Split out common code shared with notepad

Author: martenrichter

src/commonhandler.js

@@ -0,0 +1,264 @@
+/* eslint-disable node/no-callback-literal */
+/*
+    Fails Components (Fancy Automated Internet Lecture System - Components)
+    Copyright (C)  2015-2017 (original FAILS), 
+                   2021- (FAILS Components)  Marten Richter <[email protected]>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { commandOptions } from 'redis'
+
+export class CommonConnection {
+  async getBgpdf(notepadscreenid) {
+    let lecturedoc = {}
+    try {
+      const lecturescol = this.mongo.collection('lectures')
+      lecturedoc = await lecturescol.findOne(
+        { uuid: notepadscreenid.lectureuuid },
+        {
+          projection: { _id: 0, backgroundpdfuse: 1, backgroundpdf: 1 }
+        }
+      )
+      // console.log("lecturedoc",lecturedoc);
+      if (
+        !lecturedoc.backgroundpdfuse ||
+        !lecturedoc.backgroundpdf ||
+        !lecturedoc.backgroundpdf.sha
+      )
+        return null
+      return this.getFileURL(lecturedoc.backgroundpdf.sha, 'application/pdf')
+    } catch (err) {
+      console.log('error in getBgpdf pictures', err)
+    }
+  }
+
+  async getUsedPicts(notepadscreenid) {
+    let lecturedoc = {}
+    try {
+      const lecturescol = this.mongo.collection('lectures')
+      lecturedoc = await lecturescol.findOne(
+        { uuid: notepadscreenid.lectureuuid },
+        {
+          projection: { _id: 0, usedpictures: 1 }
+        }
+      )
+      // console.log("lecturedoc",lecturedoc);
+      if (!lecturedoc.usedpictures) return []
+
+      return lecturedoc.usedpictures.map((el) => {
+        return {
+          name: el.name,
+          mimetype: el.mimetype,
+          sha: el.sha.buffer.toString('hex'),
+          url: this.getFileURL(el.sha.buffer, el.mimetype),
+          urlthumb: this.getFileURL(el.tsha.buffer, el.mimetype)
+        }
+      })
+      // ok now I have the picture, but I also have to generate the urls
+    } catch (err) {
+      console.log('error in getUsedPicts pictures', err)
+    }
+  }
+
+  async sendBoardsToSocket(lectureuuid, socket) {
+    // we have to send first information about pictures
+
+    const usedpict = await this.getUsedPicts({ lectureuuid: lectureuuid })
+    if (usedpict) {
+      socket.emit('pictureinfo', usedpict)
+    }
+    const bgpdf = await this.getBgpdf({ lectureuuid: lectureuuid })
+    if (bgpdf) {
+      socket.emit('bgpdfinfo', { bgpdfurl: bgpdf })
+    } else {
+      socket.emit('bgpdfinfo', { none: true })
+    }
+
+    try {
+      const res = await this.redis.sMembers(
+        'lecture:' + lectureuuid + ':boards'
+      )
+
+      // console.log('boards', res, 'lecture:' + lectureuuid + ':boards')
+      const length = res.length
+      let countdown = length
+      if (length === 0) socket.emit('reloadBoard', { last: true })
+      for (const index in res) {
+        const boardnum = res[index]
+        // console.log('sendBoardsToSocket', boardnum, lectureuuid)
+        try {
+          const res2 = await this.redis.get(
+            commandOptions({ returnBuffers: true }),
+            'lecture:' + lectureuuid + ':board' + boardnum
+          )
+
+          countdown--
+          // console.log('send reloadboard', boardnum, res2, length)
+          const send = {
+            number: boardnum,
+            data: res2,
+            last: countdown === 0
+          }
+          socket.emit('reloadBoard', send)
+        } catch (error) {
+          console.log('error in sendboard to sockets loop', error)
+        }
+      }
+    } catch (error) {
+      console.log('error in sendboard to sockets', error)
+    }
+  }
+
+  async getLectDetail(notepadscreenid, socket) {
+    // TODO should be feed from mongodb
+
+    let lecturedoc = {}
+    try {
+      const lecturescol = this.mongo.collection('lectures')
+
+      lecturedoc = await lecturescol.findOne(
+        { uuid: notepadscreenid.lectureuuid },
+        {
+          projection: {
+            _id: 0,
+            title: 1,
+            coursetitle: 1,
+            ownersdisplaynames: 1,
+            date: 1
+          }
+        }
+      )
+    } catch (err) {
+      console.log('error in get LectDetail', err)
+    }
+
+    const lectdetail = {
+      title: lecturedoc.title,
+      coursetitle: lecturedoc.coursetitle,
+      instructors: lecturedoc.ownersdisplaynames,
+      date: lecturedoc.date
+    }
+    // if (notepadscreenid.notepaduuid) lectdetail.notepaduuid=notepadscreenid.notepaduuid;
+    socket.emit('lecturedetail', lectdetail)
+  }
+
+  // sync changes to notes
+  async addUpdateCryptoIdent(args) {
+    const identity = {
+      signKey: args.signKey,
+      cryptKey: args.cryptKey,
+      displayname: args.displayname,
+      userhash: args.userhash,
+      /* id: args.socketid, */
+      purpose: args.purpose,
+      lastaccess: Date.now().toString()
+    }
+    // Two things store it in redis until disconnect
+    const oldident = this.redis.hGet(
+      'lecture:' + args.lectureuuid + ':idents',
+      args.socketid.toString()
+    )
+    this.redis.hSet('lecture:' + args.lectureuuid + ':idents', [
+      args.socketid.toString(),
+      JSON.stringify(identity)
+    ])
+    let oldid = await oldident
+    if (oldid) oldid = JSON.parse(oldid)
+
+    // and inform about new/updated identity
+    const roomname = this.getRoomName(args.lectureuuid)
+
+    if (
+      oldid &&
+      identity.signKey === oldid.signKey &&
+      identity.cryptKey === oldid.cryptKey
+    ) {
+      this.notepadio.to(roomname).emit('identValidity', {
+        lastaccess: identity.lastaccess,
+        id: args.socketid
+      })
+    } else {
+      this.notepadio
+        .to(roomname)
+        .emit('identUpdate', { identity: identity, id: args.socketid })
+    }
+  }
+
+  async handleKeymasterQuery(args) {
+    const now = Date.now() / 1000
+    // ok, first we have to figure out if a query is already running
+    try {
+      await this.redis.executeIsolated(async (isoredis) => {
+        await isoredis.watch('lecture:' + args.lectureuuid + ':keymaster')
+        const queryInfo = await isoredis.hGet(
+          'lecture:' + args.lectureuuid + ':keymaster',
+          'queryTime'
+        )
+        /* console.log(
+          'query Info',
+          queryInfo,
+          now - Number(queryInfo),
+          now,
+          Number(queryInfo)
+        ) */
+
+        if (queryInfo && now - Number(queryInfo) < 15) {
+          // we have no key, so may be the kaymaster does not know that we exist
+          await this.addUpdateCryptoIdent(args)
+          return // do not spam the system with these queries 20 +10
+        }
+
+        const res = await isoredis
+          .multi()
+          .hSet('lecture:' + args.lectureuuid + ':keymaster', [
+            'queryTime',
+            now.toString(),
+            'bidding',
+            '0',
+            'master',
+            'none'
+          ])
+          .exec()
+        if (res !== null) {
+          const roomname = this.getRoomName(args.lectureuuid)
+          // start the bidding
+          this.notepadio.to(roomname).emit('keymasterQuery')
+        }
+      })
+    } catch (error) {
+      console.log('handleKeymasterQuery problem or multple attempts', error)
+    }
+  }
+
+  async emitAVOffers(socket, args) {
+    const alloffers = await this.redis.hGetAll(
+      'lecture:' + args.lectureuuid + ':avoffers'
+    )
+    const offers = []
+    for (const label in alloffers) {
+      const labels = label.split(':')
+      offers.push({
+        type: labels[0],
+        id: labels[1],
+        time: alloffers[label]
+      })
+    }
+    socket.emit('avofferList', { offers })
+  }
+
+  getRoomName(uuid) {
+    return uuid
+  }
+}