telegram-bot-api/bot.go

437 lines
9.6 KiB
Go

// Package tgbotapi has bindings for interacting with the Telegram Bot API.
package tgbotapi
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"github.com/technoweenie/multipartstreamer"
"io/ioutil"
"log"
"net/http"
"net/url"
"os"
"strconv"
"time"
)
// BotAPI has methods for interacting with all of Telegram's Bot API endpoints.
type BotAPI struct {
Token string `json:"token"`
Debug bool `json:"debug"`
Self User `json:"-"`
Updates chan Update `json:"-"`
Client *http.Client `json:"-"`
}
// NewBotAPI creates a new BotAPI instance.
// Requires a token, provided by @BotFather on Telegram
func NewBotAPI(token string) (*BotAPI, error) {
return NewBotAPIWithClient(token, &http.Client{})
}
// NewBotAPIWithClient creates a new BotAPI instance passing an http.Client.
// Requires a token, provided by @BotFather on Telegram
func NewBotAPIWithClient(token string, client *http.Client) (*BotAPI, error) {
bot := &BotAPI{
Token: token,
Client: client,
}
self, err := bot.GetMe()
if err != nil {
return &BotAPI{}, err
}
bot.Self = self
return bot, nil
}
// MakeRequest makes a request to a specific endpoint with our token.
// All requests are POSTs because Telegram doesn't care, and it's easier.
func (bot *BotAPI) MakeRequest(endpoint string, params url.Values) (APIResponse, error) {
resp, err := bot.Client.PostForm(fmt.Sprintf(APIEndpoint, bot.Token, endpoint), params)
if err != nil {
return APIResponse{}, err
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusForbidden {
return APIResponse{}, errors.New(APIForbidden)
}
bytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
return APIResponse{}, err
}
if bot.Debug {
log.Println(endpoint, string(bytes))
}
var apiResp APIResponse
json.Unmarshal(bytes, &apiResp)
if !apiResp.Ok {
return APIResponse{}, errors.New(apiResp.Description)
}
return apiResp, nil
}
func (bot *BotAPI) MakeMessageRequest(endpoint string, params url.Values) (Message, error) {
resp, err := bot.MakeRequest(endpoint, params)
if err != nil {
return Message{}, err
}
var message Message
json.Unmarshal(resp.Result, &message)
bot.debugLog(endpoint, params, message)
return message, nil
}
// UploadFile makes a request to the API with a file.
//
// Requires the parameter to hold the file not be in the params.
// File should be a string to a file path, a FileBytes struct, or a FileReader struct.
func (bot *BotAPI) UploadFile(endpoint string, params map[string]string, fieldname string, file interface{}) (APIResponse, error) {
ms := multipartstreamer.New()
ms.WriteFields(params)
switch f := file.(type) {
case string:
fileHandle, err := os.Open(f)
if err != nil {
return APIResponse{}, err
}
defer fileHandle.Close()
fi, err := os.Stat(f)
if err != nil {
return APIResponse{}, err
}
ms.WriteReader(fieldname, fileHandle.Name(), fi.Size(), fileHandle)
case FileBytes:
buf := bytes.NewBuffer(f.Bytes)
ms.WriteReader(fieldname, f.Name, int64(len(f.Bytes)), buf)
case FileReader:
if f.Size == -1 {
data, err := ioutil.ReadAll(f.Reader)
if err != nil {
return APIResponse{}, err
}
buf := bytes.NewBuffer(data)
ms.WriteReader(fieldname, f.Name, int64(len(data)), buf)
break
}
ms.WriteReader(fieldname, f.Name, f.Size, f.Reader)
default:
return APIResponse{}, errors.New("bad file type")
}
req, err := http.NewRequest("POST", fmt.Sprintf(APIEndpoint, bot.Token, endpoint), nil)
ms.SetupRequest(req)
if err != nil {
return APIResponse{}, err
}
res, err := bot.Client.Do(req)
if err != nil {
return APIResponse{}, err
}
defer res.Body.Close()
bytes, err := ioutil.ReadAll(res.Body)
if err != nil {
return APIResponse{}, err
}
if bot.Debug {
log.Println(string(bytes[:]))
}
var apiResp APIResponse
json.Unmarshal(bytes, &apiResp)
if !apiResp.Ok {
return APIResponse{}, errors.New(apiResp.Description)
}
return apiResp, nil
}
// GetMe fetches the currently authenticated bot.
//
// There are no parameters for this method.
func (bot *BotAPI) GetMe() (User, error) {
resp, err := bot.MakeRequest("getMe", nil)
if err != nil {
return User{}, err
}
var user User
json.Unmarshal(resp.Result, &user)
if bot.Debug {
log.Printf("getMe: %+v\n", user)
}
return user, nil
}
func (bot *BotAPI) Send(c Chattable) (Message, error) {
switch c.(type) {
case Fileable:
return bot.sendFile(c.(Fileable))
default:
return bot.sendChattable(c)
}
}
func (bot *BotAPI) debugLog(context string, v url.Values, message interface{}) {
if bot.Debug {
log.Printf("%s req : %+v\n", context, v)
log.Printf("%s resp: %+v\n", context, message)
}
}
func (bot *BotAPI) sendExisting(method string, config Fileable) (Message, error) {
v, err := config.Values()
if err != nil {
return Message{}, err
}
message, err := bot.MakeMessageRequest(method, v)
if err != nil {
return Message{}, err
}
return message, nil
}
func (bot *BotAPI) uploadAndSend(method string, config Fileable) (Message, error) {
params, err := config.Params()
if err != nil {
return Message{}, err
}
file := config.GetFile()
resp, err := bot.UploadFile(method, params, config.Name(), file)
if err != nil {
return Message{}, err
}
var message Message
json.Unmarshal(resp.Result, &message)
if bot.Debug {
log.Printf("%s resp: %+v\n", method, message)
}
return message, nil
}
func (bot *BotAPI) sendFile(config Fileable) (Message, error) {
if config.UseExistingFile() {
return bot.sendExisting(config.Method(), config)
}
return bot.uploadAndSend(config.Method(), config)
}
func (bot *BotAPI) sendChattable(config Chattable) (Message, error) {
v, err := config.Values()
if err != nil {
return Message{}, err
}
message, err := bot.MakeMessageRequest(config.Method(), v)
if err != nil {
return Message{}, err
}
return message, nil
}
// GetUserProfilePhotos gets a user's profile photos.
//
// Requires UserID.
// Offset and Limit are optional.
func (bot *BotAPI) GetUserProfilePhotos(config UserProfilePhotosConfig) (UserProfilePhotos, error) {
v := url.Values{}
v.Add("user_id", strconv.Itoa(config.UserID))
if config.Offset != 0 {
v.Add("offset", strconv.Itoa(config.Offset))
}
if config.Limit != 0 {
v.Add("limit", strconv.Itoa(config.Limit))
}
resp, err := bot.MakeRequest("getUserProfilePhotos", v)
if err != nil {
return UserProfilePhotos{}, err
}
var profilePhotos UserProfilePhotos
json.Unmarshal(resp.Result, &profilePhotos)
bot.debugLog("GetUserProfilePhoto", v, profilePhotos)
return profilePhotos, nil
}
// GetFile returns a file_id required to download a file.
//
// Requires FileID.
func (bot *BotAPI) GetFile(config FileConfig) (File, error) {
v := url.Values{}
v.Add("file_id", config.FileID)
resp, err := bot.MakeRequest("getFile", v)
if err != nil {
return File{}, err
}
var file File
json.Unmarshal(resp.Result, &file)
bot.debugLog("GetFile", v, file)
return file, nil
}
// GetUpdates fetches updates.
// If a WebHook is set, this will not return any data!
//
// Offset, Limit, and Timeout are optional.
// To not get old items, set Offset to one higher than the previous item.
// Set Timeout to a large number to reduce requests and get responses instantly.
func (bot *BotAPI) GetUpdates(config UpdateConfig) ([]Update, error) {
v := url.Values{}
if config.Offset > 0 {
v.Add("offset", strconv.Itoa(config.Offset))
}
if config.Limit > 0 {
v.Add("limit", strconv.Itoa(config.Limit))
}
if config.Timeout > 0 {
v.Add("timeout", strconv.Itoa(config.Timeout))
}
resp, err := bot.MakeRequest("getUpdates", v)
if err != nil {
return []Update{}, err
}
var updates []Update
json.Unmarshal(resp.Result, &updates)
if bot.Debug {
log.Printf("getUpdates: %+v\n", updates)
}
return updates, nil
}
// SetWebhook sets a webhook.
// If this is set, GetUpdates will not get any data!
//
// Requires URL OR to set Clear to true.
func (bot *BotAPI) SetWebhook(config WebhookConfig) (APIResponse, error) {
if config.Certificate == nil {
v := url.Values{}
if !config.Clear {
v.Add("url", config.URL.String())
}
return bot.MakeRequest("setWebhook", v)
}
params := make(map[string]string)
params["url"] = config.URL.String()
resp, err := bot.UploadFile("setWebhook", params, "certificate", config.Certificate)
if err != nil {
return APIResponse{}, err
}
var apiResp APIResponse
json.Unmarshal(resp.Result, &apiResp)
if bot.Debug {
log.Printf("setWebhook resp: %+v\n", apiResp)
}
return apiResp, nil
}
// UpdatesChan starts a channel for getting updates.
func (bot *BotAPI) UpdatesChan(config UpdateConfig) error {
bot.Updates = make(chan Update, 100)
go func() {
for {
updates, err := bot.GetUpdates(config)
if err != nil {
log.Println(err)
log.Println("Failed to get updates, retrying in 3 seconds...")
time.Sleep(time.Second * 3)
continue
}
for _, update := range updates {
if update.UpdateID >= config.Offset {
config.Offset = update.UpdateID + 1
bot.Updates <- update
}
}
}
}()
return nil
}
// ListenForWebhook registers a http handler for a webhook.
func (bot *BotAPI) ListenForWebhook(pattern string) {
bot.Updates = make(chan Update, 100)
http.HandleFunc(pattern, func(w http.ResponseWriter, r *http.Request) {
bytes, _ := ioutil.ReadAll(r.Body)
var update Update
json.Unmarshal(bytes, &update)
bot.Updates <- update
})
}
// SendChatAction sets a current action in a chat.
//
// Requires ChatID and a valid Action (see Chat constants).
func (bot *BotAPI) SendChatAction(config ChatActionConfig) error {
v, err := config.Values()
if err != nil {
return err
}
_, err = bot.MakeRequest("sendChatAction", v)
if err != nil {
return err
}
return nil
}