gramjs/gramjs/sessions/Session.js

const { generateRandomLong, getRandomInt } = require('../Helpers')
const fs = require('fs').promises
const { existsSync, readFileSync } = require('fs')
const AuthKey = require('../crypto/AuthKey')


BigInt.toJSON = function() {
    return { fool: this.fool.toString('hex') }
}
BigInt.parseJson = function() {
    return { fool: BigInt('0x' + this.fool) }
}

class Session {
    constructor(sessionUserId) {
        this.sessionUserId = sessionUserId
        this._serverAddress = null
        this._dcId = 0
        this._port = null
        // this.serverAddress = "localhost";
        // this.port = 21;
        this.authKey = undefined
        this.id = generateRandomLong(false)
        this.sequence = 0
        this.salt = 0n // Unsigned long
        this.timeOffset = 0n
        this.lastMessageId = 0n
        this.user = undefined
    }

    /**
     * Saves the current session object as session_user_id.session
     */
    async save() {
        if (this.sessionUserId) {
            const str = JSON.stringify(this, function(key, value) {
                if (typeof value === 'bigint') {
                    return value.toString() + 'n'
                } else {
                    return value
                }
            })
            console.log('current auth key will be ', this.authKey)
            await fs.writeFile(`${this.sessionUserId}.session`, str)
        }
    }

    setDC(dcId, serverAddress, port) {
        this._dcId = dcId | 0
        this._serverAddress = serverAddress
        this._port = port
    }

    get serverAddress() {
        return this._serverAddress
    }

    get port() {
        return this._port
    }

    get dcId() {
        return this._dcId
    }

    static tryLoadOrCreateNew(sessionUserId) {
        if (sessionUserId === undefined) {
            return new Session()
        }
        const filepath = `${sessionUserId}.session`


        if (existsSync(filepath)) {
            try {
                const ob = JSON.parse(readFileSync(filepath, 'utf-8'), function(key, value) {
                    if (typeof value == 'string' && value.match(/(\d+)n/)) {
                        return BigInt(value.slice(0, -1))
                    } else {
                        return value
                    }
                })

                const authKey = new AuthKey(Buffer.from(ob.authKey._key.data))
                const session = new Session(ob.sessionUserId)
                session._serverAddress = ob._serverAddress
                session._port = ob._port
                session._dcId = ob._dcId

                // this.serverAddress = "localhost";
                // this.port = 21;
                session.authKey = authKey
                session.id = ob.id
                session.sequence = ob.sequence
                session.salt = ob.salt // Unsigned long
                session.timeOffset = ob.timeOffset
                session.lastMessageId = ob.lastMessageId
                session.user = ob.user
                return session
            } catch (e) {
                return new Session(sessionUserId)
            }
        } else {
            return new Session(sessionUserId)
        }
    }

    getNewMsgId() {
        const msTime = new Date().getTime()
        let newMessageId =
            (BigInt(BigInt(Math.floor(msTime / 1000)) + this.timeOffset) << 32n) |
            (BigInt(msTime % 1000) << 22n) |
            (BigInt(getRandomInt(0, 524288)) << 2n) // 2^19

        if (this.lastMessageId >= newMessageId) {
            newMessageId = this.lastMessageId + 4n
        }
        this.lastMessageId = newMessageId
        return newMessageId
    }

    processEntities(result) {
        console.log('saving entities')
    }
}

module.exports = Session