/**

* Bootstrap the application

* - create schedule to poll blockchain

*/

// const schedule = require('node-schedule')

global.config = require('./config')

const Sonar = require('./lib/sonar')

const tmp = require('tmp')

const path = require('path')

const fs = require('fs')

const spawn = require('child_process').spawn

async function checkForModels (mineAddress, contractAddress, web3, ipfs) {

const sonar = new Sonar(web3, contractAddress, mineAddress)

console.log(`🔎️ Looking for models to train at ${contractAddress} for mine ${mineAddress}`)

const modelCount = await sonar.getNumModels()

console.log(`💃 ${modelCount} models found`)

for (let modelId = 0; modelId < modelCount; modelId++) {

const model = await sonar.getModel(modelId)

console.log(` 💃 model#${model.id} with ${model.gradientCount} gradients at IPFS:${model.weightsAddress}`)

if (model.gradientCount > Infinity) { // disable for now, should be > 0 to work ;)

try {

const gradients = await sonar.getModelGradients(modelId, model.gradientCount - 1)

console.log(`latest gradient#${gradients.id}: ${gradients.gradientsAddress} (weights: ${gradients.weightsAddress})`)

} catch (e) {

console.error(` could not fetch gradients: ${e}`)

}

}

// download & train the model

// create folder structure

const tmpDirectory = tmp.dirSync()

const tmpPaths = {}

Object.keys(config.syft.tmpFiles)

.forEach(e => {

tmpPaths[e] = path.join(tmpDirectory.name, config.syft.tmpFiles[e])

})

console.log(` ⬇️ Downloading latest model`)

// download the model from IPFS

const modelFh = fs.createWriteStream(tmpPaths.model)

await new Promise((resolve, reject) => {

ipfs.files.get(model.weightsAddress, (err, stream) => {

if (err) return reject(err)

stream.on('data', (file) => file.content.pipe(modelFh))

stream.on('end', () => resolve(`weight stored to ${tmpPaths.model}`))

})

})

// spawn syft

console.log(` 🏋️ Training the model latest model`)

const childOpts = {

shell: true,

stdio: config.debug ? 'inherit' : ['ignore', 'ignore', process.stderr]

}

const trainStart = new Date()

const sp = spawn(`syft_cmd generate_gradient`, [`-model ${tmpPaths.model}`, `-input_data ${path.join(__dirname, 'data/adapters/diabetes/diabetes_input.csv')}`, `-target_data ${path.join(__dirname, 'data/adapters/diabetes/diabetes_output.csv')}`, `-gradient ${tmpPaths.gradient}`], childOpts)

await new Promise((resolve, reject) => {

sp.on('close', code => {

if (code) reject(new Error(`error while calling syft, code=${code}`))

resolve()

})

})

config.debug && console.log(` 🏋️ Finished training the model in ${(new Date() - trainStart) / 1000} s`)

// put new gradients into IPFS

console.log(` ⬆️ Uploading new gradients to IPFS`)

const gradientFh = fs.createReadStream(tmpPaths.gradient)

const gradientsAddress = await new Promise((resolve, reject) => {

const files = [{

path: tmpPaths.gradient,

content: gradientFh

}]

ipfs.files.add(files, (err, res) => {

if (err) return console.error(err)

const obj = res.find(e => e.path === tmpPaths.gradient)

resolve(obj.hash)

})

})

// upload new gradient address to sonar

const response = await sonar.addGradient(modelId, gradientsAddress)

console.log(config.debug ? ` ✅ Successfully propagated new gradient to Sonar with tx: ${response.transactionHash} for the price of ${response.gasUsed} gas at IPFS:${gradientsAddress}` : ` ✅ Successfully propagated new gradient to Sonar at IPFS:${gradientsAddress}`)

}

if (config.pollInterval > 0) setTimeout(() => checkForModels(mineAddress, contractAddress, web3, ipfs), config.pollInterval * 1000)

}

module.exports = {

checkForModels

}