1// Package tgbotapi has bindings for interacting with the Telegram Bot API.
  2package tgbotapi
  3
  4import (
  5	"bytes"
  6	"encoding/json"
  7	"errors"
  8	"fmt"
  9	"github.com/technoweenie/multipartstreamer"
 10	"io/ioutil"
 11	"log"
 12	"net/http"
 13	"net/url"
 14	"os"
 15	"strconv"
 16	"strings"
 17	"time"
 18)
 19
 20// BotAPI has methods for interacting with all of Telegram's Bot API endpoints.
 21type BotAPI struct {
 22	Token  string       `json:"token"`
 23	Debug  bool         `json:"debug"`
 24	Self   User         `json:"-"`
 25	Client *http.Client `json:"-"`
 26}
 27
 28// NewBotAPI creates a new BotAPI instance.
 29// Requires a token, provided by @BotFather on Telegram
 30func NewBotAPI(token string) (*BotAPI, error) {
 31	return NewBotAPIWithClient(token, &http.Client{})
 32}
 33
 34// NewBotAPIWithClient creates a new BotAPI instance passing an http.Client.
 35// Requires a token, provided by @BotFather on Telegram
 36func NewBotAPIWithClient(token string, client *http.Client) (*BotAPI, error) {
 37	bot := &BotAPI{
 38		Token:  token,
 39		Client: client,
 40	}
 41
 42	self, err := bot.GetMe()
 43	if err != nil {
 44		return &BotAPI{}, err
 45	}
 46
 47	bot.Self = self
 48
 49	return bot, nil
 50}
 51
 52// MakeRequest makes a request to a specific endpoint with our token.
 53// All requests are POSTs because Telegram doesn't care, and it's easier.
 54func (bot *BotAPI) MakeRequest(endpoint string, params url.Values) (APIResponse, error) {
 55	resp, err := bot.Client.PostForm(fmt.Sprintf(APIEndpoint, bot.Token, endpoint), params)
 56	if err != nil {
 57		return APIResponse{}, err
 58	}
 59	defer resp.Body.Close()
 60
 61	if resp.StatusCode == http.StatusForbidden {
 62		return APIResponse{}, errors.New(APIForbidden)
 63	}
 64
 65	bytes, err := ioutil.ReadAll(resp.Body)
 66	if err != nil {
 67		return APIResponse{}, err
 68	}
 69
 70	if bot.Debug {
 71		log.Println(endpoint, string(bytes))
 72	}
 73
 74	var apiResp APIResponse
 75	json.Unmarshal(bytes, &apiResp)
 76
 77	if !apiResp.Ok {
 78		return APIResponse{}, errors.New(apiResp.Description)
 79	}
 80
 81	return apiResp, nil
 82}
 83
 84func (bot *BotAPI) makeMessageRequest(endpoint string, params url.Values) (Message, error) {
 85	resp, err := bot.MakeRequest(endpoint, params)
 86	if err != nil {
 87		return Message{}, err
 88	}
 89
 90	var message Message
 91	json.Unmarshal(resp.Result, &message)
 92
 93	bot.debugLog(endpoint, params, message)
 94
 95	return message, nil
 96}
 97
 98// UploadFile makes a request to the API with a file.
 99//
100// Requires the parameter to hold the file not be in the params.
101// File should be a string to a file path, a FileBytes struct, or a FileReader struct.
102func (bot *BotAPI) UploadFile(endpoint string, params map[string]string, fieldname string, file interface{}) (APIResponse, error) {
103	ms := multipartstreamer.New()
104	ms.WriteFields(params)
105
106	switch f := file.(type) {
107	case string:
108		fileHandle, err := os.Open(f)
109		if err != nil {
110			return APIResponse{}, err
111		}
112		defer fileHandle.Close()
113
114		fi, err := os.Stat(f)
115		if err != nil {
116			return APIResponse{}, err
117		}
118
119		ms.WriteReader(fieldname, fileHandle.Name(), fi.Size(), fileHandle)
120	case FileBytes:
121		buf := bytes.NewBuffer(f.Bytes)
122		ms.WriteReader(fieldname, f.Name, int64(len(f.Bytes)), buf)
123	case FileReader:
124		if f.Size == -1 {
125			data, err := ioutil.ReadAll(f.Reader)
126			if err != nil {
127				return APIResponse{}, err
128			}
129			buf := bytes.NewBuffer(data)
130
131			ms.WriteReader(fieldname, f.Name, int64(len(data)), buf)
132
133			break
134		}
135
136		ms.WriteReader(fieldname, f.Name, f.Size, f.Reader)
137	default:
138		return APIResponse{}, errors.New("bad file type")
139	}
140
141	req, err := http.NewRequest("POST", fmt.Sprintf(APIEndpoint, bot.Token, endpoint), nil)
142	ms.SetupRequest(req)
143	if err != nil {
144		return APIResponse{}, err
145	}
146
147	res, err := bot.Client.Do(req)
148	if err != nil {
149		return APIResponse{}, err
150	}
151	defer res.Body.Close()
152
153	bytes, err := ioutil.ReadAll(res.Body)
154	if err != nil {
155		return APIResponse{}, err
156	}
157
158	if bot.Debug {
159		log.Println(string(bytes[:]))
160	}
161
162	var apiResp APIResponse
163	json.Unmarshal(bytes, &apiResp)
164
165	if !apiResp.Ok {
166		return APIResponse{}, errors.New(apiResp.Description)
167	}
168
169	return apiResp, nil
170}
171
172// GetFileDirectURL returns direct URL to file
173//
174// Requires fileID
175func (bot *BotAPI) GetFileDirectURL(fileID string) (string, error) {
176	file, err := bot.GetFile(FileConfig{fileID})
177
178	if err != nil {
179		return "", err
180	}
181
182	return file.Link(bot.Token), nil
183}
184
185// GetMe fetches the currently authenticated bot.
186//
187// There are no parameters for this method.
188func (bot *BotAPI) GetMe() (User, error) {
189	resp, err := bot.MakeRequest("getMe", nil)
190	if err != nil {
191		return User{}, err
192	}
193
194	var user User
195	json.Unmarshal(resp.Result, &user)
196
197	if bot.Debug {
198		log.Printf("getMe: %+v\n", user)
199	}
200
201	return user, nil
202}
203
204// IsMessageToMe returns true if message directed to this bot
205//
206// Requires message
207func (bot *BotAPI) IsMessageToMe(message Message) bool {
208	return strings.Contains(message.Text, "@"+bot.Self.UserName)
209}
210
211// Send will send event(Message, Photo, Audio, ChatAction, anything) to Telegram
212//
213// Requires Chattable
214func (bot *BotAPI) Send(c Chattable) (Message, error) {
215	switch c.(type) {
216	case Fileable:
217		return bot.sendFile(c.(Fileable))
218	default:
219		return bot.sendChattable(c)
220	}
221}
222
223func (bot *BotAPI) debugLog(context string, v url.Values, message interface{}) {
224	if bot.Debug {
225		log.Printf("%s req : %+v\n", context, v)
226		log.Printf("%s resp: %+v\n", context, message)
227	}
228}
229
230func (bot *BotAPI) sendExisting(method string, config Fileable) (Message, error) {
231	v, err := config.Values()
232
233	if err != nil {
234		return Message{}, err
235	}
236
237	message, err := bot.makeMessageRequest(method, v)
238	if err != nil {
239		return Message{}, err
240	}
241
242	return message, nil
243}
244
245func (bot *BotAPI) uploadAndSend(method string, config Fileable) (Message, error) {
246	params, err := config.Params()
247	if err != nil {
248		return Message{}, err
249	}
250
251	file := config.GetFile()
252
253	resp, err := bot.UploadFile(method, params, config.Name(), file)
254	if err != nil {
255		return Message{}, err
256	}
257
258	var message Message
259	json.Unmarshal(resp.Result, &message)
260
261	if bot.Debug {
262		log.Printf("%s resp: %+v\n", method, message)
263	}
264
265	return message, nil
266}
267
268func (bot *BotAPI) sendFile(config Fileable) (Message, error) {
269	if config.UseExistingFile() {
270		return bot.sendExisting(config.Method(), config)
271	}
272
273	return bot.uploadAndSend(config.Method(), config)
274}
275
276func (bot *BotAPI) sendChattable(config Chattable) (Message, error) {
277	v, err := config.Values()
278	if err != nil {
279		return Message{}, err
280	}
281
282	message, err := bot.makeMessageRequest(config.Method(), v)
283
284	if err != nil {
285		return Message{}, err
286	}
287
288	return message, nil
289}
290
291// GetUserProfilePhotos gets a user's profile photos.
292//
293// Requires UserID.
294// Offset and Limit are optional.
295func (bot *BotAPI) GetUserProfilePhotos(config UserProfilePhotosConfig) (UserProfilePhotos, error) {
296	v := url.Values{}
297	v.Add("user_id", strconv.Itoa(config.UserID))
298	if config.Offset != 0 {
299		v.Add("offset", strconv.Itoa(config.Offset))
300	}
301	if config.Limit != 0 {
302		v.Add("limit", strconv.Itoa(config.Limit))
303	}
304
305	resp, err := bot.MakeRequest("getUserProfilePhotos", v)
306	if err != nil {
307		return UserProfilePhotos{}, err
308	}
309
310	var profilePhotos UserProfilePhotos
311	json.Unmarshal(resp.Result, &profilePhotos)
312
313	bot.debugLog("GetUserProfilePhoto", v, profilePhotos)
314
315	return profilePhotos, nil
316}
317
318// GetFile returns a file_id required to download a file.
319//
320// Requires FileID.
321func (bot *BotAPI) GetFile(config FileConfig) (File, error) {
322	v := url.Values{}
323	v.Add("file_id", config.FileID)
324
325	resp, err := bot.MakeRequest("getFile", v)
326	if err != nil {
327		return File{}, err
328	}
329
330	var file File
331	json.Unmarshal(resp.Result, &file)
332
333	bot.debugLog("GetFile", v, file)
334
335	return file, nil
336}
337
338// GetUpdates fetches updates.
339// If a WebHook is set, this will not return any data!
340//
341// Offset, Limit, and Timeout are optional.
342// To not get old items, set Offset to one higher than the previous item.
343// Set Timeout to a large number to reduce requests and get responses instantly.
344func (bot *BotAPI) GetUpdates(config UpdateConfig) ([]Update, error) {
345	v := url.Values{}
346	if config.Offset > 0 {
347		v.Add("offset", strconv.Itoa(config.Offset))
348	}
349	if config.Limit > 0 {
350		v.Add("limit", strconv.Itoa(config.Limit))
351	}
352	if config.Timeout > 0 {
353		v.Add("timeout", strconv.Itoa(config.Timeout))
354	}
355
356	resp, err := bot.MakeRequest("getUpdates", v)
357	if err != nil {
358		return []Update{}, err
359	}
360
361	var updates []Update
362	json.Unmarshal(resp.Result, &updates)
363
364	if bot.Debug {
365		log.Printf("getUpdates: %+v\n", updates)
366	}
367
368	return updates, nil
369}
370
371// RemoveWebhook removes webhook
372//
373// There are no parameters for this method.
374func (bot *BotAPI) RemoveWebhook() (APIResponse, error) {
375	return bot.MakeRequest("setWebhook", url.Values{})
376}
377
378// SetWebhook sets a webhook.
379// If this is set, GetUpdates will not get any data!
380//
381// Requires URL OR to set Clear to true.
382func (bot *BotAPI) SetWebhook(config WebhookConfig) (APIResponse, error) {
383	if config.Certificate == nil {
384		v := url.Values{}
385		v.Add("url", config.URL.String())
386
387		return bot.MakeRequest("setWebhook", v)
388	}
389
390	params := make(map[string]string)
391	params["url"] = config.URL.String()
392
393	resp, err := bot.UploadFile("setWebhook", params, "certificate", config.Certificate)
394	if err != nil {
395		return APIResponse{}, err
396	}
397
398	var apiResp APIResponse
399	json.Unmarshal(resp.Result, &apiResp)
400
401	if bot.Debug {
402		log.Printf("setWebhook resp: %+v\n", apiResp)
403	}
404
405	return apiResp, nil
406}
407
408// GetUpdatesChan starts and returns a channel for getting updates.
409//
410// Requires UpdateConfig
411func (bot *BotAPI) GetUpdatesChan(config UpdateConfig) (<-chan Update, error) {
412	updatesChan := make(chan Update, 100)
413
414	go func() {
415		for {
416			updates, err := bot.GetUpdates(config)
417			if err != nil {
418				log.Println(err)
419				log.Println("Failed to get updates, retrying in 3 seconds...")
420				time.Sleep(time.Second * 3)
421
422				continue
423			}
424
425			for _, update := range updates {
426				if update.UpdateID >= config.Offset {
427					config.Offset = update.UpdateID + 1
428					updatesChan <- update
429				}
430			}
431		}
432	}()
433
434	return updatesChan, nil
435}
436
437// ListenForWebhook registers a http handler for a webhook.
438func (bot *BotAPI) ListenForWebhook(pattern string) (<-chan Update, http.Handler) {
439	updatesChan := make(chan Update, 100)
440
441	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
442		bytes, _ := ioutil.ReadAll(r.Body)
443
444		var update Update
445		json.Unmarshal(bytes, &update)
446
447		updatesChan <- update
448	})
449
450	http.HandleFunc(pattern, handler)
451
452	return updatesChan, handler
453}