ubuntu

'use strict'


let redis=require('redis')
let client=redis.createClient()

let express=require('express')
let app=express()
let bodyparser=require('body-parser')
app.use(bodyparser.json())

function valid(secret){
    return'my code'
}

app.post('/flush',(req,res)=>{
    if(!valid(req.body.secret))return;
    client.flushall(()=>{
        res.json({})
    })
})

app.post('/get',(req,res)=>{
    let key=req.body.key
    if(key==undefined||!valid(req.body.secret))return;
    client.get(key,(err,val)=>{
        res.json({err,val})
    })
})
app.post('/set',(req,res)=>{
    let key=req.body.key
    let val=req.body.val
    if(key==undefined||val==undefined||!valid(req.body.secret))return;
    client.set(key,val,(err,status)=>{
        res.json({err})
    })
})
app.post('/del',(req,res)=>{
    let key=req.body.key
    if(key==undefined||!valid(req.body.secret))return;
    client.multi()
        .get(key)
        .del(key)
        .exec((err,replies)=>{
            res.json({err,val:replies[0]})
        })
})
let jobs=new Map()
let subs=new Map()//each key has job ids subscribed
function getjob(jobid){
    let job=jobs.get(jobid)
    if(job){
        clearTimeout(job.timeout)
    }else{
        job={
            jobid,
            queue:[],
            res:null,
            subs:new Set(),
        }
        jobs.set(jobid,job)
    }
    job.timeout=setTimeout(()=>{//remove if innactive
        jobs.delete(jobid)
        for(let key of job.subs){
            if(subs.has(key)){
                subs.get(key).delete(job)
            }
        }
    },100*1000)
    return job
}

app.post('/sub',(req,res)=>{
    let key=req.body.key
    let jobid=req.body.jobid
    if(key==undefined||jobid==undefined||!valid(req.body.secret))return;
    let job=getjob(jobid)
    if(!subs.has(key))subs.set(key,new Set())
    subs.get(key).add(job)
    job.subs.add(key)
    res.json({})
})

app.post('/unsub',(req,res)=>{
    let key=req.body.key
    let jobid=req.body.jobid
    if(key==undefined||jobid==undefined||!valid(req.body.secret))return;
    let job=getjob(jobid)
    if(!subs.has(key))return;
    job.subs.delete(key)
    subs.get(key).delete(job)
    if(!subs.get(key).size)subs.delete(key)
    res.json({})
})

let lastid=0
let upd1=new Map()
app.post('/upd0',(req,res)=>{
    let key=req.body.key
    if(key==undefined||!valid(req.body.secret))return;
    client.watch(key,(err)=>{
        if(err){
            res.json({err})
            throw err
        }
        client.get(key,(err,oldval)=>{
            if(err){
                res.json({err})
                throw err
            }
            let id=lastid++
            lastid=lastid%(1<<30)
            res.json({id,oldval})
            let timeout
            upd1.set(id,function callback(val,res){
                clearTimeout(timeout)
                if(upd1.get(id)!=callback){
                    client.unwatch()
                    return
                }
                upd1.delete(id)
                if(val==null){//timeout called
                    client.unwatch()
                }else{
                    client.multi()
                        .set(key,val)
                        .exec((err,replies)=>{
                            if(replies){
                                res.json({err})
                                if(!err&&subs.has(key)){
                                    for(let job of subs.get(key)){
                                        if(job.res){
                                            job.res.json({key,val,oldval})
                                            job.res=null
                                        }else{
                                            job.queue.push({key,val,oldval})
                                        }
                                    }
                                }
                            }else{
                                res.json({err:'externally modified'})
                            }
                        })
                }
            })
            timeout=setTimeout(upd1.get(id),30*1000)
        })
    })
})
app.post('/upd1',(req,res)=>{
    let key=req.body.key
    let val=req.body.val
    let id=req.body.id
    if(key==undefined||val==undefined||id==undefined||!valid(req.body.secret))return;
    if(upd1.has(id)){
        upd1.get(id)(val,res)
    }else{
        res.json({err:'invalid id or took too long'})
    }
})

app.post('/poll',(req,res)=>{
    let jobid=req.body.jobid
    if(jobid==undefined||!valid(req.body.secret))return;
    let job=getjob(jobid)
    if(job.queue[0]){
        res.json(job.queue[0])
        job.queue.shift()
    }else{
        job.res=res
        setTimeout(()=>{
            if(job.res==res){
                job.res=null
                res.json({timeout:true})
            }
        },10*1000)
    }
})

client.on('error',function(err){
    console.log('error '+err)
})
app.listen(3000)