constructor(modelName, root = '') {

firebase.initializeApp(config)

this.database = firebase.database()

const modelsRoot = `${root}/agentscript/models`

this.transforms = {}

this.transformsRef = this.database.ref(

`${modelsRoot}/${modelName}/transforms`

)

this.transformsRef.once('value', ev => {

const initialDB = util.objectToString(ev.val())

console.log('Initial Database', initialDB)

})

this.transformsRef.on('child_added', ev => {

console.log('child_added', ev, ev.key, ev.val())

this.addTransform(ev.key, ev.val().function)

})

this.transformsRef.on('child_removed', ev => {

console.log('child_removed', ev, ev.key, ev.val())

this.removeTransform(ev.key)

// delete this.transforms[ev.key]

})

}

addTransform(name, fcnBody) {

const xfm = {}

xfm.function = new Function('model, util', fcnBody)

xfm.resultRef = this.transformsRef.child(name + '/result')

this.transforms[name] = xfm

}

removeTransform(name) {

this.transformsRef.child(name).remove()

delete this.transforms[name]

}

step(model) {

util.forLoop(this.transforms, (val, key) => {

const name = key

const fcn = this.transforms[name].function

const ref = this.transforms[name].resultRef

const result = fcn(model, util)

// If result is a object, this turns it into a string!

// Need ref.child() ?

try {

ref.set(result)

} catch (error) {

console.log(name, fcn, ref, result)

throw Error('ref.set error')

}

})

}