Go SDK for Dropbox

db.go

package dropbox

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strconv"
	"time"
)

const TimeFormat = time.RFC1123Z

type OAuthToken struct {
	Key, Secret string
}

type token interface {
	key() string
	secret() string
}

func buildAuthString(consumerToken AppToken, tok token) string {
	var buf bytes.Buffer
	buf.WriteString(`OAuth oauth_version="1.0", oauth_signature_method="PLAINTEXT"`)
	fmt.Fprintf(&buf, `, oauth_consumer_key="%s"`, url.QueryEscape(consumerToken.Key))
	fmt.Fprintf(&buf, `, oauth_timestamp="%v"`, time.Now().Unix())
	sigend := ""
	if tok != nil {
		sigend = url.QueryEscape(tok.secret())
		fmt.Fprintf(&buf, `, oauth_token="%s"`, url.QueryEscape(tok.key()))
	}
	fmt.Fprintf(&buf, `, oauth_signature="%s&%s"`, url.QueryEscape(consumerToken.Secret), sigend)
	return buf.String()
}

type Error struct {
	Code    int
	Message string
}

func (e Error) Error() string {
	return fmt.Sprintf("%d: %s", e.Code, e.Message)
}

func doRequest(r *http.Request, consumerTok AppToken, accessTok token) (*FileReader, error) {
	r.Header.Set("Authorization", buildAuthString(consumerTok, accessTok))
	resp, err := http.DefaultClient.Do(r)
	if err != nil {
		return nil, err
	}
	if resp.StatusCode != http.StatusOK {
		defer resp.Body.Close()
		var info struct {
			Error string `json:"error"`
		}
		json.NewDecoder(resp.Body).Decode(&info)
		return nil, Error{
			Code:    resp.StatusCode,
			Message: info.Error}
	}
	return newFileReader(resp), nil
}

func apiURL(path string) url.URL {
	return url.URL{
		Scheme: "https",
		Host:   apiHost,
		Path:   "/" + apiVersion + path}
}

func GetAuthorizeURL(requestToken RequestToken, callback *url.URL) *url.URL {
	params := url.Values{"oauth_token": {requestToken.Key}}
	if callback != nil {
		params.Add("oauth_callback", callback.String())
	}
	return &url.URL{
		Scheme:   "https",
		Host:     webHost,
		Path:     "/" + apiVersion + "/oauth/authorize",
		RawQuery: params.Encode()}
}

type AppToken OAuthToken
type RequestToken OAuthToken
type AccessToken OAuthToken

func (at AccessToken) key() string {
	return at.Key
}

func (at AccessToken) secret() string {
	return at.Secret
}

func (rt RequestToken) key() string {
	return rt.Key
}

func (rt RequestToken) secret() string {
	return rt.Secret
}

func postForToken(u url.URL, appToken AppToken, accessToken token) (OAuthToken, error) {
	r, e := http.NewRequest("POST", u.String(), nil)
	if e != nil {
		return OAuthToken{}, e
	}
	rc, e := doRequest(r, appToken, accessToken)
	if e != nil {
		return OAuthToken{}, e
	}
	defer rc.Close()
	var buf bytes.Buffer
	buf.ReadFrom(rc)
	vals, e := url.ParseQuery(buf.String())
	if e != nil {
		return OAuthToken{}, e
	}
	return OAuthToken{
		Key:    vals.Get("oauth_token"),
		Secret: vals.Get("oauth_token_secret")}, nil
}

func StartAuth(appToken AppToken) (RequestToken, error) {
	u := apiURL("/oauth/request_token")
	t, e := postForToken(u, appToken, nil)
	return RequestToken(t), e
}

func FinishAuth(appToken AppToken, requestToken RequestToken) (AccessToken, error) {
	u := apiURL("/oauth/access_token")
	t, e := postForToken(u, appToken, requestToken)
	return AccessToken(t), e
}

type accessType int

const (
	AppFolder accessType = iota
	Dropbox
)

type Config struct {
	Access accessType
	Locale string
}

type Client struct {
	AppToken    AppToken
	AccessToken AccessToken
	Config      Config
}

type AccountInfo struct {
	ReferralLink string `json:"referral_link"`
	DisplayName  string `json:"display_name"`
	Uid          uint64 `json:"uid"`
	Country      string `json:"country"`
	QuotaInfo    struct {
		Shared uint64 `json:"shared"`
		Quota  uint64 `json:"quota"`
		Normal uint64 `json:"normal"`
	}            `json:"quota_info"`
	Email string `json:"email"`
}

type FileMetadata struct {
	Size        string         `json:"size"`
	Rev         string         `json:"rev"`
	ThumbExists bool           `json:"thumb_exists"`
	Bytes       int64          `json:"bytes"`
	Modified    string         `json:"modified"`
	Path        string         `json:"path"`
	IsDir       bool           `json:"is_dir"`
	Icon        string         `json:"icon"`
	Root        string         `json:"root"`
	MimeType    string         `json:"mime_type"`
	Revision    int64          `json:"revision"`
	Hash        *string        `json:"hash"`
	Contents    []FileMetadata `json:"contents"`
}

func (md *FileMetadata) ModTime() time.Time {
	t, _ := time.Parse(TimeFormat, md.Modified)
	return t
}

type Link struct {
	URL     string `json:"url"`
	Expires string `json:"expires"`
}

func (s *Client) doGet(u url.URL) (*FileReader, error) {
	r, e := http.NewRequest("GET", u.String(), nil)
	if e != nil {
		return nil, e
	}
	return doRequest(r, s.AppToken, s.AccessToken)
}

func (s *Client) getForJson(u url.URL, jdata interface{}) error {
	buf, err := s.doGet(u)
	if err != nil {
		return err
	}
	defer buf.Close()
	return json.NewDecoder(buf).Decode(jdata)
}

func (s *Client) postForJson(u url.URL, jdata interface{}) error {
	r, e := http.NewRequest("POST", u.String(), nil)
	if e != nil {
		return e
	}
	rc, e := doRequest(r, s.AppToken, s.AccessToken)
	if e != nil {
		return e
	}
	defer rc.Close()
	return json.NewDecoder(rc).Decode(jdata)
}

const (
	apiVersion  = "1"
	apiHost     = "api.dropbox.com"
	contentHost = "api-content.dropbox.com"
	webHost     = "www.dropbox.com"
)

func (s *Client) GetAccountInfo() (*AccountInfo, error) {
	u := apiURL("/account/info")
	u.RawQuery = s.Config.localeQuery()
	var info AccountInfo
	if e := s.getForJson(u, &info); e != nil {
		return nil, e
	}
	return &info, nil
}

func (s *Client) root() string {
	if s.Config.Access == Dropbox {
		return "dropbox"
	}
	return "sandbox"
}

func (s *Client) GetMetadata(path string, list bool) (*FileMetadata, error) {
	u := apiURL("/metadata/" + s.root() + path)
	v := url.Values{"list": {strconv.FormatBool(list)}}
	u.RawQuery = s.Config.setLocale(v).Encode()

	var md FileMetadata
	if e := s.getForJson(u, &md); e != nil {
		return nil, e
	}
	return &md, nil
}

func contentURL(path string) url.URL {
	return url.URL{
		Scheme: "https",
		Host:   contentHost,
		Path:   "/" + apiVersion + path}
}

type ThumbSize string

const (
	ThumbSmall  ThumbSize = "small"
	ThumbMedium ThumbSize = "medium"
	ThumbLarge  ThumbSize = "large"
	ThumbL      ThumbSize = "l"
	ThumbXL     ThumbSize = "xl"
)

func (s *Client) GetThumb(path string, size ThumbSize) (*FileReader, error) {
	u := contentURL("/thumbnails/" + s.root() + path)
	if size != "" {
		u.RawQuery = url.Values{"size": {string(size)}}.Encode()
	}
	rc, e := s.doGet(u)
	return rc, e
}

func (s *Client) AddFile(path string, contents io.Reader, size int64) (*FileMetadata, error) {
	return s.putFile(path, contents, size, url.Values{"overwrite": {"false"}})
}

func (s *Client) UpdateFile(path string, contents io.Reader, size int64, parentRev string) (*FileMetadata, error) {
	return s.putFile(path, contents, size, url.Values{"parent_rev": {parentRev}})
}

func (s *Client) ForceFile(path string, contents io.Reader, size int64) (*FileMetadata, error) {
	return s.putFile(path, contents, size, url.Values{"overwrite": {"true"}})
}

func (s *Client) putFile(path string, contents io.Reader, size int64, vals url.Values) (*FileMetadata, error) {
	u := contentURL("/files_put/" + s.root() + path)
	if vals == nil {
		vals = make(url.Values)
	}
	u.RawQuery = s.Config.setLocale(vals).Encode()
	r, e := http.NewRequest("PUT", u.String(), contents)
	if e != nil {
		return nil, e
	}
	r.ContentLength = size
	buf, err := doRequest(r, s.AppToken, s.AccessToken)
	if err != nil {
		return nil, err
	}
	var md FileMetadata
	dec := json.NewDecoder(buf)
	if e := dec.Decode(&md); e != nil {
		return nil, e
	}
	return &md, nil
}

type FileReader struct {
	io.ReadCloser
	// -1 if unknown.
	Size        int64
	ContentType string
}

func newFileReader(r *http.Response) *FileReader {
	return &FileReader{
		r.Body,
		r.ContentLength,
		r.Header.Get("Content-Type")}
}

func (s *Client) GetFile(path string) (*FileReader, error) {
	return s.doGet(contentURL("/files/" + s.root() + path))
}

func (s *Client) GetLink(path string) (*Link, error) {
	u := apiURL("/shares/" + s.root() + path)
	u.RawQuery = s.Config.localeQuery()
	var link Link
	if e := s.postForJson(u, &link); e != nil {
		return nil, e
	}
	return &link, nil
}

func (s *Client) GetMedia(path string) (*Link, error) {
	u := apiURL("/media/" + s.root() + path)
	u.RawQuery = s.Config.localeQuery()
	var link Link
	if e := s.postForJson(u, &link); e != nil {
		return nil, e
	}
	return &link, nil
}

func (c *Config) localeQuery() string {
	return c.setLocale(url.Values{}).Encode()
}

func (c *Config) setLocale(v url.Values) url.Values {
	if c.Locale != "" {
		v.Set("locale", c.Locale)
	}
	return v
}

func (s *Client) fileOp(op string, vals url.Values) (*FileMetadata, error) {
	u := apiURL("/fileops/" + op)
	vals.Set("root", s.root())
	u.RawQuery = s.Config.setLocale(vals).Encode()
	var md FileMetadata
	if e := s.postForJson(u, &md); e != nil {
		return nil, e
	}
	return &md, nil
}

func (s *Client) Move(from, to string) (*FileMetadata, error) {
	return s.fileOp("move", url.Values{"from_path": {from}, "to_path": {to}})
}

func (s *Client) Copy(from, to string) (*FileMetadata, error) {
	return s.fileOp("copy", url.Values{"from_path": {from}, "to_path": {to}})
}

func (s *Client) CreateDir(path string) (*FileMetadata, error) {
	return s.fileOp("create_folder", url.Values{"path": {path}})
}

func (s *Client) Delete(path string) (*FileMetadata, error) {
	return s.fileOp("delete", url.Values{"path": {path}})
}

func (c *Client) Search(path, query string, limit int) ([]FileMetadata, error) {
	u := apiURL("/search/" + c.root() + path)
	v := url.Values{"query": {query}}
	if limit > 0 {
		v.Set("limit", strconv.Itoa(limit))
	}
	u.RawQuery = c.Config.setLocale(v).Encode()
	var md []FileMetadata
	if e := c.getForJson(u, &md); e != nil {
		return nil, e
	}
	return md, nil
}

dbsh.go

package main

import (
	"bufio"
	"dropbox"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"os/exec"
	gpath "path"
	"strings"
	"text/tabwriter"
	"time"
	"unicode"
)

func Ls(db *dropbox.Client, args []string) error {
	md, e := db.GetMetadata(Cwd, true)
	if e != nil {
		return e
	}
	w := tabwriter.NewWriter(os.Stdout, 0, 2, 1, ' ', 0)
	defer w.Flush()
	for _, f := range md.Contents {
		fmt.Fprintf(w, "%d\t%s\t%s\t\n", f.Bytes, f.ModTime().Format(time.Stamp), gpath.Base(f.Path))
	}
	return nil
}

func Cd(db *dropbox.Client, args []string) error {
	dest := args[0]
	if dest == ".." {
		Cwd = gpath.Dir(Cwd)
		return nil
	}
	dest = mkabs(dest)
	md, e := db.GetMetadata(dest, false)
	if e != nil {
		return e
	}
	if md.IsDir {
		Cwd = dest
		return nil
	}
	return fmt.Errorf("No such dir: %s", dest)
}

func Cat(db *dropbox.Client, args []string) error {
	rc, e := db.GetFile(mkabs(args[0]))
	if e != nil {
		return e
	}
	defer rc.Close()
	if !strings.HasPrefix(rc.ContentType, "text/") {
		return fmt.Errorf("Not a content type you should cat: %s", rc.ContentType)
	}
	_, e = io.Copy(os.Stdout, rc)
	return e
}

func Put(db *dropbox.Client, args []string) error {
	srcfile := args[0]
	if !gpath.IsAbs(srcfile) {
		srcdir, e := os.Getwd()
		if e != nil {
			return e
		}
		srcfile = gpath.Join(srcdir, srcfile)
	}
	src, e := os.Open(srcfile)
	if e != nil {
		return e
	}
	defer src.Close()
	fi, e := src.Stat()
	if e != nil {
		return e
	}
	destpath := gpath.Join(Cwd, gpath.Base(srcfile))
	fmt.Printf("Uploading to %s\n", destpath)
	_, e = db.AddFile(destpath, src, fi.Size())
	return e
}

func Get(db *dropbox.Client, args []string) error {
	fname := mkabs(args[0])
	destdir, e := os.Getwd()
	if e != nil {
		return e
	}
	destfile := gpath.Join(destdir, gpath.Base(fname))
	r, e := db.GetFile(fname)
	if e != nil {
		return e
	}
	defer r.Close()
	fmt.Printf("Saving to %s\n", destfile)
	dest, e := os.Create(destfile)
	if e != nil {
		return e
	}
	defer dest.Close()
	_, e = io.Copy(dest, r)
	return e
}

func Share(db *dropbox.Client, args []string) error {
	link, e := db.GetLink(mkabs(args[0]))
	if e != nil {
		return e
	}
	fmt.Println(link.URL)
	return nil
}

func mkabs(path string) string {
	if !gpath.IsAbs(path) {
		return gpath.Join(Cwd, path)
	}
	return path
}

func Mv(db *dropbox.Client, args []string) error {
	from, to := mkabs(args[0]), mkabs(args[1])
	_, e := db.Move(from, to)
	return e
}

func Cp(db *dropbox.Client, args []string) error {
	from, to := mkabs(args[0]), mkabs(args[1])
	_, e := db.Copy(from, to)
	return e
}

func Rm(db *dropbox.Client, args []string) error {
	_, e := db.Delete(mkabs(args[0]))
	return e
}

func Mkdir(db *dropbox.Client, args []string) error {
	_, e := db.CreateDir(mkabs(args[0]))
	return e
}

func Whoami(db *dropbox.Client, args []string) error {
	ai, e := db.GetAccountInfo()
	if e != nil {
		return e
	}
	b, e := json.MarshalIndent(ai, "", "   ")
	if e != nil {
		return e
	}
	fmt.Println(string(b))
	return nil
}

func Find(db *dropbox.Client, args []string) error {
	r, e := db.Search(Cwd, args[0], 0)
	if e != nil {
		return e
	}
	for _, m := range r {
		fmt.Println(m.Path)
	}
	return nil
}

type Cmd struct {
	Fn       func(*dropbox.Client, []string) error
	ArgCount int
}

func tryCmd(c *dropbox.Client, cname string, args []string) error {
	if len(args) == 0 {
		return fmt.Errorf("Last argument needs to be a dropbox path.")
	}
	fname := args[len(args)-1]
	args = args[:len(args)-1]
	f, e := c.GetFile(mkabs(fname))
	if e != nil {
		return e
	}
	defer f.Close()
	cmd := exec.Command(cname, args...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.Stdin = f
	return cmd.Run()
}

var cmds = map[string]Cmd{
	"pwd": {func(*dropbox.Client, []string) error {
		fmt.Println(Cwd)
		return nil
	}, 0},
	"mv":     {Mv, 2},
	"cp":     {Cp, 2},
	"cd":     {Cd, 1},
	"rm":     {Rm, 1},
	"mkdir":  {Mkdir, 1},
	"share":  {Share, 1},
	"cat":    {Cat, 1},
	"ls":     {Ls, 0},
	"find":   {Find, 1},
	"whoami": {Whoami, 0},
	"help": {func(*dropbox.Client, []string) error {
		for k := range cmds {
			fmt.Println(k)
		}
		return nil
	}, 0},
	"put": {Put, 1},
	"get": {Get, 1},
	"exit": {func(*dropbox.Client, []string) error {
		os.Exit(0)
		return nil
	}, 0},
}

// Global mutable var. Oh noes.
var Cwd = "/"

func tokenize(s string) []string {
	curr := make([]rune, 0, 32)
	res := make([]string, 0, 10)
	var in_word, last_slash bool
	for _, r := range s {
		if last_slash || (!unicode.IsSpace(r) && (r != '\\')) {
			curr = append(curr, r)
			in_word = true
		} else {
			if in_word {
				res = append(res, string(curr))
				curr = curr[0:0]
				in_word = false
			}
		}
		last_slash = r == '\\'
	}
	if len(curr) > 0 {
		res = append(res, string(curr))
	}
	return res
}

var AppToken = dropbox.AppToken{
	Key:    "<redacted>",
	Secret: "<redacted>"}
var AccessToken = dropbox.AccessToken{
	Key:    "<redacted>",
	Secret: "<redacted>"}

func main() {
	db := &dropbox.Client{
		AppToken:    AppToken,
		AccessToken: AccessToken,
		Config: dropbox.Config{
			Access: dropbox.Dropbox,
			Locale: "us",
		}}
	in := bufio.NewReader(os.Stdin)
	for {
		fmt.Printf("%s > ", gpath.Base(Cwd))
		lineb, _, e := in.ReadLine()
		if e != nil {
			if e == io.EOF {
				break
			}
			panic(e)
		}
		tokens := tokenize(string(lineb))
		if len(tokens) == 0 {
			continue
		}

		cmd, ok := cmds[tokens[0]]
		if !ok {
			if e := tryCmd(db, tokens[0], tokens[1:]); e != nil {
				fmt.Printf("ERROR: %v\n", e)
			}
		} else {
			args := tokens[1:]
			if len(args) != cmd.ArgCount && cmd.ArgCount != -1 {
				fmt.Printf("ERROR: %s expected %d args, got %d.\n", tokens[0], cmd.ArgCount, len(args))
			} else if e := cmd.Fn(db, args); e != nil {
				fmt.Printf("ERROR: %v\n", e)
			}
		}
	}
}