var pull = require('pull-stream')
var ref = require('ssb-ref')
var plugs = require('patchbay/plugs')
var message_compose = plugs.first(exports.message_compose = [])
var sbot_log = plugs.first(exports.sbot_log = [])
var feed_summary = plugs.first(exports.feed_summary = [])
var message_unbox = plugs.first(exports.message_unbox = [])
var get_id = plugs.first(exports.get_id = [])
var avatar_image_link = plugs.first(exports.avatar_image_link = [])
var update_cache = plugs.first(exports.update_cache = [])
var h = require('../lib/h')

exports.screen_view = function (path, sbot) {
  if (path === '/private') {
    var id = get_id()

    return feed_summary((opts) => {
      return pull(
        sbot_log(opts),
        loosen(10), // release tight loops if they continue too long (avoid scroll jank)
        unbox(),
        pull.through((item) => {
          if (item.value) {
            update_cache(item)
          }
        })
      )
    }, [
      message_compose({type: 'post', recps: [], private: true}, {
        prepublish: function (msg) {
          msg.recps = [id].concat(msg.mentions).filter(function (e) {
            return ref.isFeed(typeof e === 'string' ? e : e.link)
          })
          if (!msg.recps.length) {
            throw new Error('cannot make private message without recipients - just mention the user in an at reply in the message you send')
          }
          return msg
        },
        placeholder: `Write a private message \n\n\n\nThis can only be read by yourself and people you have @mentioned.`
      })
    ], {
      windowSize: 1000
    })
  }
}

exports.message_meta = function (msg) {
  if (msg.value.content.recps || msg.value.private) {
    return h('span.private', [
      map(msg.value.content.recps, function (id) {
        return avatar_image_link(typeof id === 'string' ? id : id.link, 'thumbnail')
      })
    ])
  }
}

function unbox () {
  return pull(
    pull.filter(function (msg) {
      return typeof msg.value.content === 'string'
    }),
    pull.map(function (msg) {
      return message_unbox(msg) || { timestamp: msg.timestamp }
    })
  )
}

function map (ary, iter) {
  if (Array.isArray(ary)) return ary.map(iter)
}

function loosen (max) {
  var lastRelease = Date.now()
  return pull.asyncMap(function (item, cb) {
    if (Date.now() - lastRelease > max) {
      setImmediate(() => {
        lastRelease = Date.now()
        cb(null, item)
      })
    } else {
      cb(null, item)
    }
  })
}