Add vk bridge (#1372)

* Add vk bridge

* Vk bridge attachments

* Vk bridge forwarded messages

* Vk bridge sample config and code cleanup

* Vk bridge add vendor

* Vk bridge message edit

* Vk bridge: fix fetching names of other bots

* Vk bridge: code cleanup

* Vk bridge: fix shadows declaration

* Vk bridge: remove UseFileURL

1 files changed, 359 insertions, 0 deletions

diff --git a/vendor/github.com/SevereCloud/vksdk/v2/api/api.go b/vendor/github.com/SevereCloud/vksdk/v2/api/api.go
new file mode 100644
index 00000000..56da7784
--- /dev/null
+++ b/vendor/github.com/SevereCloud/vksdk/v2/api/api.go
@@ -0,0 +1,359 @@
+/*
+Package api implements VK API.
+
+See more https://vk.com/dev/api_requests
+*/
+package api // import "github.com/SevereCloud/vksdk/v2/api"
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"mime"
+	"net/http"
+	"net/url"
+	"reflect"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/SevereCloud/vksdk/v2"
+	"github.com/SevereCloud/vksdk/v2/internal"
+	"github.com/SevereCloud/vksdk/v2/object"
+)
+
+// Api constants.
+const (
+	Version   = vksdk.API
+	MethodURL = "https://api.vk.com/method/"
+)
+
+// VKontakte API methods (except for methods from secure and ads sections)
+// with user access key or service access key can be accessed
+// no more than 3 times per second. The community access key is limited
+// to 20 requests per second.
+//
+// Maximum amount of calls to the secure section methods depends
+// on the app's users amount. If an app has less than
+// 10 000 users, 5 requests per second,
+// up to 100 000 – 8 requests,
+// up to 1 000 000 – 20 requests,
+// 1 000 000+ – 35 requests.
+//
+// The ads section methods are subject to their own limitations,
+// you can read them on this page - https://vk.com/dev/ads_limits
+//
+// If one of this limits is exceeded, the server will return following error:
+// "Too many requests per second". (errors.TooMany).
+//
+// If your app's logic implies many requests in a row, check the execute method.
+// It allows for up to 25 requests for different methods in a single request.
+//
+// In addition to restrictions on the frequency of calls, there are also
+// quantitative restrictions on calling the same type of methods.
+//
+// After exceeding the quantitative limit, access to a particular method may
+// require entering a captcha (see https://vk.com/dev/captcha_error),
+// and may also be temporarily restricted (in this case, the server does
+// not return a response to the call of a particular method, but handles
+// any other requests without problems).
+//
+// If this error occurs, the following parameters are also passed in
+// the error message:
+//
+// CaptchaSID - identifier captcha.
+//
+// CaptchaImg - a link to the image that you want to show the user
+// to enter text from that image.
+//
+// In this case, you should ask the user to enter text from
+// the CaptchaImg image and repeat the request by adding parameters to it:
+//
+// captcha_sid - the obtained identifier;
+//
+// captcha_key - text entered by the user.
+//
+// More info: https://vk.com/dev/api_requests
+const (
+	LimitUserToken  = 3
+	LimitGroupToken = 20
+)
+
+// VK struct.
+type VK struct {
+	accessTokens []string
+	lastToken    uint32
+	MethodURL    string
+	Version      string
+	Client       *http.Client
+	Limit        int
+	UserAgent    string
+	Handler      func(method string, params ...Params) (Response, error)
+
+	mux      sync.Mutex
+	lastTime time.Time
+	rps      int
+}
+
+// Response struct.
+type Response struct {
+	Response      json.RawMessage `json:"response"`
+	Error         Error           `json:"error"`
+	ExecuteErrors ExecuteErrors   `json:"execute_errors"`
+}
+
+// NewVK returns a new VK.
+//
+// The VKSDK will use the http.DefaultClient.
+// This means that if the http.DefaultClient is modified by other components
+// of your application the modifications will be picked up by the SDK as well.
+//
+// In some cases this might be intended, but it is a better practice
+// to create a custom HTTP Client to share explicitly through
+// your application. You can configure the VKSDK to use the custom
+// HTTP Client by setting the VK.Client value.
+//
+// This set limit 20 requests per second for one token.
+func NewVK(tokens ...string) *VK {
+	var vk VK
+
+	vk.accessTokens = tokens
+	vk.Version = Version
+
+	vk.Handler = vk.defaultHandler
+
+	vk.MethodURL = MethodURL
+	vk.Client = http.DefaultClient
+	vk.Limit = LimitGroupToken
+	vk.UserAgent = internal.UserAgent
+
+	return &vk
+}
+
+// getToken return next token (simple round-robin).
+func (vk *VK) getToken() string {
+	i := atomic.AddUint32(&vk.lastToken, 1)
+	return vk.accessTokens[(int(i)-1)%len(vk.accessTokens)]
+}
+
+// Params type.
+type Params map[string]interface{}
+
+// Lang - determines the language for the data to be displayed on. For
+// example country and city names. If you use a non-cyrillic language,
+// cyrillic symbols will be transliterated automatically.
+// Numeric format from account.getInfo is supported as well.
+//
+// 	p.Lang(object.LangRU)
+//
+// See all language code in module object.
+func (p Params) Lang(v int) Params {
+	p["lang"] = v
+	return p
+}
+
+// TestMode allows to send requests from a native app without switching it on
+// for all users.
+func (p Params) TestMode(v bool) Params {
+	p["test_mode"] = v
+	return p
+}
+
+// CaptchaSID received ID.
+//
+// See https://vk.com/dev/captcha_error
+func (p Params) CaptchaSID(v string) Params {
+	p["captcha_sid"] = v
+	return p
+}
+
+// CaptchaKey text input.
+//
+// See https://vk.com/dev/captcha_error
+func (p Params) CaptchaKey(v string) Params {
+	p["captcha_key"] = v
+	return p
+}
+
+// Confirm parameter.
+//
+// See https://vk.com/dev/need_confirmation
+func (p Params) Confirm(v bool) Params {
+	p["confirm"] = v
+	return p
+}
+
+// WithContext parameter.
+func (p Params) WithContext(ctx context.Context) Params {
+	p[":context"] = ctx
+	return p
+}
+
+func buildQuery(sliceParams ...Params) (context.Context, url.Values) {
+	query := url.Values{}
+	ctx := context.Background()
+
+	for _, params := range sliceParams {
+		for key, value := range params {
+			if key != ":context" {
+				query.Set(key, FmtValue(value, 0))
+			} else {
+				ctx = value.(context.Context)
+			}
+		}
+	}
+
+	return ctx, query
+}
+
+// defaultHandler provides access to VK API methods.
+func (vk *VK) defaultHandler(method string, sliceParams ...Params) (Response, error) {
+	u := vk.MethodURL + method
+	ctx, query := buildQuery(sliceParams...)
+	attempt := 0
+
+	for {
+		var response Response
+
+		attempt++
+
+		// Rate limiting
+		if vk.Limit > 0 {
+			vk.mux.Lock()
+
+			sleepTime := time.Second - time.Since(vk.lastTime)
+			if sleepTime < 0 {
+				vk.lastTime = time.Now()
+				vk.rps = 0
+			} else if vk.rps == vk.Limit*len(vk.accessTokens) {
+				time.Sleep(sleepTime)
+				vk.lastTime = time.Now()
+				vk.rps = 0
+			}
+			vk.rps++
+
+			vk.mux.Unlock()
+		}
+
+		rawBody := bytes.NewBufferString(query.Encode())
+
+		req, err := http.NewRequestWithContext(ctx, "POST", u, rawBody)
+		if err != nil {
+			return response, err
+		}
+
+		req.Header.Set("User-Agent", vk.UserAgent)
+		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+		resp, err := vk.Client.Do(req)
+		if err != nil {
+			return response, err
+		}
+
+		mediatype, _, _ := mime.ParseMediaType(resp.Header.Get("Content-Type"))
+		if mediatype != "application/json" {
+			_ = resp.Body.Close()
+			return response, &InvalidContentType{mediatype}
+		}
+
+		err = json.NewDecoder(resp.Body).Decode(&response)
+		if err != nil {
+			_ = resp.Body.Close()
+			return response, err
+		}
+
+		_ = resp.Body.Close()
+
+		switch response.Error.Code {
+		case ErrNoType:
+			return response, nil
+		case ErrTooMany:
+			if attempt < vk.Limit {
+				continue
+			}
+
+			return response, &response.Error
+		}
+
+		return response, &response.Error
+	}
+}
+
+// Request provides access to VK API methods.
+func (vk *VK) Request(method string, sliceParams ...Params) ([]byte, error) {
+	token := vk.getToken()
+
+	reqParams := Params{
+		"access_token": token,
+		"v":            vk.Version,
+	}
+
+	sliceParams = append(sliceParams, reqParams)
+
+	resp, err := vk.Handler(method, sliceParams...)
+
+	return resp.Response, err
+}
+
+// RequestUnmarshal provides access to VK API methods.
+func (vk *VK) RequestUnmarshal(method string, obj interface{}, sliceParams ...Params) error {
+	rawResponse, err := vk.Request(method, sliceParams...)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(rawResponse, &obj)
+}
+
+func fmtReflectValue(value reflect.Value, depth int) string {
+	switch f := value; value.Kind() {
+	case reflect.Invalid:
+		return ""
+	case reflect.Bool:
+		return fmtBool(f.Bool())
+	case reflect.Array, reflect.Slice:
+		s := ""
+
+		for i := 0; i < f.Len(); i++ {
+			if i > 0 {
+				s += ","
+			}
+
+			s += FmtValue(f.Index(i).Interface(), depth)
+		}
+
+		return s
+	case reflect.Ptr:
+		// pointer to array or slice or struct? ok at top level
+		// but not embedded (avoid loops)
+		if depth == 0 && f.Pointer() != 0 {
+			switch a := f.Elem(); a.Kind() {
+			case reflect.Array, reflect.Slice, reflect.Struct, reflect.Map:
+				return FmtValue(a.Interface(), depth+1)
+			}
+		}
+	}
+
+	return fmt.Sprint(value)
+}
+
+// FmtValue return vk format string.
+func FmtValue(value interface{}, depth int) string {
+	if value == nil {
+		return ""
+	}
+
+	switch f := value.(type) {
+	case bool:
+		return fmtBool(f)
+	case object.Attachment:
+		return f.ToAttachment()
+	case object.JSONObject:
+		return f.ToJSON()
+	case reflect.Value:
+		return fmtReflectValue(f, depth)
+	}
+
+	return fmtReflectValue(reflect.ValueOf(value), depth)
+}