export class AccesRights {

    constructor(config, debug){
        this.debug = debug
        this.config = config
        this.rights = config.accessRights
    }

    refreshAccessRights(config){
        this.rights = config.accessRights
    }

    expandPattern(pattern, uid, cnxId=null) {
        if(/\[CNXID\]/.test(pattern) && !cnxId) return(null)
        let item = pattern.replace(/\[UID\]/g, uid)
        if(cnxId) item = item.replace(/\[CNXID\]/g, cnxId)
        return(item)
    }

    expandPatterns(patterns, uid, cnxId=null) {
        return(patterns.map(item => this.expandPattern(item, uid, cnxId)).filter(item => item != null))
    }

    mustSubscribe(uid, roles, cnxId=null) {
        if(roles.indexOf('*')<0) roles.push('*')
        let chans = []
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.mustSubscribe) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) {
                    chans = this.merge(chans, this.expandPatterns(rightBlock.mustSubscribe, uid, cnxId))
                }
            }
        }
        return(chans)
    }

    isMandatory(uid, roles, chan, cnxId=null){
        return(this.mustSubscribe(uid, roles, cnxId).filter(this.chanMatch.bind(this, chan)).length>0)
    }

    canSubscribe(uid, roles, myChan, cnxId=null) {        
        if(roles.indexOf('*')<0) roles.push('*')
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.canSubscribe) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) {
                    let canSubList = this.expandPatterns(rightBlock.canSubscribe, uid, cnxId)
                    if(canSubList.find(this.chanMatch.bind(this, myChan))) return(true)
                }
            }
        }
        //if(this.debug) console.log(`Roles : ${roles} cannot subscribe on ${myChan}`)        
        return(false)
    }

    canPublish(uid, roles, myChan, cnxId=null) {
        if(roles.indexOf('*')<0) roles.push('*')
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.canPublish) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) {  
                    let canPubList = this.expandPatterns(rightBlock.canPublish, uid, cnxId)
                    if(canPubList.find(this.chanMatch.bind(this, myChan))) return(true)
                }
            }
        }
        //if(this.debug) console.log(`Roles : ${roles} cannot publish on ${myChan}`)        
        return(false)
    }

    canSet(uid, roles, myKey, cnxId=null){
        if(roles.indexOf('*')<0) roles.push('*')
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.canSet) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) { 
                    let canSetList = this.expandPatterns(rightBlock.canSet, uid, cnxId)
                    if(canSetList.find(this.chanMatch.bind(this, myKey))) return(true)
                }
            }
        }
        //if(this.debug) console.log(`Roles : ${roles} cannot set ${myKey}`)        
        return(false)        
    }

    canGet(uid, roles, myKey, cnxId=null){
        if(roles.indexOf('*')<0) roles.push('*')
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.canGet) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) { 
                    let canGetList = this.expandPatterns(rightBlock.canGet, uid, cnxId)
                    if(canGetList.find(this.chanMatch.bind(this, myKey))) return(true)
                }
            }
        }
        //if(this.debug) console.log(`Roles : ${roles} cannot get ${myKey}`)        
        return(false)        
    }

    canDo(roles, action, uid=null){
        if(roles.indexOf('*')<0) roles.push('*')
        for(let myRole of roles){
            for(let rightBlock of this.rights) {
                if(!rightBlock.canDo) continue
                if((rightBlock.roles=='*') || (rightBlock.roles.indexOf(myRole)>-1)) { 
                    if(rightBlock.canDo.indexOf(action)>-1) {
                        if((rightBlock.uuids) && Array.isArray((rightBlock.uuids))) {
                            // !!! Separate condition so if rightBlock.uuids but not uid in it, we don't give access !
                            if(rightBlock.uuids.includes(uid)) return(true) // null should never be in config uuids => old style calls are safe
                        } else { // no uuid block => role is sufficient to give access
                            return(true)
                        }
                    }
                }
            }
        }

        //Anti-shoot-your-foot
        if((action=='reloadAccessRights') && (roles.includes('EIC_Dev'))) {
            console.error('Prevented you from shooting your foot ! \nPlease keep least EIC_Dev in reload access rights !')
            return(true)
        }

        //if(this.debug) console.log(`Roles : ${roles} cannot do ${action}`)        
        return(false)        
    }

    chanMatch(myChan, configChan) {
        if((!myChan) || (typeof(myChan)!='string')) return(false)
        let re = new RegExp('^'+configChan.replace(/\*/g,'(.+)')+'$','g')
        return(myChan.match(re)!=null)
    }

    merge(x, y) {
        let tmp = x
        for(let yitem of y) if(tmp.indexOf(yitem)<0) tmp.push(yitem)
        return(tmp)
    }

}