import redis from 'redis'
export class RedisConnexion {

    constructor(options) {
        this.config = options.config;
        this.debug = options.debug;

        this.subscriptions = {}; // Externally fed
        this.wssConnections = {}; // Externally fed
        this.redPillsUuids = []; // Externally fed

        this.redisClient = redis.createClient({
            socket: {
                tls: this.config.redis.tls,
                host: this.config.redis.host,
                port: this.config.redis.port
            }
        });

        this.redisSubscriber = null;
        this.redisClient.on('error', (err) => {
            console.error('Redis error: ', err);
        });

        if(this.debug) console.log('Redis started...')
    }

    getSubscribedUuids(chan){
        let uuids = []
        let re
        for(let subChan in this.subscriptions){
            if(subChan==chan){
                uuids = [...uuids, ...this.subscriptions[subChan]]
            } else {
                re = new RegExp('^'+subChan.replace(/\*/g,'(.+)')+'$','g')
                if(chan.match(re)!=null){
                    uuids = [...uuids, ...this.subscriptions[subChan]]
                }
            }
        }
        return(uuids)
    }

    async redisLogin(){
        if(this.debug) console.log(`Connecting to Redis (${this.config.redis.host}:${this.config.redis.port}, tls:${this.config.redis.tls?'yes':'no'})...`);
        await this.redisClient.connect();
        if(this.debug) console.log('Connected to Redis !');
        if(this.config.redis.user) {
            await this.redisClient.sendCommand(['AUTH', this.config.redis.user, this.config.redis.pass]);
            if(this.debug) console.log('Logged into Redis !');
        } else {
            if(this.debug) console.log('Connected (anon) to Redis...');
        }
        if(this.debug) {
            var redisTime = await this.redisClient.time();
            console.log('Redis time:', redisTime);
        }
    }

    async redisChansStart(){
        this.redisSubscriber = this.redisClient.duplicate();
        await this.redisSubscriber.connect();
        if(this.config.redis.user) {
            await this.redisSubscriber.sendCommand(['AUTH', this.config.redis.user, this.config.redis.pass]);
        }
        this.redisSubscriber.pSubscribe(this.config.redis.basePrefix + '*', this.redisReceive.bind(this));
        if(this.debug) console.log('PSubscription OK ', this.config.redis.basePrefix + '*');
    }

    async redisSubscribe(chanName, callBack){
        if(!chanName.startsWith(this.config.redis.basePrefix)) chanName = this.config.redis.basePrefix  + chanName
        await this.redisSubscriber.subscribe(chanName, callBack);
    }

    async redisPublish(chanName, msg){
        if(typeof (msg) != 'string') msg = JSON.stringify(msg);
        if(!chanName.startsWith(this.config.redis.basePrefix)) chanName = this.config.redis.basePrefix + chanName
        await this.redisClient.publish(chanName, msg);
    }

    async redisRefreshSession(k){
        await this.redisClient.expire(k, this.config.server.sessionExpiration);
    }

    async redisSet(k, v, exp = 0, customPrefix=null){
        if(typeof(v) != 'string') v = JSON.stringify(v);
        if(customPrefix!==null) k = customPrefix + k
        else if(!k.startsWith(this.config.redis.basePrefix)) k = this.config.redis.basePrefix + k
        if(this.debug) console.log('Redis SET ', k);
        try { await this.redisClient.set(k, v) }
        catch(err) { console.error('Redis crash doing Redis set: ', k, v) }
        if(exp > 0) {
            try { await this.redisClient.expire(k, exp) }
            catch(err) { console.error('Redis crash doing Redis expire: ', k, exp) }
        }
    }

    async redisGet(k, customPrefix=null){
        if(customPrefix!==null) k = customPrefix + k
        else if(!k.startsWith(this.config.redis.basePrefix)) k = this.config.redis.basePrefix + k
        if(this.debug) console.log('Redis GET ',  k)
        let v=null
        try { v = await this.redisClient.get(k) }
        catch(err) { console.error('Redis crash doing Redis get: ', k) }      
        return(v);
    }

    async redisDel(k, customPrefix=null){
        if(customPrefix!==null) k = customPrefix + k
        else if(!k.startsWith(this.config.redis.basePrefix)) k = this.config.redis.basePrefix + k
        if(this.debug) console.log('Deleting ',  k);
        await this.redisClient.del(k);
    }


    async redisGetTtl(k, customPrefix=null){
        if(customPrefix!==null) k = customPrefix + k
        else if(!k.startsWith(this.config.redis.basePrefix)) k = this.config.redis.basePrefix + k
        if(this.debug) console.log('Redis Get TTL ',  k)
        let v=null
        try { v = await this.redisClient.ttl(k) }
        catch(err) { console.error('Redis crash doing Redis ttl: ', k) }      
        return(v);
    }
    
    async redisSetTtl(k, ttl, customPrefix=null){
        if(customPrefix!==null) k = customPrefix + k
        else if(!k.startsWith(this.config.redis.basePrefix)) k = this.config.redis.basePrefix + k
        if(this.debug) console.log('Redis Set TTL  ',  k);
        try { await this.redisClient.expire(k, ttl) }
        catch(err) { console.error('Redis crash doing Redis expire: ', k, ttl) }
    }    

    async redisXadd(streamName, kvObj, max = ''){
        if(!streamName.startsWith(this.config.redis.basePrefix)) streamName = this.config.redis.basePrefix  + streamName
        if(this.debug) console.log('Redis XADD ', streamName, kvObj);
        let arr = ['XADD', streamName]
        if(max != '') arr = [...arr, ...['MAXLEN', '~', (1*max).toString()]]
        arr.push('*')
        let payload = '""'
        try{ payload = JSON.stringify(kvObj) }
        catch(e) { console.warn('cannot historize bad json: ',kvObj) }
        arr.push('streamData')
        arr.push(payload)
        let sid = null
        try { sid = await this.redisClient.sendCommand(arr); }
        catch(err) { console.error('Redis crash doing Redis command: ', arr, err) }
        return(sid);
    }

    async redisXrange(streamName, start = '-', end = '+', withPayload = true){
        if(!streamName.startsWith(this.config.redis.basePrefix)) streamName = this.config.redis.basePrefix + streamName
        if(this.debug) console.log('Redis XRANGE ', streamName);
        if(typeof(start)!='string') start = start.toString()
        if(typeof(end)!='string') end = end.toString()
        let arr = ['XRANGE', streamName, start, end];
        let res = []
        try { res = await this.redisClient.sendCommand(arr) }
        catch(err) { console.error('Redis crash doing Redis command: ', arr, err.msg) }

        if(withPayload){
            let o = {};
            for (let row of res) { // We'll take only the first content of the stream (the value of the key 'streamdata')
                let payload = ''
                try{ payload = JSON.parse(row[1][1]) }
                catch(e) { console.warn('cannot unhistorize bad json: ',row[1][1]) }
                o[row[0]] = payload
            }
            return(o);
        } else {
            return(res.map(row => row[0]))
        }
    }

    isHistorizedChan(chan){
        if(!chan.startsWith(this.config.redis.basePrefix)) chan = this.config.redis.basePrefix + chan
        var matches = this.config.redis.historizeChannels.filter((e) => {
            if(!e.startsWith(this.config.redis.basePrefix)) e = this.config.redis.basePrefix + e
            if(e.indexOf('*') > -1) {
                let r = new RegExp('^'+e.replace(/\*/g,'(.+)')+'$','g')
                return(chan.match(r) != null);
            } else return(chan == e);
        });
        return(matches.length > 0);
    }
  
    async getProcessInfo(){
        if(this.debug) console.log('Redis NIFO  ');
        try { 
            const rawInfo = await this.redisClient.INFO()
            let arr = rawInfo.replace(/\r/g,'').split('\n')
            arr = arr.filter(item => (item.trim()!='') && (!item.trim().startsWith('#')))
            let infoObject = arr.reduce((acc, val) => { kv = val.split(':',2); if(kv.length>0){ acc[kv[0]] = kv[1] } return(acc) }, {})
         }
        catch(err) { console.error('Redis crash doing Redis INFO: ') }
        return(infoObject)
    }

    async redisReceive(msg, chan){
        if(this.debug) console.log('From Redis chan:', chan, msg);
        
        try {
            msg = JSON.parse(msg);
        } catch {
            console.warn(`Ignoring non-json on channel ${chan} : ${msg}`);
            return;
        }

        if(this.redPillsUuids.length>0) { // Any dev bus console in RedPills (promiscuous) mode ?
            if(this.debug) console.log(`Will send to  ${this.redPillsUuids.length} REDPILLS`);
            let shortChan = chan.startsWith(this.config.redis.basePrefix) ? chan.substr(this.config.redis.basePrefix.length) : chan
            let payload ={
                'event': 'REDISMSG',
                'payload': {
                    'bmsg':{ // Extra encapsulation to avoid triggering normal listeners on FE
                        'msg': msg,
                        'chan': shortChan,
                    }
                }
            }
            for(var uuid of this.redPillsUuids) {                
                if(uuid in this.wssConnections) {
                    this.wssConnections[uuid].send(JSON.stringify(payload));
                }
            }
        }

        if(this.debug) console.log('will now fanout...', chan, msg);
        const uuids = this.getSubscribedUuids(chan)
        if(uuids.length>0) { // Anyone interested at all about this chan ?
            if(this.debug) console.log(`Will broadcast to ${uuids.length} web clients`);
            let shortChan = chan.startsWith(this.config.redis.basePrefix) ? chan.substr(this.config.redis.basePrefix.length) : chan
            let payload ={
                'event': 'REDISMSG',
                'payload': {
                    'msg': msg,
                    'chan': shortChan,

                }
            }
            console.log('=====>',uuids)
            for(var uuid of uuids) {
                if(uuid in this.wssConnections) {
                    if(this.debug) console.log('Sending to ', uuid, payload);
                    this.wssConnections[uuid].send(JSON.stringify(payload));
                }
            }
        }
    }

}


// redis-cli -h redis.backend.eismea.eu --tls --user default