package streaming
import (
"fmt"
"github.com/sirupsen/logrus"
"net/http"
"time"
"github.com/gin-gonic/gin"
"github.com/gorilla/websocket"
)
// StreamGETHandler swagger:operation GET /api/v1/streaming streamGet
//
// Initiate a websocket connection for live streaming of statuses and notifications.
//
// The scheme used should *always* be `wss`. The streaming basepath can be viewed at `/api/v1/instance`.
//
// On a successful connection, a code `101` will be returned, which indicates that the connection is being upgraded to a secure websocket connection.
//
// As long as the connection is open, various message types will be streamed into it.
//
// GoToSocial will ping the connection every 30 seconds to check whether the client is still receiving.
//
// If the ping fails, or something else goes wrong during transmission, then the connection will be dropped, and the client will be expected to start it again.
//
// ---
// tags:
// - streaming
//
// produces:
// - application/json
//
// schemes:
// - wss
//
// parameters:
// - name: access_token
// type: string
// description: Access token for the requesting account.
// in: query
// required: true
// - name: stream
// type: string
// description: |-
// Type of stream to request.
//
// Options are:
//
// `user`: receive updates for the account's home timeline.
// `public`: receive updates for the public timeline.
// `public:local`: receive updates for the local timeline.
// `hashtag`: receive updates for a given hashtag.
// `hashtag:local`: receive local updates for a given hashtag.
// `list`: receive updates for a certain list of accounts.
// `direct`: receive updates for direct messages.
// in: query
// required: true
// security:
// - OAuth2 Bearer:
// - read:streaming
//
// responses:
// '101':
// schema:
// type: object
// properties:
// stream:
// type: array
// items:
// type: string
// enum:
// - user
// - public
// - public:local
// - hashtag
// - hashtag:local
// - list
// - direct
// event:
// description: |-
// The type of event being received.
//
// `update`: a new status has been received.
// `notification`: a new notification has been received.
// `delete`: a status has been deleted.
// `filters_changed`: not implemented.
// type: string
// enum:
// - update
// - notification
// - delete
// - filters_changed
// payload:
// description: |-
// The payload of the streamed message.
// Different depending on the `event` type.
//
// If present, it should be parsed as a string.
//
// If `event` = `update`, then the payload will be a JSON string of a status.
// If `event` = `notification`, then the payload will be a JSON string of a notification.
// If `event` = `delete`, then the payload will be a status ID.
// type: string
// example: "{\"id\":\"01FC3TZ5CFG6H65GCKCJRKA669\",\"created_at\":\"2021-08-02T16:25:52Z\",\"sensitive\":false,\"spoiler_text\":\"\",\"visibility\":\"public\",\"language\":\"en\",\"uri\":\"https://gts.superseriousbusiness.org/users/dumpsterqueer/statuses/01FC3TZ5CFG6H65GCKCJRKA669\",\"url\":\"https://gts.superseriousbusiness.org/@dumpsterqueer/statuses/01FC3TZ5CFG6H65GCKCJRKA669\",\"replies_count\":0,\"reblogs_count\":0,\"favourites_count\":0,\"favourited\":false,\"reblogged\":false,\"muted\":false,\"bookmarked\":fals…//gts.superseriousbusiness.org/fileserver/01JNN207W98SGG3CBJ76R5MVDN/header/original/019036W043D8FXPJKSKCX7G965.png\",\"header_static\":\"https://gts.superseriousbusiness.org/fileserver/01JNN207W98SGG3CBJ76R5MVDN/header/small/019036W043D8FXPJKSKCX7G965.png\",\"followers_count\":33,\"following_count\":28,\"statuses_count\":126,\"last_status_at\":\"2021-08-02T16:25:52Z\",\"emojis\":[],\"fields\":[]},\"media_attachments\":[],\"mentions\":[],\"tags\":[],\"emojis\":[],\"card\":null,\"poll\":null,\"text\":\"a\"}"
// '401':
// description: unauthorized
// '400':
// description: bad request
func (m *Module) StreamGETHandler(c *gin.Context) {
l := logrus.WithField("func", "StreamGETHandler")
streamType := c.Query(StreamQueryKey)
if streamType == "" {
c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("no stream type provided under query key %s", StreamQueryKey)})
return
}
accessToken := c.Query(AccessTokenQueryKey)
if accessToken == "" {
c.JSON(http.StatusUnauthorized, gin.H{"error": fmt.Sprintf("no access token provided under query key %s", AccessTokenQueryKey)})
return
}
// make sure a valid token has been provided and obtain the associated account
account, err := m.processor.AuthorizeStreamingRequest(c.Request.Context(), accessToken)
if err != nil {
c.JSON(http.StatusUnauthorized, gin.H{"error": "could not authorize with given token"})
return
}
// prepare to upgrade the connection to a websocket connection
upgrader := websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
CheckOrigin: func(r *http.Request) bool {
// we fully expect cors requests (via something like pinafore.social) so we should be lenient here
return true
},
}
// do the actual upgrade here
conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
if err != nil {
l.Infof("error upgrading websocket connection: %s", err)
return
}
defer conn.Close() // whatever happens, when we leave this function we want to close the websocket connection
// inform the processor that we have a new connection and want a s for it
s, errWithCode := m.processor.OpenStreamForAccount(c.Request.Context(), account, streamType)
if errWithCode != nil {
c.JSON(errWithCode.Code(), errWithCode.Safe())
return
}
defer close(s.Hangup) // closing stream.Hangup indicates that we've finished with the connection (the client has gone), so we want to do this on exiting this handler
// spawn a new ticker for pinging the connection periodically
t := time.NewTicker(30 * time.Second)
// we want to stay in the sendloop as long as possible while the client is connected -- the only thing that should break the loop is if the client leaves or something else goes wrong
sendLoop:
for {
select {
case m := <-s.Messages:
// we've got a streaming message!!
l.Trace("received message from stream")
if err := conn.WriteJSON(m); err != nil {
l.Debugf("error writing json to websocket connection: %s", err)
// if something is wrong we want to bail and drop the connection -- the client will create a new one
break sendLoop
}
l.Trace("wrote message into websocket connection")
case <-t.C:
l.Trace("received TICK from ticker")
if err := conn.WriteMessage(websocket.PingMessage, []byte(": ping")); err != nil {
l.Debugf("error writing ping to websocket connection: %s", err)
// if something is wrong we want to bail and drop the connection -- the client will create a new one
break sendLoop
}
l.Trace("wrote ping message into websocket connection")
}
}
l.Trace("leaving StreamGETHandler")
}