
	portableCmd.Flags().StringVarP(&portableUsername, "username", "u", "", "Leave empty to use an auto generated value")
	portableCmd.Flags().StringVarP(&portablePassword, "password", "p", "", "Leave empty to use an auto generated value")
	portableCmd.Flags().StringVarP(&portableLogFile, logFilePathFlag, "l", "", "Leave empty to disable logging")
	portableCmd.Flags().StringSliceVarP(&portablePublicKeys, "public-key", "k", []string{}, "")
	portableCmd.Flags().StringSliceVarP(&portablePermissions, "permissions", "g", []string{"list", "download"},
		"User's permissions. \"*\" means any permission")
	portableCmd.Flags().StringArrayVar(&portableAllowedExtensions, "allowed-extensions", []string{},
		"Allowed file extensions case insensitive. The format is /dir::ext1,ext2. For example: \"/somedir::.jpg,.png\"")
	portableCmd.Flags().StringArrayVar(&portableDeniedExtensions, "denied-extensions", []string{},
		"Denied file extensions case insensitive. The format is /dir::ext1,ext2. For example: \"/somedir::.jpg,.png\"")
	portableCmd.Flags().BoolVarP(&portableAdvertiseService, "advertise-service", "S", true,
		"Advertise SFTP service using multicast DNS")
	portableCmd.Flags().BoolVarP(&portableAdvertiseCredentials, "advertise-credentials", "C", false,
		"If the SFTP service is advertised via multicast DNS, this flag allows to put username/password inside the advertised TXT record")
	portableCmd.Flags().IntVarP(&portableFsProvider, "fs-provider", "f", 0, "0 means local filesystem, 1 Amazon S3 compatible, "+
		"2 Google Cloud Storage")
	portableCmd.Flags().StringVar(&portableS3Bucket, "s3-bucket", "", "")
	portableCmd.Flags().StringVar(&portableS3Region, "s3-region", "", "")
	portableCmd.Flags().StringVar(&portableS3AccessKey, "s3-access-key", "", "")
	portableCmd.Flags().StringVar(&portableS3AccessSecret, "s3-access-secret", "", "")
	portableCmd.Flags().StringVar(&portableS3Endpoint, "s3-endpoint", "", "")
	portableCmd.Flags().StringVar(&portableS3StorageClass, "s3-storage-class", "", "")
	portableCmd.Flags().StringVar(&portableS3KeyPrefix, "s3-key-prefix", "", "Allows to restrict access to the virtual folder "+
		"identified by this prefix and its contents")
	portableCmd.Flags().StringVar(&portableGCSBucket, "gcs-bucket", "", "")
	portableCmd.Flags().StringVar(&portableGCSStorageClass, "gcs-storage-class", "", "")
	portableCmd.Flags().StringVar(&portableGCSKeyPrefix, "gcs-key-prefix", "", "Allows to restrict access to the virtual folder "+
		"identified by this prefix and its contents")
	portableCmd.Flags().StringVar(&portableGCSCredentialsFile, "gcs-credentials-file", "", "Google Cloud Storage JSON credentials file")
	portableCmd.Flags().IntVar(&portableGCSAutoCredentials, "gcs-automatic-credentials", 1, "0 means explicit credentials using a JSON "+
		"credentials file, 1 automatic")
	rootCmd.AddCommand(portableCmd)
}

func parseFileExtensionsFilters() []dataprovider.ExtensionsFilter {
	var extensions []dataprovider.ExtensionsFilter
	for _, val := range portableAllowedExtensions {
		p, exts := getExtensionsFilterValues(strings.TrimSpace(val))
		if len(p) > 0 {
			extensions = append(extensions, dataprovider.ExtensionsFilter{
				Path:              path.Clean(p),
				AllowedExtensions: exts,
				DeniedExtensions:  []string{},
			})
		}
	}
	for _, val := range portableDeniedExtensions {
		p, exts := getExtensionsFilterValues(strings.TrimSpace(val))
		if len(p) > 0 {
			found := false
			for index, e := range extensions {
				if path.Clean(e.Path) == path.Clean(p) {
					extensions[index].DeniedExtensions = append(extensions[index].DeniedExtensions, exts...)
					found = true
					break
				}
			}
			if !found {
				extensions = append(extensions, dataprovider.ExtensionsFilter{
					Path:              path.Clean(p),
					AllowedExtensions: []string{},
					DeniedExtensions:  exts,
				})
			}
		}
	}
	return extensions
}

func getExtensionsFilterValues(value string) (string, []string) {
	if strings.Contains(value, "::") {
		dirExts := strings.Split(value, "::")
		if len(dirExts) > 1 {
			dir := strings.TrimSpace(dirExts[0])
			exts := []string{}
			for _, e := range strings.Split(dirExts[1], ",") {
				cleanedExt := strings.TrimSpace(e)
				if len(cleanedExt) > 0 {
					exts = append(exts, cleanedExt)
				}
			}
			if len(dir) > 0 && len(exts) > 0 {
				return dir, exts
			}
		}
	}
	return "", nil
}