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

vendor/github.com/SevereCloud/vksdk/v2/longpoll-bot/longpoll.go

@@ -0,0 +1,219 @@
+/*
+Package longpoll implements Bots Long Poll API.
+
+See more https://vk.com/dev/bots_longpoll
+*/
+package longpoll // import "github.com/SevereCloud/vksdk/v2/longpoll-bot"
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/SevereCloud/vksdk/v2"
+	"github.com/SevereCloud/vksdk/v2/api"
+	"github.com/SevereCloud/vksdk/v2/events"
+	"github.com/SevereCloud/vksdk/v2/internal"
+)
+
+// Response struct.
+type Response struct {
+	Ts      string              `json:"ts"`
+	Updates []events.GroupEvent `json:"updates"`
+	Failed  int                 `json:"failed"`
+}
+
+// LongPoll struct.
+type LongPoll struct {
+	GroupID int
+	Server  string
+	Key     string
+	Ts      string
+	Wait    int
+	VK      *api.VK
+	Client  *http.Client
+	cancel  context.CancelFunc
+
+	funcFullResponseList []func(Response)
+
+	events.FuncList
+}
+
+// NewLongPoll returns a new LongPoll.
+//
+// The LongPoll 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.
+func NewLongPoll(vk *api.VK, groupID int) (*LongPoll, error) {
+	lp := &LongPoll{
+		VK:      vk,
+		GroupID: groupID,
+		Wait:    25,
+		Client:  http.DefaultClient,
+	}
+	lp.FuncList = *events.NewFuncList()
+
+	err := lp.updateServer(true)
+
+	return lp, err
+}
+
+// NewLongPollCommunity returns a new LongPoll for community token.
+//
+// The LongPoll 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.
+func NewLongPollCommunity(vk *api.VK) (*LongPoll, error) {
+	resp, err := vk.GroupsGetByID(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	lp := &LongPoll{
+		VK:      vk,
+		GroupID: resp[0].ID,
+		Wait:    25,
+		Client:  http.DefaultClient,
+	}
+	lp.FuncList = *events.NewFuncList()
+
+	err = lp.updateServer(true)
+
+	return lp, err
+}
+
+func (lp *LongPoll) updateServer(updateTs bool) error {
+	params := api.Params{
+		"group_id": lp.GroupID,
+	}
+
+	serverSetting, err := lp.VK.GroupsGetLongPollServer(params)
+	if err != nil {
+		return err
+	}
+
+	lp.Key = serverSetting.Key
+	lp.Server = serverSetting.Server
+
+	if updateTs {
+		lp.Ts = serverSetting.Ts
+	}
+
+	return nil
+}
+
+func (lp *LongPoll) check(ctx context.Context) (response Response, err error) {
+	u := fmt.Sprintf("%s?act=a_check&key=%s&ts=%s&wait=%d", lp.Server, lp.Key, lp.Ts, lp.Wait)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
+	if err != nil {
+		return response, err
+	}
+
+	resp, err := lp.Client.Do(req)
+	if err != nil {
+		return response, err
+	}
+	defer resp.Body.Close()
+
+	err = json.NewDecoder(resp.Body).Decode(&response)
+	if err != nil {
+		return response, err
+	}
+
+	err = lp.checkResponse(response)
+
+	return response, err
+}
+
+func (lp *LongPoll) checkResponse(response Response) (err error) {
+	switch response.Failed {
+	case 0:
+		lp.Ts = response.Ts
+	case 1:
+		lp.Ts = response.Ts
+	case 2:
+		err = lp.updateServer(false)
+	case 3:
+		err = lp.updateServer(true)
+	default:
+		err = &Failed{response.Failed}
+	}
+
+	return
+}
+
+func (lp *LongPoll) autoSetting(ctx context.Context) error {
+	params := api.Params{
+		"group_id":    lp.GroupID,
+		"enabled":     true,
+		"api_version": vksdk.API,
+	}.WithContext(ctx)
+	for _, event := range lp.ListEvents() {
+		params[string(event)] = true
+	}
+
+	// Updating LongPoll settings
+	_, err := lp.VK.GroupsSetLongPollSettings(params)
+
+	return err
+}
+
+// Run handler.
+func (lp *LongPoll) Run() error {
+	return lp.RunWithContext(context.Background())
+}
+
+// RunWithContext handler.
+func (lp *LongPoll) RunWithContext(ctx context.Context) error {
+	return lp.run(ctx)
+}
+
+func (lp *LongPoll) run(ctx context.Context) error {
+	ctx, lp.cancel = context.WithCancel(ctx)
+
+	err := lp.autoSetting(ctx)
+	if err != nil {
+		return err
+	}
+
+	for {
+		select {
+		case _, ok := <-ctx.Done():
+			if !ok {
+				return nil
+			}
+		default:
+			resp, err := lp.check(ctx)
+			if err != nil {
+				return err
+			}
+
+			ctx = context.WithValue(ctx, internal.LongPollTsKey, resp.Ts)
+
+			for _, event := range resp.Updates {
+				err = lp.Handler(ctx, event)
+				if err != nil {
+					return err
+				}
+			}
+
+			for _, f := range lp.funcFullResponseList {
+				f(resp)
+			}
+		}
+	}
+}
+
+// Shutdown gracefully shuts down the longpoll without interrupting any active connections.
+func (lp *LongPoll) Shutdown() {
+	if lp.cancel != nil {
+		lp.cancel()
+	}
+}
+
+// FullResponse handler.
+func (lp *LongPoll) FullResponse(f func(Response)) {
+	lp.funcFullResponseList = append(lp.funcFullResponseList, f)
+}