var Pushable = require('pull-pushable')
var deepEqual = require('deep-equal')

exports.name = 'progressStream'
exports.version = require('../package.json').version
exports.manifest = {
  read: 'source'
}

exports.init = function (ssb, config) {
  return {
    read: function (opts) {
      var lastValue = deepClone(ssb.progress())

      var timer = setInterval(() => {
        var newValue = ssb.progress()
        if (!deepEqual(newValue, lastValue)) {
          lastValue = deepClone(newValue)
          pushable.push(lastValue)
        }
      }, 200)

      var pushable = Pushable(() => {
        clearInterval(timer)
      })

      pushable.push(lastValue)
      return pushable
    }
  }
}

function deepClone (obj) {
  return JSON.parse(JSON.stringify(obj))
}